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2A Step Down VOLTAGE REGULATOR Powered By Docstoc
                                                         2A Step Down VOLTAGE REGULATOR

GENERAL DESCRIPTION                                      FEATURES
The CM2593/P is a monolithic integrated circuit that     ◆    3.3V, 5V and adjustable output versions

provide all the active functions for a step-down         ◆    Adjustable version output voltage range, 1.23V to 37V +4%

switching regulator, capable of driving a 2A load              max over line and load condition
                                                         ◆    SOP-8L packages
without additional transistor component. Requiring a
                                                         ◆    Voltage mode non-synchronous PWM control
minimum number of external component, the board
                                                         ◆    Thermal-shutdown and current-limit protection
space can be saved easily. The external shutdown
                                                         ◆    ON/OFF shutdown control input
function can be controlled by TTL logic level and        ◆    Input voltage range up to 40V
then   come   into    standby   mode. The     internal   ◆    Output load current: 2A
compensation makes feedback control have good            ◆    150 kHz fixed frequency internal oscillator
line and load regulation without external design.        ◆    Low power standby mode
Regarding protected function, thermal shutdown is        ◆    Built-in switching transistor on chip

to prevent over temperature operating from damage,
and current limit is against over current operating of
the output switch. The CM2593/P operates at a
switching frequency of 150Khz thus allowing smaller
sized filter components than what would be needed        APPLICATIONS
with lower frequency switching regulators. Other
                                                              Simple High-efficiency step-down(buck) regulator
features include a guaranteed +4% tolerance on
                                                              Efficient pre-regulator for linear regulators
output voltage under specified input voltage and
                                                              On-card switching regulators
output load conditions, and +15% on the oscillator
                                                              Battery / Car Charger
frequency. The output version included fixed 3.3V,
                                                              Positive to negative converter
5V, and an adjustable type. The packages are
                                                              Digital Still and Video Cameras
available in a standard 8-lead SOP8.


                            Figure 1. Basic Application Circuit with CM2593/P fixed version

2007/01/25 Rev. 1.4                    Champion Microelectronic Corporation                                   Page 1
                                                    2A Step Down VOLTAGE REGULATOR


                            Sop08                                                Sop08
                      Top View(CM2593)                                    Top View(CM2593P)


2007/01/25 Rev. 1.4                Champion Microelectronic Corporation                       Page 2
                                                             2A Step Down VOLTAGE REGULATOR


  Pin No.           Symbol                                             Description

    1       VIN                    Operating voltage input

    2       Out                    Switching output

    3       FB                     Output voltage feedback control

    4       SD                     ON/OFF Shutdown

    5-8     GND                    Ground Pin


                                                  CM2593/P X X         X

                       Lead Free                      Output Voltage            Package Type

                   Blank: Normal                   C: Adjustable               S: SOP-O8 package
                   G: Lead Free package            SC: 3.3V
                                                   ZJC: 5V

             Symbol                             Parameter                       Rating               Unit
                  VCC                        Supply Voltage                      +45                  V
                  VSD                  ON/OFF Pin input voltage               -0.3 to +25             V
                  VFB                     Feedback Pin voltage               -0.3 to +25              V

                  VOUT                 Output voltage to Ground                   -1                  V
                  PD                        Power dissipation              Internally limited         W
                  TST                      Storage temperature               -65 to +150              C
                  TOP                     Operating temperature              -40 to +125              C
                  VOP                       Operating voltage                +4.5 to +45              V

                  θJa                       Thermal Resistance                    75                 °/W

                  θJc                       Thermal Resistance                    14                 °/W

2007/01/25 Rev. 1.4                       Champion Microelectronic Corporation                           Page 3
                                                                 2A Step Down VOLTAGE REGULATOR

     ELECTRICAL CHARACTERISTICS(All Output Voltage Versions)
Unless otherwise specified, VIN=12V for 3.3V, 5V, adjustable version and VIN=24V for the 12V version. ILOAD = 0.2A

 Symbol                 Parameter                            Conditions                   Min.        Typ.           Max.      Unit
                                                  VFB=1.3V                                                           -50
     IB   B   Feedback bias current                                                                    -10                      nA
                                                  (Adjustable version only)                                          -100
                                                               TJ=25℃                     127         150            173
   FOSC       oscillator frequency                                                                                              Khz
                                                          -40℃<=TJ<=125℃                  110         150            173
              Oscillator frequency of short When current limit occurred
   Fscp                                                                                                30             60       Khz
              circuit protect               and VFB <0.55V
                                                  IOUT=1.5A                                                          1.4
   VSAT       saturation voltage                  no outside circuit                                  1.15                       V
                                                  VFB=0V force driver on
              Max. Duty Cycle(ON)                 VFB=0V force driver on                              100
    DC                                                                                                                          %
              Min. Duty cycle(OFF)                VFB=12V force driver off                              0
                                                  peak current                                                       3.3
    ICL       current limit                       no outside circuit                       2.4         2.8                       A
                                                  VFB=0 force driver on
                                             no outside circuit
              Output = 0      Output leakage                                                                         -200       uA
     IL                                      VFB=12 force driver off
              Output = 1                     VIN=24V                                                   -5                       mA
     IQ       Quiescent Current                   VFB=12 force driver off                               5             10        mA
              Standby Quiescent                   ON/OFF pin=5V                                                      150
   ISTBY                                                                                               70                       uA
              Current                             VIN=24V                                                            200
    VIL                                           Low (regulator ON)                        -                        0.6
              ON/OFF pin logic input
                                                                                                       1.3                       V
    VIH       threshold voltage                   High (regulator OFF)                     2.0                         -

              ON/OFF pin logic
     IH                                           VLOGIC=2.5V (OFF)                                                  -0.01
              input current                                                                                                     uA
     IL       ON/OFF pin input current            VLOGIC=0.5V (ON)                                    -0.1            -1

              Over temperature shutdown           Tj increasing                                       175                       o
    Ts                                                                                                                           C
              threshold                           Tj decreasing                                       150

2007/01/25 Rev. 1.4                        Champion Microelectronic Corporation                                              Page 4
                                                          2A Step Down VOLTAGE REGULATOR

                      Symbol        Parameter              Conditions             Typ.         Limit           Unit
                                                          5V < VIN < 40V                                         V
                       VFB       Output Feedback         0.2A < ILOAD < 2A        1.235      1.193/1.18         VMIN
CM2593/P-ADJ                                         VOUT programmed for 3V                  1.267/1.28        VMAX
                        η            Efficiency         VIN = 12V, ILOAD=2A        75                            %

                                                         5.5V < VIN < 40V                    3.168/3.135
                       VOUT        Output voltage                                  3.3                          VMIN
CM2593/P-3.3V                                            0.2A < ILOAD < 2A                   3.432/3.465
                        η            Efficiency         VIN = 12V, ILOAD=2A        75                            %

                                                         8V < VIN < 40V                       4.8/4.75
                       VOUT       Output voltage                                    5                          VMIN
 CM2593/P-5V                                            0.2A < ILOAD < 2A                     5.2/5.25
                        η            Efficiency        VIN = 12V, ILOAD=2A         80                           %

Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC.

2007/01/25 Rev. 1.4                    Champion Microelectronic Corporation                                   Page 5
                                                          2A Step Down VOLTAGE REGULATOR

                                                               Thermal Considerations
Pin Functions
                                                               The SOP-8 package needs a heat sink under most
This is the positive input supply for the IC switching         conditions . The size of the heat-sink depends on the

regulator. A suitable input bypass capacitor must be           input voltage, the output voltage, the load current and the

present at this pin to minimize voltage transients and to      ambient     temperature.     The     CM2593/P      junction

supply the switching currents needed by the regulator.         temperature rises above ambient temperature for a 2A
                                                               load and different input and output voltages. The data
Out                                                            for these curves was taken with the CM2593/P (SOP-8
Internal switch and power output. The voltage at this pin
                                                               package) operating as a buck switching regulator in an
switches between (+VIN – VSAT) and approximately –
                                                               ambient temperature of 25oC (still air). These temperature
0.5V, with a duty cycle of approximately VOUT / VIN. The
                                                               increments are all approximate and are affected by many
PC board copper area connected to this pin should be
                                                               factors. Some of these factors include board size,
kept a minimum in order to reduce the coupling
                                                               shape ,thickness ,position ,location, and even board
sensitivity to the circuitry
                                                               temperature. Other factors are trace width, total printed
Ground                                                         circuit copper area, copper thickness , single or
Circuit ground.                                                double-sided, multi-layer board and amount of solder on
Feedback                                                       the board. Higher ambient temperatures require more
Complete the feedback loop by sensing the regulated
                                                               heat sinking.
output voltage
                                                               For the best thermal performance ,wide copper traces
                                                               and generous amounts of printed circuit board copper
Allows the switching regulator circuit to be shutdown          should be used in the board layout. (One exception is the
using logic level signals thus dropping the total input        out(switch) pin, which should not have large areas of
supply current to approximately 100uA. Pulling this pin        copper.) Large areas of copper provide the best transfer
below a threshold voltage of approximately 1.3V turns          of heat(lower thermal resistance) to the surrounding air,
the regulator on, and pulling this pin above 1.3V (up to a     and moving air lowers the thermal resistance even
maximum of 25V) shuts the regulator down. If this              further.
                                                               The effectiveness of the PC board to dissipate heat also
shutdown feature is not needed, the ON /OFF pin can
                                                               depends on the size, quantity and spacing of other
be wired to the ground pin or it can be left open, in either
                                                               components on the board , as well as whether the
case the regulator will be in the ON condition.
                                                               surrounding air is still or moving. Furthermore, some of
                                                               these components such as the catch diode will add heat
                                                               to the PC board and heat can vary as the input voltage
                                                               changes. For the inductor, depending on the physical
                                                               size, type of core material and the DC resistance, it could
                                                               either act as a heat sink taking heat away from the board,
                                                               or it could add heat to the board.

2007/01/25 Rev. 1.4                    Champion Microelectronic Corporation                               Page 6
                                                                        2A Step Down VOLTAGE REGULATOR


  470uF/50V                                             CM2593/P
        2   1              VIN             1                            8
                                                   VIN            GND

    1           2                          2                            7
                                                   OUT            GND
                                                                            Output Voltage Fixed : R1=NC , R2=0
                    1                      3                            6
                                                   FB             GND
        5A/40V                                                              Output Voltage Adj : Vo=Vref*(1+(R2/R1))
                                           4                            5
                                                   SD             GND
                        68uF                                                Vfb = 1.235V ;    R1=1K~5K

        2   1                                  1          2   2         1

    220uF/25V           VOUT                        R2            R1

APPLICATIONS Demo Board Layout

                               TOP Layer                                                     BOT Layer

Notice :

1. R1/R2 must be close to Pin3 (VFB ), but keep feedback wiring away from inductor.

2. Inductor/diode must be close to Pin2 (Vout ), heavy lines must be keep short and thick .
3. Please to refer to Circuit and Demo Board Layout (the Fig. as above)

2007/01/25 Rev. 1.4                            Champion Microelectronic Corporation                             Page 7
                                                 2A Step Down VOLTAGE REGULATOR

Thermal Resistance vs. Different Cooper Area Layout Design

                                                                       Dog-Bone Layout

          Minimum Footprint , θJA = 75℃/W                                      2
                                                             Copper Area = 10mm , θJA = 64℃/W

                           2                                                    2
        Copper Area = 30mm , θJA = 54℃/W                     Copper Area = 50mm , θJA = 51℃/W

        Copper Area = 70mm , θJA = 49℃/W

2007/01/25 Rev. 1.4             Champion Microelectronic Corporation                     Page 8
                                                                                                                                                                                                                2A Step Down VOLTAGE REGULATOR

                                                               Typical Performance Characteristics
                                                               (Test Figure 1 above unless otherwise specified)

                                                                         T y p ic a l P e rfo rm a n c e C h a ra c te ris tic s                                                                                              Efficiency                                                                      Switch Saturation Voltage
                                                                                N o rm a lize d O u tp u t V o lta g e
                                                             5 .10                                                                                                                                                                                                                                       1 : -40 oC
                                                                                                                    V IN = 20 V , I L O A D = 2 A
                                                                                                                                                                                                                                                                                                         2 : 25 o C

                                                                                                                                                                                                                                                                SATURATION VOLTAGE (V)
                                                                                                                    N orm alized at TJ = 25 C                                                                                                                                             1.6            3 : 125oC
                       OUTPUT VOLTAGE CHANGE

                                                                                                                                                                                                                                           2A Load
                                                             5.0 5                                                                                                                             95


                                                             5.0 0
                                                                                                                                                                                               85              5V                                                                         1.4
                                                             4 .95                                                                                                                             80                                                                                         1.3
                                                                                                                                                                                               75                                                                                                    3
                                                             4.9 0                                                                                                                                                                                                                        1.2
                                                                         -5 0       -25           0    25           50       75        100     125                                             70                                                                                                        2.0             3        4              5
                                                                                                                                                                                                         8      10     15      20   25     30   35    40
                                                                                    JU N C T IO N T E M P E R A T U R E( o C )                                                                                                                                                                                      SWITCH CURRENT(A)
                                                                                                                                                                                                                   JUNCTION TEMPERATURE(oC)

                                                                                Switch Current Limit                                                                                                                                                                                                     Shutdown Quiescent Current
                                                                                                                                                                                                             Operating Quiescent Current
                                                                                                                                                              SUPPLY CURRENT (mA)
Output voltage Vo(V)

                                               6.0                                                                                                                                  20.0
                                                                                      VIN =10V             20V 30V
                                                                                                                                                                                                                                                                   CURRENT (uA)
                                                                                                                                                                                    15.0                                                                                                  100.0
                                                                                                                                                                                                                                     Switch                                                              1
                                               4.0                                                                                                                                                                                                                                                                                          =5
                                                                                                                                                                                                                                      ON                                                                 2                         VON/OFF
                                                                                                                                                                                                                                                                                           80.0                                             V
                                                                                                                                                                                    10.0                                                                                                                     3                    1 : -40 oC
                                                                                                                                                                                                                                                                                                                                  2 : 25 oC
                                               2.0                                                                                                                                                                             Switch OFF                                                                                         3 : 125 oC
                                                                                                                                                                                     5.0                                                                                                   40.0

                                                                                                                                                                                     0.0                                                                                                    0.0               10        20        30          40
                                                                                                                                                                                                   -50       -25      0       25    50     75   100       125                                                      SUPPLY VOLOTAGE (V)
                                                                     0          1         2       3        4         5        6            7
                                                                                      Output current Io (A)                                                                                                  JUNCTION TEMPERATURE(oC)
                                                                                                                                                                                                                    ON/OFF Threshold
                                                                                Minimum Operating Supply                                                                                                                Voltage                                                                       O N /O F F P in C u r r e n t
                                                                                        Voltage                                                                                                                                                                                                              ( S in k in g )
                                                                                                                                                                                             4.0                                                                                             V IN = 4 0 V
                                                                                                                                                        THRESHOLD VOLTAGE

                                                                                                                                                                                                                                                                                         - 4 0o C ≤ T J ≤ 1 2 5 C
                                        SUPPLY VOLTAGE (V)



                                                                            VOUT =1.23V                                                                                                      1.0
                                                                1.0         ILOAD
                                                                                                                                                                                                                                                                          1 .4                  5        10        15   20   22   23     24        25
                                                                0.0                                                                                                                          0.0
                                                                                                                                                                                                                                                                                                    O N /O F F P IN V O L T A G E (V )
                                                                         -50 -25              0       25       50        75 100 125                                                                  -50 -25              0    25   50      75 100        125

                                                                                                                                  o                                                                                                             o
                                                                                JUNCTION TEMPERATURE (                                C)                                                                 JUNCTION TEMPERATURE (                      C)

                                                               2007/01/25 Rev. 1.4                                                                    Champion Microelectronic Corporation                                                                                                                              Page 9
                                                                                                        2A Step Down VOLTAGE REGULATOR

                                        Switch                                                         Feedback Pin Bias
                                      Frequency                                                            Current                                                              Thermal protection
              200                                                                   50.0

                                                                                    40.0                                                                           8

                                                                                                                                            Output voltage Vo(V)
                                                                     BIAS CURRENT

                                                                                    30.0                                                                           6


                                                                                    20.0                                                                           4
                                                                                                        Adjustable Version
                                                                                                               Only                                                2
               50                                                                   10.0
                                                                                     0.0                                                                                50    75   100     125     150   175   200
               0.0                                                                           -50 -25    0   25    50       75    100 125
                         -50 -25     0   25      50   75   100 125                                                                                                            JUNCTION TEMPERATURE( C)
                                                                                                                            o   C)
                                                                                                JUNCTION TEMPERATURE(
                           JUNCTION TEMPERATURE ( C)

                                   Light Load operation                                                  Heavy Load operation                                                          Load step

                                                                                    Iout                                                       /D
                                                                                                                                             1A IV
                                                                              Vout ripple
                                                                              20m /div
V ripple
 0m /div
    V                                                                                                                                         V IV
                                                                                                                                           50m /D

                                                                                                                                                                        V=in 12V
                                                                                            Vin=12V              5us/div
              V=in 12V                                                                                                                                                    out=
                                                                                                                                                                        V 5V
              V 5V                                                                          Iload=2A                                                                             O
                                                                                                                                                                        ILOAD=0AT 2A
              Iload 0A

                 2007/01/25 Rev. 1.4                                 Champion Microelectronic Corporation                                                                              Page 10
                                                  2A Step Down VOLTAGE REGULATOR


                                             8-PIN SOP (S08)

                      PIN 1 ID


                                     8-Pin SOP w/ Power Pad (PS08)


2007/01/25 Rev. 1.4              Champion Microelectronic Corporation     Page 11
                                                          2A Step Down VOLTAGE REGULATOR

                                              IMPORTNT NOTICE

Champion Microelectronic Corporation (CMC) reserves the right to make changes to its products or to discontinue
any integrated circuit product or service without notice, and advises its customers to obtain the latest version of
relevant information to verify, before placing orders, that the information being relied on is current.

A few applications using integrated circuit products may involve potential risks of death, personal injury, or severe
property or environmental damage.        CMC integrated circuit products are not designed, intended, authorized, or
warranted to be suitable for use in life-support applications, devices or systems or other critical applications. Use of
CMC products in such applications is understood to be fully at the risk of the customer. In order to minimize risks
associated with the customer’s applications, the customer should provide adequate design and operating safeguards.

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5F, No. 11, Park Avenue II,                                   7F-6, No.32, Sec. 1, Chenggong Rd.,
Science-Based Industrial Park,                                Nangang District, Taipei City 115,
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T E L : +886-3-567 9979                                       T E L : +886-2-2788 0558
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2007/01/25 Rev. 1.4                   Champion Microelectronic Corporation                                 Page 12