Calculated
Input Variables Values National Semiconductor
Application Note 1246
T-PERIOD 4.00 uS 0.000004 Sanjaya Maniktala
F-SWITCHING 250.00 KHz 250000.0000000000 Sep-02
T-ON 2.28 uS 0.0000022800
T-OFF 1.72 uS 0.0000017200
RLOAD 2.5 Ohms
ILOAD 2.00 A
VI 10.00 V
VO 5.00 V
VDIODE 0.70 V
L 10.00 uH 0.0000100000
CIN 10.00 uF 0.0000100000
(ESR) 100.00 mOhms 0.1000000000
COUT 100.00 uF 0.0001000000
(ESR) 100.00 mOhms 0.1000000000
Duty Cycle D 57.00% % 0.5700000000 Note: Duty cycle calculations do not include switch vo
1-D 43.00% % 0.4300000000
Discontinious Load
Current (DCM) 0.49 A Note: B19 font color is red in DCM, r2 not valid
2
r-Ratio = IRIPP-pp/IOUT 0.49 0.24 =r
IRIPP-pp 0.98 A Note: Calculations in Column D are hidden/locked by
RMS CURRENTS
Input Cap 1.01 A
Output Cap 0.28 A
Switch 1.53 A
Diode 1.32 A
Inductor 2.02 A
AVG. CURRENTS
Switch 1.14 A
Diode 0.86 A
Inductor 2.00 A
Cap. Pwr. - Diss.
Input Cap 102.61 mW
Output Cap 8.01 mW
Peak Current
Switch 2.49 A
Inductor 2.49 A
Diode 2.49 A
VINDUCTOR (TON) FLUXAC (TON)
5.00 V 1.14E-05 V*S
VINDUCTOR (TOFF) FLUXAC (TOFF)
5.70 V 9.80E-06 V*S
DCFLUX DENSITY
2.00E-02 V*S
PeakFLUX DENSITY
2.00E-02 V*S
COUT FZERO
1.59E+04 Hz
ations do not include switch voltage drop
red in DCM, r2 not valid
olumn D are hidden/locked by changing font color to white
Calculated
Input Variables Values National Semiconductor
Application Note 1246
T-PERIOD 0.63 uS 0.000000625 Sanjaya Maniktala
F-SWITCHING 1600.00 KHz 1600000 Sep-02
T-ON 0.45 uS 4.48446E-07
T-OFF 0.18 uS 1.76554E-07
RLOAD 170 Ohms
ILOAD 0.10 A
VI 5.00 V
VO 17.00 V
VDIODE 0.70 V
L 10.00 uH 0.00001
CIN 10.00 uF 0.00001
(ESR) 100.00 mOhms 0.1
COUT 2.20 uF 0.0000022
(ESR) 100.00 mOhms 0.1
Duty Cycle D 71.75% % 0.72 Note: Duty cycle calculations do not include switch voltage
I-D 28.25% % 0.28
Discontinious Load
Current (DCM) 0.11 A Note: B19 font color is red in DCM, r2 not valid
2
r-Ratio = IRIPP-pp/IOUT 2.24 5.03 =r
IRIPP-pp 0.22 A Note: Calculations in Column D are hidden/locked by chang
RMS CURRENTS
Input Cap 0.25 A
Output Cap 0.20 A
Switch 0.36 A
Diode 0.22 A
Inductor 0.42 A
AVG. CURRENTS
Switch 0.25 A
Diode 0.10 A
Inductor 0.35 A
Cap. Pwr. - Diss.
Input Cap 6.31 mW
Output Cap 4.02 mW
Peak Current
Switch 0.750875 A
Inductor 0.750875 A
Diode 0.750875 A
VINDUCTOR (TON) FLUXAC (TON)
5.00 V 2.24E-06 V*S
VINDUCTOR (TOFF) FLUXAC (TOFF)
12.70 V 2.24E-06 V*S
DCFLUX DENSITY
3.54E-06 V*S
PeakFLUX DENSITY
4.66E-06 V*S
COUT FZERO
7.24E+05 Hz
RHPZERO
2.16E+05 Hz
ot include switch voltage drop
, r2 not valid
e hidden/locked by changing font color to white
Calculated
Input Variables Values National Semiconductor
Application Note 1246
T-PERIOD 3.33 uS 3.33333E-06 Sanjaya Maniktala
F-SWITCHING 300.00 KHz 300000 Sep-02
T-ON 2.39 uS 2.39171E-06
T-OFF 0.94 uS 9.4162E-07
RLOAD 60.00 Ohms
ILOAD 0.20 A
VI 5.00 V sdgsggh
VO (NEG) 12.00 V
VDIODE 0.70 V
L 10.00 uH 0.00001
CIN 10.00 uF 0.00001
(ESR) 100.00 mOhms 0.1
COUT 10.00 uH 0.00001
(ESR) 100.00 mOhms 0.1
Duty Cycle D 71.75% % 0.72 Note: Duty cycle calculations do not include switch voltag
1-D 28.25% % 0.28
Discontinious Load
Current (DCM) 0.17 A Note: B19 font color is red in DCM, r2 not valid
r-Ratio = IRIPP-pp/IOUT 5.98 35.75 = r2
IRIPP-pp 1.20 A Note: Calculations in Column D are hidden/locked by chan
RMS CURRENTS
Input Cap 0.09 A
Output Cap 0.72 A
Switch 1.20 A
Diode 0.75 A Note: Diode RMS(cathode) is specifically used to compute R
Inductor 1.41 A Not used in power calculations
AVG. CURRENTS
Switch 0.508 A
Diode 0.20 A
Inductor 0.71 A
Cap. Pwr. - Diss.
Input Cap 0.75 mW
Output Cap 52.35 mW
Peak Current
Switch 2.82 A
Inductor 2.82 A
Diode 2.82 A
VINDUCTOR (TON) FLUXAC (TON)
5.00 V 1.20E-05 V*S
VINDUCTOR (TOFF) FLUXAC (TOFF)
12.70 V 1.20E-05 V*S
DCFLUX DENSITY
2.00E-06 V*S
PeakFLUX DENSITY
7.98E-06 V*S
COUT FZERO
1.59E+05 Hz
RHPZERO
1.06E+05 Hz
do not include switch voltage drop
DCM, r2 not valid
D are hidden/locked by changing font color to white
ecifically used to compute RMS Cap Current, General: ICRMS2 = DiodeRMS2 - Iout 2
Sheet4
Radius Circumference Radius
40
0.66 0.66 0.66
1.89 11.94 1.89 35
1.98 13.18 1.98
2.62 16.34 2.62 30
3.62 21.78 3.62
4.78 31.16 4.78 25
Circumference
20
2.62
15 1.98
1.69247198 1.89
10
5
0
-5
-10
0.66 1.89 1.98 2.62
Radius
Page 10
Sheet4
Page 11
Sheet4
Pi Data y = 5.2909x - 2.6747
R² = 0.9368
4.78
35.00
3.62 30.00
25.00
Pi Data
20.00
15.00 Linear (Pi
Data)
10.00
5.00
3.62 4.78
0.00
0.66 1.89 1.98 2.62 3.62 4.78
Pi Data
40.00
35.00 y = 4.6736x
R2 = 0.921
30.00
25.00
20.00
15.00
10.00
Pi Data
Page 12
Sheet4
5.00
0.00
0.66 1.89 1.98 2.62 3.62 4.78
Page 13
Sheet4
Pi Data
Linear (Pi
Data)
Page 14
Sheet4
Page 15