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					     dsPIC® Digital Signal Controllers (DSC)

                                                                                     Level 4




Microchip’s dsPIC® Digital Signal Controllers (DSCs) are an excellent choice for use in
common, multi-loop switch-mode power supplies (SMPSs) and other power-conversion
applications. The dsPIC30F1010 and dsPIC30F2020/2023 (dsPIC30F202X) DSCs have a high-
speed, 1 nanosecond (ns) resolution pulse-width-modulator (PWM) and 2 million sample per
second (MSPS), 10-bit analog-to-digital (A/D) converter onboard for low latency and high-
resolution control. The devices are ideal for AC/DC converters, isolated DC/DC power-
converters and other power-conversion applications, such as embedded power-supply
controllers, power inverters and Uninterruptible Power Supplies (UPSs).

Microchip is a leading supplier of microcontrollers and analog control products to the power-
conversion industry. The Company’s microcontrollers have long been used in intelligent power
supplies for communications, power-sequencing, soft-start and topology control. However,
until now, a lack of effective solutions has hampered the development of supplies using digital
control of the complete power-conversion loop. The dsPIC30F1010 and dsPIC202X DSCs free
designers to implement complete digital control of their products.

Example Applications

   AC to DC Converters
   DC to DC Converters
   Power Factor Correction (PFC)
   Uninterruptible power supply (UPS)
   Inverters
   Embedded Power-Supply Controllers
   Circuit Breakers, Arc Fault Detection
   Digital Lighting


dsPIC DSC SMPS Devices


The new DSCs enable full control of the power-conversion process via software running on the
DSC and through its high-performance integrated peripherals. Designers are no longer limited
by analog-control design techniques. Components no longer need to be “oversized” to
account for component variation. There is no need to worry about component drift and
temperature compensation. Manual tuning at the end of the manufacturing line can be a thing
of the past. Fewer product platforms are required to serve a wider range of applications, as
they are differentiated through software, rather than hardware. Additionally, new, fully-digital
topologies help provide designers with a higher degree of freedom to develop supplies with
improved power density and improved cost effectiveness.

Figure 1 below shows a block diagram of the dsPIC-SMPS products. The PWM onboard the
dsPIC30F1010 and dsPIC30F202X devices offers 1 ns duty cycle resolution and seven modes
of operation, including standard, complementary, push-pull and variable-phase. The 10-bit
A/D converter has up to 12 input channels and samples at up to 2 MSPS. Advanced sampling
capabilities include individual triggers for each of four sample and holds, and precise, uniquely
timed or simultaneous sampling. The dsPIC30F1010 has 6 Kbytes of Flash and two PWM
generators, and the dsPIC30F202X have 12 Kbytes of Flash and four PWM generators. All
devices in this family operate between 3.0 and 5.5 volts. Additional features include:

       Onboard high-speed analog comparators (2 or 4)
       30 MIPS performance at 5.0 volts
       Small footprint QFN package (6 mm x 6 mm)
       Fast, deterministic response
       Extended temperature operation (-40 to 125 degrees Celsius)
       Optional PWM dither mode for Electromagnetic Interference (EMI) reduction




 Part Number        Pins       Flash     SRAM        2 MSPS 10        High       Communication /
                                (Kb)     (Bytes)        bit ADC         Speed             Timers
                                                       CH x S&H         PWM
dsPIC30F1010          28          6         256         6 CH x 2         2x2           UART, I2C™,
                                                          S&H                         SPI, 2 x Timers
dsPIC30F2020          28         12         512         8 CH x 4         4x2           UART, I2C™,
                                                          S&H                         SPI, 3 x Timers
dsPIC30F2023          44         12         512        12 CH x 4         4x2           UART, I2C™,
                                                          S&H                         SPI, 3 x Timers

CH – Channel
S&H – Sample and Hold


Note: This table does not list all microcontrollers and digital signal controllers available. If the
specific mix of peripherals desired is not shown, you can use the following links to:
        complete 8-bit PICmicro® MCU selection chart
        complete dsPIC digital signal controllers selection chart

Benefits of Digital Loop Control

By using digital loop control to implement power conversion products developers can realize
many benefits to their design and business. These are enabled by the ability to perform the
power conversion control via reprogrammable software and the performance and features of
the Microchip DSC solutions. Benefits can include the following.

Increased Power Density
      Reduce System Size via Component Count and Size Reduction

Lower Cost, Improved Time to Market & Ease of Manufacturing
     Feature-Rich Designs with Fewer Components
     Power Factor Correction Performed by DSC Software
     Complexity Designing for Component Tolerance/Drift Reduced
     Fewer Hardware Platforms Supports Varied-End Products Through Software
     Manufacturing Line Tuning Eliminated – No Component Tolerance Issues
     End-of-Line Configuration Possible (Load Limits, Communication
             Protocols, etc.)
     Improved Self-Test Capability Simplifies/Speeds Product Testing

New, Cost-Effective Features
      Adapt to Changing Load (Capacitive, Inductive, Resistive, Current Demands)
      Better Transient Response Specifications – Not Limited to Linear Techniques
      Managed Voltage Transitions Eliminate “Over specified” Components

Improved Reliability
     Supplies Can Be Restricted From Operating Out of Specification
     Fewer Components Help Reliability
     Lower Cost Redundancy Options

Protect Intellectual Property
      Key Innovative IP Implemented in Secured Flash Software



Benefits of the dsPIC-SMPS

The benefits of the dsPIC-DSC SMPS digital signal controllers for digital power conversion
applications are many. The dsPIC DSC SMPS controllers are Self-Contained SMPS Solutions
that do not require much in the way of external support chips as they have all the necessary
peripherals to do the job. As opposed to solutions from others the dsPIC DSC SMPS does not
need the following external components because they are all performed internally:

        NO   External PWM
        NO   External ADC
        NO   External Power Management Chip
        NO   Crystal Required
        NO   Separate Chip for Communications
        NO   Separate Chip for Power Factor Correction

So when using the dsPIC DSC SMPS solution in applications developers can obtain a 50%
reduction in component count over other solutions.

In addition to the space and cost saving features that are in the dsPIC DSC SMPS solution it
also has special features specifically enabling advanced power conversion. These include
Intelligent Power. The independent PWM, ADC and Analog Comparators peripherals form the
Intelligent Power Peripheral via an internal configurable control fabric that enables them to
interact directly with one another. Below is some of the capability and benefits offered by the
configurable control fabric.

Configurable Control Fabric
      Controls Coordination between Comparators, PWM, and ADC
      Set-up via Software / Operates Independently of Software
      Precisely Times ADC Conversions
      Controls PWM Response to Faults
Benefits of Configurable Control Fabric
      Provides Real-Time Response without Firmware Intervention
               Expands Control Range of Options
      Adaptable for a Wide Variety of Control Methodologies
      Provides Fail-Safe Control
Developed with Deep Understanding of SMPS
      Many Years of Working With and Delivering Products to
              the Power-Conversion Industry

				
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posted:12/4/2011
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