Datasheet

www.microchip.com/lighting LED Lighting Solutions Design Guide 13
LED Lighting Solutions
High Performance Digital Control
Devices in the PIC18F, PIC24 and dsPIC33F families offer
8-bit and 16-bit solutions for fast calculation of digital control
loops. In addition, these families have device variants with
fast ADC peripherals and specialized PWM modules that are
optimized for power control applications.
A selection of devices for digital power control is shown in
the table below. There are many other Microchip devices that
could be used, but these devices represent low-cost and
small package choices.
Devices in the PIC18F family have an 8-bit CPU with a
hardware multiplier. The PIC18 is a good choice for moderate
control loop rates (1-10 KHz). Devices in the dsPIC33F family
have a 16-bit CPU with DSP resources. This family is a good
choice if you need to execute multiple control loops at a
faster rate. Devices in the PIC24 family offer an intermediate
solution with 16-bit calculation performance.
The dsPIC33FJ06GS202 device has a Power Supply PWM
module that can generate high switching frequencies with
very fine edge resolution. This PWM module can also
generate phase shifted PWM signals for advanced power
supply applications.
The 28-pin dsPIC33FJ06GS202 device can provide a highly
integrated solution for LED lighting applications. The PWM
peripheral can drive 3 strings of LEDs, replacing 3 separate
analog control ICs. Furthermore, there are resources left
over for active power factor correction (PFC) and digital
communications.
LED Lighting Development Kit Reference Design
The LED Lighting Development Kit demonstrates the
capabilities of Microchips “GS” series of dsPIC Digital Signal
Controllers (DSC) in High Brightness (HB) LED applications.
More information is available at: www.microchip.com/LED.
Web Links
www.microchip.com/smps
www.microchip.com/pic24
www.microchip.com/pic18
Multiple LED Driver Application with PFC
VAC
lPFC
VBUS
I1
I2
I3
Drive 2
Drive 3
Drive 1
I1 I2 I3
LED Drive 1 LED Drive 2 LED Drive 3
V
BUS
PFC
PFC
Drive
V
AC
120
V
AC
PFC Drive
dsPIC33FJ06GS202
MCP1416
Serial
Comm.
GPIO
40 MIPS DSP
10-bit
ADC
Output Compare
PWM3
PWM1
PWM2
PWM4
Selected Devices for Digital Power Control
Device Pins Architecture ADC PWM
PIC18F23K22 28 8-bit MCU 10-bit, 100 KSPS 3 Enhanced, 2 Standard
PIC24FJ16GA002 28 16-bit MCU 10-bit, 500 KSPS 5 Standard
dsPIC33FJ06GS202 28 16-bit DSC 10-bit, 2 MSPS 4 Power Supply