Microchip Technology MCP1631 Evaluation Board MCP1631RD-DCPC1 MCP1631RD-DCPC1 Data Sheet

Product codes
MCP1631RD-DCPC1
Page of 32
MCP1631HV Digitally Controlled Programmable Current Source Reference Design
DS51798A-page 6
© 2009 Microchip Technology Inc.
1.2
WHAT IS THE MCP1631HV DIGITALLY CONTROLLED PROGRAMMABLE 
CURRENT SOURCE REFERENCE DESIGN?
This board utilizes Microchip’s MCP1631HV-3.3 (high-speed PIC
®
 MCU PWM 
TSSOP-20, 3.3V supply version).
The MCP1631HV Digitally Controlled Programmable Current Source Reference 
Design is a complete stand-alone constant current LED power supply with a dimming 
ratio of 10:1. The board is capable of delivering a maximum of 1 Amp @ 8.5W output 
power. Efficiency is typically 85% at the maximum power.
TABLE 1-1:
DEFAULT OUTPUT CAPABILITY IN DRIVING LED MODE
The board may also be re-programmed to charge Li-Ion, NiMH, and NiCd  battery 
packs. The MCP1631HV Digitally Controlled Programmable Current Source Reference 
Design is capable of charging one to four NiMH/NiCd batteries connected in series or 
one to two Li-Ion batteries in series. See Table 1-2 for detailed charger capabilities.
TABLE 1-2:
MULTI-CHEMISTRY CHARGER CAPABILITY
 
The input voltage range for the reference board is 3.5V to 16V.
An input terminal block is provided to apply the input voltage to the board. An output 
header with 5 pins is also provided as a means to connect the load LEDs or battery 
pack and an external 10 k
Ω thermistor. When used, thermistors should either be 
mounted on the LED heatsink next to the LED case or internal to the MiMH/NiCd 
battery pack.
A programming header compatible with the PICkit
TM
2 and ICD 2 programmers is on 
board for updating the firmware contained in the PIC16F616. Firmware updates are 
required to switch between LED, NiMH/NiCd, and Li-Ion modes of operation.
1.3
WHAT THE MCP1631HV DIGITALLY CONTROLLED PROGRAMMABLE 
CURRENT SOURCE KIT INCLUDES
The MCP1631HV Digitally Controlled Programmable Current Source kit includes:
• The MCP1631HV Digitally Controlled Programmable Current Source Reference 
Design,102-00234
• Important Information “Read First”
Maximum 
output current
Dimming ratio
Maximum 
Output power
Overvoltage 
protection
Thermal 
shutdown
700 mA
10:1
8.5W
9V
40
°
C
Note 1:
Maximum output current can be modified in the source code.  Absolute max is 1A 
@8.5W.
2:
For an easy start with the MCP1631HV Digitally Controlled Programmable Current 
Source Reference Design Board, this option is not enabled in the compiled .hex file 
which is available on the Microchip website.
Battery Chemistry
1 Cell
2 Cells
3 Cells
4 Cells
Li-Ion
1A
500 mA
NA
NA
NiMH or NiCd
700 mA
700 mA
700 mA
700 mA
Note:
The SEPIC converter is capable of buck-boost operation. The duty cycle 
may be changed in the source code to allow boost operation. Set the 
00234R1.h
” header file pre-processor duty cycle definition to:
#define OSCILLATOR_DUTY_CYCLE  25
for 25% duty cycle and to allow boost operation.