Product Overview
© 2011 Microchip Technology Inc. DS51999A-page 11
1.3 WHAT IS THE MCP1640 12V/50 mA TWO CELLS INPUT BOOST
CONVERTER REFERENCE DESIGN?
The MCP1640 12V/50 mA Two Cells Input Boost Converter Reference Design is
designed to demonstrate the MCP1640 device’s high-voltage boost capability above its
typical output range of 5.5V. This board boosts the low-voltage input to 12V and up to
70 mA load. By changing the sense resistors (R
T
and R
B
on Figure 1-2), a lower/higher
output than 12V will be obtained. The MCP1640 Input Boost Converter was developed
to help engineers reduce product design cycle time.
At 2.0V input and 12V output, the board is capable of a maximum of 50 mA load current.
The N-MOS switch is connected between the inductor and the main switch, allowing
the application to output higher voltage (see Figure 1-2).
The converter is configured as nonsynchronous; a Schottky diode is connected
between the inductor and the High-Voltage Output (V
OUT
High). At start-up, MCP1640
starts as the current generator for the Output Capacitor (C
OUT
). Because at this time,
the internal N-MOS switch is OFF, a Start-up Resistor (R
Start
), connected in parallel with
the N-MOS switch, should be used.
FIGURE 1-2: MCP1640 12V/50 mA Two Cells Input Boost Converter
Reference Design Block Diagram.
1.4 WHAT DOES THE MCP1640 12V/50 mA TWO CELLS INPUT BOOST
CONVERTER REFERENCE DESIGN KIT INCLUDE?
The MCP1640 Input Boost Converter kit includes:
• MCP1640 12V/50 mA Two Cells Input Boost Converter Reference Design, 102-00386
• Important Information Sheet
Load
Two Cells Input
V
OUT
V
IN
Switch
N-MOS
EN
SW
L
Boost
R
Start
R
T
V
OUT
High > 6V
FB
C
IN
C
OUT
R
B
GND
