User manual

MCP250XX User’s Guide
DS51266C-page 40  2004 Microchip Technology Inc.
A.2 VPP Step-up Regulator
FIGURE A-1: V
PP
STEP-UP REGULATOR CIRCUIT
VCC
VIN
VREF
U2
.25 - 1%
R1
C7
C4
Q3 PFET – MTSF2P02
Q2 PFET – MTSF2P02
.1 µF .1 µF .1 µF
C5 C6
Q1
D1
680 pF
10
COMPIN– COMPIN+ OAIN– OAIN+ OAV CATHODE ANODE GND
CAP
OAOUT
SWE
SWC
DRVC
SENSE
9 7 6 5 1 2
4 12 811
LM78S40
GND
GND
GND
GND
AK
GND
GND GND GND
R3
160
L1
{Value}
R4
C3
R7
10K
23.7K
100 µF - 16V 6.3 MM
R5
R8
VCC
VDD
10K
R2
100
2.21K - 1%
3 16 15 14 13
µ
µ
NVPP_ON
NVPP_ON
V
PP
VCC