Datasheet

MCP1640 12V/50 mA Two Cells Input Boost Converter Reference Design
DS51999A-page 10 © 2011 Microchip Technology Inc.
1.2.1 MCP1640 Key Features
• Up to 96% Typical Efficiency
• 800 mA Typical Peak Input Current Limit:
-I
OUT
> 100 mA @ 1.2V V
IN
, 3.3V V
OUT
-I
OUT
> 350 mA @ 2.4V V
IN
, 3.3V V
OUT
-I
OUT
> 350 mA @ 3.3V V
IN,
5.0V V
OUT
• Low Start-up Voltage: 0.65V, typical 3.3V V
OUT
@ 1 mA
• Low Operating Input Voltage: 0.35V, typical 3.3V
OUT
@ 1 mA
• Adjustable Output Voltage Range: 2.0V to 5.5V
• Maximum Input Voltage ≤ V
OUT
< 5.5V
• Automatic PFM/PWM Operation (MCP1640/C):
- PFM Operation Disabled (MCP1640B/D)
- PWM Operation: 500 kHz
• Low Device Quiescent Current: 19 µA, typical PFM mode
• Internal Synchronous Rectifier
• Internal Compensation
• Inrush Current Limiting and Internal Soft-Start
• Selectable, Logic Controlled, Shutdown States:
- True Load Disconnect Option (MCP1640/B)
- Input to Output Bypass Option (MCP1640C/D)
• Shutdown Current (All States): < 1 µA
• Low Noise, Anti-Ringing Control
• Overtemperature Protection
FIGURE 1-1: Typical MCP1640 Single Cell Input Boost Converter.
V
IN
EN
GND
V
FB
SW
V
IN
1.5V
V
OUT
3.3V @ 100 mA
C
OUT
10 µF
C
IN
4.7 µF
L
1
4.7 µH
V
OUT
+
-
536 KΩ
309 KΩ
Alkaline