MCP1642B Datasheet, PDF (14/32 Pages) Microchip Technology – 1.8A Input Current Switch, 1 MHz Low-Voltage Start-Up Synchronous Boost Regulator

MCP1642B/D
4.2 Functional Description
The MCP1642B/D devices are compact,
high-efficiency, fixed-frequency, step-up DC-DC
converters that provide an easy-to-use power supply
solution for applications powered by either one-cell,
two-cell, or three-cell alkaline, Ultimate Lithium, NiCd,
or NiMH, or one-cell Li-Ion or Li-Polymer batteries.
Figure 4-1 depicts the functional block diagram of the
MCP1642B/D devices.
V_OUT
V_IN
SW
EN
P_GND
S_GND
Internal
Bias
Gate Drive
and
Shutdown
Control
Logic
Oscillator
Direction
Control
Soft-Start
0V
OC_REF
I_ZERO
I_LIMIT
I_SENSE
Slope
Compensation
S
PWM
Logic
*
V_OUT
EA
1.21V
0.9 x V_REF
V_FB
V_FB (NC)
PG
FIGURE 4-1:
* Available in Fixed Output option only. See
Section 4.2.4 “Fixed Output Voltage”.
MCP1642B/D Block Diagram.
DS20005253A-page 14
 2014 Microchip Technology Inc.