MIC25400 Datasheet, PDF (3/27 Pages) Micrel Semiconductor – 2A Dual Output PWM Synchronous Buck Regulator IC

Micrel, Inc.
MIC25400
Pin Number
13
14
15
16
17
18
19
20
21
22
23
24
EP
Pin Name
EN/DLY2
PG2
CS2
PGND2
LSD2
BST2
SW2
VIND2
PVDD
VIN
VIND1
SW1
GND
Pin Description
Enable/Delay 2 (Input): This pin can be used to disable V_OUT2. When
used to disable V_OUT2, this pin must be pulled down to ground in less
than 1µs for proper operation. It is also used for soft-start of the
output. Soft start capacitor range is 4.7nf to 22nf. See Functional
Description section for additional information.
Power Good 2 (Output) Open drain. Device is in the OFF state. i.e.,
high when output is within 90% of regulation
Current Sense 2 (Input) Place a resistor from SW2 to this pin to
program the current limit point from 0.5A to 2.7A
Power Ground 2 (Input)
Low-side Drive 2 (Output): External low-side N-Channel MOSFET
driver. Use 4.5V rated MOSFETs.
Boost 2 (Input): Provides voltage for high-side internal MOSFET for
Channel 2. Connect a 0.01µF capacitor from SW2 to BST2 pin and a
diode-to-PVDD.
Switch Node 2 (Output): Source of internal high-side power MOSFET.
Supply voltage (Input): For the drain of internal high-side power
MOSFET 4.5V to 13.2V.
5V Internal Linear Regulator (Output): PVDD is the external MOSFET
gate drive for LSD1 and LSD2 and an internal supply bus for the IC.
Connect to an external 1µF bypass capacitor. When VIN is <6V, this
regulator operates in drop-out mode. Connect VDD to VIN when VIN
<6V.
Supply voltage (Input): For the internal 5V linear regulator. 4.5V to
13.2V.
Supply voltage (Input): For the drain of internal high-side power
MOSFET 4.5V to 13.2V.
Switch Node 1 (Output): Source of internal high-side power MOSFET.
Exposed thermal pad for package only. Connect to ground. Must
make a full connection to the ground plane to maximize thermal
performance of the package.
January 2011
3
M9999-020111-C