MIC2159 Datasheet, PDF (2/17 Pages) Micrel Semiconductor – SYNCHRONOUS-itty™ Step-Down Converter IC

Micrel
Ordering Information
Part Number Output Voltage
MIC2159YMME
Adj
Pin Configuration
Frequency
400KHz
MIC2159
Juction Temperature
Range
-40°C to +125°C
Package
10-lead ePAD MSOP
Pin Description
Pin Number
(MSOP-10)
1
2
Pin Name
V_IN
V_DD
3
CS
4
COMP/EN
5
FB
6
GND
7
LSD
8
VSW
9
HSD
10
BST
10-lead e-PAD MSOP (MME)
Pin Function
Supply voltage (Input): 3V to 14.5V
5V Internal Linear Regulator (Output): V_DD is the external MOSFET gate drive supply voltage
and an internal supply bus for the IC. When Vin is ≤5V, V_DD should be connected to Vin.
Current Sense. Current-limit comparator non-inverting input. The current limit is sensed across
the FET during the ON time. The current can be set by the resistor in series with the CS pin.
Compensation (Input): Dual function pin. Pin for external compensation. If this pin is pulled
below 0.2V, with the reference fully up the device shuts down (50µA typical current draw)
Feedback (Input): Input to error amplifier. Regulates error amplifier to 0.8V.
Ground (Return)
Low-Side Drive (Output): High-current driver output for external synchronous MOSFET.
Switch (Return): High-side MOSFET driver return
High-Side Drive (Output): High current output-driver for the high-side MOSFET.
When Vin is below 5v, 2.5v threshold FETs should be used. At Vin > 5V, 4.5V threshold FETs
should be used.
Boost (Input): Provides the drive voltage for the high-side MOSFET driver. The gate drive
voltage is higher than the source voltage by V_IN minus a diode drop.
October 2006
2
M9999-101206