Micrel, Inc.

MIC2165

September 2010

2

M9999-092410-E

Ordering Information

Part Number

Voltage

Switching Frequency

Junction Temp. Range

Package

Lead Finish

MIC2165YMME

Adj.

600kHz

–40° to +125°C

10-pin ePad MSOP

Pb-Free

Pin Configuration

10-Pin ePad MSOP (MME)

Pin Description

Pin

Number

Pin Name

Pin Function

1

FB

Feedback (Input): Input to the transconductance amplifier of the control loop. The FB pin is regulated to

0.8V. A resistor divider connecting the output to FB is used to set the desired output voltage.

2

PGOOD

Power Good (Output): Open Drain Output. The PGOOD pin is externally tied with a resistor to VDD.

3

EN

Enable (Input): A logic level control of the output. The EN pin is CMOS-compatible. Logic high = enable,

logic low = shutdown. In the off state, supply current of the device is greatly reduced (typically 5µA). The

EN pin should not be left open. Connect to VIN if sequencing not required.

4

VIN

Supply Voltage: Input voltage for the internal +5V linear regulator. The VIN operating voltage range is

from 4.5V to 28V. A 0.1µF capacitor between VIN and the ground is required.

5

VDD

5V Internal Linear Regulator (Output): VDD is the external MOSFET gate drive supply voltage and an

internal supply bus for the IC. VDD is created by internal LDO from VIN. When VIN <+5.5V, VDD Should

be tied to VIN. A 2.2µF (minimum) ceramic capacitor from VDD to GND

operation.

6

DL

Low-Side Gate Drive (Output): High-current driver output for external low-side MOSFET. The DL driving

voltage swings from ground to VDD.

7

PGND

Power Ground. PGND is the ground path for the MIC2165 buck converter power stage. The PGND pin

connects to the sources of low-side N-Channel MOSFETs, the negative terminals of input capacitors,

and the negative terminals of output capacitors. The loop for the power ground should be as small as

possible and separate from the Signal ground (GND) loop.

8

DH

High-Side Gate Drive (Output): High-current driver output for external high-side MOSFET. The DH

driving voltage is floating on the switch node voltage (SW). It swings from ground-to-VDD minus the

diode drop.

9

SW

Switch Node (Input): High current output driver return. The SW pin connects directly to the switch node.

Due to the high speed switching on this pin, the SW pin should be routed away from sensitive nodes.

Current-Sense Input (Input): SW pin also senses the current by monitoring the voltage across the low-

side MOSFET during OFF-time. The current sensing is necessary for short circuit protection and zero

current cross comparator. In order to sense the current accurately, connect the low-side MOSFET drain

to SW using a Kelvin connection.

10

BST

Boost (Output): Bootstrapped voltage to the high-side N-channel MOSFET driver. A Schottky diode is

connected between the VDD pin and the BST pin. A boost capacitor of 0.1μF is connected between the

BST pin and the SW pin. Adding a small resistor at BST pin can slow down the turn-on time of high-side

N-Channel MOSFETs.

EP

GND

Thermal Pad and Signal ground. GND is the ground path for VDD and the control circuitry. The loop for

the signal ground should be separate from the power ground (PGND) loop.