Micrel, Inc.

MIC3201

February 2011

2

M9999-021011-B

Part Number

Marking

Junction Temp. Range

Package

Lead Finish

MIC3201YME

MIC3201YME

-40°C to +125°C

8-Pin ePAD SOIC

Pb-Free

Note:

1. YME

Pin Configuration

8-Pin ePAD SOIC (ME)

Pin Description

Pin Number

Pin Name

Pin Function

1

VCC

the output of a linear regulator which is powered from VIN. A 1µF ceramic capacitor is

recommended for bypassing and should be placed as close as possible to the VCC and AGND

pins. Do not connect to an external load.

2

CS

Current Sense Input. The CS pin provides the high-side current sense to set the LED current

with an external sense resistor.

3

VIN

Input Power Supply. VIN is the input supply pin to the internal circuitry and the positive input to

the current sense comparator. Due to the high frequency switching noise, a 10µF ceramic

capacitor is recommended to be placed as close as possible to VIN and the power ground

(PGND) pin for bypassing. Please refer to layout recommendations.

4

AGND

Ground pin for analog circuitry. Internal signal ground for all low power sections.

5

EN

Enable Input. The EN pin provides a logic level control of the output and the voltage has to be

2.0V or higher to enable the current regulator. The output stage is gated by the DIM pin. When

the EN pin is pulled low, the regulator goes to off state and the supply current of the device is

greatly reduced (below 1µA). In the off state, the output drive is placed in a "tri-stated" condition,

where MOSFET is in an “off” or non-conducting state. Do not drive the EN pin above the supply

voltage.

6

DIM

PWM Dimming Input. The DIM pin provides the control for brightness of the LED. A PWM input

can be used to control the brightness of LED. DIM high enables the output and its voltage has to

be at least 2.0V or higher. DIM low disables the output, regardless of EN “high” state.

7

PGND

Power Ground pin for Power FET. Power Ground (PGND) is the ground path for the high current

hysteretic mode. The current loop for the power ground should be as small as possible and

separate from the Analog ground (AGND) loop. Refer to the layout considerations for more

details.

8

LX

Drain of Internal Power MOSFET. The LX pin connects directly to the inductor and provides the

switching current necessary to operate in hysteretic mode. Due to the high frequency switching

and high voltage associated with this pin, the switch node should be routed away from sensitive

nodes.

EP

GND

Connect to PGND.