Micrel, Inc.

MIC28304

Ordering Information

Part Number

Switching

Frequency

Features

Package

Junction

Temperature

Range

Lead

Finish

MIC28304-1YMP

200kHz to 600kHz

HyperLight Load

64-pin 12mm × 12mm QFN

–40°C to +125°C

Pb-Free

MIC28304-2YMP

200kHz to 600kHz

Hyper Speed Control

64-pin 12mm × 12mm QFN

–40°C to +125°C

Pb-Free

Pin Configuration

64-Pin 12mm × 12mm QFN (MP)

(Top View)

Pin Description

Pin Number

Pin Name

Pin Function

1, 2, 3, 54, 64

GND

Analog Ground. Ground for internal controller and feedback resistor network. The analog ground

return path should be separate from the power ground (PGND) return path.

4

ILIM

Current Limit Setting. Connect a resistor from SW (pin #4) to ILIM to set the over-current threshold

for the converter.

5, 60

VIN

Supply Voltage for Controller. The VIN operating voltage range is from 4.5V to 70V. A 0.47

μF

ceramic capacitor from VIN (pin # 60) to AGND is required for decoupling. The pin # 5 should be

externally connected to either PVIN or pin # 60 on PCB.

6, 40 to 48, 51

SW

Switch Node and Current-Sense 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. The SW pin also senses the current by monitoring the voltage across

the low-side MOSFET during OFF time.

March 25, 2014

2

Revision 1.1