Micrel, Inc.

MIC26600

September 2010

2

M9999-091710-C

Ordering Information

Part Number

Voltage

Switching Frequency

Junction Temperature Range

Package

Lead Finish

MIC26600YJL

Adjustable

300kHz

−40°C to +125°C

28-pin 5mm

Pb-Free

Pin Configuration

28-Pin 5mm

Pin Description

Pin

Number

Pin Name

Pin Function

13,14,15,

16,17,18,

19

PVIN

4.5V to 26V. Input capacitors between the PVIN pins and the power ground (PGND) are required and

keep the connection short.

24

EN

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

reduced (typically 0.7mA).

25

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 feedback to the output is used to adjust the desired output

voltage.

26

SGND

Signal ground. SGND must be connected directly to the ground planes. Do not route the SGND pin to

the PGND Pad on the top layer, see PCB layout guidelines for details.

27

VDD

operating voltage range is from 4.5V to 5.5V. A 2.2µF ceramic capacitor from the VDD pin-to-PGND

must be placed next to the IC.

2,5,6,7,8,

21

PGND

Power Ground. PGND is the ground path for the MIC26600 buck converter power stage. The PGND

pin connects to the sources of low-side N-Channel internal 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 (SGND) loop.

22

CS

Current Sense (Input): High current output driver return. The CS pin connects directly to the switch

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

nodes. CS pin also senses the current by monitoring the voltage across the low-side internal

MOSFET during OFF-time.