Micrel, Inc.

MIC26601

July 2011

2

M9999-071311-A

Ordering Information

Part Number

Voltage

Switching Frequency

Junction Temperature

Range

Package

Lead

Finish

MIC26601YJL

Adjustable

600kHz

–40°C to +125°C

28-Pin 5mm

Pb-Free

Pin Configuration

28-Pin 5mm

Pin Description

Pin Number

Pin Name

Pin Function

1

PVDD

5V Internal Linear Regulator (Output): PVDD supply is the power MOSFET gate drive supply voltage

ceramic capacitor from the PVDD pin to PGND (Pin 2)

must be place next to the IC.

3

NC

No Connect.

4, 9, 10,

11, 12

SW

Switch Node (Output): Internal connection for the high-side MOSFET source and low-side MOSFET

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

nodes.

2, 5, 6, 7, 8,

21

PGND

Power Ground. PGND is the ground path for the MIC26601 buck converter power stage. The PGND

pins connect to the low-side N-Channel internal MOSFET gate drive supply ground, the sources of

the 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.

13,14,15,

16,17,18,19

PVIN

4.5V to 28V. Input capacitors between the PVIN pins and the Power Ground (PGND) are required and

keep the connection short.

20

BST

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

connected between the PVDD 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 the BST pin can slow down the turn-on time of

high-side N-Channel MOSFETs.