MIC24054 Datasheet, PDF (2/30 Pages) Micrel Semiconductor – 12V, 9A High-Efficiency Buck Regulator

Micrel, Inc.
MIC24054
Ordering Information
Part Number
MIC24054YJL
Switching Frequency Voltage
600kHz
Adjustable
Package
28-Pin 5mm × 6mm QFN
Junction Temperature
Range
–40°C to +125°C
Lead Finish
Pb-Free
Pin Configuration
28-Pin 5mm x 6mm QFN (JL)
(Top View)
Pin Description
Pin Number Pin Name
1
PVDD
2, 5, 6, 7, 8, 21 PGND
3
4, 9, 10, 11, 12
13,14,15,
16,17,18,19
NC
SW
PVIN
20
BST
Pin Function
5V Internal Linear Regulator output. PVDD supply is the power MOSFET gate drive supply voltage
and created by internal LDO from VIN. When VIN < +5.5V, PVDD should be tied to PVIN pins. A
2.2µF ceramic capacitor from the PVDD pin to PGND (Pin 2) must be placed next to the IC.
Power Ground. PGND is the ground path for the MIC24054 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.
No Connect.
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.
High-Side N-internal MOSFET Drain Connection input. The PVIN operating voltage range is from
4.5V to 19V. Input capacitors between the PVIN pins and the power ground (PGND) are required
and keep the connection short.
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.
October 2012
2
M9999-102512-A