MIC2103 Datasheet, PDF (2/36 Pages) Micrel Semiconductor – 75V, Synchronous Buck Controllers featuring Adaptive On-Time Control

Micrel, Inc.
MIC2103/04
Ordering Information
Part Number
MIC2103YML
MIC2104YML
Switching
Frequency
200kHz to 600kHz
200kHz to 600kHz
Features
Hyper Light Load
Hyper Speed Control
Package
16-pin 3mm x 3mm MLF
16-pin 3mm x 3mm MLF
Junction
Temperature Range
–40°C to +125°C
–40°C to +125°C
Lead Finish
Pb-Free
Pb-Free
Pin Configuration
16-Pin 3mm x 3mm MLF (ML)
(TOP VIEW)
Pin Description
Pin Number
Pin Name
1
VDD
2
PVDD
3
ILIM
4
DL
5
PGND
6
FREQ
7
DH
8
SW
Pin Function
Internal +5V linear regulator output. VDD is the internal supply bus for the device. A 1μF ceramic
capacitor from VDD to AGND is required for decoupling. In the applications with VIN<+5.5V, VDD
should be tied to VIN to by-pass the linear regulator.
5V supply input for the low-side N-channel MOSFET driver, which can be tied to VDD externally.
A 1μF ceramic capacitor from PVDD to PGND is recommended for decoupling.
Current Limit Setting. Connect a resistor from SW to ILIM to set the over-current threshold for the
converter.
Low-Side Drive output. High-current driver output for external low-side MOSFET of a buck
converter. The DL driving voltage swings from ground to V_DD. Adding a small resistor between DL
pin and the gate of the low-side N-channel MOSFET can slow down the turn-on and turn-off
speed of the MOSFET.
Power Ground. PGND is the return path for the buck converter power stage. The PGND pin
connects to the sources of low-side N-Channel external MOSFET, the negative terminals of input
capacitors, and the negative terminals of output capacitors. The return path for the power ground
should be as small as possible and separate from the Signal ground (AGND) return path.
Switching Frequency Adjust input. Tie this pin to VIN to operate at 600kHz and place a resistor
divider to reduce the frequency.
High-Side Drive output. High-current driver output for external high-side MOSFET of a buck
converter. The DH driving voltage is floating on the switch node voltage (V_SW). Adding a small
resistor between DH pin and the gate of the high-side N-channel MOSFET can slow down the
turn-on and turn-off speed of the MOSFET.
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. In order to sense the current accurately, connect
the low-side MOSFET drain to the SW pin using a Kelvin connection.
August 2012
2
M9999-080712-A