MIC2103 Datasheet, PDF (3/36 Pages) Micrel Semiconductor – 75V, Synchronous Buck Controllers featuring Adaptive On-Time Control

Micrel, Inc.
MIC2103/04
Pin Description (Continued)
Pin Number
9, 11
10
12
13
14
15
16
EP
Pin Name
NC
BST
AGND
FB
PG
EN
VIN
ePad
Pin Function
No connection.
Voltage Supply Pin input for the high-side N-channel MOSFET driver, which can be powered by a
bootstrapped circuit connected between VDD and SW, using a Schottky diode and a 0.1μF
ceramic capacitor. Adding a small resistor at BST pin can slow down the turn-on speed of the
high-side MOSFET.
Signal ground for VDD and the control circuitry, which is connected to Thermal Pad electronically.
The signal ground return path should be separate from the power ground (PGND) return path.
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 set the
desired output voltage.
Power Good output. Open Drain Output, an external pull-up resistor to VDD or external power
rails is required.
Enable input. A logic signal to enable or disable the buck converter operation. The EN pin is
CMOS compatible. Logic high enables the device, logic low shutdowns the regulator. In the
disable mode, the V_DD supply current for the device is minimized to 0.7mA typically.
Supply voltage. The VIN operating voltage range is from 4.5V to 75V. A 1μF ceramic capacitor
from VIN to AGND is required for decoupling.
Exposed Pad. Connect the EPAD to PGND plain on the PCB to improve the thermal
performance.
August 2012
3
M9999-080712-A