MIC2176-1 Datasheet, PDF (2/31 Pages) Micrel Semiconductor – Wide Input Voltage, Synchronous Buck Controllers Featuring Adaptive On-Time Control

Micrel, Inc.
Ordering Information
Part Number
MIC2176-1YMM
MIC2176-2YMM
MIC2176-3YMM
Output
Voltage
Adjustable
Adjustable
Adjustable
Switching Frequency Junction Temperature Range
100kHz
200kHz
300kHz
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
Package
10-pin MSOP
10-pin MSOP
10-pin MSOP
MIC2176
Lead Finish
Pb-Free
Pb-Free
Pb-Free
Pin Configuration
10-Pin MSOP (MM)
Pin Description
Pin
Number
Pin Name
1
HSD
2
EN
3
FB
4
GND
5
VDD
6
DL
7
PGND
8
DH
Pin Function
High-Side MOSFET Drain Connection (Input): The HSD pin in the input of the adaptive On-time
control circuitry. A 0.1uF ceramic capacitor between the HSD pin and the power ground (PGND) is
required and must be place as close as possible to the IC.
Enable (Input): A logic level control of the output. The EN pin is CMOS compatible. Logic high or
floating = enable, logic low = shutdown. In the off state, the V_DD supply current of the device is
reduced (typically 0.7mA). Do not connect the EN pin to the HSD pin.
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.
Signal ground. GND is the ground path for the device bias voltage V_DD and the control circuitry. The
loop for the signal ground should be separate from the power ground (PGND) loop.
V_DD Bias (Input): Power to the internal reference and control sections of the MIC2176. The V_DD
operating voltage range is from 4.5V to 5.5V. A 1µF ceramic capacitor from the VDD pin to the PGND
pin must be placed next to the IC.
Low-Side Drive (output): High-current driver output for external low-side MOSFET. The DL driving
voltage swings from ground to V_DD.
Power Ground. PGND is the ground path for the buck converter power stage. The PGND pin
connects to the sources of low-side N-Channel external 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 (GND) loop.
High-Side Drive (output): High-current driver output for external high-side MOSFET. 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 MOSFETs can slow down the turn-on and turn-off time of the
MOSFETs.
November 2010
2
M9999-111710-A