MIC2164 MICREL [Micrel Semiconductor], MIC2164 Datasheet - Page 2

• Manufacturer Part Number: MIC2164
• Description: Constant Frequency, Synchronous Buck Controllers Featuring Adaptive On-Time Control
• Manufacturer: MICREL [Micrel Semiconductor]

Micrel, Inc.
Ordering Information
Pin Configuration
Pin Description
September 2009
MIC2164-2YMM
MIC2164-3YMM
Part Number
MIC2164YMM
Number
Pin
10
1
2
3
4
5
6
7
8
9
Pin Name
PGND
HSD
GND
BST
EN
DH
FB
DL
LX
IN
Voltage
Adj.
Adj.
Adj.
Pin Function
High-Side N-MOSFET Drain Connection (input): Power to the drain of the external high-side N-channel
MOSFET. The HSD operating voltage range is from 3V to 28V. Input capacitors between HSD and the
power ground (PGND) are required.
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, supply current of the device is greatly reduced (typically
0.8mA).
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 input voltage V
for the signal ground should be separate from the power ground (PGND) loop.
Input Voltage (input): Power to the internal reference and control sections of the MIC2164/-2/-3. The IN
operating voltage range is from 3V to 5.5V. A 1µF and 0.1µF ceramic capacitors from IN to GND are
recommended for clean operation.
Low-Side Drive (output): High-current driver output for external low-side MOSFET. The DL driving
voltage swings from ground-to-IN.
Power Ground. PGND is the ground path for the MIC2164/-2/-3 buck converter power stage. The PGND
pin connects to the sources of low-side N-Channel 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 (LX). It swings from ground to V
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.
Switch Node and Current Sense input: High current output driver return. The LX pin connects directly to
the switch node. Due to the high speed switching on this pin, the LX pin should be routed away from
sensitive nodes. LX 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 LX
using a Kelvin connection.
Boost (output): Bootstrapped voltage to the high-side N-channel MOSFET driver. A Schottky diode is
connected between the IN pin and the BST pin. A boost capacitor of 0.1μF is connected between the
BST pin and the LX pin. Adding a small resistor in series with the boost capacitor can slow down the
turn-on time of high-side N-Channel MOSFETs.
Switching Frequency
300kHz
600kHz
1MHz
10-Pin MSOP (MM)
Junction Temp. Range
–40° to +125°C
–40° to +125°C
–40° to +125°C
2
10-pin MSOP
10-pin MSOP
10-pin MSOP
IN
Package
and the control circuitry. The loop
IN
minus the diode drop.
M9999-090409-B
MIC2164/-2/-3
Lead Finish
Pb-Free
Pb-Free
Pb-Free