MIC2202 Datasheet, PDF (6/18 Pages) Micrel Semiconductor – HIGH EFFICIENCY 2MHZ SYNCHRONOUS BUCK CONVERTER 1UP STABLE PWM REGULATOR

MIC2202
Functional Description
V_IN
V_IN provides power to the output and to the internal bias
supply. The supply voltage range is from 2.3V to 5.5V. A
minimum 1µF ceramic is recommended for bypassing the
input supply.
Enable
The enable pin provides a logic level control of the output. In
the off state, supply current of the device is greatly reduced
(typically <1µA). Also, in the off state, the output drive is
placed in a “tri-stated” condition, where both the high side
P-Channel MOSFET and the low-side N-Channel are in an off
or non-conducting state. Do not drive the enable pin above
the supply voltage.
Sync_In
Sync_In pin enables the ability to change the fundamental
switching frequency. The Sync_In frequency has a minimum
frequency of 1.6MHz and a maximum sync frequency of
2.5MHz.
Careful attention should be paid to not driving the Sync_In pin
greater than the supply voltage. While this will not damage
the device, it can cause improper operation.
Micrel
Sync_Out
Sync_Out is an open collector output that provides a signal
equal to the internal oscillator frequency. This creates the
ability for multiple MIC2202s to be connected together in a
master-slave configuration for frequency matching of the
converters. A typical 10kΩ is recommended for a pull-up
resistor.
Bias
The bias supply is an internal 2.3V linear regulator that
supplies the internal biasing voltage to the MIC2202. A 10nF
ceramic capacitor is required on this pin for bypassing. Do not
use the bias pin as a supply. The bias pin was designed to
supply internal power only.
Feedback
The feedback pin provides the control path to control the
output. A resistor divider connecting the feedback to the
output is used to adjust the desired output voltage. Refer to
the feedback section in the “Applications Information” for
more detail.
10kΩ
MIC2202
“Master”
VIN
SW
BIAS
SYNC_IN
SYNC_OUT
FB
MIC2202
“Slave”
VIN
SW
BIAS
SYNC_IN
SYNC_OUT
FB
Figure 1. Master-Slave Operation
M9999-052104
6
May 2004