MIC23030 Evaluation Board
8MHz PWM 400mA Buck Regulator
with HyperLight Load™
HyperLight Load is a trademark of Micrel, Inc. MLF is a registered trademark of Amkor Technology.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
August 2008
M9999-072208-A
General Description
The MIC23030 is a 400mA 8MHz switching regulator
featuring HyperLight Load™ mode. The MIC23030 is
highly efficient throughout the entire output current range,
drawing just 21µA of quiescent current in operation. The
tiny 1.6 x 1.6mm MLF
®
package, in combination with the
8MHz switching frequency, enables a compact sub-1mm
height solution with only three external components. The
MIC23030 provides accurate output voltage regulation
under the most demanding conditions and responds
extremely quickly to a load transient with exceptionally
small output voltage ripple.
Factoring in the output current, the internal circuitry of the
MIC23030 automatically selects between two modes of
operation for optimum efficiency. Under light load
conditions, the MIC23030 goes into HyperLight Load™
mode. HyperLight Load™ uses a Pulse-Frequency
Modulation (PFM) control scheme that controls the off time
at light load. This proprietary architecture reduces the
amount of switching needed at light loads, thereby
increasing operating efficiency. The MIC23030 attains up
to 83% efficiency at 1mA output load. As the load current
increases beyond approximately 100mA, the device
operates using the Pulse-Width Modulation (PWM) method
for up to 91% efficiency at higher loads. The two modes of
operation ensure the highest efficiency across the entire
load range.
The MIC23030 operates from an input voltage range of
2.7V to 5.5V and features internal power MOSFETs that
deliver up to 400mA of output current. This step-down
regulator provides an output voltage accuracy of +/-2.5%
across the junction temperature range of -40ºC to +125ºC.
The MIC23030 is available in fixed or adjustable versions
supporting an output voltage as low as 0.7V.
Requirements
The MIC23030 evaluation board requires an input power
source that is able to deliver greater than 500mA at 2.7V
to the MIC23030. The output load can either be an active
(electronic) or passive (resistive) load.
Getting Started
1.
Connect an external supply to the V
IN
(J1)
terminal
. Apply the desired input voltage to V
IN
(J1) and ground (J2) terminals of the evaluation
board, paying careful attention to polarity and
supply voltage (2.7V
≤
V
IN
≤
5.5V). An ammeter
may be placed between the input supply and the
V
IN
(J1) terminal. Be sure to monitor the supply
voltage at the V
IN
(J1) terminal, since the ammeter
and/or power lead resistance can reduce the
voltage supplied to the device.
2.
Connect a load to the V
OUT
(J3) and ground
terminal (J4)
. The load can be either passive
(resistive) or active (electronic load). An ammeter
may be placed between the load and the output
terminal. Ensure the output voltage is monitored at
the V
OUT
(J3) terminal.
3.
Enable the MIC23030
. The MIC23030 evaluation
board has a pull-up resistor to V
IN
. To disable the
device, apply a voltage below 0.5V to the EN (J5)
terminal or place a jumper on JP1 to ground the
enable. In the absence of the pull-up resistor, the
device is enabled by applying a voltage greater
than 1.2V to the EN (J5) terminal. The enable pin
must be either pulled high or low for proper
operation. Removing the pull-up resistor and
leaving the pin floating will cause the regulator to
operate in an indeterminable state.
Output Voltage
The MIC23030 evaluation board is available with the
following output voltage options listed below:
Ordering Information
Part Number
Description
MIC23030-AYMT EV Adjustable Output Evaluation Board
MIC23030-CYMT EV 1.0V Fixed Output Evaluation Board
MIC23030-4YMT EV 1.2V Fixed Output Evaluation Board
MIC23030-FYMT EV 1.5V Fixed Output Evaluation Board
MIC23030-GYMT EV 1.8V Fixed Output Evaluation Board
Note: Other voltage options available on request
