MIC23031 Evaluation Board
4MHz PWM 400mA Buck Regulator
with HyperLight Load
®
HyperLight Load is a registered trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
June 17, 2014
Revision 2.0
General Description
The MIC23031 is a 400mA 4MHz switching regulator
featuring HyperLight Load
®
mode. The MIC23031 is
highly-efficient throughout the entire output current range,
drawing just 21µA of quiescent current in operation. The
tiny 1.6mm
1.6mm Thin DFN package in combination
with the 4MHz switching frequency enables a compact
sub-1mm height solution with only three external
components. The MIC23031 provides accurate output
voltage regulation under the most demanding conditions
responding extremely quickly to a load transient with
exceptionally small output voltage ripple.
Factoring in the output current, the internal circuitry of the
MIC23031 automatically selects between two modes of
operation for optimum efficiency. Under light-load
conditions, the MIC23031 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 MIC23031 attains up
to 88% 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 93% efficiency at higher loads. The two modes of
operation ensure the highest efficiency across the entire
load range.
The MIC23031 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
40
C to
125
C.
The MIC23031 is available in fixed or adjustable versions
supporting an output voltage as low as 0.7V.
Datasheets and support documentation are available on
Micrel’s web site at:
www.micrel.com
.
Requirements
The MIC23031 evaluation board requires an input power
source that is able to deliver greater than 500mA at 2.7V
to the MIC23031. The output load can either be an active
(electronic) or passive (resistive) load.
Getting Started
1. Connect an external supply to the VIN (J1)
terminal.
Apply the desired input voltage to VIN (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 VIN (J1) terminal. Be sure to monitor
the supply voltage at the VIN (J1) terminal, since the
ammeter and/or power-lead resistance can reduce the
voltage supplied to the device.
2. Connect a load to the VOUT (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 VOUT (J3) terminal.
3. Enable the MIC23031.
The MIC23031 evaluation board has a pull-up resistor
to VIN. To disable the device, apply a voltage below
0.5V to the EN (J5) terminal or place a jumper on JP1
to ground EN. 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 EN pin must be
either pulled high or low for proper operation. Remove
the pull-up regulator to operate in an indeterminable
state.
Output Voltage
The MIC23031 evaluation board is available with the
output voltage options listed in the Ordering Information
table.
Ordering Information
Part Number
Description
MIC23031-AYMT EV
Adjustable-Output Evaluation Board
MIC23031-CYMT EV
1.0V Fixed-Output Evaluation Board
MIC23031-4YMT EV
1.2V Fixed-Output Evaluation Board
MIC23031-FYMT EV
1.5V Fixed-Output Evaluation Board
MIC23031-GYMT EV
1.8V Fixed-Output Evaluation Board
Note
: Other voltage options available upon request.
