MIC26903 Evaluation Board
28V, 9A HyperLight Load
®
Synchronous DC-DC Buck Regulator
SuperSwitcher IIG™
Hyper Speed Control and Hyper Speed Control are trademarks of Micrel, Inc.
MLF and MicroLead Frame are registered trademark of Amkor Technology, 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
July 2011
M9999-071511-A
T
ON
er power-sag
rt feature is provided to reduce the inrush
sho
tio
n board is for 9A applications
d supporting documentation can b nd on
General Description
The MIC26903 DC-DC regulator operates ov
supply range of 4.5V to 28V, and provides a regu
at up to 9A of outpu
er an input
lated output
s adjustable
the device
t current. The output voltage i
to 0.8V with a typical accuracy of ±1%, and
operates at a switching frequency of 600kHz. T
frequency remains fairly constant, with chang
voltage and output load.
he switching
es in input
s the same
s the Hyper
eavy loads,
d conditions
Micrel’s Hyper Light Load™ architecture provide
high-efficiency and ultra-fast transient response a
Speed Control™ architecture under medium to h
but also maintains high efficiency under light loa
by transitioning to variable frequency, discontin
operation.
uous mode
ripple control
provided to
conditions. An
The MIC26903 utilizes an adaptive
architecture. An undervoltage lockout feature is
ensure proper operation und
internal soft-sta
current. Foldback current limit and “hiccup” mode
protection and thermal shutdown ensures protec
during fault conditions.
Note: This evaluatio
rt-circuit
n of the IC
.
Datasheet an e fou
Micrel’s web site at: www.micrel.com
.
Requirements
The MIC26903 provides a 5V regulated outp
voltage V ranging from 5.5V to 28V. Wh
ut for input
IN
en V
IN
< 5.5V,
VDD should be tied to PVIN pins to bypass the internal
linear regulator by a jumper. The output load can either be
an active or passive load.
Precautions
The evaluation board does not have reverse polarity
protection. Applying a negative voltage to the V
IN
terminal
may damage the device. In addition, the maximum V
IN
operating voltage of the MIC26903 evaluation board is
28V. Exceeding 29V on VIN could damage the device.
ly to the V
IN
terminal.
e to the V
IN
and ground
board, paying careful
ly voltage. An ammeter
input supply and the V
IN
board. Ensure that the
t the V
IN
terminal. The
sistance can reduce the
and ground terminals.
e (resistive) or active (as
mmeter can be placed
terminal. Ensure that
ed at the V
OUT
terminal.
, 1.2V, 1.5V, 1.8V, 2.5V,
If a different voltage is
n be adjusted by changing the feedback
resistors. See “Output Voltage” section.
e the MIC26903. The EN pin is provided on the
evaluati output of the MIC26903 turns on
O threshold. The output of
the MIC26 ay be turned off by shorting the EN
pin to ground. A connection on the board provides
easy access to the enable pin.
Ordering Information
Part Number Description
Getting Started
1. Connect an external supp
Apply the desired input voltag
terminals of the evaluation
attention to polarity and supp
may be placed between the
terminal to the evaluation
supply voltage is monitored a
ammeter and/or power lead re
voltage supplied to the input.
2. Connect the load to the V
OUT
The load can be either passiv
in an electronic load). An a
between the load and the V
OUT
the output voltage is monitor
V
OUT
can be set to 0.9V, 1.0V
3.3V, or 5.0V by a jumper.
needed, it ca
3. Enabl
on board. The
when V
DD
exceeds the UVL
903 m
MIC26903YJL EV
9A HLL DC-DC Regulator Evaluation
Board
