IRDC3898-P3V3
8/15/2013
Confidential
This evaluation board is a preliminary version meant for the engineering evaluation of the IR3898.
Based on the results of the continuing evaluation, this board can evolve and change without notice
1
USER GUIDE FOR IR3898 EVALUATION BOARD
3.3Vout
DESCRIPTION
The IR3898 is a synchronous buck
converter,
providing a
compact, high
performance and flexible solution in a small
4mm X 5 mm Power QFN package.
Key features offered by the IR3898 include
internal Digital Soft Start/Soft Stop, precision
0.5Vreference
voltage,
Power
Good
,
thermal protection, programmable switching
frequency, Enable input, input under-voltage
lockout for proper start-up, enhanced line/
load regulation with feed forward, external
frequency synchronization with smooth
clocking, internal LDO and pre-bias start-
up.
Pulse by pulse current limit and output over-
current protection function is implemented by
sensing the voltage developed across the on-
resistance
of
the
synchronous
rectifier
MOSFET for optimum cost and performance
and the current limit is thermally compensated.
This user guide contains the schematic and bill
of materials for the IR3898 evaluation board.
The guide describes operation and use of the
evaluation board itself. Detailed application
information for IR3898 is available in the
IR3898 data sheet.
BOARD FEATURES
•
V
in
= +12V (+ 13.2V Max)
• V
out
= +3.3V @ 0-6A
•
F
s
= 1MHz
•
L = 1.0uH
•
C
in
= 3x10uF (ceramic 1206) + 1X330uF (electrolytic)
•
C
out
= 3x22uF (ceramic 0805)
Sup
IR
Buck
TM
