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dc1523af
DEMO MANUAL DC1523A
DESCRIPTION
LTC3789EGN:
High Efficiency Synchronous
4-Switch Step-Up/Step-Down
DC/DC Converter
Demonstration circuit 1523A features the LTC
®
3789EGN,
a high efficiency switching step-up/down controller. The
DC1523A input range is from 5V to 36V. The output volt-
age is 12V. The board is capable of delivering up to 5A of
output current over the input voltage range.
The LTC3789EGN is a high performance switching regula-
tor controller designed to regulate the output using input
voltages above, below or equal to the output voltage.
Synchronous operation provides very high efficiency, up
to 97%. Constant frequency current mode architecture
allows phase-lockable frequency from 200kHz to 600kHz.
An accurate output current limit provides support for
battery charging. A wide input and output range with
L
, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
smooth transfer function through all operating modes
makes the product ideal for automotive, telecom and
battery systems.
The MODE/PLLIN pin can select between pulse skipping
mode and forced continuous mode operation and allows
the IC to be synchronized to an external clock. A Power
Good output pin indicates when the output is within 7.5%
of its set point.
Design files for this circuit board are available at
http://www.linear.com/demo
PARAMETER
CONDITIONS/ NOTES
VALUE
Minimum Input Voltage
5V
Maximum Input Voltage
36V
Output Voltage V
OUT
Regulation
V
IN
= 5V to 36V, I
OUT
= 0A to 5A
12V ±2%
Maximum Continuous Output Current
Some Airfl ow May be Needed at Low Input
Voltage and Continuous Full Load
5A DC
Default Operating Frequency
R3 = 121k
400kHz
External Clock Synchronous Frequency Range
200kHz to 600kHz
Effi ciency
V
IN
= 5V to 36V, I
OUT
= 5A
88% to 97%. See Figures 3 and 6
Load Transient
See Figure 5
