Linear Technology DC1891A Demo Manual

DESCRIPTION
Demonstration circuit 1891A is a 2-phase high efficiency
nonisolated SEPIC (single ended primary inductor con-
verter) converter featuring the LTC
controller. The DC1891A converts a 6V to 60V input to
a 12V output and provides 6A of output current. The
converter operates at 300kHz (600kHz output ripple) with
efficiency around 90%. With a proper amount of airflow,
the DC1891A converter can generate over 6A of output
current. The DC1891A can be easily modified to generate
output voltages in the range from 0.8V to 48V.
PERFORMANCE SUMMARY
PARAMETER
Minimum Input Voltage
Maximum Input Voltage
V
OUT
Typical Output Ripple V
OUT
Nominal Switching Frequency
Low Noise PolyPhase
Also, the DC1891A can be optimized for specific input volt-
ages. The narrowing of input voltage range can increase
3862-2 switching the converter's efficiency. Therefore, a narrow input voltage
®
range is more desirable.
The LTC3862-2 can be synchronized to an external clock
of up to 400kHz. Please refer to LTC3862-2 data sheet for
design details and applications information.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology, PolyPhase and the Linear logo are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Specifications are at T
CONDITIONS
I = 0A to 6A
OUT
I = 0A to 6A
OUT
V = 6V to 60V, I
IN
V = 6V to 60V, I
IN
DEMO MANUAL DC1891A
DC/DC Converter
= 25°C
A
= 0A to 6A
OUT
= 0A to 6A
OUT
LTC3862-2
SEPIC
®
VALUE
6V
60V
12V ±3%
100mV
P-P
300kHz
dc1891af
1