1
dc2641af
DEMO MANUAL DC2641A
DESCRIPTION
LTC7801EUFD
High Input Voltage
Synchronous Buck Converter
Demonstration circuit 2641A is a single output synchro-
nous buck converter featuring the LTC7801EUFD in the
24-lead QFN package. The input voltage range is from
16V to 100V and the output is 12V/10A. The DC2641A is
configured with a sense resistor for overcurrent protec-
tion. Inductor DCR current sensing is optional.
The board has a lot of features including an optional
onboard NMOS LDO for DRVCC, a switch-mode power
supply for EXTV
CC
, jumper selectable 100% duty cycle
operation in dropout, a mode selector pin that allows
the converter to run in CCM, pulse-skip, adjustable burst
L
, LT, LTC, LTM, Linear Technology, Burst Mode, PolyPhase and the Linear logo are registered
trademarks of Analog Devices, Inc. All other trademarks are the property of their respective
owners.
PERFORMANCE SUMMARY
clamp or default Burst Mode
®
operation, a PGOOD output
voltage monitor and PLLIN for PolyPhase
®
operation.
The
LTC7801
data sheet gives a complete description
of the part, operation and application information and
must be read in conjunction with this demo manual for
DC2641A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2641A
Specifications are at T
A
= 25°C
PARAMETER
CONDITIONS
VALUE
Input Voltage Range
16V ~ 100V
Output Voltage V
OUT
V
IN
= 16~100V, I
OUT
= 0~10A, JP4: FCM
12V ± 2% (11.76V ~ 12.24V)
Maximum Output Current I
OUT,MAX
V
IN
= 16~100V
10A
Default Operating Frequency (Typical)
150kHz
External Clock Sync. Frequency Range
75kHz – 850kHz
Typical Full Load Efficiency (See Figure 4)
V
IN
= 48V, V
OUT
= 12V, I
OUT
= 10A, f
SW
= 150 kHz
95.3%