Linear Technology LTC1702 Demo Manual

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DESCRIPTIO
Demonstration circuit DC275 is a dual, high efficiency
®
regulator using the LTC
troller. The LTC1702 is optimized for high efficiency with
low input voltages. Typical applications are power for a
digital signal processor (DSP), microprocessor and/or
an application specific integrated circuit (ASIC). The
input voltage of the LTC1702 can range from 3V to 7V.
One of the output voltages (V
other (V ) is programmable from 1.6V to 2.5V by
OUT1
means of a jumper. The LTC1702 includes two complete,
on-chip, independent switching regulator controllers,
each designed to drive a pair of external N-channel
MOSFET devices in a voltage mode control, synchronous
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PERFOR A CE SU
PARAMETER
V
IN
V
OUT2
I
OUT2
Typical Output Ripple
V
OUT1
I
OUT1
Typical Output Ripple
I
Q
TYPICAL PERFOR A CE CHARACTERISTICS A D BOARD PHOTO
LTC1702 Efficiency
100
V = 5V
IN
V = 3.3V
OUT
V = 2.5V
OUT
90
V = 1.6V
OUT
80
70
0 5 10
LOAD CURRENT (A)
1702 switching regulator con-
) is fixed at 3.3V and the
OUT2
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ARY
CONDITIONS
Input Voltage Range
Fixed Output Voltage
Maximum Output Load Current
I = 15A
OUT
Jumper Selectable Output Voltage
Maximum Output Load Current
I = 15A
OUT
Supply Current in Shutdown
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15
1702 G01
DEMO MANUAL DC275
Dual 550kHz Synchronous
2-Phase 15A DC/DC Converter
buck configuration. The LTC1702 also provides open-
drain logic outputs (PGOOD1 and PGOOD2) that indicate
whether either output has risen to within 5% of the final
output voltage. An optional latching fault mode protects
the load if the output rises 15% above the intended
voltage. The LTC1702 uses a constant 550kHz switching
frequency, minimizing external component size and maxi-
mizing load transient performance. Operating efficien-
cies exceeding 90% are obtained for load current currents
from 1A to 14A. Additionally, the supply current in
shutdown is less than 100µA. Gerber files for this circuit
board are available. Call the LTC factory.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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DC/DC CONVERTER
LTC1702
4.75V to 7V
1.6V, 1.8V, 2V or 2.5V
VALUE
3.3V
15A
18mV
15A
17mV
100µA
1