LT8722
Ultracompact 4A, 15V,
Full Bridge Driver with SPI
FEATURES
DESCRIPTION
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25-Bit Digital Output Voltage Control
The LT®8722 is a high performance, high efficiency,
monolithic full bridge DC/DC converter. One side of the
full bridge is driven by a pulse width modulation (PWM)
buck power stage, while the other side of the full bridge
is driven by a linear power stage. The LT8722 can deliver
up to 54W1 of power to its load while only requiring
a single inductor. An integrated 25-bit digital-to-analog
converter (DAC) is used to control the LT8722 output
voltage. Two additional 9-bit DACs control the positive and
negative output current limits. An analog output telemetry
pin can be used to monitor SPI selectable parameters
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Wide Input Voltage Range: 3.1V to 15V
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4A Output Current
1
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High Output Power: Up to 54W
High Efficiency at High Frequency
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92.6% Efficiency at 4A, 15V , f = 3MHz
IN SW
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SPI Interface Allows User to:
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Set Output Regulation Voltage
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Set Output Current Limits
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Check Device Status
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Enable/Disable Output
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Integrated 4A Power Switches
such as V , V , I
or the LT8722 junction tempera-
IN OUT OUT
Silent Switcher® Architecture
ture. The serial peripheral interface (SPI) can be used to
configure and control the LT8722 allowing for flexibility
to set the desired output voltage, output current limits,
voltage limits, switching frequency and control ON/OFF
behavior. The SPI operates at up to 10MHz allowing for
fast readback and control. The LT8722 operates from a
single 3.1V to 15V supply. Silent Switcher techniques are
used to minimize EMI/EMC emissions while delivering
high efficiency at high switching frequencies. The LT8722
is available in a 3mm × 3mm LQFN package.
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Analog Output for Diagnostics/Telemetry
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Adjustable and Synchronizable: 500kHz to 3MHz
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Small 3mm × 3mm 18-Lead LQFN
APPLICATIONS
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Driving a Thermo Electric Cooler (TEC) with Fine Control
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Transmit Optical Sub-Assembly (TOSA) Cooling
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Erbium Doped Fiber Amplifier (EDFA) Temperature
Regulation
Photonic Integrated Circuit (PIC) Cooling
LiDAR Mirror Control
Motor Control
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1
V
TEC
= 13.5V/ 4A with V = 15V, f = 1MHz
IN SW
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All registered trademarks and trademarks are the property of their respective owners.
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TYPICAL APPLICATION
Electrical Efficiency in
Cooling Configuration
13.5V/ 4A TEC Driver
95
V
IN
LDR
V
IN
3.1V TO 15V
+
4.7μF
0.1μF
150nF
80
65
50
35
20
5
V
TEC LOAD
0.1μF
OUT
V
BST
IN
4.7μF
0.1μF
–
1μH
SCK
MOSI
MISO
CS
SW
FROM SPI
MASTER
LT8722
SFB
1μF
V
DDIO
V
EN
SWEN
SYNC
A
OUT
TO ADC
DDIO
2.7V TO 6V
0.1μF
f
= 3MHz
SW
IN
V
CC
V
= 15V
1μF
R
= 2.5Ω
LOAD
GND
8722 TA01a
0
1
2
3
4
LOAD CURRENT (A)
8722 TA01b
Rev. 0
1
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