LT3796/LT3796-1
100V Constant-Current and
Constant-Voltage Controller
with Dual Current Sense
DescripTion
The LT®3796/LT3796-1 are DC/DC controllers designed to
regulate a constant-current or constant-voltage and are
ideal for driving LEDs. The fixed frequency and current
mode architecture result in stable operation over a wide
range of supply and output voltages. Two ground referred
voltage FB pins serve as the input for several LED protec-
tion features, and also allow the converter to operate as a
constant-voltage source. The LT3796/LT3796-1 feature a
programmable threshold output current sense amplifier
with rail-to-rail common mode range. A separate high
side amplifier is gain configurable with two resistors and
can be used to regulate a second current or a voltage
in combination with one of the FB pins. The PWM input
provides LED dimming ratios of up to 3000:1.
FeaTures
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3000:1 True Color PWM™ Dimming
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Wide Input Voltage Range: 6V to 100V
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Current Monitoring Up to 100V
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High Side PMOS Disconnect and PWM Switch Driver
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Constant-Current and Constant-Voltage Regulation
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Dual Current Sense Amplifiers with Reporting
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C/10 Detection for Battery and SuperCap Charging
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Linear Current Sense Threshold Programming
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Short-Circuit Protection
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Adjustable Frequency: 100kHz to 1MHz
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Frequency Synchronization (LT3796)
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Independent Top Gate Enable Pin (LT3796-1)
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Programmable Open LED Protection with VMODE Flag
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Programmable Undervoltage Lockout with Hysteresis
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Soft-Start with Programmable Fault Restart Timer
The LT3796-1 is optimized for a second output current
regulation loop that can be enabled/disabled with a PMOS
switch, either to drive a second LED string or to extend
analog dimming range.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and True
Color PWM is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203,
7746300.
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Available in 28-Lead TSSOP Package
applicaTions
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High Power LED, High Voltage LED, Dual String
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Battery and SuperCap Chargers
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Accurate Current Limited Voltage Regulators
Typical applicaTion
Boost LED Driver with Input Current Monitor
Efficiency vs VIN
22µH
50mΩ
V
IN
100
9V TO 60V
100V (TRANSIENT)
2.2µF
×4
2k
95
2.2µF
×3
1M
1M
499k
V
V
CSP
CSN
GATE
90
IN
S
13.7k
EN/UVLO
118k
85
97.6k
V
SENSE
REF
15mΩ
CTRL
80
75
70
LT3796
GND
FB1
ISP
CSOUT
CSOUT
PWM
10nF
100k
40.2k
100k
PWM
ISMON
SYNC
0
10
20
30
(V)
40
50
60
0.1µF
620mΩ
INTV
CC
V
IN
ISN
TG
37961 TA01b
FAULT
FAULT
INTV
INTV
CC
CC
VMODE
VMODE
V
C
RT
FB2
SS
4.7µF
85V LED
400mA
31.6k
250kHz
10k
0.1µF
10nF
37961 TA01a
3796fb
1
For more information www.linear.com/3796