LTC3892/LTC3892-1
60V Low I , Dual, 2-Phase
Q
Synchronous Step-Down
DC/DC Controller
DescripTion
FeaTures
The LTC®3892/LTC3892-1 is a high performance dual
step-down DC/DC switching regulator controller that
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Wide V Range: 4.5V to 60V (65V Abs Max)
IN
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Wide Output Voltage Range: 0.8V ≤ V
≤ 99% • V
OUT
IN
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Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE) drives all N-channel synchronous power MOSFET stages.
No External Bootstrap Diodes Required
Power loss and noise are minimized by operating the two
controller output stages out-of-phase.
Low Operating I : 29μA (One Channel On)
Q
Selectable Gate Drive UVLO Thresholds
The gate drive voltage can be programmed from 5V to
10V to allow the use of logic or standard-level FETs and
to maximize efficiency. Internal switches in the top gate
drivers eliminate the need for external bootstrap diodes.
Out-of-Phase Operation Reduces Required Input
Capacitance and Power Supply Induced Noise
Phase-Lockable Frequency: 75kHz to 850kHz
Programmable Fixed Frequency: 50kHz to 900kHz
Selectable Continuous, Pulse Skipping or Low Ripple
Burst Mode® Operation at Light Loads
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Awide4.5Vto60Vinputsupplyrangeencompassesawide
rangeofintermediatebusvoltagesandbatterychemistries.
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Output voltages up to 99% of V can be regulated. OPTI-
Selectable Current Limit (LTC3892)
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LOOP® compensation allows the transient response and
loop stability to be optimized over a wide range of output
capacitance and ESR values.
Very Low Dropout Operation: 99% Duty Cycle
Power Good Output Voltage Monitors (LTC3892)
Low Shutdown I : 3.6μA
Q
Small 32-Lead 5mm × 5mm QFN Package (LTC3892)
The 29μA no-load quiescent current extends operating
run time in battery powered systems. For a comparision
of the LTC3892 to the LTC3892-1, see Table 1 in the Pin
Functions section of this data sheet.
L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are
registered trademarks of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620,
6144194, 6177787, 6580258.
Small 28-Lead TSSOP Package (LTC3892-1)
applicaTions
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Automotive and Industrial Power Systems
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Distributed DC Power Systems
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High Voltage Battery Operated Systems
Typical applicaTion
High Efficiency Dual 5V/12V Output Step-Down Converter
VIN
12.5V TO 60V
RUN1
TG1
VIN
RUN2
TG2
47µF
Efficiency vs Output Current
96
BOOST1
BOOST2
0.1µF
0.1µF
V
OUT
= 12V
IN
8mΩ
5.6µH
V
5mΩ
15µH
V
OUT2
OUT1
V
= 5V
95
94
93
92
91
90
89
88
5V
12V
SW1
SW2
Burst Mode OPERATION
8A
5A
BG1
BG2
220µF
150µF
LTC3892
+
+
SENSE1
SENSE2
100k
1nF
1nF
–
–
SENSE1
SENSE2
GATE DRIVE
DRV =5V
V
FB1
V
CC
FB2
DRV =6V
CC
ITH1
TRACK/SS1
ITH2
TRACK/SS2
DRV =8V
CC
DRV =10V
CC
7.15k
VPRG1
DRVSET
7.5k
34.8k
0.01
0.1
1
10
DRVUV
LOAD CURRENT (A)
100pF
0.1µF
100pF
0.1µF
3892 F01b
INTV
GND
DRV
CC
CC
2.2nF
1nF
0.1µF
4.7µF
3892 TA01
38921f
1
For more information www.linear.com/LTC3892