LTC3834-1
30μA I Synchronous
Q
Step-Down Controller
U
FEATURES
DESCRIPTIO
TheLTC®3834-1isahighperformancestep-downswitch-
ing regulator controller that drives an all N-channel syn-
chronous power MOSFET stage. A constant-frequency
current mode architecture allows a phase-lockable fre-
quency of up to 650kHz.
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Wide Output Voltage Range: 0.8V V OUT 10V
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Low Operating IQ: 30μA
OPTI-LOOP® Compensation Minimizes COUT
1ꢀ Output Voltage Accuracy
Wide VIN Range: 4V to 36V
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Phase-Lockable Fixed Frequency 140kHz to 650kHz
The 30μA no-load quiescent current extends operating
life in battery powered systems. OPTI-LOOP compen-
sation allows the transient response to be optimized over
a wide range of output capacitance and ESR values. The
LTC3834-1 featuresaprecision0.8Vreference. The4Vto
36V input supply range encompasses a wide range of bat-
tery chemistries.
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Dual N-Channel MOSFET Synchronous Drive
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Very Low Dropout Operation: 99% Duty Cycle
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Adjustable Output Voltage Soft-Start or Tracking
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Output Current Foldback Limiting
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Output Overvoltage Protection
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Low Shutdown IQ: 4μA
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Selectable Continuous, Pulse-Skipping or
Burst Mode® Operation at Light Loads
The TRACK/SS pin ramps the output voltage during start-
up. Current foldback limits MOSFET heat dissipation
during short-circuit conditions. An enhanced feature set
part (LTC3834) is available.
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Small 16-Lead Narrow SSOP or 5mm × 3mm
DFN Package
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Comparison of LTC3834 and LTC3834-1
CLKOUT/
APPLICATIO S
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Automotive Systems
PART #
PHASMD
EXTV
PGOOD
PACKAGES
CC
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Telecom Systems
LTC3834
LTC3834-1
YES
YES
NO
YES
FE20/4 × 5 QFN
GN16/3 × 5 DFN
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Battery-Operated Digital Devices
Distributed DC Power Systems
NO
NO
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, LT, LTC, LTM, Burst Mode, PolyPhase and OPTI-LOOP are registered trademarks of
Linear Technology Corporation. All other trademarks are the property of their respective
owners. Protected by U.S. Patents, including 5408150, 5481178, 5705919, 5929620,
6304066, 6498466, 6580258, 6611131.
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TYPICAL APPLICATIO
Efficiency and Power Loss
vs Load Current
High Efficiency Step-Down Converter
10000
1000
100
10
100
90
PLLLPF
V
IN
V
IN
4V TO 36V
10μF
RUN
TG
0.01μF
80
0.22μF
TRACK/SS
70
BOOST
SW
3.3μH
V
OUT
0.012Ω
I
TH
3.3V
5A
60
50
560pF
54.2k
LTC3834-1
150pF
40
30
20
10
SGND
PLLIN/MODE
INTV
CC
150μF
4.7μF
68.1k
V
FB
BG
1
–
+
SENSE
SENSE
215k
PGND
0
0.1
0.000001
0.0001
0.01
1
OUTPUT CURRENT (A)
38341 TA01
38341 TA01b
38341f
1