LTC3834-1 Datasheet, PDF (1/28 Pages) Linear Technology – 30μA IQ Synchronous Step-Down Controller

LTC3834-1
30μA I_Q Synchronous
Step-Down Controller
FEATURES
■ _{Wide Output Voltage Range: 0.8V V OUT 10V}
■ _{Low Operating IQ: 30μA}
■ _OPTI-LOOP^® _{Compensation Minimizes COUT}
■ _{±1% Output Voltage Accuracy}
■ _{Wide VIN Range: 4V to 36V}
■ _{Phase-Lockable Fixed Frequency 140kHz to 650kHz}
■ _{Dual N-Channel MOSFET Synchronous Drive}
■ _{Very Low Dropout Operation: 99% Duty Cycle}
■ _{Adjustable Output Voltage Soft-Start or Tracking}
■ _{Output Current Foldback Limiting}
■ _{Output Overvoltage Protection}
■ _{Low Shutdown IQ: 4μA}
■ _{Selectable Continuous, Pulse-Skipping or}
Burst Mode^® Operation at Light Loads
■ _{Small 16-Lead Narrow SSOP or 5mm × 3mm}
DFN Package
U
APPLICATIO S
■ _{Automotive Systems}
■ _{Telecom Systems}
■ _{Battery-Operated Digital Devices}
■ _{Distributed DC Power Systems}
DESCRIPTIO
The LTC^®3834-1 is a high performance step-down switch-
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.
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 features a precision 0.8V reference . The 4V to
36V input supply range encompasses a wide range of bat-
tery chemistries.
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.
Comparison of LTC3834 and LTC3834-1
PART #
LTC3834
CLKOUT/
PHASMD
YES
EXTV_CC
YES
PGOOD
YES
LTC3834-1
NO
NO
NO
PACKAGES
FE20/4 × 5 QFN
GN16/3 × 5 DFN
, 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.
TYPICAL APPLICATIO
High Efficiency Step-Down Converter
0.01μF
560pF
54.2k
68.1k
215k
PLLLPF
V_IN
RUN
TG
TRACK/SS
BOOST
I_TH
LTC3834-1
SW
150pF
SGND
PLLIN/MODE
V_FB
SENSE^–
SENSE⁺
INTV_CC
BG
PGND
0.22μF
10μF
3.3μH 0.012Ω
4.7μF
V_IN
4V TO 36V
V_OUT
3.3V
5A
150μF
38341 TA01
Efficiency and Power Loss
vs Load Current
100
10000
90
80
1000
70
60
100
50
40
10
30
20
1
10
0
0.000001
0.0001
0.01
OUTPUT CURRENT (A)
0.1
1
38341 TA01b
38341f
1