POWER LOSS (mW)
LTC3834-1
30 A I Synchronous
Q
Step-Down Controller
FEATURES
DESCRIPTIO
Wide Output Voltage Range: 0.8V V 10V The LTC 3834-1 is a high performance step-down switch-
OUT
Low Operating I : 30A ing regulator controller that drives an all N-channel syn-
Q
OPTI-LOOP Compensation Minimizes C chronous power MOSFET stage. A constant-frequency
OUT
1% Output Voltage Accuracy current mode architecture allows a phase-lockable fre-
Wide V Range: 4V to 36V quency of up to 650kHz.
IN
Phase-Lockable Fixed Frequency 140kHz to 650kHz
The 30A no-load quiescent current extends operating
Dual N-Channel MOSFET Synchronous Drive
life in battery powered systems. OPTI-LOOP compen-
Very Low Dropout Operation: 99% Duty Cycle
sation allows the transient response to be optimized over
Adjustable Output Voltage Soft-Start or Tracking
a wide range of output capacitance and ESR values. The
Output Current Foldback Limiting
LTC3834-1 features a precision 0.8V reference . The 4V to
Output Overvoltage Protection
36V input supply range encompasses a wide range of bat-
Low Shutdown I : 4A
Q
tery chemistries.
Selectable Continuous, Pulse-Skipping or
The TRACK/SS pin ramps the output voltage during start-
Burst Mode Operation at Light Loads
up. Current foldback limits MOSFET heat dissipation
Small 16-Lead Narrow SSOP or 5mm 3mm
during short-circuit conditions. An enhanced feature set
DFN Package
part (LTC3834) is available.
U
Comparison of LTC3834 and LTC3834-1
APPLICATIO S
CLKOUT/
Automotive Systems
PART # PHASMD EXTV PGOOD PACKAGES
CC
Telecom Systems
LTC3834 YES YES YES FE20/4 5 QFN
Battery-Operated Digital Devices
LTC3834-1 NO NO NO GN16/3 5 DFN
Distributed DC Power Systems
, 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
Efficiency and Power Loss
High Efficiency Step-Down Converter vs Load Current
10000
100
PLLLPF V
IN V
IN
90
4V TO 36V
10F
RUN TG
0.01F
1000
80
0.22F
TRACK/SS
70
BOOST
3.3H 0.012 V
OUT
I
TH
SW 3.3V 100
60
560pF
LTC3834-1
5A
50
150pF
54.2k
10
40
SGND INTV
CC 150F
4.7F
PLLIN/MODE 30
68.1k
V BG
FB 20 1
SENSE
215k 10
+
SENSE PGND
0 0.1
0.000001 0.0001 0.01 1
OUTPUT CURRENT (A)
38341 TA01
38341 TA01b
38341f
1
EFFICIENCY (%)
U
ULTC3834-1
ABSOLUTE AXI U RATI GS
(Note 1)
Input Supply Voltage (V ).........................36V to 0.3V Peak Output Current <10s (TG, BG)......................... 3A
IN
Top Side Driver Voltage (BOOST) ..............42V to 0.3V INTV Peak Output Current ................................ 50mA
CC
Switch Voltage (SW) ....................................36V to 5V Operating Temperature Range (Note 2) .. 40C to 85C
INTV (BOOST-SW).................................8.5V to 0.3V Junction Temperature (Note 3)............................. 125C
CC,
RUN, TRACK/SS ......................................... 7V to 0.3V Storage Temperature Range ................. 65C to 150C
+
SENSE , SENSE Voltages.........................11V to 0.3V Lead Temperature
PLLIN/MODE, PLLLPF ......................... INTV to 0.3V (GN Package, Soldering, 10 sec) ...................... 300C
CC
I V Voltages .......................................2.7V to 0.3V
TH, FB
PI CO FIGURATIO
TOP VIEW
TOP VIEW
PLLLPF 1 16 PLLIN/MODE PLLLPF 1 16 PLLIN/MODE
+
+
I 2 15 SENSE I 2 15 SENSE
TH TH
TRACK/SS 3 14 SENSE
TRACK/SS 3 14 SENSE
V 4 13 RUN V 4 13 RUN
FB
FB
17
SGND 5 12 BOOST SGND 5 12 BOOST
PGND 6 11 TG
PGND 6 11 TG
BG 7 10 SW BG 7 10 SW
INTV 8 9 V INTV 8 9 V
CC IN CC IN
GN PACKAGE
DHC PACKAGE
16-LEAD PLASTIC SSOP
16-Pin (5mm 3mm) PLASTIC DFN
T = 150C, = 90C/W
JMAX JA
T = 125C, = 43.5C/W
JMAX JA
EXPOSED PAD (PIN 17) IS SGND
MUST BE SOLDERED TO PCB
UUW
ORDER I FOR ATIO
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC3834EDHC-1#PBF LTC3834EDHC-1#TRPBF 38341 16-Lead (5mm 3mm) Plastic DFN 40C to 85C (Note 2)
LTC3834IDHC-1#PBF LTC3834IDHC-1#TRPBF 38341 16-Lead (5mm 3mm) Plastic DFN 40C to 85C
LTC3834EGN-1#PBF LTC3834EGN-1#TRPBF 38341 16-Lead Plastic SSOP 40C to 85C (Note 2)
LTC3834IGN-1#PBF LTC3834IGN-1#TRPBF 38341 16-Lead Plastic SSOP 40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *Temperature grades are identified by a label on the shipping container.
Consult LTC Marketing for information on nonstandard lead based finish parts.
For more information on lead free part marking, go to: