LTC7813
Low I , 60V Synchronous
Q
Boost+Buck Controller
Fea T Descrip T
n
Synchronous Boost and Buck Controllers The LTC 7813 is a high performance synchronous
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When Cascaded, Allows V Above, Below, or Equal Boost+Buck DC/DC switching regulator controller that
IN
to Regulated V of Up to 60V drives all N-channel power MOSFET stages. It contains
OUT
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Wide Bias Input Voltage Range: 4.5V to 60V independent step-up (boost) and step-down (buck)
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Output Remains in Regulation Through Input Dips controllers that can regulate two separate outputs or be
(e.g. Cold Crank) Down to 2.2V cascaded to regulate an output voltage from an input
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Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE) voltage that can be above, below, or equal to the output
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Low EMI with Low Input and Output Ripple voltage. The LTC7813 operates from a wide 4.5V to 60V
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Fast Output Transient Response input supply range. When biased from the output of the
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No External Bootstrap Diodes Required boost regulator, the LTC7813 can operate from an input
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High Light Load Efficiency supply as low as 2.2V after start-up. The 34A no-load
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Low Operating I : 29A (One Channel On) quiescent current (both channels on) extends operating
Q
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Low Operating I : 34A (Both Channels On) runtime in battery-powered systems.
Q
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R or Lossless DCR Current Sensing
SENSE
Unlike conventional buck-boost regulators, the LTC7813s
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Buck Output Voltage Range: 0.8V V 60V
OUT
cascaded Boost+Buck solution has continuous, non-
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Boost Output Voltage Up 60V
pulsating, input and output currents, substantially reducing
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Phase-Lockable Frequency (75kHz to 850kHz)
voltage ripple and EMI. The LTC7813 has independent
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Small 32-Pin 5mm 5mm QFN Package
feedback and compensation points for the boost and buck
regulation loops, enabling a fast output transient response
a T
that can be externally optimized.
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Automotive and Industrial Power Systems L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
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High Power Battery Operated Systems
owners.
Typical a T
Wide Input Range to 10V/10A Low I Cascaded Boost+Buck Regulator
Q
V
IN
2.2H 10H
8V TO 60V
V , 12V** V
MID OUT
DOWN TO
10V
2.2V AFTER
10A*
6.8F 22F
22F
47F 47F
START-UP 47F
3 4 3
1.62k 2.32k
15k
R
B1
33pF
332k
0.1F 1F
0.1F
R
0.1F A1
11.5k
SENSE2+ SENSE2 BG2 SW2 BOOST2 TG2 V V TG1 BOOST1 SW1 BG1 SENSE1+ SENSE1 V
FB2 BIAS FB1
LTC7813 EXTV
CC
RUN1 RUN2 I I TRACK/SS1 SS2 FREQ PLLIN/MODE GND DRV INTV VPRG2 ILIM DRVUVDRVSET
TH1 TH2 CC CC
7813 TA01
V
IN
0.1F
8.87k 6.19k
4.7F 0.1F
37.4k
100pF 470pF
0.1F
3300pF 22nF
* WHEN V <8V MAXIMUM LOAD CURRENT AVAILABLE IS REDUCED
IN
**V = 12V WHEN V < 12V
MID IN
V FOLLOWS V WHEN VIN > 12V
MID IN
7813f
1
For more information www.linear.com/LTC7813
ion pplica
ions pplica
ion uresLTC7813
a Te Maxi Mu M r a T p in c F T
(Note 1)
TOP VIEW
Bias Input Supply Voltage (V ) .............. 0.3V to 65V
BIAS
Topside Driver Voltages
BOOST1, BOOST2 .................................. 0.3V to 76V
32 31 30 29 28 27 26 25
Switch Voltage (SW1, SW2) .......................... 5V to 70V
SW1 1 24 DRV
CC
DRV , (BOOST1-SW1), (BOOST2-SW2) ....0.3V to 11V
CC
TG1 2 23 SS2
BG1, BG2, TG1, TG2 ........................................... (Note 8)
TRACK/SS1 DRVSET
3 22
RUN1, RUN2 Voltages ................................ 0.3V to 65V
VPRG2 4 21 DRVUV
33
+ +
SENSE1 , SENSE2 , SENSE1
GND
I 5 20 I
TH1 TH2
SENSE2 Voltages ..................................... 0.3V to 65V
V 6 19 V
FB1 FB2
+
PLLIN/MODE, FREQ, DRVSET Voltages ....... 0.3V to 6V SENSE1 7 18 ILIM
SENSE1 8 17 RUN2
EXTV Voltage ......................................... 0.3V to 14V
CC
9 10 11 12 13 14 15 16
ITH1, ITH2, V Voltages ............................ 0.3V to 6V
FB1
V Voltage ............................................... 0.3V to 65V
FB2
VPRG2 Voltage ............................................ 0.3V to 6V
TRACK/SS1, SS2 Voltages ........................... 0.3V to 6V
UH PACKAGE
Operating Junction Temperature Range (Notes 2, 3)
32-LEAD (5mm 5mm) PLASTIC QFN
T = 150C, = 44C/W
JMAX JA
LTC7813E, LTC7813I .......................... 40C to 125C
EXPOSED PAD (PIN 33) IS GND, MUST BE SOLDERED TO PCB
LTC7813H .......................................... 40C to 150C
LTC7813MP ....................................... 55C to 150C
Storage Temperature Range .................. 65C to 150C
o r Der i n F Ma T
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC7813EUH#PBF LTC7813EUH#TRPBF 7813 32-Lead (5mm 5mm) Plastic QFN 40C to 125C
LTC7813IUH#PBF LTC7813IUH#TRPBF 7813 32-Lead (5mm 5mm) Plastic QFN 40C to 125C
LTC7813HUH#PBF LTC7813HUH#TRPBF 7813 32-Lead (5mm 5mm) Plastic QFN 40C to 150C
LTC7813MPUH#PBF LTC7813MPUH#TRPBF 7813 32-Lead (5mm 5mm) Plastic QFN 55C to 150C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to: