LT3791-1
60V 4-Switch Synchronous
Buck-Boost Controller
Fea T Descrip T
n
4-Switch Single Inductor Architecture Allows V The LT 3791-1 is a synchronous 4-switch buck-boost volt-
IN
Above, Below or Equal to V age/current regulator controller. The controller can regulate
OUT
n
Synchronous Switching: Up to 98.5% Efficiency output voltage, output current, or input current with input
n
Wide V Range: 4.7V to 60V voltages above, below, or equal to the output voltage. The
IN
n
2% Output Voltage Accuracy: 1.2V V < 60V constant-frequency, current mode architecture allows its
OUT
n
6% Output Current Accuracy: 0V V < 60V frequency to be adjusted or synchronized from 200kHz
OUT
n
Input and Output Current Regulation with Current to 700kHz. No top FET refresh switching cycle is needed
Monitor Outputs in buck or boost operation. With 60V input, 60V output
n
No Top FET Refresh in Buck or Boost capability and seamless transitions between operating
n
V Disconnected from V During Shutdown regions, the LT3791-1 is ideal for voltage regulator, bat-
OUT IN
n
C/10 Charge Termination and Output Shorted Flags tery/super-capacitor charger applications in automotive,
n
Capable of 100W or greater per IC industrial, telecom, and even battery-powered systems.
n
38-Lead TSSOP with Exposed Pad
For new designs we recommend the LT8390: 60V synchro-
nous 4-switch buck-boost controller due to its numerous
a T
performance improvements over the LT3791-1.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Analog
n
Automotive, Telecom, Industrial Systems
Devices, Inc. All other trademarks are the property of their respective owners.
n
High Power Battery-Powered System
Typical a T
120W (24V 5A) Buck-Boost Voltage Regulator
V 0.003
IN
12V TO
+
58V
4.7F 47F
V
IN INTV 100V
CC 80V
1F 4.7F
50
+
BST2
IVINN 220F
Efficiency vs Load Current
470nF 35V
IVINP 0.015 V
OUT
BST1 0.1F 100
24V
TEST1 4.7F
499k 499k 5A
TG1 50V 95
0.1F
EN/UVLO 2
73.2k
SWI
90
OVLO 10H
BG1
INTV
56.2k 27.4k CC
85
3.83k
LT3791-1 SNSP
80
100k 200k
0.004
SHORT
75
C/10
SNSN
CCM
70
PGND
IVINMON V = 12V
IN
BG2 65
V = 24V
ISMON IN
V = 54V
IN
CLKOUT SW2
60
PWMOUT TG2
0 1 2 3 4 5
V
ISP
REF
LOAD CURRENT (A)
0.1F 37911 TA01b
PWM ISN
FB
CTRL
100k 37911 TA01a
SS SYNC V RT SGND
C
5.1k 147k
33nF
200kHz
10nF
37911fb
1
For more information www.linear.com/LT3791-1
EFFICIENCY (%)
ion pplica
ions pplica
ion uresLT3791-1
a Te Maxi Mu M r a T p c F T
(Note 1)
TOP VIEW
Supply Voltages
CTRL 1 38 OVLO
Input Supply (V ) .....................................................60V
IN
SS 2 37 FB
SW1, SW2 ......................................................1V to 60V
PWM 3 36 V
C
C/10, SHORT .............................................................15V
C/10 4 35 RT
EN/UVLO, IVINP, IVINN, ISP, ISN ..............................60V
SHORT 5 34 SYNC
INTV , (BST1-SW1), (BST2-SW2) .............................6V
CC
V 6 33 CLKOUT
REF
CCM, SYNC, RT, CTRL, OVLO, PWM ..........................6V
ISMON 7 32 CCM
IVINMON, ISMON, FB, SS, VC, V ...........................6V
REF
IVINMON 8 31 PWMOUT
IVINP-IVINN, ISP-ISN, SNSP-SNSN .......................0.5V
EN/UVLO 9 30 SGND
SNSP, SNSN ...........................................................0.3V 39
IVINP 10 29 TEST1
SGND
Operating Junction Temperature (Notes 2, 3)
IVINN 11 28 SNSN
LT3791E-1/LT3791I-1 ......................... 40C to 125C
V 12 27 SNSP
IN
LT3791H-1 ......................................... 40C to 150C
INTV 13 26 ISN
CC
LT3791MP-1....................................... 55C to 150C TG1 14 25 ISP
BST1 15 24 TG2
Storage Temperature Range .................. 65C to 150C
SW1 16 23 NC
Lead Temperature (Soldering, 10 sec) ...................300C
PGND 17 22 BST2
BG1 18 21 SW2
BG2 19 20 PGND
FE PACKAGE
38-LEAD PLASTIC TSSOP
T = 150C, = 28C/W
JMAX JA
EXPOSED PAD (PIN 39) IS SGND, MUST BE SOLDERED TO PCB
o r D i n F Ma T