LTC3857-1_15 Datasheet, PDF (38/38 Pages) Linear Technology – Low IQ, Dual, 2-Phase Synchronous Step-Down Controller

LTC3857-1
TYPICAL APPLICATION
High Efficiency 2-Phase 12V/150W Step-Down Converter
R_B1
698k
C_F1
10pF C1
R_A1
1nF
49.9k
C_ITH1A 68pF
R_ITH1 2.94k
C_ITH1 3300pF _{CSS1 0.1μF}
V_OUT
SENSE1⁺ PGOOD2
SENSE1^– PGOOD1
V_FB1
BG1
SW1
BOOST1
I_TH1
TG1
LTC38571
TRACK/SS1
I_LIM
PHSMD
CLKOUT
PLLIN/MODE
SGND
EXTV_CC
RUN1
RUN2
FREQ
V_IN
INTV_CC
PGND
TG2
BOOST2
100k ^INTVCC
100k
C_B1
0.47μF
D1
C_INT
4.7μF
D2
C_B2
0.47μF
SS1 SS2
SW2
I_TH1
I_TH2
BG2
MBOT1
L1
6μH
MTOP1
R_SENSE1
5mΩ
C_OUT1
22μF
16V
V_IN
C_IN
19V TO 28V
10μF
10μF
50V
50V
MTOP2
L2
R_SENSE2
6μH
5mΩ
MBOT2
C_OUT2
22μF
16V
V_FB1
C2
1nF
V_FB2
SENSE2^–
SENSE2⁺
C_OUT1, C_OUT2: SANYO 1670C22M
L1: SUMIDA CDEP106-6ROM
L2: SUMIDA CDEP106-6ROM
MTOP1, MTOP2: INFINEON BSZ097NO4LS
MBOT1, MBOT2: INFINEON BSZ097NO4LS
38571 TA07
10μF
16V
V_OUT
12V
12.5A
10μF
16V
RELATED PARTS
PART NUMBER
LTC3859
LTC3868/LTC3868-1
LTC3858/LTC3858-1
LTC3890/LTC3890-1
LTC3834/LTC3834-1
LTC3835/LTC3835-1
LT3845
LTC3824
DESCRIPTION
COMMENTS
Low I_Q, Triple Output Buck/Buck-Boost Synchronous
DC/DC Controller
Low I_Q, Dual Output 2-Phase Synchronous
Step-Down DC/DC Controller with 99% Duty Cycle
Low I_Q, Dual Output 2-Phase Synchronous
Step-Down DC/DC Controller with 99% Duty Cycle
60V, Low I_Q, Dual 2-Phase Synchronous Step-Down
DC/DC Controller with 99% Duty Cycle
Low I_Q, Synchronous Step-Down DC/DC Controller
Low I_Q, Synchronous Step-Down DC/DC Controller
Low I_Q, High Voltage Synchronous Step-Down
DC/DC Controller
Low I_Q, High Voltage DC/DC Controller, 100%
Duty Cycle
Outputs (≥5V) Remain in Regulation Through Cold Crank, 2.5V ≤ V_IN ≤ 38V,
V_OUT(BUCK) Up to 24V, V_OUT(BOOST) Up to 60V, I_Q = 55μA,
Phase-Lockable Fixed Operating Frequency 50kHz to 900kHz,
4V ≤ V_IN ≤ 24V, 0.8V ≤ V_OUT ≤ 14V, I_Q = 170μA,
Phase-Lockable Fixed Operating Frequency 50kHz to 900kHz,
4V ≤ V_IN ≤ 38V, 0.8V ≤ V_OUT ≤ 24V, I_Q = 170μA,
Phase-Lockable Fixed Operating Frequency 50kHz to 900kHz,
4V ≤ V_IN ≤ 60V, 0.8V ≤ V_OUT ≤ 24V, I_Q = 50μA,
Phase-Lockable Fixed Operating Frequency 140kHz to 650kHz,
4V ≤ V_IN ≤ 36V, 0.8V ≤ V_OUT ≤ 10V, I_Q = 30μA,
Phase-Lockable Fixed Operating Frequency 140kHz to 650kHz,
4V ≤ V_IN ≤ 36V, 0.8V ≤ V_OUT ≤ 10V, I_Q = 80μA,
Adjustable Fixed Operating Frequency 100kHz to 500kHz,
4V ≤ V_IN ≤ 60V, 1.23V ≤ V_OUT ≤ 36V, I_Q = 120μA, TSSOP-16
Selectable Fixed 200kHz to 600kHz Operating Frequency,
4V ≤ V_IN ≤ 60V, 0.8V ≤ V_OUT ≤ V_IN, I_Q = 40μA, MSOP-10E
38 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ^● FAX: [phone] ^● www.linear.com
38571fc
LT 0112 REV C • PRINTED IN USA
© LINEAR TECHNOLOGY CORPORATION 2009