LTC3892-1_15 Datasheet, PDF (1/36 Pages) Linear Technology – 60V Low IQ, Dual, 2-Phase Synchronous Step-Down DC/DC Controller

LTC3892/LTC3892-1
Features
60V Low I_Q, Dual, 2-Phase
Synchronous Step-Down
DC/DC Controller
Description
n _{Wide VIN Range: 4.5V to 60V (65V Abs Max)}
n _{Wide Output Voltage Range: 0.8V ≤ VOUT ≤ 99% • VIN}
n _{Adjustable Gate Drive Level 5V to 10V (OPTI-DRIVE)}
n _{No External Bootstrap Diodes Required}
n _{Low Operating IQ: 29μA (One Channel On)}
n _{Selectable Gate Drive UVLO Thresholds}
n _{Out-of-Phase Operation Reduces Required Input}
Capacitance and Power Supply Induced Noise
n _{Phase-Lockable Frequency: 75kHz to 850kHz}
n _{Programmable Fixed Frequency: 50kHz to 900kHz}
n _{Selectable Continuous, Pulse Skipping or Low Ripple}
Burst Mode^® Operation at Light Loads
n _{Selectable Current Limit (LTC3892)}
n _{Very Low Dropout Operation: 99% Duty Cycle}
n _{Power Good Output Voltage Monitors (LTC3892)}
n _{Low Shutdown IQ: 3.6μA}
n _{Small 32-Lead 5mm × 5mm QFN Package (LTC3892)}
n _{Small 28-Lead TSSOP Package (LTC3892-1)}
Applications
n _{Automotive and Industrial Power Systems}
n _{Distributed DC Power Systems}
n _{High Voltage Battery Operated Systems}
The LTC^®3892/LTC3892-1 is a high performance dual
step-down DC/DC switching regulator controller that
drives all N-channel synchronous power MOSFET stages.
Power loss and noise are minimized by operating the two
controller output stages out-of-phase.
The gate drive voltage can be programmed from 5V to
10V to allow the use of logic or standard-level FETs and
to maximize efficiency. Internal switches in the top gate
drivers eliminate the need for external bootstrap diodes.
A wide 4.5V to 60V input supply range encompasses a wide
range of intermediate bus voltages and battery chemistries.
Output voltages up to 99% of V_IN can be regulated. OPTI-
LOOP^® compensation allows the transient response and
loop stability to be optimized over a wide range of output
capacitance and ESR values.
The 29μA no-load quiescent current extends operating
run time in battery powered systems. For a comparision
of the LTC3892 to the LTC3892-1, see Table 1 in the Pin
Functions section of this data sheet.
L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Linear Technology and the Linear logo are
registered trademarks of Linear Technology Corporation. All other trademarks are the property
of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620,
6144194, 6177787, 6580258.
Typical Application
High Efficiency Dual 5V/12V Output Step-Down Converter
VIN
12.5V TO 60V
47µF
V_OUT1
5V
8A
220µF
5mΩ 5.6µH
0.1µF
RUN1 VIN RUN2
TG1
BOOST1
TG2
BOOST2
SW1
SW2
BG1
BG2
LTC3892
0.1µF
15µH 8mΩ
SENSE1+
1nF
SENSE1–
SENSE2+
SENSE2–
1nF
V_FB1
ITH1
TRACK/SS1
V_FB2
ITH2
TRACK/SS2
VPRG1
DRVSET
7.5k
DRVUV
100pF
2.2nF
0.1µF
INTV_CC GND DRV_CC
0.1µF
4.7µF
34.8k
0.1µF 100pF
1nF
V_OUT2
12V
5A
150µF
100k
7.15k
3892 TA01
For more information www.linear.com/LTC3892
E_Ef_ff_fii_cc_ii_ee_nn_cycy_vsv_Os_utO_puu_ttp_Cuu_rt_reC_nu_t rrent
96
V_IN = 12V
95 VOUT = 5V
Burst Mode OPERATION
94
93
92
91
90
89
88
0.01
GATE DRIVE
DRV_CC=5V
DRV_CC=6V
DRV_CC=8V
DRV_CC=10V
0.1
1
LOAD CURRENT (A)
10
3892 F01b
38921f
1