Datasheet LT8601 (Analog Devices)

LT8601 42V Triple Monolithic Synchronous Step-Down Regulator
FEATURES DESCRIPTION
n
Flexible Power Supply System Providing Three
The LT®8601 is a triple channel, current mode, monolithic
Outputs Over a Wide Input Voltage Range
buck switching regulator with a programmable power-on n
Two High Voltage Synchronous Buck Regulators
reset. All regulators are synchronized to a single oscillator n
3V to 42V Input Voltage Range
with an adjustable frequency from 250kHz to 2.2MHz. The n
Output Currents Up to 2.5A and 1.5A
LT8601 can be configured for micropower Burst Mode or n
High Efficiency Up to 93%
pulse-skipping operation at light load. Micropower opera- n
One Low Voltage Synchronous Buck Regulator
tion results in quiescent current of 30µA with all three n
2.6V to 5.5V Input Voltage Range
regulators operating as shown in the application below n
Output Current Up to 1.8A and 95% Efficiency
with no load applied. n
Resistor Programmable and Synchronizable
The high voltage channels are synchronous buck regula-
from 250kHz to 2.2MHz Switching Frequency
n tors that operate from an input of 3.0V to 42V. The output
Low Ripple Burst Mode
®
Operation
n currents are up to 1.5A (OUT1) and 2.5A (OUT2). The
30µA IQ at 12VIN to 3.3VOUT2
n low voltage channel operates from an input of 2.6V to
Output Ripple < 15mV
n 5.5V. Internal synchronous power switches provide high
Programmable Power-On Reset
n efficiency with output currents up to 1.8A. The LT8601 Power Good Indicators n uses a 2-phase clock with channel 1 operating 180° from 2-Phase Clock Reduces Input Current Ripple n channels 2 and 3 to reduce input ripple current on both Available in Thermally Enhanced 40-Lead QFN HV and LV inputs. All channels have cycle-by-cycle cur- (6mm × 6mm) Package n rent limit, providing protection against shorted outputs. AEC-Q100 Qualified for Automotive Applications Thermal shutdown provides additional protection.
APPLICATIONS
The LT8601 is available in a 40-lead 6mm × 6mm QFN n package. Automotive Systems n Distributed Supply Regulation All registered trademarks and trademarks are the property of their respective owners. n Industrial Controls and Power Supplies
TYPICAL APPLICATION Automotive Input Stepped Down to 5V, 3.3V and 1.8V Outputs at 2MHz
IN VIN BST1 6V TO 24V, PV LT8601 3.3μH IN1
HV Channel Efficiency, V
TRANSIENTS OUT1
OUT1 = 5V LV Channel Efficiency, VOUT3 = 1.8V
SW1 TO 42V PVIN2 5V, 1.5A 100 2.0 100 1.0 EN/UVLO FB1 90 1.8 90 0.9 POREN 22μF EFFICIENCY EFFICIENCY RST 80 1.6 80 0.8 3 BST2 PG1-3 70 VIN = 12V 1.4 POWER LOSS (W) 70 0.7 POWER LOSS (W) RUN3 1μH OUT2 SW2 60 1.2 60 0.6 3.3V, 1A* OUT2 BIAS FB2 50 1.0 50 0.5 PVIN3 47μF 40 0.8 40 0.4 INTVCC EFFICIENCY (%) POWER EFFICIENCY (%) POWER 30 LOSS 0.6 30 LOSS 0.3 CPOR 1μH 20 0.4 20 0.2 OUT3 2 SW3 f f TRKSS1, 2 1.8V, 1.8A 10 SW = 1MHz 0.2 10 SW = 1MHz 0.1 FB3 fSW = 2MHz fSW = 2MHz 0 0 0 0 RT 22μF 0 0.3 0.6 0.9 1.2 1.5 0 0.3 0.6 0.9 1.2 1.5 1.8 SYNC GND LOAD CURRENT (A) LOAD CURRENT (A) 8601 TA01b 8601 TA01c 8601 TA01a *IMAX = 2.5A – IPVIN3 – IBIAS Rev. B Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts