Datasheet LT3992 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Monolithic Dual Tracking 3A Step-Down Switching Regulator |
| Pages / Page | 36 / 1 — FeaTures. DescripTion. Wide Input Range:. – Operation from 3V to 60V. … |
| File Format / Size | PDF / 678 Kb |
| Document Language | English |
FeaTures. DescripTion. Wide Input Range:. – Operation from 3V to 60V. Independent Supply, Shutdown, Soft-Start, UVLO,
Model Line for this Datasheet
Text Version of Document
LT3992 Monolithic Dual Tracking 3A Step-Down Switching Regulator
FeaTures DescripTion
n
Wide Input Range:
The LT®3992 is a dual current mode PWM step-down
– Operation from 3V to 60V
DC/DC converter with two internal 4.6A switches. Inde- n
Independent Supply, Shutdown, Soft-Start, UVLO,
pendent input voltage, shutdown, feedback, soft-start,
Programmable Current Limit and Programmable
UVLO current limit and comparator pins for each channel
Power Good for Each 3A Regulator
simplify complex power supply tracking and sequencing n
Die Temperature Monitor
requirements. n
Adjustable/Synchronizable Fixed Frequency
To optimize efficiency and component size, both convert-
Operation from 250kHz to 2MHz with Synchronized
ers have a programmable maximum current limit and are
Clock Output
synchronized to either a common external clock input, or n
Independent Synchronized Switching Frequencies
a resistor settable fixed 250kHz to 2MHz internal oscillator.
Optimize Component Size
A frequency divider is provided for channel 1 to further n
Antiphase Switching
optimize component size. At all frequencies, a 180° phase n
Outputs Can Be Paralleled
relationship between channels is maintained, reducing volt- n Flexible Output Voltage Tracking age ripple and component size. A clock output is available n Low Dropout: 95% Maximum Duty Cycle for synchronizing multiple regulators. n 5mm × 5mm QFN Package n Minimum input to output voltage ratios are improved by FMEA Compliant 38-Pin Exposed Pad TSSOP Package allowing the switch to stay on through multiple clock cycles
applicaTions
only switching off when the boost capacitor needs recharg- ing. Independent channel operation can be programmed n Automotive Supplies using the SHDN pin. Disabling both converters reduces n Distributed Supply Regulation the total quiescent current to <10µA. 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 owners.
Typical applicaTion 12V and 5V 2-Stage Multi-Frequency Step-Down Converter Independent Synchronized
VIN1 15V TO 60V
Switching Frequencies Extend
4.7µF
Full Frequency Input Range
VOUT2 VIN1 VIN2 SHDN1 SHDN2 BST1 BST2 CH1 SW1 SW2 400kHz 20V/DIV 22µH 2.2µH 0.1µF IND1 IND2 0.1µF VOUT1 LT3992 VOUT2 12V V 5V OUT1 VOUT2 1A 2A CH2 400kHz 22µF FB1 FB2 42.2k 47µF 1600kHz 1.6MHz 100k 8.06k 113k 8.06k CMPI1 CMPI2 FB1 5V/DIV PG CMPO1 CMPO2 SS1 SS2 VIN = 60V 500ns/DIV 3992 TA01b ILIM1 ILIM2 VC1 VC2 0.1µF CLKOUT 33pF RT/SYNC CLKOUT 33pF 1600kHz 0.1µF 680pF DIV TJ 680pF GND 100k 15k 48.7k 102k 10nF 10k 60.4k 3992 TA01a 3992fa For more information www.linear.com/LT3992 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Typical Application Related Parts
FeaTures DescripTion
n
Wide Input Range:
The LT®3992 is a dual current mode PWM step-down
– Operation from 3V to 60V
DC/DC converter with two internal 4.6A switches. Inde- n
Independent Supply, Shutdown, Soft-Start, UVLO,
pendent input voltage, shutdown, feedback, soft-start,
Programmable Current Limit and Programmable
UVLO current limit and comparator pins for each channel
Power Good for Each 3A Regulator
simplify complex power supply tracking and sequencing n
Die Temperature Monitor
requirements. n
Adjustable/Synchronizable Fixed Frequency
To optimize efficiency and component size, both convert-
Operation from 250kHz to 2MHz with Synchronized
ers have a programmable maximum current limit and are
Clock Output
synchronized to either a common external clock input, or n
Independent Synchronized Switching Frequencies
a resistor settable fixed 250kHz to 2MHz internal oscillator.
Optimize Component Size
A frequency divider is provided for channel 1 to further n
Antiphase Switching
optimize component size. At all frequencies, a 180° phase n
Outputs Can Be Paralleled
relationship between channels is maintained, reducing volt- n Flexible Output Voltage Tracking age ripple and component size. A clock output is available n Low Dropout: 95% Maximum Duty Cycle for synchronizing multiple regulators. n 5mm × 5mm QFN Package n Minimum input to output voltage ratios are improved by FMEA Compliant 38-Pin Exposed Pad TSSOP Package allowing the switch to stay on through multiple clock cycles
applicaTions
only switching off when the boost capacitor needs recharg- ing. Independent channel operation can be programmed n Automotive Supplies using the SHDN pin. Disabling both converters reduces n Distributed Supply Regulation the total quiescent current to <10µA. 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 owners.
Typical applicaTion 12V and 5V 2-Stage Multi-Frequency Step-Down Converter Independent Synchronized
VIN1 15V TO 60V
Switching Frequencies Extend
4.7µF
Full Frequency Input Range
VOUT2 VIN1 VIN2 SHDN1 SHDN2 BST1 BST2 CH1 SW1 SW2 400kHz 20V/DIV 22µH 2.2µH 0.1µF IND1 IND2 0.1µF VOUT1 LT3992 VOUT2 12V V 5V OUT1 VOUT2 1A 2A CH2 400kHz 22µF FB1 FB2 42.2k 47µF 1600kHz 1.6MHz 100k 8.06k 113k 8.06k CMPI1 CMPI2 FB1 5V/DIV PG CMPO1 CMPO2 SS1 SS2 VIN = 60V 500ns/DIV 3992 TA01b ILIM1 ILIM2 VC1 VC2 0.1µF CLKOUT 33pF RT/SYNC CLKOUT 33pF 1600kHz 0.1µF 680pF DIV TJ 680pF GND 100k 15k 48.7k 102k 10nF 10k 60.4k 3992 TA01a 3992fa For more information www.linear.com/LT3992 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Typical Application Related Parts
