Datasheet LTC3126 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 42V, 2.5A Synchronous Step-Down Regulator with No-Loss Input PowerPath |
| Pages / Page | 30 / 1 — FeaTures. DescripTion. Seamless, Automatic Transition Between Two Input. … |
| File Format / Size | PDF / 2.1 Mb |
| Document Language | English |
FeaTures. DescripTion. Seamless, Automatic Transition Between Two Input. Power Sources. Wide Input Voltage Range: 2.4V to 42V
Model Line for this Datasheet
Text Version of Document
LTC3126 42V, 2.5A Synchronous Step-Down Regulator with No-Loss Input PowerPath
FeaTures DescripTion
n
Seamless, Automatic Transition Between Two Input
The LTC®3126 is a high efficiency synchronous buck
Power Sources
converter with an internal no-loss PowerPath™ supporting n
Wide Input Voltage Range: 2.4V to 42V
seamless operation from two separate input power sources. n
Wide Output Voltage Range: 0.818V to VIN
Pin-selectable ideal diode-OR and priority input modes n
Up to 2.5A Continuous Output Current
with user programmable undervoltage lockout thresholds n
Pin-Selectable Priority and Ideal Diode-OR Modes
provide full control over the transition between the input n
Burst Mode
®
Operation, IQ = 2µA
power sources. The fast, automatic switchover provided n 95% Efficiency at 1A, VIN = 12V, VOUT = 5V by the internal PowerPath eliminates the need for hold-up n 1µA Current in Shutdown capacitors and minimizes disturbances on the output rail. n Programmable Input UVLO Thresholds An active input channel indicator and independent input n Input Valid, Priority Channel and PGOOD Indicators and output power good signals provide complete feedback n 200kHz to 2.2MHz Fixed Frequency PWM of the power system status. n Synchronizable to an External Clock A wide 2.4V to 42V input voltage range, 2.5A output cur- n Current Mode Control with 60ns Minimum On-Time rent capability and 2µA Burst Mode operation quiescent n Minimal External Components current facilitate use of the LTC3126 with a wide variety n Thermally Enhanced 28-Lead 4mm × 5mm QFN and of power sources including supercapacitors, automo- 28-Lead TSSOP Packages tive batteries, unregulated wall adapters and single to multicell stacks of most battery chemistries. Additional
applicaTions
features include 1µA current in shutdown, internal soft- n start and thermal protection. The LTC3126 is available Portable Industrial/Communications Test Equipment n in thermally enhanced 28-lead 4mm × 5mm QFN and Battery and Supercapacitor Backup Power n 28-lead TSSOP packages. Automotive Power with Battery Backup n Uninterruptible Power Supplies L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion 2MHz, 3.3V/2.5A Supply from Automotive and Battery Inputs
0.1µF 0.1µF AUTOMOTIVE
Switchover to Battery Power, 2.5A Load
10V TO 24V V BST2 COM2 BST1 COM1 IN1 2.2µH VOUT 42V TRANSIENT 15µF PVIN1 SW 3.3V EXTV V CC 47µF 2.5A IN1 5V/DIV + VIN2 10pF 1.13M VIN2 5V/DIV BATTERY 4.7µF PVIN2 4.2V TO 24V + FB AUTOMOTIVE PV INPUT UNPLUGGED CC LTC3126 374k VCC V ENA OUT 200mV/DIV 4.7µF VREF PRIORITY INDUCTOR CURRENT 2A/DIV 499k VALID1 VSET1 VALID2 PRIORITY 5V/DIV PGOOD 249k V 3126 TA01b SET2 50µs/DIV 249k PWM/SYNC 16.5k DIODE RT GND PGND 3126 TA01a 3126f For more information www.linear.com/LTC3126 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Quick Reference Operation Applications Information Typical Applications Package Description Typical Application Related Parts
FeaTures DescripTion
n
Seamless, Automatic Transition Between Two Input
The LTC®3126 is a high efficiency synchronous buck
Power Sources
converter with an internal no-loss PowerPath™ supporting n
Wide Input Voltage Range: 2.4V to 42V
seamless operation from two separate input power sources. n
Wide Output Voltage Range: 0.818V to VIN
Pin-selectable ideal diode-OR and priority input modes n
Up to 2.5A Continuous Output Current
with user programmable undervoltage lockout thresholds n
Pin-Selectable Priority and Ideal Diode-OR Modes
provide full control over the transition between the input n
Burst Mode
®
Operation, IQ = 2µA
power sources. The fast, automatic switchover provided n 95% Efficiency at 1A, VIN = 12V, VOUT = 5V by the internal PowerPath eliminates the need for hold-up n 1µA Current in Shutdown capacitors and minimizes disturbances on the output rail. n Programmable Input UVLO Thresholds An active input channel indicator and independent input n Input Valid, Priority Channel and PGOOD Indicators and output power good signals provide complete feedback n 200kHz to 2.2MHz Fixed Frequency PWM of the power system status. n Synchronizable to an External Clock A wide 2.4V to 42V input voltage range, 2.5A output cur- n Current Mode Control with 60ns Minimum On-Time rent capability and 2µA Burst Mode operation quiescent n Minimal External Components current facilitate use of the LTC3126 with a wide variety n Thermally Enhanced 28-Lead 4mm × 5mm QFN and of power sources including supercapacitors, automo- 28-Lead TSSOP Packages tive batteries, unregulated wall adapters and single to multicell stacks of most battery chemistries. Additional
applicaTions
features include 1µA current in shutdown, internal soft- n start and thermal protection. The LTC3126 is available Portable Industrial/Communications Test Equipment n in thermally enhanced 28-lead 4mm × 5mm QFN and Battery and Supercapacitor Backup Power n 28-lead TSSOP packages. Automotive Power with Battery Backup n Uninterruptible Power Supplies L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks and PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion 2MHz, 3.3V/2.5A Supply from Automotive and Battery Inputs
0.1µF 0.1µF AUTOMOTIVE
Switchover to Battery Power, 2.5A Load
10V TO 24V V BST2 COM2 BST1 COM1 IN1 2.2µH VOUT 42V TRANSIENT 15µF PVIN1 SW 3.3V EXTV V CC 47µF 2.5A IN1 5V/DIV + VIN2 10pF 1.13M VIN2 5V/DIV BATTERY 4.7µF PVIN2 4.2V TO 24V + FB AUTOMOTIVE PV INPUT UNPLUGGED CC LTC3126 374k VCC V ENA OUT 200mV/DIV 4.7µF VREF PRIORITY INDUCTOR CURRENT 2A/DIV 499k VALID1 VSET1 VALID2 PRIORITY 5V/DIV PGOOD 249k V 3126 TA01b SET2 50µs/DIV 249k PWM/SYNC 16.5k DIODE RT GND PGND 3126 TA01a 3126f For more information www.linear.com/LTC3126 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Quick Reference Operation Applications Information Typical Applications Package Description Typical Application Related Parts
