LM5157 Boost SEPIC Flyback Converter

Specifications

Product Overview

The LM5157 is a Texas Instruments Power_Management IC for boost, SEPIC, and flyback converter topologies. Its BIAS input operating range is 2.9 V to 45 V, and boost converter input operation can extend from 1.5 V to 45 V when BIAS is at least 2.9 V. The boost converter output is specified up to 48 V, with the SW pin transient constrained to 50 V or below.

The device integrates a 45 mOhm internal N-channel MOSFET and provides a 6.5 A minimum peak current limit for the LM5157 option. Switching frequency is dynamically programmable with an external resistor across 100 kHz to 2.2 MHz, and external synchronization supports 100 kHz to 2200 kHz. Control and monitoring limits include ±1% FB reference accuracy, shutdown current of 2.6 uA maximum, and operating current of 670 uA maximum.

The package is a 16-pin WQFN (RTE) with a 3.00 mm x 3.00 mm nominal body. Thermal data includes 44.4°C/W junction-to-ambient resistance for the RTE QFN package and 32.7°C/W on the LM5157EVM-BST evaluation board.

Key Features

• Boost, SEPIC, and flyback converter topology support
• 2.9 V to 45 V BIAS operating range
• Boost input down to 1.5 V with BIAS supply
• 48 V boost output operating voltage capability
• 50 V SW-to-AGND DC absolute maximum rating
• 45 mOhm integrated N-channel MOSFET RDS(on)
• 100 kHz to 2.2 MHz programmable switching frequency
• External synchronization from 100 kHz to 2200 kHz
• 6.5 A LM5157 minimum peak current limit
• ±1% feedback reference accuracy
• 2.6 uA maximum shutdown current
• -40°C to 125°C operating junction temperature

Typical Applications

• Boost converter power stages
• SEPIC converter power stages
• Flyback converter power stages
• 48 V output conversion designs
• Wide BIAS input power designs
• Externally synchronized switching supplies
• Low shutdown current power systems
• Compact 16-pin WQFN power designs

Procurement Notes

When requesting a quote for LM5157, buyers should confirm the manufacturer, package or case, required quantity, target date code, compliance documents, packing method, destination country and expected delivery schedule.

If alternatives are acceptable, buyers should share the approved vendor list, required electrical or optical limits, package constraints and qualification requirements. Any alternative part should be reviewed by the buyer's engineering team before production use.

For power IC and power device sourcing, voltage rating, current rating, power dissipation, package thermal performance, protection features, qualification grade and application conditions should be reviewed before approval.