Texas Instruments LM5157 Q1 Series Manual

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LM5157x-Q1 2.2-MHz Wide V

1 Features

• AEC-Q100 qualified for automotive applications
– Temperature grade 1: –40°C to +125°C T
• Functional Safety-Capable
– Documentation available to aid functional safety
system design
• Suited for wide operating range for car battery

applications

– 2.9-V to 45-V input operating range
– 48-V maximum output (50-V abs max)
– Minimum boost supply voltage of 1.5 V when
BIAS ≥ 2.9 V
– Input transient protection up to 50 V
– Minimized battery drain
• Low shutdown current (I
• Low operating current (I
• Small solution size and low cost
– Maximum switching frequency up to 2.2 MHz
– 16-pin QFN package (3 mm × 3 mm) with
wettable flanks
– Integrated error amplifier allows primary-side
regulation without optocoupler (flyback)
– Minimized undershoot during cranking (start-
stop application)
– Accurate current limit (see the
Comparison Table)
• EMI mitigation
– Selectable dual random spread spectrum
– Lead-less package
• Higher efficiency with low-power dissipation
– 45-mΩ R switch
DSON
– Fast switching, small switching loss
• Avoid AM band interference and crosstalk
– Optional clock synchronization
– Dynamically programmable wide switching
frequency from 100 kHz to 2.2 MHz
• Integrated protection features
– Constant current limiting over input voltage
– Selectable hiccup mode overload protection
– Programmable line UVLO
– OVP protection
– Thermal shutdown
• Accurate ±1% accuracy feedback reference
• Adjustable soft start
• PGOOD indicator
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
Copyright © 2021 Texas Instruments Incorporated
intellectual property matters and other important disclaimers. UNLESS OTHERWISE NOTED, this document contains PRODUCTION
DATA.
50-V Boost/SEPIC/Flyback Converter with Dual
IN
Random Spread Spectrum
A
≤ 2.6 µA)
Q
≤ 700 µA)
Q
Device
Product Folder Links: LM5157-Q1 LM51571-Q1
SNVSBK8A – OCTOBER 2020 – REVISED MARCH 2021
SNVSBK8A – OCTOBER 2020 – REVISED MARCH 2021
• Create a custom design using the LM5157x-Q1
with the WEBENCH ®
2 Applications
• Battery-powered wide input boost, SEPIC, flyback
converter
• Automotive voltage stabilizer in SEPIC
• Automotive start-stop application
• Automotive emergency call application/backup
battery booster
• High voltage LiDAR power supply
• Automotive LED bias supply
• Multiple-output flyback without optocoupler
• Holdup capacitor charger
• Audio amplifier power supply
• Piezo driver/motor driver bias supply

3 Description

The LM5157x-Q1 device is a wide input range, non-
synchronous boost converter with integrated 50-V,
6.5-A (LM5157-Q1) or 50-V, 4.33-A (LM51571-Q1)
power switch.
The device can be used in boost, SEPIC, and flyback
topologies. The device can start up from a single-cell
battery with a minimum of 2.9 V. It can operate with
the input supply voltage as low as 1.5 V if the BIAS
pin is greater than 2.9 V.
Device Information
PART NUMBER PACKAGE
LM5157-Q1
WQFN (16)
LM51571-Q1
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
V
SUPP LY
BIAS VCC
UVLO
RT
SS
PGND AGND
Typical SEPIC Application
LM5157-Q1, LM51571-Q1
LM5157-Q1, LM51571-Q1
Power Designer
(1)
BODY SIZE (NOM)
3.00 mm × 3.00 mm
SW
FB
COMP
PGO OD
MODE
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