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LMR51403

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4.5V-to-42V 0.3A synchronous buck converter with 25µA quiescent current

Product details

Rating Catalog Operating temperature range (°C) -40 to 150 TI functional safety category Functional Safety-Capable Topology Buck Type Converter (Integrated Switch) Iout (max) (A) 0.3 Vin (min) (V) 4.5 Vin (max) (V) 42 Switching frequency (min) (kHz) 400 Switching frequency (max) (kHz) 1100 Features Enable, Forced PWM, Over Current Protection, Pre-Bias Start-Up, Synchronous Rectification Control mode current mode Vout (min) (V) 0.8 Vout (max) (V) 28 Iq (typ) (µA) 25
Rating Catalog Operating temperature range (°C) -40 to 150 TI functional safety category Functional Safety-Capable Topology Buck Type Converter (Integrated Switch) Iout (max) (A) 0.3 Vin (min) (V) 4.5 Vin (max) (V) 42 Switching frequency (min) (kHz) 400 Switching frequency (max) (kHz) 1100 Features Enable, Forced PWM, Over Current Protection, Pre-Bias Start-Up, Synchronous Rectification Control mode current mode Vout (min) (V) 0.8 Vout (max) (V) 28 Iq (typ) (µA) 25
SOT-23 (DBV) 6 8.12 mm² 2.9 x 2.8
  • Functional Safety-Capable
  • Configured for rugged industrial applications
    • 4V to 42V input voltage range
    • Input transient protection up to 50V
    • 300mA continuous output current
    • 80ns minimum switching on time
    • Fixed 400kHz and 1.1MHz switching frequency
    • –40°C to 150°C junction temperature range
    • 96% maximum duty cycle
    • Monotonic start-up with prebiased output
    • Short-circuit protection with hiccup mode
    • Precision enable
    • ±1.5% tolerance voltage reference
  • Small design size and ease of use
    • Integrated synchronous rectification
    • Internal compensation for ease of use
    • SOT-23 package
  • Various options in pin-to-pin compatible package
    • PFM and forced PWM (FPWM) options
  • Pin-to-pin compatible with the LMR51610, LMR51406, LMR16006, LV2862, LMR50410, TPS560430, and LMR54410
  • Create a custom design using the LMR51403 with the WEBENCH ™ Power Designer
  • Functional Safety-Capable
  • Configured for rugged industrial applications
    • 4V to 42V input voltage range
    • Input transient protection up to 50V
    • 300mA continuous output current
    • 80ns minimum switching on time
    • Fixed 400kHz and 1.1MHz switching frequency
    • –40°C to 150°C junction temperature range
    • 96% maximum duty cycle
    • Monotonic start-up with prebiased output
    • Short-circuit protection with hiccup mode
    • Precision enable
    • ±1.5% tolerance voltage reference
  • Small design size and ease of use
    • Integrated synchronous rectification
    • Internal compensation for ease of use
    • SOT-23 package
  • Various options in pin-to-pin compatible package
    • PFM and forced PWM (FPWM) options
  • Pin-to-pin compatible with the LMR51610, LMR51406, LMR16006, LV2862, LMR50410, TPS560430, and LMR54410
  • Create a custom design using the LMR51403 with the WEBENCH ™ Power Designer

The LMR51403 is a wide-VIN, easy-to-use synchronous buck converter capable of driving up to 300mA load current. With a wide input range of 4V to 42V, the device is designed for a wide range of industrial applications for power conditioning from an unregulated source.

The LMR51403 operates at 400kHz and 1.1MHz switching frequency to support use of relatively small inductors for an optimized design size. The LMR51403 has a pulse frequency modulation (PFM version) to realize high efficiency at light load and forced pulse width modulation (FPWM version) to achieve constant frequency and small output voltage ripple over the full load range. Soft-start and compensation circuits are implemented internally, which allow the device to be used with minimal external components.

The device has built-in protection features, such as cycle-by-cycle current limit, hiccup mode short-circuit protection, and thermal shutdown in case of excessive power dissipation.

The LMR51403 is a wide-VIN, easy-to-use synchronous buck converter capable of driving up to 300mA load current. With a wide input range of 4V to 42V, the device is designed for a wide range of industrial applications for power conditioning from an unregulated source.

The LMR51403 operates at 400kHz and 1.1MHz switching frequency to support use of relatively small inductors for an optimized design size. The LMR51403 has a pulse frequency modulation (PFM version) to realize high efficiency at light load and forced pulse width modulation (FPWM version) to achieve constant frequency and small output voltage ripple over the full load range. Soft-start and compensation circuits are implemented internally, which allow the device to be used with minimal external components.

The device has built-in protection features, such as cycle-by-cycle current limit, hiccup mode short-circuit protection, and thermal shutdown in case of excessive power dissipation.

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Technical documentation

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* Data sheet LMR51403 4V to 42V, 300mA, Synchronous Buck Converter in a SOT-23 Package datasheet PDF | HTML 19 Nov 2024
Functional safety information LMR51403 Functional Safety FIT Rate, FMD and Pin FMA PDF | HTML 09 Oct 2024

Design & development

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Evaluation board

LMR51603EVM — LMR51603 evaluation module

The LMR51603EVM is a fully assembled and tested circuit designed to help users easily evaluate and test the operation and functionality of the LMR51603 converter. This evaluation module operates typical 12V input and provides a 5V output at 300mA. Integrated low RDS(ON) power MOSFETs enable high (...)
User guide: PDF | HTML
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Package Pins CAD symbols, footprints & 3D models
SOT-23 (DBV) 6 Ultra Librarian

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