LM34917A

ACTIVE

2.3x2mm, 8-33V, 1.25A, Constant On-Time Non-Synchronous Buck Regulator w/ Intelligent Current Limit

Product details

Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 1.25 Vin (min) (V) 8 Vin (max) (V) 33 Switching frequency (min) (kHz) 50 Switching frequency (max) (kHz) 2000 Features Enable, Over Current Protection Control mode Constant on-time (COT) Vout (min) (V) 2.5 Vout (max) (V) 30 Iq (typ) (µA) 680 Duty cycle (max) (%) 97
Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 1.25 Vin (min) (V) 8 Vin (max) (V) 33 Switching frequency (min) (kHz) 50 Switching frequency (max) (kHz) 2000 Features Enable, Over Current Protection Control mode Constant on-time (COT) Vout (min) (V) 2.5 Vout (max) (V) 30 Iq (typ) (µA) 680 Duty cycle (max) (%) 97
DSBGA (YZR) 12 3.9375 mm² 2.25 x 1.75
  • Functional Input Voltage Range: 8V to 33V
  • DSBGA package
  • Input Over-Voltage Shutdown at ≊35V
  • Transient Capability to 50V
  • Integrated N-Channel buck switch
  • Valley current limit varies with VIN and VOUT to reduce excessive inductor current
  • On-time is reduced when in current limit
  • Integrated start-up regulator
  • No loop compensation required
  • Ultra-Fast transient response
  • Maximum switching frequency: 2 MHz
  • Operating frequency remains nearly constant with load current and input voltage variations
  • Programmable soft-start
  • Precision internal reference
  • Adjustable output voltage
  • Thermal shutdown

Package

  • 12-Bump DSBGA Package

All trademarks are the property of their respective owners.

  • Functional Input Voltage Range: 8V to 33V
  • DSBGA package
  • Input Over-Voltage Shutdown at ≊35V
  • Transient Capability to 50V
  • Integrated N-Channel buck switch
  • Valley current limit varies with VIN and VOUT to reduce excessive inductor current
  • On-time is reduced when in current limit
  • Integrated start-up regulator
  • No loop compensation required
  • Ultra-Fast transient response
  • Maximum switching frequency: 2 MHz
  • Operating frequency remains nearly constant with load current and input voltage variations
  • Programmable soft-start
  • Precision internal reference
  • Adjustable output voltage
  • Thermal shutdown

Package

  • 12-Bump DSBGA Package

All trademarks are the property of their respective owners.

The LM34917A Step-Down Switching Regulator features all the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying at least 1.25A to the load. To reduce excessive switch current due to the possibility of a saturating inductor the valley current limit threshold changes with input and output voltages, and the on-time is reduced when current limit is detected. This buck regulator contains an N-Channel Buck Switch, and is available in the 12 pin DSBGA package. The constant on-time feedback regulation scheme requires no loop compensation, results in fast load transient response, and simplifies circuit implementation. The operating frequency remains constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The valley current limit results in a smooth transition from constant voltage to constant current mode when current limit is detected, reducing the frequency and output voltage, without the use of foldback. Additional features include: VCC under-voltage lock-out, input over-voltage shutdown, thermal shutdown, gate drive under-voltage lock-out, and maximum duty cycle limit.

The LM34917A Step-Down Switching Regulator features all the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying at least 1.25A to the load. To reduce excessive switch current due to the possibility of a saturating inductor the valley current limit threshold changes with input and output voltages, and the on-time is reduced when current limit is detected. This buck regulator contains an N-Channel Buck Switch, and is available in the 12 pin DSBGA package. The constant on-time feedback regulation scheme requires no loop compensation, results in fast load transient response, and simplifies circuit implementation. The operating frequency remains constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The valley current limit results in a smooth transition from constant voltage to constant current mode when current limit is detected, reducing the frequency and output voltage, without the use of foldback. Additional features include: VCC under-voltage lock-out, input over-voltage shutdown, thermal shutdown, gate drive under-voltage lock-out, and maximum duty cycle limit.

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Technical documentation

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Type Title Date
* Data sheet Ultra Small 33V,1.25A Constant On-Time Buck Sw Reg w/Intelligent Current Limit datasheet (Rev. D) 07 Mar 2013
Selection guide Power Management Guide 2018 (Rev. R) 25 Jun 2018
EVM User's guide AN-1601 LM34917A Evaluation Board (Rev. D) 25 Apr 2013

Design & development

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Simulation model

LM34917A PSpice Transient Model

SNOM554.ZIP (85 KB) - PSpice Model
Simulation model

LM34917A Unencrypted PSpice Transient Model

SNOM553.ZIP (4 KB) - PSpice Model
Calculation tool

LM34917AQUICK-CALC — LM34917A Quick Start Calculator

Package Pins CAD symbols, footprints & 3D models
DSBGA (YZR) 12 Ultra Librarian

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