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LM5115

ACTIVE

75V, Secondary Side Post Regulator/ Synchronous Buck Controller

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LM5141 ACTIVE Low Iq, Wide Input Range Synchronous Buck Controller Optional spread spectrum for improved EMI.

Product details

Vin (min) (V) 4.5 Vin (max) (V) 75 Vout (min) (V) 0.75 Vout (max) (V) 13.5 Switching frequency (min) (kHz) 1000 Switching frequency (max) (kHz) 1000 Features Frequency synchronization Operating temperature range (°C) -40 to 125 Regulated outputs (#) 1 Number of phases 1 Rating Catalog Control mode Voltage mode, current mode Type Controller
Vin (min) (V) 4.5 Vin (max) (V) 75 Vout (min) (V) 0.75 Vout (max) (V) 13.5 Switching frequency (min) (kHz) 1000 Switching frequency (max) (kHz) 1000 Features Frequency synchronization Operating temperature range (°C) -40 to 125 Regulated outputs (#) 1 Number of phases 1 Rating Catalog Control mode Voltage mode, current mode Type Controller
TSSOP (PW) 16 32 mm² 5 x 6.4 WSON (NHQ) 16 25 mm² 5 x 5
  • Self-Synchronization to Main Channel Output
  • Standalone DC/DC Synchronous Buck Mode
  • Leading Edge Pulse Width Modulation
  • Voltage-Mode Control with Current Injection and Input Line Feed-Forward
  • Operates from AC or DC Input up to 75V
  • Wide 4.5V to 30V Bias Supply Range
  • Wide 0.75V to 13.5V Output Range.
  • Top and Bottom Gate Drivers Sink 2.5A Peak
  • Adaptive Gate Driver Dead-Time Control
  • Wide Bandwidth Error Amplifier (4MHz)
  • Programmable Soft-Start
  • Thermal Shutdown Protection
  • TSSOP-16 or Thermally Enhanced WSON-16 Packages

All trademarks are the property of their respective owners.

  • Self-Synchronization to Main Channel Output
  • Standalone DC/DC Synchronous Buck Mode
  • Leading Edge Pulse Width Modulation
  • Voltage-Mode Control with Current Injection and Input Line Feed-Forward
  • Operates from AC or DC Input up to 75V
  • Wide 4.5V to 30V Bias Supply Range
  • Wide 0.75V to 13.5V Output Range.
  • Top and Bottom Gate Drivers Sink 2.5A Peak
  • Adaptive Gate Driver Dead-Time Control
  • Wide Bandwidth Error Amplifier (4MHz)
  • Programmable Soft-Start
  • Thermal Shutdown Protection
  • TSSOP-16 or Thermally Enhanced WSON-16 Packages

All trademarks are the property of their respective owners.

The LM5115 is a versatile switching regulator controller. It has two main application configurations. The first is utilizing the Secondary Side Post Regulation (SSPR) technique to implement multiple output power converters. In the second configuration, it can be used as a standalone synchronous buck controller (Please see for more details). The SSPR technique develops a highly efficient and well regulated auxiliary output from the secondary side switching waveform of an isolated power converter. Regulation of the auxiliary output voltage is achieved by leading edge pulse width modulation (PWM) of the main channel duty cycle. Leading edge modulation is compatible with either current mode or voltage mode control of the main output. The LM5115 drives external high side and low side NMOS power switches configured as a synchronous buck regulator. A current sense amplifier provides overload protection and operates over a wide common mode input range. Additional features include a low dropout (LDO) bias regulator, error amplifier, precision reference, adaptive dead time control of the gate signals and thermal shutdown.

The LM5115 is a versatile switching regulator controller. It has two main application configurations. The first is utilizing the Secondary Side Post Regulation (SSPR) technique to implement multiple output power converters. In the second configuration, it can be used as a standalone synchronous buck controller (Please see for more details). The SSPR technique develops a highly efficient and well regulated auxiliary output from the secondary side switching waveform of an isolated power converter. Regulation of the auxiliary output voltage is achieved by leading edge pulse width modulation (PWM) of the main channel duty cycle. Leading edge modulation is compatible with either current mode or voltage mode control of the main output. The LM5115 drives external high side and low side NMOS power switches configured as a synchronous buck regulator. A current sense amplifier provides overload protection and operates over a wide common mode input range. Additional features include a low dropout (LDO) bias regulator, error amplifier, precision reference, adaptive dead time control of the gate signals and thermal shutdown.

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Technical documentation

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Type Title Date
* Data sheet LM5115 Secondary Side Post Regulator / Synchronous Buck Controller datasheet (Rev. E) 21 Mar 2013
White paper Valuing wide VIN, low EMI synchronous buck circuits for cost-driven, demanding a (Rev. A) 10 Apr 2019
Analog Design Journal Reduce buck-converter EMI and voltage stress by minimizing inductive parasitics 21 Jul 2016
EVM User's guide AN-1368 LM5115/5025A Evaluation Board (Rev. A) 26 Apr 2013
EVM User's guide AN-1367 LM5115 HV DC Evaluation Board (Rev. B) 24 Apr 2013
EVM User's guide AN-1542 LM5115A Evaluation Board (Rev. B) 24 Apr 2013

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TSSOP (PW) 16 View options
WSON (NHQ) 16 View options

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