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TPS51125A

ACTIVE

4.5-V to 28-V, dual-synchronous buck controller with 100-mA LDOs and flexible external components

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TPS51397A ACTIVE 4.5-V to 24-V input, 10-A, synchronous step-down regulator Offers a lower IQ and is soft start adjustable with an extended positive operating temperature range in a smaller package.

Product details

Vin (min) (V) 5.5 Vin (max) (V) 28 Vout (min) (V) 2 Vout (max) (V) 5.5 Iout (max) (A) 20 Iq (typ) (mA) 0.55 Switching frequency (min) (kHz) 300 Switching frequency (max) (kHz) 460 Features Enable, Light Load Efficiency, Power good, Synchronous Rectification Operating temperature range (°C) -40 to 85 Regulated outputs (#) 2 Number of phases 1 Rating Catalog Control mode D-CAP Type Controller
Vin (min) (V) 5.5 Vin (max) (V) 28 Vout (min) (V) 2 Vout (max) (V) 5.5 Iout (max) (A) 20 Iq (typ) (mA) 0.55 Switching frequency (min) (kHz) 300 Switching frequency (max) (kHz) 460 Features Enable, Light Load Efficiency, Power good, Synchronous Rectification Operating temperature range (°C) -40 to 85 Regulated outputs (#) 2 Number of phases 1 Rating Catalog Control mode D-CAP Type Controller
VQFN (RGE) 24 16 mm² 4 x 4
  • Wide Input Voltage Range: 5.5 V to 28 V
  • Output Voltage Range: 2 V to 5.5 V
  • Built-in 100-mA 5-V/3.3-V LDO with Switches
  • Built-in 1% 2-V Reference Output
  • With/Without Out-of-Audio™ Mode Selectable Light Load and PWM only Operation
  • Internal 1.6-ms Voltage Servo Softstart
  • Adaptive On-Time Control Architecture with Four Selectable Frequency Setting
  • 4500 ppm/°C RDS(on) Current Sensing
  • Built-In Output Discharge
  • Power Good Output
  • Built-in OVP/UVP/OCP
  • Thermal Shutdown (Non-latch)
  • QFN24 (RGE)
  • Wide Input Voltage Range: 5.5 V to 28 V
  • Output Voltage Range: 2 V to 5.5 V
  • Built-in 100-mA 5-V/3.3-V LDO with Switches
  • Built-in 1% 2-V Reference Output
  • With/Without Out-of-Audio™ Mode Selectable Light Load and PWM only Operation
  • Internal 1.6-ms Voltage Servo Softstart
  • Adaptive On-Time Control Architecture with Four Selectable Frequency Setting
  • 4500 ppm/°C RDS(on) Current Sensing
  • Built-In Output Discharge
  • Power Good Output
  • Built-in OVP/UVP/OCP
  • Thermal Shutdown (Non-latch)
  • QFN24 (RGE)

The TPS51125A is a cost effective, dual-synchronous buck controller targeted for notebook system power supply solutions. It provides 5-V and 3.3-V LDOs and requires few external components. The 270-kHz VCLK output can be used to drive an external charge pump, generating gate drive voltage for the load switches without reducing the main converter’s efficiency. The TPS51125A supports high efficiency, fast transient response and provides a combined power-good signal. Out-of-Audio mode light-load operation enables low acoustic noise at much higher efficiency than conventional forced PWM operation. Adaptive on-time D-CAP control provides convenient and efficient operation. The part operates with supply input voltages ranging from 5.5 V to 28 V and supports output voltages from 2 V to 5.5 V. The TPS51125A is available in a 24-pin QFN package and is specified from -40°C to 85°C ambient temperature range.

The TPS51125A is a cost effective, dual-synchronous buck controller targeted for notebook system power supply solutions. It provides 5-V and 3.3-V LDOs and requires few external components. The 270-kHz VCLK output can be used to drive an external charge pump, generating gate drive voltage for the load switches without reducing the main converter’s efficiency. The TPS51125A supports high efficiency, fast transient response and provides a combined power-good signal. Out-of-Audio mode light-load operation enables low acoustic noise at much higher efficiency than conventional forced PWM operation. Adaptive on-time D-CAP control provides convenient and efficient operation. The part operates with supply input voltages ranging from 5.5 V to 28 V and supports output voltages from 2 V to 5.5 V. The TPS51125A is available in a 24-pin QFN package and is specified from -40°C to 85°C ambient temperature range.

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Type Title Date
* Data sheet Dual-Synchronous, Step-Down Controller With OOA Operation and 100-mA LDOs datasheet (Rev. F) 10 Sep 2012
User guide TPS51125A Buck Controller Evaluation Module User's Guide (Rev. A) PDF | HTML 31 Jan 2022

Design & development

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Simulation model

TPS51125 Unencrypted PSpice Average Model Package (Rev. B)

SLIM147B.ZIP (73 KB) - PSpice Model
Simulation model

TPS51125 Unencrypted PSpice Transient Model Package (Rev. B)

SLIM134B.ZIP (52 KB) - PSpice Model
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VQFN (RGE) 24 View options

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