4.5V to 28V Input, 3A Output, Synchronous 350kHz FCCM Step-Down Converter

4.5V to 28V Input, 3A Output, Synchronous 350kHz FCCM Step-Down Converter - TPS54308


The TPS54308 is a 4.5-V to 28-V input voltage range, 3-A synchronous buck converter. The device includes two integrated switching FETs, internal loop compensation and 5-ms internal soft start to reduce component count.

By integrating the MOSFETs and employing the SOT-23 package, the TPS54308 achieves the high power density and offers a small footprint on the PCB.

The TPS54308 operates in force continous conduction mode (FCCM) during light load conditions, the switching frequency is maintained at an almost constant level over entire load range.

Cycle-by-cycle current limit in both high-side MOSFET protects the converter in an overload condition and is enhanced by a low-side MOSFET freewheeling current limit which prevents current runaway. Hiccup mode protection is triggered if the overcurrent condition has persisted for longer than the present time.


  • 4.5-V to 28-V Wide Input Voltage Range
  • Integrated 85-mΩ and 40-mΩ MOSFETs for 3-A, Continuous Output Current
  • Low 2-µA Shutdown, 300-µA Quiescent Current
  • Internal 5-mS Soft-Start
  • Fixed 350-kHz Switching Frequency
  • Peak Current Mode Control
  • Internal Loop Compensation
  • Overcurrent Protection for Both MOSFETs with Hiccup Mode Protection
  • Over Voltage Protection
  • Thermal Shutdown
  • SOT-23 (6) Package
  • Create a Custom Design Using the TPS54308 With the WEBENCH® Power Designer

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Parametrics Compare all products in Buck Converter (Integrated Switch)

Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Regulated Outputs (#)
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Control Mode
Duty Cycle (Max) (%)
Operating Temperature Range (C)
Package Group
TPS54308 TPS54331
4.5    3.5   
28    28   
1    0.8   
26    25   
3    3   
1    1   
350    570   
350    570   
0.3    0.11   
Forced Pulse Width Modulation (FPWM) Mode
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Light Load Efficiency
UVLO Adjustable   
Current Mode    Current Mode   
100    90   
-40 to 125    -40 to 150   
Catalog    Catalog   
SOT-23-THIN    SO PowerPAD
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WEBENCH® Designer TPS54308

  Min   Max Range
Vin  V 4.5 to 28.0V
Vout  V 0.596 to 25V
Iout  A ≤ 3A
Ambient Temp  °C -40 to 85°C

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