TPS40345 3V to 20V Input, 25A, Synchronous Buck Controller with FSS, 600kHz |


3V to 20V Input, 25A, Synchronous Buck Controller with FSS, 600kHz



The TPS40345 is a synchronous buck controller that operates from 3-V to 20-V input and which can be used in cost-optimized applications. The controller implements a voltage-mode control architecture with input-voltage feed-forward compensation that responds instantly to a change in input voltage. The switching frequency is fixed at 600 kHz.

The frequency spread spectrum (FSS) feature adds to the switching frequency, significantly reducing the peak EMI noise and making it much easier to comply with EMI standards.

The TPS40345 offers design with a variety of user-programmable functions, including soft-start, overcurrent protection (OCP) levels, and loop compensation.

OCP level may be programmed by a single external resistor connected from the LDRV pin to circuit ground. During initial power on, the TPS40345 enters a calibration cycle, measures the voltage at the LDRV pin, and sets an internal OCP voltage level. During operation, the programmed OCP voltage level is compared to the voltage drop across the low-side FET when it is on to determine whether there is an overcurrent condition. The TPS40345 then enters a shutdown and restart cycle until the fault is removed.


  • Input Voltage Range From 3 V to 20 V
  • 600-kHz Switching Frequency
  • High- and Low-Side FET RDS(on) Current Sensing
  • Programmable Thermally Compensated OCP Levels
  • Programmable Soft-Start
  • 600-mV, 1.3% Reference Voltage
  • Voltage Feed-Forward Compensation
  • Supports Prebiased Output
  • Frequency Spread Spectrum
  • Thermal Shutdown Protection at 145°C
  • 10-Pin 3-mm × 3-mm VSON Package With Ground Connection to Thermal Pad

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Parametrics Compare all products in Buck controllers (external switch)

Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Regulated outputs (#)
Number of Phases
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Duty cycle (Max) (%)
Operating temperature range (C)
Package Group
Control mode
TPS40345 TPS53119
3     3    
20     26    
0.6     0.6    
18     5.5    
25     20    
1     1    
1     1    
600     250    
600     970    
2.5     0.4    
Power Good
Pre-Bias Start-Up
Spread Spectrum
Synchronous Rectification    
Light Load Efficiency
Power Good
Pre-Bias Start-Up    
90     90    
-20 to 85     -20 to 85    
Catalog     Catalog    
VSON | 10     VQFN | 16    
Controller     Controller    
Voltage Mode     D-CAP    

Design tool

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WEBENCH® Designer TPS40345

  Min   Max Range
Vin  V 3.0 to 20.0V
Vout  V 0.6 to 18V
Iout  A ≤ 25A
Ambient Temp  °C -40 to 125°C