4.5V to 14V Input, 15A Synchronous Step-Down SWIFT™ Converter - TPS56121


4.5V to 14V Input, 15A Synchronous Step-Down SWIFT™ Converter


The TPS56121 device is a high-efficiency and high-current synchronous buck converter designed to operate from a supply of 4.5 V to 14 V. The device can produce an output voltage as low as 0.6 V at loads up to 15 A. Integrated NexFET™ Power MOSFETs provide a small footprint and ease of use.

The device implements a voltage-mode control with voltage feed-forward compensation that responds instantly to input voltage change.

The TPS56121 is available in a thermally enhanced 22-pin PQFN (DQP) PowerPAD package.

The device offers design flexibility with a variety of user programmable functions, including soft-start, overcurrent protection (OCP) levels, and loop compensation. OCP levels are programmed by a single external resistor connected from the ILIM pin to the circuit ground. During the initial power-on sequence, the device enters a calibration cycle, measures the voltage at the ILIM 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 and then enters a shutdown/restart cycle until the fault is removed.


  • 4.5-V to 14-V Input Voltage Range
  • Incorporates Power Block Technology
  • Up to 15-A Output Current
  • Fixed-Frequency Options of 300 kHz, 500 kHz,
    and 1 MHz
  • High-Side and Low-Side MOSFET RDS(on) Sensing
  • Programmable Soft-Start
  • 600-mV Reference Voltage With 1% Accuracy
  • Voltage Mode Control with Feed-Forward
  • Supports Prebiased Output
  • Thermal Shutdown
  • 22-Pin 5-mm × 6-mm PQFN PowerPAD™ Package

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Parametrics Compare all products in Step-Down (Buck) Converter

Regulated Outputs (#)
Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Switching Frequency (Max) (kHz)
Switch Current Limit (Typ) (A)
Iq (Typ) (mA)
Duty Cycle (Max) (%)
Soft Start
Special Features
Control Mode
Vref Accuracy (Typ) (%)
Operating Temperature Range (C)
Approx. Price (US$)
TPS56121 TPS56221
1     1    
4.5     4.5    
14     14    
0.6     0.6    
12     12    
15     25    
Buck     Buck    
1000     1000    
21     35    
2.5     2.5    
93     93    
Adjustable     Adjustable    
External     External    
Power Good
Adjustable Current Limit
Synchronous Rectification    
Light Load Efficiency
Synchronous Rectification    
Voltage Mode     Voltage Mode    
1     1    
Catalog     Catalog    
-40 to 125     -40 to 125    
3.50 | 1ku     3.75 | 1ku    
New! Interactive Design
Click to instantly view a schematic, charts, Bill of Materials, and Operating Values.
    Min   Max   Range  
  Vin V 4.5 to 14.0V  
  Vout V 0.6 to 12.0V  
  Iout A ≤ 15A  
  Ambient Temp °C -40 to 125°C  
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