TPS65251-1 4.5-V to 18-V input, 3A/2A/2A output, Synchronous triple buck converter | TI.com

TPS65251-1 (ACTIVE) 4.5-V to 18-V input, 3A/2A/2A output, Synchronous triple buck converter

 

Description

The TPS65251-x features three synchronous wide-input range, high-efficiency buck converters. The converters are designed to simplify its application while giving the designer the option to optimize their usage according to the target application.

The converters can operate in 5-, 9-, 12- or 15-V systems and have integrated power transistors. The output voltage can be set externally using a resistor divider to any value between 0.8 V and close to the input supply. Each converter features an enable pin that allows a delayed start-up for sequencing purposes, soft-start pin that allows adjustable soft-start time by choosing the soft-start capacitor, and a current limit (RLIMx) pin that enables the designer to adjust current limit by selecting an external resistor and optimize the choice of inductor. The current mode control allows a simple RC compensation.

The switching frequency of the converters can either be set with an external resistor connected to ROSC pin or can be synchronized to an external clock connected to the SYNC pin if needed. The switching regulators are designed to operate from 300 kHz to 2.2 MHz. 180° out-of-phase operation between Buck 1 and Buck 2, 3 (Buck 2 and 3 run in phase) minimizes the input filter requirements.

TPS65251-x features a supervisor circuit that monitors each converter output. The PGOOD pin is asserted when sequencing is done, all PG signals are reported and a selectable end of reset time lapses. The polarity of the PGOOD signal is active high.

All converters feature an automatic low-power pulse PFM skipping mode, which improves efficiency during light loads and standby operation, while ensuring a very-low output ripple, allowing for a value of less than 2% at low output voltages.

Features

  • Wide Input Supply Voltage Range (4.5 to 18 V)
  • Output Range 0.8 V to VIN – 1 V
  • Continuous Loading: 3 A (Buck 1),
    2 A (Buck 2 and 3)
  • Maximum Current: 3.5 A (Buck 1),
    2.5 A (Buck 2 and 3)
  • Adjustable Switching Frequency
    300 kHz to 2.2 MHz Set by External Resistor
  • Dedicated Enable for Each Buck
  • External Synchronization Pin for Oscillator
  • Adjustable Current Limit Set by External Resistor
  • Soft-Start Pins
  • Current-Mode Control With Simple Compensation
    Circuit
  • Power Good
  • Automatic PFM/PWM Operation
  • VQFN Package, 40-Pin 6-mm × 6-mm RHA

Parametrics

Compare all products in Buck converters (integrated switch) Email Download to Excel
Part number Order 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) Features Control mode Duty cycle (Max) (%) Operating temperature range (C) Rating Package Group Type Package size: mm2:W x L (PKG)
TPS65251-1 Order now 4.5     17     0.8     17     3     3     300     2200     1     Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Phase Interleaving
Power Good
Synchronous Rectification
UVLO Adjustable    
Current Mode     90     -40 to 125     Catalog     VQFN | 40     Converter     40VQFN: 36 mm2: 6 x 6 (VQFN | 40)    
TPS65251 Order now 4.5     18     0.8     17     3     3     300     2200     20     Adjustable Current Limit
Enable
Frequency Synchronization
Phase Interleaving
Power Good
Synchronous Rectification
UVLO Adjustable    
Current Mode     100     -40 to 125     Catalog     VQFN | 40     Converter     40VQFN: 36 mm2: 6 x 6 (VQFN | 40)    
TPS65251-2 Order now 4.5     17     0.8     17     3     3     300     2200     1     Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Phase Interleaving
Power Good
Synchronous Rectification
UVLO Adjustable    
Current Mode     90     -40 to 125     Catalog     VQFN | 40     Converter     40VQFN: 36 mm2: 6 x 6 (VQFN | 40)    
TPS65251-3 Order now 4.5     17     0.8     17     3     3     300     2200     1     Adjustable Current Limit
Enable
Frequency Synchronization
Light Load Efficiency
Phase Interleaving
Power Good
Synchronous Rectification
UVLO Adjustable    
Current Mode     90     -40 to 125     Catalog     VQFN | 40     Converter     40VQFN: 36 mm2: 6 x 6 (VQFN | 40)    
TPS65261 Order now 4.5     18     0.6       3     3     250     2000     0.6     Enable
Light Load Efficiency
Power Good
Synchronous Rectification
UVLO Adjustable    
Current Mode     95     -40 to 85