• Efficiency up to 95% for each switching regulator
• Switching regulator specifications:
  • Input voltage range: 4.5 to 18 V
  • V_OUT range: 0.6 V-90%V_IN
  • SW1, SW2 I_OUT: 4-A max
  • SW3, SW4 I_OUT: 2-A max
• Prebias start-up algorithm minimizes voltage dip during start-up
• Internal undervoltage lockout (UVLO), overcurrent protection (OCP), overvoltage protection (OVP), and overtemperature protection (OTP)
• AECQ-100 grade 1 option
• Thermally enhanced 7-mm × 7-mm 48-pin, 0.5-mm pitch VQFN package
• Pin accessible features:
  • Adjustable V_OUT with external feedback resistors
  • Sequencing control through precision enable pins for each switcher
  • Resistor adjustable PWM switching frequency from 275 kHz to 2.2 MHz
  • Clock sync input and clock output
  • Soft-start delay through external capacitor
  • Current sharing between SW1 and SW2 and between SW3 and SW4 allows support of higher current needs if required
• PMBus runtime control and status
  • Runtime voltage positioning through adjustment of V_REF
  • Enable and disable of each switcher
  • Fault and status monitoring
• User-configurable PMBus/I²C options, saved in EEPROM
  • Power supply turn-on and turn-off sequencing
  • Sequencing can be based on fixed time delays or PGOOD dependence
  • Initial voltage positioning through VREF configuration
  • PWM frequency adjustment for each switcher
  • Individual PWM phase alignment for each switcher to minimize ripple and capacitor size
  • Adjustable current limit on each regulator enables size and cost optimization of inductors
  • Soft-start time

• Small cellular base stations (BTS) (for example: picocells and microcells); macro BTS (using multiple PMUs)
• Power over ethernet (PoE) powered communications infrastructure equipment
• Automotive infotainment and telematics
• Powering DSP and MCUs
• Industrial and factory automation
• Systems requiring small form factor, high-efficiency, high-ambient operating temperature, and flexible power management

The TPS65400 is an integrated PMU optimized for applications requiring small form factor and high power conversion efficiency, enabling small space-constrained equipment with high ambient operating temperature without cooling. The device provides high-power efficiency at a system level by enabling a single stage conversion from an intermediate distribution bus with an optimized combination of regulators.

Simplified Schematic

The TPS65400 implements a PMBus-I²C-compatible digital interface. It helps Core Chip optimize system performance by run-time changing regulated voltage, power sequence, phase interleaving, operating frequency, read back operating status, and so forth.

The TPS65400 consists of four high-current buck switching regulators (SW1, SW2, SW3, and SW4) with integrated FETs. The switching power supplies are intended for powering high-current digital circuits such as the processor, FPGA, ASIC, memory, and digital I/Os. SW1 and SW2 support 4 A each, and SW3 and SW4 support 2 A each. The switching frequency of each regulator is independently adjustable up to 2.2 MHz.

Current limit programmability on each switcher enables optimization of inductor ratings for a particular application configuration not requiring the maximum current capability.

The TPS65400 can be powered from a single-input voltage rail between 4.5 and 18 V, making it suitable for applications running off a 5- or 12-V intermediate power distribution bus.

Sequencing requirements can be met using the individual enable terminals or by programming the sequence through the I²C bus into the on-board EEPROM. Output voltages can be set through external resistor networks and VREF can be programmed from 0.6 V to 1.87 V in 10-mV steps. All control and status info can be accessed through a PMBus-compatible I²C bus.

The TPS65400 provides a high level of flexibility for monitoring and control through the I²C bus while providing the option of programmability through the use of external components and voltage levels for systems not using I²C.