1 Features

• Qualified for Automotive Applications
• AEC-Q100 Qualified with the Following Results:
  • Device Temperature Grade 1: –40°C to +125°C Ambient Operating Temperature
  • Device HBM ESD Classification Level 2
  • Device CDM ESD Classification Level C4B
• One High-VIN Step-Down DC-DC Converter
  • Input Range of 3.6 V to 36 V
  • 250-mΩ High-Side MOSFET
  • Maximum Load Current 3.2 A, Output Adjustable 1.1 V to 20 V
  • Adjustable Switching Frequency 100 kHz to 2.5 MHz
  • Synchronizes to External Clock
  • High Efficiency at Light Loads With Pulse-Skipping Eco-mode™ Control Scheme
  • Maximum 140-µA Operating Quiescent Current
  • Reset Output-Pin (Active Low, Open-Drain)
• One High-VIN Low-Dropout (LDO) Voltage Regulator
  • Input Range of 3 V to 36 V
  • 280-mA Current Capability With Typical 35-µA Quiescent Current in No-Load Condition
  • Low-Dropout Voltage of 300 mV at
    I_O = 200 mA (Typical)
• Overcurrent Protection for Both Regulators
• Overtemperature Protection
• 14-Pin HTSSOP Package With PowerPAD™ Integrated Circuit Package

2 Applications

• Automotive Infotainment and Cluster
• Advanced Driver Assistance System (ADAS)
• Automotive Telematics, eCall

3 Description

The TPS65321A-Q1 device is a combination of a high-VIN DC-DC step-down converter, referred to as the buck regulator, with an adjustable switch-mode frequency from 100-kHz to 2.5-MHz, and a high-VIN 280-mA low-dropout (LDO) regulator. The input range is 3.6 V to 36 V for the buck regulator, and 3 V to
36 V for the LDO regulator. The buck regulator has an integrated high-side MOSFET with an active-low, open-drain power-good output-pin (nRST). The LDO regulator features a low-input supply current of 45-μA typical in no-load, also has an integrated MOSFET. Low-voltage tracking feature enables TPS65321A-Q1 to track the input supply during cold-crank conditions.

The buck regulator provides a flexible design to fit system needs. The external loop compensation circuit allows for optimization of the converter response for the appropriate operating conditions. A low-ripple pulse-skip mode reduces the no-load input-supply current to maximum 140 μA.

The device has built-in protection features such as soft start, current-limit, thermal sensing and shutdown due to excessive power dissipation. Furthermore, the device has an internal undervoltage-lockout (UVLO) function that turns off the device when the supply voltage is too low.

1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application Schematic

Buck Efficiency Versus Output Current