SBVS397A September   2023  – November 2023 TPS7B4256-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Tracker Output Voltage (VOUT)
        1. 6.3.1.1 Output Voltage Equal to Reference Voltage
        2. 6.3.1.2 Output Voltage Less Than the Reference Voltage
        3. 6.3.1.3 Output Voltage Larger Than the Reference Voltage
      2. 6.3.2 Reverse Current Protection
      3. 6.3.3 Undervoltage Lockout
      4. 6.3.4 Thermal Protection
      5. 6.3.5 Current Limit
      6. 6.3.6 Output Short to Battery
      7. 6.3.7 Tracking Regulator With an Enable Circuit
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 Operation With VIN < 3 V
      4. 6.4.4 Disable With ADJ/EN Control
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Dropout Voltage
      2. 7.1.2 Reverse Current
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Input and Output Capacitor Selection
        2. 7.2.2.2 Feedback Resistor Selection
        3. 7.2.2.3 Feedforward Capacitor
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Package Mounting
        2. 7.4.1.2 Board Layout Recommendations to Improve PSRR and Noise Performance
        3. 7.4.1.3 Power Dissipation and Thermal Considerations
        4. 7.4.1.4 Thermal Performance Versus Copper Area
        5. 7.4.1.5 Layout Examples
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Device Nomenclature
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

3 Description

The TPS7B4256-Q1 is a monolithic, integrated, low-dropout (LDO) voltage tracker. The device is available in 8-pin SOIC and HSOIC packages. The TPS7B4256-Q1 is designed to provide power supply to off-board sensors in an automotive environment. Because the risk of failure in cables that deliver off-board power is high, the device comes with integrated protection features against fault conditions such as short to battery, reverse polarity, output short to ground (current limit), and overtemperature (thermal shutdown). The device incorporates a back-to-back PMOS topology that eliminates the need for an external diode that is otherwise required to help protect against fault conditions that result in flow of reverse current. The device is designed to handle a 45-V (absolute maximum) input voltage and survive the automotive load dump transient conditions.

A reference voltage applied at the adjustable input pin (ADJ/EN) is tracked with a very tight 6 mV (max) tolerance at the FB pin across temperature. This tracking enables the TPS7B4256-Q1 to deliver a power-supply voltage with high precision for loads up to 70 mA. The reference voltage can be directly connected to the ADJ/EN pin or scaled down to lower values with the help of an external resistor divider at the ADJ/EN pin to a minimum of 2 V. The output voltage can be made equal to the voltage at the ADJ/EN pin (± the tracking tolerance) by tying the FB pin directly to the OUT pin or scaled to higher values with the help of a resistive voltage divider between the FB and the OUT pin.

Package Information
PART NUMBER PACKAGE(1) PACKAGE SIZE(2)
TPS7B4256-Q1 DDA (HSOIC, 8) 4.9 mm × 6 mm
D (SOIC, 8)
(1) For more information, see the Mechanical, Packaging, and Orderable Information.
(2) The package size (length × width) is a nominal value and includes pins, where applicable.

The TPS7B4256-Q1 provides an effective buffer to the reference voltage of an ADC and securely transmits this voltage (or a scaled version thereof) over a long cable to power off-board sensors. If the sensor is ratiometric and the output is sampled by the ADC, the described features of the TPS7B4256-Q1 help significantly improve the reliability and accuracy of the sensor measurements.

By setting the ADJ/EN input pin low, the TPS7B4256-Q1 switches to standby mode and reduces the quiescent current consumption of the LDO to less than 3.5 μA.