SBVS477A May   2025  – July 2025 TPS7B4259-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
      2. 6.3.2 Reverse Current Protection
      3. 6.3.3 Power Good
      4. 6.3.4 Undervoltage Lockout
      5. 6.3.5 Thermal Protection
      6. 6.3.6 Current Limit
      7. 6.3.7 Output Short to Battery
    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 < 3.3V
      4. 6.4.4 Disable With ADJ and EN Controls
  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
      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
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Device Nomenclature
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

3 Description

The TPS7B4259-Q1 is a monolithic, integrated low-dropout voltage tracker. The device is available in an 8-pin HSOIC package. The TPS7B4259-Q1 is designed to reliably provide power to off-board sensors with a wire harness, even in harsh automotive environments. In such severe operating conditions, the cables in the harness are potentially exposed to various fault conditions, increasing the risk of failure. Such conditions include short to ground, short to battery, and overtemperature. The TPS7B4259-Q1 comes with integrated protection features against each of these fault conditions, as well as protection against reverse polarity. The device incorporates a topology containing two back-to-back P-channel metal-oxide semiconductor field-effect transistors (MOSFETs). This PMOS topology eliminates the need for an external diode that is otherwise required to prevent the flow of reverse current. The high 150mA current rating of the device potentially allows a single tracker to power multiple off-board sensors simultaneously. The device is designed to handle a 45V (absolute maximum) input voltage and survive the automotive load dump transient conditions.

The TPS7B4259-Q1 features an independent enable pin (EN) and power-good functionality that detects both under- and overvoltage fault conditions. By setting the EN input pin low, the TPS7B4259-Q1 switches to standby mode. In this mode the quiescent current consumption of the LDO is less than 3.8μA (max).

Package Information
PART NUMBERPACKAGE(1)PACKAGE SIZE(2)
TPS7B4259-Q1DDA (HSOIC, 8)6mm × 4.9mm
(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 TPS7B4259-Q1 provides a protective buffer to the ADC and microcontroller (MCU) against fault conditions, while securely transferring power to the off-board sensors. A reference voltage applied at the adjustable input pin (ADJ) is tracked with a very tight 6mV (max) tolerance at the OUT pin. This tolerance holds true for all variations across the specified line, load, and temperature values. For ratiometric sensors whose output is sampled by the ADC, this tight tracking tolerance is particularly beneficial. This tolerance verifies the error between the ADC full-scale reference and the sensor power supply voltage is minimal. The ratiometricity of the sensor measurement is thereby maintained.

If the ADC full-scale reference voltage equals the sensor supply voltage, connect the reference voltage directly to the ADJ pin. If the sensor supply is lower than the reference, use a resistive divider at the ADJ pin. This divider helps scale down the reference voltage (to a minimum of 2V) to match the sensor supply voltage.