LT1573IS8#TRPBF

Overview

The LT1573IS8#TRPBF is a Low Dropout PNP Regulator Driver manufactured by Analog Devices Inc. It operates with a single supply voltage ranging from 2.8V to 10V and supports output currents up to 5A when paired with an external PNP transistor. The device features a precision internal reference of 1.265V, enabling adjustable or fixed output voltages with 1% accuracy. It includes latching overload protection to minimize heat sink requirements and offers fast transient response capabilities. The component is housed in an 8-lead plastic SO (S8) package and functions within a temperature range of -40°C to 125°C.

Feature Summary

• Provides latching overcurrent protection that minimizes thermal stress and reduces the need for large heat sinks during fault conditions.
• Enables fast transient response with minimal bulk capacitance requirements due to high-speed drive characteristics.
• Delivers precise output voltage regulation with a 1% tolerance on the internal reference voltage.
• Supports single-supply operation within a low input voltage range of 2.8V to 10V.

Applications

• Microprocessor power supplies requiring high current and low dropout performance
• High-current low dropout regulator circuits using external PNP pass transistors
• Systems needing fast load transient response with reduced output capacitance

Procurement Notes

Verify the specific suffix TRPBF indicates tape and reel packaging upon procurement. Confirm the IS8 variant corresponds to the industrial temperature grade (-40°C to 125°C). Ensure compatibility with external PNP transistors such as the D45H11 for specified current ratings. Check for RoHS compliance status through official manufacturer documentation before integration.

Selection Notes

Select this driver for applications requiring high current delivery with minimal dropout voltage. Consider the external PNP transistor's gain-bandwidth product and saturation voltage to determine overall circuit performance. Evaluate thermal resistance and PCB copper area for adequate heat dissipation. Ensure the input voltage range matches the system requirements between 2.8V and 10V.

Part Context

The LT1573 series serves as a dedicated driver for external PNP power transistors, forming a complete linear regulator solution. It replaces traditional discrete regulator designs by integrating error amplification, reference generation, and protection logic. This approach allows designers to achieve high efficiency and fast response times while maintaining cost-effectiveness in power management systems.

Replacement Considerations

Consult factory for military grade parts. No direct public substitute part numbers are confirmed in the provided documentation.

FAQ

How is the output voltage set for the adjustable version?

The output voltage is set by an external resistor divider connected to the feedback pin, which maintains the pin voltage at the internal 1.265V reference.

What triggers the overcurrent latch-off function?

The latch-off is triggered when the DRIVE pin drops below its saturation voltage due to excessive base current demand, indicating an overload condition.

How can the latch be reset after an overcurrent event?

The latch can be reset by pulling the SHDN pin high, grounding the LATCH pin, or cycling the input power off and back on.