LT1575CS8-3.5#PBF

Voltage Regulators - Linear Regulator Controllers Overview

The LT1575CS8-3.5#PBF is a fixed-output low dropout regulator controller from Analog Devices, housed in an 8-lead plastic SOIC package. It provides a precise 3.5V output with ±0.6% tolerance at room temperature and ±1% over the operating range. The device drives external N-channel MOSFETs to achieve ultrafast transient response, eliminating the need for bulky tantalum or electrolytic capacitors. Key electrical parameters include a typical quiescent current of 12mA, a maximum input voltage of 22V, and a high-side current limit threshold of 50mV.

Voltage Regulators - Linear Regulator Controllers Feature Summary

• Ultrafast transient response capability that eliminates the requirement for expensive bulk output capacitors
• High-side sense current limit amplifier with programmable time-out latchoff protection
• Multifunction shutdown pin supporting overvoltage protection, thermal shutdown, and latchoff reset
• Precision-trimmed fixed output voltage versions ensuring tight regulation tolerances

Voltage Regulators - Linear Regulator Controllers Applications

• Microprocessor core supplies for Pentium and PowerPC processors
• GTL termination circuits
• Low voltage logic supplies
• Voltage conversion stages such as 5V to 3.3V or 3.3V to 2.5V

Voltage Regulators - Linear Regulator Controllers Procurement Notes

Verify the specific suffix CS8 corresponds to the 8-lead plastic SOIC package variant when sourcing. Confirm the -3.5 designation matches the required 3.5V fixed output level. Ensure the component meets RoHS compliance requirements for your assembly process. Check for any recent production change notices regarding marking or material declarations.

Voltage Regulators - Linear Regulator Controllers Selection Notes

Select this part when system design demands extremely fast load transient response without the cost and board space of bulk capacitors. It is suitable for applications requiring a fixed 3.5V rail driven by an external N-channel MOSFET. Consider the high-side current sensing requirements and ensure the external MOSFET gate drive characteristics align with the GATE pin output swing capabilities.

Voltage Regulators - Linear Regulator Controllers Part Context

This component belongs to the LT1575/LT1577 family of ultrafast transient response low dropout regulators. While the LT1575 offers single-channel control in an 8-pin package, the LT1577 provides dual-channel functionality in a 16-pin narrow SOIC. Both families share the same core architecture for driving external pass transistors to meet modern microprocessor power delivery standards.

Voltage Regulators - Linear Regulator Controllers Replacement Considerations

LT1575CN8-3.5#PBF (PDIP version)

Voltage Regulators - Linear Regulator Controllers FAQ

How does the LT1575CS8-3.5#PBF eliminate bulk output capacitors?

It achieves superior regulator bandwidth and transient load performance by responding to load changes in nanoseconds, allowing the use of only high-frequency ceramic decoupling capacitors.

What is the function of the SHDN pin?

The SHDN pin is a multifunction shutdown input that provides latchoff capability during current limit time-outs, overvoltage protection, or thermal shutdown events.