LT1959IS8

Overview

The LT1959IS8 is a high-efficiency, constant-frequency DC/DC buck regulator housed in an 8-lead SOIC package. It operates with an input voltage range of 4.5V to 15V and delivers up to 4A of load current. The device features a typical switching frequency of 500kHz, allowing for the use of small external inductors. Output voltage regulation includes a typical linear adjustment rate of 4mV and a load adjustment rate of 10mV under specified conditions. The shutdown supply current is typically 20µA when the SHDN pin is at 0V.

Feature Summary

• Constant-frequency operation enables stable performance with compact passive components
• Integrated shutdown control minimizes power consumption during inactive states
• High switching frequency supports space-constrained surface-mount designs

Applications

• On-board voltage regulation in large systems
• Power supply for disk drives
• Portable handheld devices
• Personal computer subsystems

Procurement Notes

Verify the specific suffix IS8 confirms the 8-lead SOIC package configuration. Confirm that the part number corresponds to the standard Linear Technology (Analog Devices) manufacturing source. Ensure compatibility with the required thermal dissipation capabilities for the intended load current. Check for any specific ordering suffixes that might alter the pinout or electrical characteristics compared to the standard datasheet specifications.

Selection Notes

Select this component when a compact, high-efficiency step-down solution is required for inputs between 4.5V and 15V. It is suitable for applications needing up to 4A output current with minimal external component count. Consider the 500kHz switching frequency for balancing efficiency and filter size. Ensure the thermal environment supports the SOIC package's heat dissipation limits for continuous high-current operation.

Part Context

The LT1959 belongs to a family of efficient DC/DC converters designed for portable and board-level applications. The IS8 variant specifically denotes the 8-lead SOIC package option, distinguishing it from other package types like the DD package used in related demonstration circuits. This form factor is optimized for surface-mount assembly in space-sensitive electronics.

Replacement Considerations

Direct substitutes include other Analog Devices buck regulators with similar input ranges and current capabilities. Verify pin-to-pin compatibility if replacing in existing layouts. Cross-reference thermal performance and switching frequency requirements to ensure equivalent system behavior.