LIA136

Overview

The LIA136 is a low voltage optically isolated error amplifier integrating a precision shunt reference, error amplifier, and NPN phototransistor. It operates with an input voltage range of 1.6V to 10V over temperatures from -40°C to +110°C. The device features a 1.299V reference voltage with ±1.5% accuracy across the full temperature range. Key electrical characteristics include a current transfer ratio (CTR) of 500% to 2000%, a bandwidth of 10 kHz, and a common mode transient immunity of 20 V/ns. The collector dark current is minimized at high temperatures compared to the LIA135 variant.

Feature Summary

• Integrates a precision programmable shunt reference, error amplifier, and optocoupler in a single package for simplified feedback loop design.
• Features reduced dark current at high temperatures and enhanced common mode transient immunity due to an accessible phototransistor base pin.
• Provides industry-leading dynamic range by ensuring bias current does not pass through the LED, eliminating bias-related optical current.

Applications

• Low Voltage Power Supply Feedback
• Isolated Power Supply Feedback
• AC-to-DC Power Supplies
• DC-to-DC Converters

Procurement Notes

Verify the specific package type required for the application, as the LIA136 is available in 8-pin DIP, surface mount tube, and tape & reel configurations. Confirm that the operating temperature range up to +110°C aligns with system thermal requirements. Ensure proper handling procedures are followed due to ESD sensitivity and verify moisture sensitivity level compliance during assembly.

Selection Notes

Select the LIA136 over the LIA135 when operation at elevated temperatures up to +110°C is required or when higher common mode transient immunity is necessary. The accessible base pin allows for external components to further reduce dark current and improve noise immunity. Ensure the minimum input voltage of 1.6V is supported by the secondary side supply rail.

Part Context

The LIA136 belongs to the LIA135/LIA136 family of low voltage optically isolated error amplifiers manufactured by IXYS Integrated Circuits Division. These devices serve as functional equivalents to discrete precision shunt regulators combined with optocouplers, such as the 431 type, but offer integrated compensation and lower voltage operation capabilities within a compact 8-pin package.

Replacement Considerations

The LIA135 is the primary related part number within the same series, differing primarily in temperature rating and CMTI specifications. No other public substitute part numbers are documented in the official datasheet.

FAQ

What is the function of Pin 2 on the LIA136?

Pin 2 provides access to the base of the output NPN phototransistor. This allows users to connect external resistors or capacitors to extend the operational temperature range by reducing dark current and to enhance immunity to common mode transients.

How does the LIA136 achieve low voltage operation?

The device is designed to operate with an input voltage as low as 1.6V. Power for the internal error amplifier, reference, and LED is supplied via the LED pin, allowing it to be biased directly from low voltage rectified secondary outputs without auxiliary windings.