LT3081IT7#PBF

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Overview

The LT3081IT7#PBF is a 1.5A low dropout linear regulator in a 7-lead TO-220 package, rated for -40°C to 125°C. It features a wide input voltage range of 1.2V to 36V and an adjustable output from 0V to 34.5V set by a single resistor. Key specifications include a typical dropout voltage of 1.23V at 1.5A, a precision 50µA SET pin current with 1% initial accuracy, and <1mV load regulation. The device includes an output current monitor (IMON = IOUT/5000), a junction temperature monitor (1µA/°C), and programmable current limiting.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Feature Summary

• Single-resistor programming architecture using a precision 50µA reference current source allows output voltage adjustment from zero to 34.5V.
• Integrated system monitoring capabilities via dedicated pins providing output current scaling and die junction temperature proportional currents.
• Extended safe operating area and rugged design withstand reverse input and reverse output-to-input voltages without reverse current flow.
• Internal protection circuitry includes reverse-battery protection, reverse-current protection, thermal limiting, and externally programmable current limit.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Applications

• Rugged industrial power supplies requiring high reliability and fault tolerance
• Post regulators for switching supplies to reduce noise and ripple
• Low output voltage supplies capable of adjusting down to 0V
• Intrinsic safety applications benefiting from extended SOA and current limiting

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Procurement Notes

Verify the specific suffix IT7 corresponds to the 7-lead TO-220 plastic package and the Industrial temperature grade (-40°C to 125°C). Confirm RoHS compliance and lead-free finish status as indicated by the #PBF designation. Ensure ordering documentation matches the manufacturer's official part numbering scheme for Analog Devices Inc. components.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Selection Notes

Select this component when a high-current linear regulator with integrated monitoring is required. The single-resistor voltage setting simplifies design compared to traditional divider networks. Consider the TO-220 package for through-hole mounting and adequate thermal dissipation. Verify that the minimum load current requirement of 5mA is accommodated in the application design.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Part Context

The LT3081 belongs to a family of high-performance LDOs designed for harsh environments. Unlike standard regulators, it utilizes a true current source reference, making loop gain independent of output voltage. This architecture ensures consistent performance across the entire adjustment range. The device supports paralleling for increased current or heat spreading capabilities.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators Replacement Considerations

LT3081EFE#PBF: Same electrical specifications but in a 16-lead TSSOP surface mount package.

Voltage Regulators - Linear, Low Drop Out (LDO) Regulators FAQ

How is the output voltage programmed on the LT3081?

The output voltage is set by connecting a single resistor between the SET pin and ground. A precision internal 50µA current source flows out of the SET pin, creating a voltage drop across the resistor that defines VOUT.

What is the function of the IMON pin?

The IMON pin provides an output current proportional to the load current, typically equal to ILOAD divided by 5000. This allows for external monitoring of the output current using a sense resistor.

Can the LT3081 operate without input or output capacitors?

Yes, the LT3081 is stable with or without input and output capacitors, although adding capacitors can improve ripple rejection and transient response characteristics.