SOA, Current Expansion & Temperature Monitor Output

Linear Technology announced the launch of a robust 800mA wide input voltage range linear regulator (product name: LT3089) featuring key usability, monitoring, and protection functions. This device features an expanded Safe Operating Area (SOA) compared to conventional regulators, making it ideal for high input-to-output voltage and high output current applications where legacy regulators limit output.

The LT3089 features a current source reference for single resistor output voltage setting and output regulation capability down to 0V. Output current limit can be externally set using a single resistor. The regulator architecture, combined with low millivolt line and load regulation, allows multiple ICs to be easily paralleled for higher heat dissipation and output current. The current monitor output allows current to be summed with set current for line drop compensation, where the LT3089 output can increase current to compensate for line drop.

The LT3089 achieves excellent line and load regulation below 2mV, independent of output voltage, and features an input voltage range of 1.2V to 36V. This device is well-suited for applications requiring multiple rails. Output voltage can be programmed from 0V to 34.5V with a single resistor using 1.2V dropout. The on-chip trimmed 50µA current reference provides ±1% accuracy. Regulation, transient response, and output noise (27µVRMS) are independent of output voltage due to the device's voltage follower architecture. The LT3089 can be configured as a 2-terminal current source using only two resistors. For stability, input or output capacitors can operate in linear regulator mode or current source mode of operation.

The LT3089 provides multiple monitoring and protection functions. Current limit can be programmed with a single resistor. Monitor output provides current outputs proportional to temperature (1µA/°C) and output current (200µA/A), enabling easy ground-referenced measurements. The current monitor can be used to compensate for cable drop. The LT3089's internal protection circuitry includes reverse input protection, reverse current protection, internal current limit, and thermal shutdown.

Robert Dobkin, Vice President and Engineering CTO of Linear Technology, stated, "The LT3089 regulator's robust architecture, protection and monitoring functions provide designers with new tools for reliable designs. Various surface mount packages are available, including DD-Pak packages for high power dissipation and for low power applications. System power and temperature can be easily monitored for proper operation."

The LT3089 is offered in thermally enhanced surface mount compatible packages including a low-profile (0.75mm) 12-pin 4mm x 4mm DFN, 16-pin thermally enhanced TSSOP, and 7-pin DD-Pak. All packages dissipate 2W in surface mount applications without heatsinks. Available in a wide range of temperature grades: E and I grades at –40°C to 125°C, H grade at –40°C to 150°C, and high-reliability MP grade at –55°C to 150°C. The E grade is priced at $2.13 per unit in quantities of 1,000. For more information, refer to www.linear.com/product/LT3089.