Regulator features diagnostic and safety functions

Linear Technology has unveiled a high-voltage, low-noise, low-dropout-voltage linear regulator suitable for active antenna supplies, industrial power supplies and battery-powered systems.

The LT3050 offers precision, a programmable current limit and a diagnostic capability, according to the company.

The device delivers up to 100mA output current with a 340mV dropout voltage at full load.

The LT3050 features a 2-45V input voltage range, delivering adjustable output voltages from 0.6V to 44.5V.

A single capacitor at the REF/BYP pin provides programmable low-noise operation - only 30uVRMS across a wide bandwidth of 10Hz to 100kHz - and a reference soft-start functionality, preventing output voltage overshoot at turn-on.

The output voltage tolerance is accurate at +/-2 per cent over line, load and temperature.

The LT3050 provides several diagnostic and safety functions.

First, a single resistor at the Imax pin programs current limit, accurate to +/-5 per cent over the full input voltage and temperature range.

In addition, a single resistor at the Imin pin programs a minimum output current detector; this is useful for identifying open-circuit conditions.

A current monitor function sources current equal to 1/100th of output current, allowing the user to measure output current or to calculate the device's power dissipation.

A logic fault pin asserts low if the LT3050 is in current limit, operating below its minimum output current (open circuit) or is in thermal shutdown.

The LT3050's internal protection circuitry includes reverse-battery protection, reverse-output protection, reverse-current protection, internal default current limiting and thermal limiting.

The device operates with a small, low-cost, 2.2uF ceramic output capacitor, optimising stability and transient response.

This tiny external capacitor can be used without the addition of series resistance (ESR), as is common with many other regulators.

The LT3050's wide input and output voltage ranges, fast transient response, low quiescent current of 50uA in operation and less than 1uA in shutdown make it a suitable choice for active antenna supplies, industrial power supplies, battery-powered systems requiring optimum runtime and high-reliability power supplies requiring diagnostic information and protection functions.

The LT3050EDDB and the LT3050IDDB are housed in the 12-lead 2 x 3mm DFN package, while the LT3050EMS8E and the LT3050IMS8E are available in the 12-lead thermally enhanced MSOP package, all offering a compact footprint.

Both E- and I-grade versions are available from stock with an operating junction temperature of -40C to +125C, while the MP grade operates from -55C to +125C (MSOP package only, LT3050MPMS8E).

According to the company, 1,000-piece pricing starts at USD1.55 (GBP1.05) and USD1.75 each for the DFN-package E and I grades respectively and USD1.55, USD1.75 and USD4.19 each for the MSOP-package E, I and MP grades respectively.

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