Linear Technology Corp. announces a new high reliability, military plastic MP-grade version of the LT1175, a 500 mA negative micropower low dropout regulator. The MP-grade LT1175 is offered in SOIC-8 and DD-Pak packages with a -55° to +125°C operating junction temperature range. With a wide input voltage range of -4.3 to -20 V, the LT1175 features micropower operating currents of 45 uA quiescent and 10 uA in shutdown, preventing output voltage rise under no-load conditions. The device's reference amplifier topology ensures precision DC characteristics and the ability to maintain good loop stability with a wide range of output capacitors. The device's power transistor anti-saturation design enables very low dropout voltage of 500 mV (typical at full load). Fixed 5 V and adjustable (-3.8 to -19.5 V) output voltage versions are available.
Several features make the LT1175 very user-friendly. The SHDN pin can interface directly to either positive or negative logic levels. Unlike prior regulators, the increase in quiescent current during a dropout condition is actively limited. The LT1175 offers complete protection including user-selectable current limit at 200, 400, 600 and 800 mA, power limiting (current limit foldback), thermal shutdown, and the ability to force the output to reverse voltage without damage or latchup.