ULTRA-PRECISE, DUAL MICROPOWER LDO VOLTAGE REGULATOR FOR POWER-SENSITIVE MILITARY APPLICATIONS

• 75mA Auxiliary, Adjustable Output LDO Regulator and Power Shutdown Pin for the Main Output
• Integrates Guaranteed 250mA Output Current Regulator
• Very Low Quiescent Current (170microA typical at light loads) and Very Low Dropout Voltage (Typically 60mV at 1mA Load Current and 470mV at 250mA Load Current on the Main Output)
• Precise Line and Load Regulation of 0.2 Percent Over Full Military Temperature Range

Santa Clara, Calif. -- July 7, 1995 -- An ultra-precise dual micropower LDO (low dropout) voltage regulator that features both a guaranteed 250mA output current main regulator and an auxiliary, adjustable 75mA output regulator on the same chip is now available from National Semiconductor's Military/Aerospace Division for aircraft, satellite, armor, missile and ground communications applications.

The LP2956 provides designers with a flexible solution to shorten development cycles, conserve power and improve reliability when power supplies require extensive regulation and minimal printed circuit board space. Targeted applications benefiting from the LP2956's micropower and precision specifications include handheld/battery-powered equipment such as manpack radios, mines and portable test equipment, or such equipment as inertial navigation and satellite systems that require precise regulation of switching power supplies.

Besides the two separate on-chip regulators, the LP2956 contains a power shutdown pin for the main output to conserve energy, an auxiliary comparator for fault or low-input voltage detection, current and thermal limiting at extremely light loads, tight line regulation and a low quiescent current of 170mA at light loads. The convenient additional, auxiliary regulator output is always on, regardless of the main output status, so that it can power memory circuits.

The LP2956 also features a very low dropout voltage of typically 60mV at 1mA load current and 470mV at a 250mA load current on the main output, an adjustable output voltage range of 1.24V to 29V and precise line and load regulation of 0.2 percent guaranteed over the full military temperature range. Additional features include a 5V tap that allows designers to fix the output at 5V without external resistors, and reverse battery protection.

The LP2956AMJ/883 LDO dual voltage regulator is fully MIL-STD-883 qualified under National's newly validated QML system to operate over the military temperature range of - 55 to +125ºC. In addition, this device has a DESC Standard Military Drawing (SMD) number of 5962-9554701QEA.

MIL95008

Lit. #108575-001