Dual-Rail Linear Regulators

Two new CMOS dual input low dropout (LDO) voltage regulators from National Semiconductor offer the industry’s lowest dropout. Optimized for low-voltage, high current applications in PCs and set-top boxes, this new family of LDOs enables high efficiency linear conversion while consuming ultralow quiescent current of only 3mA under all conditions.

In contrast, the quiescent current of bipolar alternatives increases to over 100mA as the regulator approaches dropout.

The LP388x family now includes the two new devices, the LP3881 and LP3882, and the recently released LP3883, providing a significant power savings to customers. They use a separate input to power the control circuitry; the power input may be fed independently from the high current supply facilitating conversion from input rails of less than 2.5V. The CMOS dual input architecture allows for an ultralow input voltage and low output voltages down to 1.2V. The dropout voltage for the LP3883/2/1 is typically 210 mV, 110mV, and 75 mV at 3A, 1.5A, and 0.8A, and a maximum of 420 mV, 270 mV, 160 mV overtemperature.

For more information, visit www.national.com.