LP3997 Datasheet | National Semiconductor

Description The LP3997 regulator is designed to meet the requirements of portable, battery-powered systems, providing accurate output voltage, low noise, and low quiescent current. The LP3997 provides 3.3V output at up to 250m A load current. When switched in shutdown mode, the power consumption is virtually zero. The LP3997 is designed to be stable with space saving ceramic capacitors as small as 1µF. The LP3997 also includes an out-of-regulation error flag. When the output is more than 5% below its nominal voltage, the error flag sets to low. If a capacitor is connected to device’s delay pin, a delayed power-on reset signal will be generated. n n n n n Less than 70µA Typical IQ at 250m A. Virtually Zero IQ (Disabled). Themal and Short Circuit Protection. 3.3V Output. For other voltage options, please contact your local NSC sales office. Package 8 Lead MSOP For other package options contact your NSC sales office. Applications n n n n n Portable Consumer Electronics Cellular Handsets Laptop and Palm puters PDA’s Digital Cameras Features n Low, 140m V, Dropout at 250m A Load. n Stable with Ceramic Capactor. n Low Noise, with Bypass Capacitor. Typical Application Circuit © 2004 National Semiconductor Corporation DS200929 .national. Functional Block Diagram Pin Descriptions Pin # 1 2 3 4 5 6 7 Name CNOISE DELAY GND VIN VOUT SENSE ERROR Description Noise bypass pin. For low noise applications a 0.1µF or larger ceramic capacitor should be connected from this pin to ground A capacitor connected from this pin to ground will allow a delayed power-on-reset signal at the ERROR (pin 7) output. Ground pin. Local ground for CNOISE and COUT. Input supply pin. Bypass this with a 1µF capacitor. Output voltage, Connect COUT between this pin and ground. Connect this pin to VOUT (pin 5). This open drain output is an error flag output which goes low when VOUT drops 5% below it nominal voltage. This pin also provides a power-on-reset signal if a...