The LP2950 and LP2951 are micropower voltage regulators that are specifically designed to maintain proper regulation with an extremely low input�to�output voltage differential. These devices feature a very low quiescent bias current 75 �A and are capable of supplying output currents in excess of 100 mA. Internal current and thermal limiting protection is provided. The LP2951 has three additional features. The first is the Error Output that can be used to signal external circuitry of an out of regulation condition, as a microprocessor power�on reset. The second feature allows the output voltage to be preset 3.0 V output (depending on the version) or programmed from V. It consists of a pinned out resistor divider along with direct access to the Error Amplifier feedback input. The third feature is a Shutdown input that allows a logic level signal to turn�off or turn�on the regulator output. Due to the low input�to�output voltage differential and bias current specifications, these devices are ideally suited for battery powered computer, consumer, and industrial equipment where an extension of useful battery life is desirable. The LP2950 is available in the three pin case 29 and DPAK packages, and the LP2951 is available in the eight pin dual�in�line, SO�8 and Micro�8 surface mount packages. The `A' suffix devices feature an initial output voltage tolerance � 0.5%.
(Top View) Heatsink surface (shown as terminal 4 in case outline drawing) is connected to Pin SO�8 D SUFFIX CASE 751Low Quiescent Bias Current of 75 �A Low Input�to�Output Voltage Differential 100 �A and
� 0.5% Allows Use as a Regulator or Reference Extremely Tight Line and Load Regulation Requires Only 1.0 �F Output Capacitor for Stability Internal Current and Thermal Limiting
Error Output Signals an Out of Regulation Condition Output Programmable from 29 V Logic Level Shutdown InputOutput 1 Sense 2 Shutdown 3 Gnd 4 (Top View) Input Feedback VO Tap Error Output
See detailed ordering and shipping information in the package dimensions section on page 13 of this data sheet.
Output Voltage Package TO�92 Suffix Z DPAK Suffix DT SO�8 Suffix D Micro�8 Suffix DM DIP�8 Suffix LP2951CN LP2951ACN Adjustable Not Available Not Available LP2951CN LP2951ACN Operating Junction Temperature Range to +125�C1% Output Voltage Precision 25�C 0.5% Output Voltage Precision = 25�C
Input Battery or Unregulated 182 k Error Amplifier 1.23 V Reference Gnd Battery or Unregulated DC Input 8 2 Output 1 Sense �F VO Tap k 7 Error Amplifier k 75 mV/ 60 mV Feedback 330 k Output 1.0 �F
Rating Symbol VCC PD Value 30 Unit Vdc W Input Voltage Power Dissipation and Thermal Characteristics Maximum Power Dissipation Case 751(SO�8) D Suffix Thermal Resistance, Junction�to�Ambient Thermal Resistance, Junction�to�Case Case 369A (DPAK) DT Suffix [Note 1] Thermal Resistance, Junction�to�Ambient Thermal Resistance, Junction�to�Case Case (TO�226AA/TO�92) Z Suffix Thermal Resistance, Junction�to�Ambient Thermal Resistance, Junction�to�Case Case 626 N Suffix Thermal Resistance, Junction�to�Ambient Case (Micro�8) DM Suffix Thermal Resistance, Junction�to�Ambient Feedback Input Voltage Internally Limited RJA RJC RJA RJC RJA RJC RJA Vfb Vsd �C/W Vdc �C
to +30 Shutdown Input Voltage Error Comparator Output Voltage Operating Junction Temperature Storage Temperature Range Verr to +150 Tstg
NOTE: 1. The Junction�to�Ambient Thermal Resistance is determined by PC board copper area per Figure 26. 2. ESD data available upon request.