AS2931 100mA Low Dropout Voltage Regulator FEATURES • • • • • • • • 5.0V, 4.5V, 4.0V, 3.5V, 3.3V, and 3.0V Versions are Available Output Current in Excess of 100 mA Input-Output Differential is Less Than 0.6V Mirror-Image Insertion Protection Internal Thermal Overload Protection Available in TO-220, TO-92, SOT-89, and SO-8 Package Types Available as Adjustable with TTL Compatible Switch Similar Improved to Industry Standard LM2931 • • • • Reverse Battery Protection Short Circuit Protection 60V Load Dump Protection -20V Reverse Transient Protection • • • Portable Instrumentation Radio Control Systems Cordless Telephones APPLICATION PRODUCT DESCRIPTION The AS2931 is a low power voltage regulator. This device is an excellent choice for use in battery-powered applications such as cordless telephones, radio control systems, and portable computers. The AS2931 features offers very low quiescent currents (0.4 mA.), and very low drop output voltage (typ. 50 mV at light load and 300 mV at 100 mA). Other features include the logiccompatible On/Off input which enables the regulator to be switched on and off. The AS2931 is offered in a 3-pin TO-92/TO-220 package compatible with other 5V regulators and SOT-89/SO-8 package. The regulator output voltage may be internally pin-strapped for a 3.5V, 3.3V, 3.0V, or programmed from 3V to 24V with an external pair of resistors. PIN CONNECTIONS ORDERING INFORMATION TO-92 3-PIN AS2931AN-X AS2931N-X SO-8 SOT-89 3-PIN AS2931AM1-X AS2931M1-X AS2931AS-X AS2931S-X AS2931CS-X TO-220 3/5 PIN AS2931AU-X AS2931U-X AS2931CU-X OPER. TEMP. RANGE -40°C to +85°C -40°C to +85°C -40°C to +85°C 8-Pin Surface Mount (S) Fixed Output VOUT 1 GND 2 1 2 3 6 GND BYP 4 5 ON/OFF Top View AS2931 3 VOUT GND 1. VIN 2. GND 3. VOUT Front View GND 3 1 2 7 GND SOT-89 (M1) TO-92 (N) TO-220-3 (U) Fixed 1 VIN AS2931 X = Output Voltages (X = 3.0V, 3.3V, 3.5V) or blank for Adj.) AS2931 8 Bottom View 2 VIN VIN GND 8-Pin Surface Mount (S) Adj Output 3 VOUT Top View VOUT 1 GND 2 8 VIN 7 GND AS2931 GND 3 6 GND ADJ 4 5 ON/OFF Top View Rev. 10/11/00 AS2931 ABSOLUTE MAXIMUM RATINGS Power Dissipation........................................... Internally limited Lead Temp. (soldering, 5 Seconds) ................................. 260°C Storage Temperature Range ........................... -65°C to +150°C Operating Junction Temperature Range ........... -40°C to +85°C Input Supply Voltage............................................. -0.3 to +26V ESD Rating.........................................................................2KV ELECTRICAL CHARACTERISTICS at VS = 14V, TA = 25°C, IO = 10 mA, C2 = 100 µF, unless otherwise specified. ( Note 1) Parameter Conditions Min 3.0 Volt Version AS2931A Typ Max Min AS2931A-3 Output Voltage 3.3 Volt Version Output Voltage V 3.00 3.15 AS2931-3.3 V 2.85 3.30 3.36 3.20 3.30 3.39 V 3.30 3.39 AS2931A-5 3.16 3.30 AS2931-5 3.43 V 5.19 4.75 5.00 5.25 V 5.25 4.5 5.5 V 3.20 4.81 6V <VIN< 26V, IO =100 mA Over Temp. 3.09 3.00 3.00 3.12 2.88 AS2931A-3.3 5 Volt Version Output Voltage AS2931-3 2.91 3.23 6V < VIN< 26V, IO = 100 mA Over Temp. Units Max 3.06 2.94 6V<VIN< 26V, IO = 100 mA Over Temp. AS2931 Typ 3.00 5.00 4.75 All Voltage Options Long Term Stability Line Regulation Load Regulation Dropout Voltage Quiescent Current Maximum Operational Input Voltage Maximum Line Transient Reverse Polarity Input Voltage, DC Reverse Polarity Input Voltage, Transient Output Noise Voltage Ripple Rejection 20 20 mV/1000 9V < VIN < 16V 6V < VIN < 26V, 5 mA < IO < 100 mA 2.0 4.0 14 10 30 50 4.0 30 mV 14 50 mV IO=10 mA IO=50 mA IO=100 mA IO < 10 mA, 6V < VIN < 26V -40°C < Tj < 85°C IO = 100 mA, VIN = 14V, TJ = 25°C 0.05 0.07 0.3 0.4 0.2 0.1 0.6 1.0 0.05 0.07 0.3 0.4 0.2 0.1 0.6 1.0 V V V mA 15 15 mA 26 33 26 33 V RL= 500Ω, VO<5.5V, 100ms 60 70 50 70 V VO > -0.3V, RL = 500Ω -15 -30 -15 30 V -50 -80 -50 -80 V 500 500 80 80 µVrms dB 1% Duty Cycle, τ < 100ms, RL = 500Ω 10Hz-100kHz, COUT=100µF FO = 120Hz Note 1: See TYPICAL APPLICATIONS notes to ensure constant junction temperature, low duty cycle pulse testing used. Note 2: All limits are at 25°C or over the full operating temperature junction range of -40°C to +85°C. Note 3: The maximum power dissipation is a function of maximum junction temperature, total thermal resistance, and ambient temperature. Note 4: Human body model, 100 µF discharged through 1.5 KΩ. Rev. 10/11/00 AS2931 Application Hints The AS2931 requires an output capacitor for device stability. The value required varies greatly depending upon the application circuit and other factors. The high frequency characteristics of electrolytic capacitors depend greatly on the type and also on the manufacturer. Sometimes only bench testing is the only means to determine the proper capacitor type and value. The high quality 100 µF aluminum electrolytic covers all general application circuits, this stability can be obtained with a tantalum electrolytic value of 47 µF. Another critical point of electrolytic characteristics is its performance over temperature. The AS2931 is designed to operate starting at -40°C which may not be true in the case of electrolytic. Higher temperatures generally no problem. The electrolytic. type in aluminum will freeze around -30°C. This could cause an oscillation at output of regulator. At a lower temperature requirement by many applications the capacitor should maintain its performance. So as a result, for an application which regulator junction temperature does not exceed 25°C, the output capacitor can be reduced by the factor of two over the value needed for the entire temperature range. Other points with linear regulators is that the twitch higher output current stability decreases. In most applications the AS2931 is operating at few milliamps. In these applications the output capacitance can be further reduced. For example, when the regulator is running at 10mA output current the output capacitance value is half compared to the same regulator that is running at 100 mA. With the AS2931 adjustable regulator, the minimum value of output capacitance is a function of the output voltage. The value decreases with higher output voltages, since the internal loop gain is reduced. The worst case occurs at the lower temperature and maximum operating currents, the entire circuit and the electrolytic, should be cooled down to the minimum temperature. The minimum of 0.6 volts required at the input of regulator above the output to keep the power dissipation and die heating to its minimum. After the value for the capacitor has been determined for actual use, the value should be doubled. Rev. 10/11/00 AS2931 TYPICAL CHARACTERISTICS QUIESCENT CURRENT QUIESCENT CURRENT 30 15 ~ ~ ~ ~ 3 IO = 50mA 2 1 IO = 0mA VIN = 14V 25 20 15 10 5 0 40 80 120 IO = 100mA 0.3 IO = 50mA IO = 10mA 90 0 80 0.5 500 0.4 0.3 0.2 50 POWER DISSIPATION (W) 16 14 12 10 ºC/W HEAT SINK 10 8 6 0.5 0.4 0.3 0 0.4" LENGTH FROMPC BOARD 30 OUTPUT VOLTAGE (V) 1 0.1 0 30 60 90 FREQUENCY (Hz) 120 10 20 30 40 50 60 70 80 90 OPERATION DURING LOAD DUMP 0.01 AMBIENT TEMPERATURE (ºC) 0.4 0.3 MAXIMUM POWER DISSIPATION LM29315.0 IO = 10mA 0.1 25 0.125" LEAD LENGTH FROM PC BOARD 0.5 AMBIENT TEMPERATURE (ºC) 0.2 20 0.6 0 OUTPUT VOLTAGE (V) 0.6 15 0.7 0 10 OUTPUT IMPEDANCEΩ)( POWER DISSIPATION (W) 0.7 10 0.8 0.2 0 10 20 30 40 50 60 70 80 90 100 0.9 5 0.9 AMBIENT TEMPERATURE (ºC) 0.8 30 20 0.1 6.0 MAXIMUM POWER DISSIPATION (SO8) 0 10 MAXIMUM POWER DISSIPATION (TO-92) NO HEAT SINK INPUT VOLTAGE (V) 1.0 TJ = -40ºC 1.0 0 5.0 24 200 0 2 4.0 21 INPUT VOLTAGE (V) 18 4 1.0 18 TJ = 85ºC 300 100 INFINITE HEAT SINK 20 2.0 3.0 400 MAXIMUM POWER DISSIPATION (TO-220) 3.0 15 TJ = 25ºC OUTPUT CURRENT (mA) 22 4.0 12 0 0 LOW VOLTAGE BEHAVIOR 5.0 9 100 0.1 120 LM2931 5.0 IO = 100 mA 2.0 6 PEAK OUTPUT CURRENT 800 JUNCTION TEMPERATURE (ºC) 6.0 3 OUTPUT VOLTAGE (V) 0 40 1.14 0.6 0 OUTPUT VOLTAGE (V) 60 OUTPUT CURRENT (mA) 0.5 0 1.18 1.16 DROPOUT VOLTAGE INPUT OUTPUT DIFFERENTIAL (V) INPUT OUTPUT DIFFERENTIAL (V) DROPOUT VOLTAGE 0.1 1.22 1.20 OUTPUT CURRENT (mA) 0.6 0.2 30 0 JUNCTION TEMPERATURE (ºC) 0.4 1.26 1.24 1.10 0 -40 LM2931CT ADJUSTABLE 1.28 1.12 0 POWER DISSIPATION (W) 10 REFERENCE VOLTAGE 1.30 REFERENCE VOLTAGE (V) 20 QUIESCENT CURRENT (mA) QUIESCENT CURRENT (mA) 25 150 70 60 50 40 30 20 10 0 ~ ~ 6 4 2 0 -2 -100 ~ ~ CO = 100µF RL = 500W 0 100 200 300 400 500 TIME (ms) Rev. 10/11/00 AS2931 TYPICAL APPLICATIONS AS2931 Fixed Output AS2931 SCHEMATIC DIAGRAM Rev. 10/11/00