AS29372 AUSTIN | Alldatasheet
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VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. LOW-DROPOUT VOLTAGE REGULATOR AVAILABLE AS MILITARY SPECIFICATIONS ! MIL-STD-883, Class B
FEATURES
! High output voltage accuracy ! Guaranteed 750mA output ! Low quiescent current ! Low dropout voltage ! Extremely tight load and line regulation ! Very low temperature coefficient ! Current and thermal limiting ! Input can withstand -20V reverse battery and +60V positive transients ! Logic-controlled electronic shutdown ! Output programmable from 1.24V to 26V ! Available in a 7-lead flatpack package
APPLICATIONS
! Battery powered equipment ! Cellular telephones ! Laptop, notebook, and palmtop computers ! PCMCIA VCC and VPP Regulation/Switching ! Bar code scanners ! Automotive electronics ! SMPS post-regulator/DC to DC modules ! High efficiency linear power supplies OPTIONS MARKING ! Package 7-Lead Flatpack F For more products and information please visit our web site at www.austinsemiconductor.com PIN ASSIGNMENT (Top View)
7 Lead Flatpack (F)
The AS29372 is an efficient voltage regulator with very low dropout voltage and very low quiescent current. Key features include protection against reversed battery, fold-back current limiting, and automotive “load dump” protection. A logic compatible input is provided, which allows the device to be switched on and off. GND SHDN ADJ V IN VIN OUT OUT
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. *Across the full operating temperature, the minimum input voltage range for full output current is 4.3V to 26V . Output will remain in-regulation at lower output voltages and low current loads down to an input of 2V at 25°C. ABSOLUTE MAXIMUM RATINGS 1 θ JC = 14°C/W
ELECTRICAL CHARACTERISTICS
Limits in standard typeface are for T J = 25°C and limits in boldface apply over the full operating temperature range, -40°C to +125°C. Unless otherwise specified, V IN = VOUT + 1V , IL = 5mA, CL = 10µF. The AS29372 are programmed for a 5V output voltage, and VSHUTDOWN < 0.6V . SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS ∆VO /∆T Output Voltage Temperature Coef.(note 2) 20 100 ppm/°C ∆VO /∆VIN Line Regulation VIN = VOUT + 1V to 26V IL = 2mA 0.03 0.10 0.40 % ∆VO /∆IL Load Regulation IL = 5 to 700 mA (note 3 & 4) 0.04 0.16 0.20 % IL = 5mA 80 150 180 IL = 100mA 200 250 320 IL = 500mA 300 450 600 IL = 5mA, VO = 5 ± 0.1V 160 250 300 µA IL = 100mA, VO = 5 ± 0.1V 1 2.5 IL = 500mA, VO = 5 ± 0.1V 8 13 ∆VO /∆PD Thermal Regulation (note 9) 0.05 0.2 %/W Reference Voltage (note 7) 1.204 1.26 V Adjust Pin Bias Current 20 40 60 nA mVDropout Voltage (note 5)V IN - VO mA IGND Ground Pin Current (note 6)
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. ELECTRICAL CHARACTERISTICS (Cont.) Shutdown Input PARAMETER CONDITIONS MIN TYP MAX UNITS Low (ON) 0.7 High (OFF) 2.0 VSHUTDOWN = 2.4V 30 50 100 VSHUTDOWN = 26V 450 600 750 Regulator Output Current in Shutdown (note 8) 3 10 20 µA Input Logic Voltage V Shutdown Pin Input Current µA NOTES: 1. Unless otherwise specified, VIN = VOUT = 1V , IL = 5mA, CL = 10µF, TJ = TA. Device shall be biased in accordance with Figure 1 with VSHUTDOWN < 0.6V , VIN = 6V , RL = 300 kilohms ±1%. 2. Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range. 3. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Changes in output voltage due to heating effects are covered by the thermal regulation specification. 4. This parameter is tested up to 600mA; however, limits are guaranteed but not tested to 750mA. 5. Dropout voltage is defined as the input-to-output differential at which the output voltage drops 100mV below its nominal value measured at 1V differential. At very low values of programmed output voltage, the minium input supply voltage of 2V (2.3V over temperature) must be taken into account. 6. Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the load current plus the ground pin current. 7. V REF < VOUT < (VIN - 1V), 4.3V < VIN < 26V , 5mA < IL < 600mA, TJ < TJMAX. 8. See Figure 1 with R L > 150 kilohms, VSHUTDOWN > 2V , VIN < 26V , VOUT = 0. 9. Thermal regulation is defined as the change in output voltage at a time (t) after a change in power dissipation is applied, excluding line and load regulation effects. Specification is for a 200mA load pulse at V IN = 20V (at 4W pulse) for t = 10ms.
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. SCHEMATIC DIAGRAM
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. TYPICAL CHARACTERISTICS
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. TYPICAL CHARACTERISTICS (Cont.)
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. APPLICATIONS INFORMATION External Capacitors A 10µF (or greater) capacitor is required between the output and ground to prevent oscillations due to instability. Most types of tantalum or aluminum electrolytics will be adequate; film types will work, but are costly and therefore not recommended. Many aluminum electrolytics have electrolytes that freeze at about -30°C, so solid tantalums are recommended for operation below -25°C. The important parameters of the capacitor are an effective series resistance of about 5Ω or less and a resonant frequency above 500kHz. The value of this capacitor may be increased without limit. At lower values of output current, less output capacitance is required for output stability. The capacitor can be reduced to 0.5µF for current below 10mA or 0.15µF for currents below 1mA. Adjusting the AS29372 to voltages below 5V runs the error amplifier at lower gains so that more output capacitance is needed. For the worst-case situation of 750mA load at 1.23V output (Output shorted to Adjust) a 22µF (or greater) capacitor should be used. Programming the Output Voltage The AS29372 may be programmed for any output voltage between its 1.235V reference and its 26V maximum rating. An external pair of resistors is required, as show in Figure 1. The complete equation for the output voltage is V OUT = VREF x {1 + R1/R2} - |IFB|R1 where VREF Is the nominal 1.235 reference voltage and I FB is the Adjust pin bias current, nominally 20nA. The minimum recommended load current of 1µA forces an upper limit of 1.2MΩ on the value R 2, if the regulator must work with no load (a condition often found in CMOS in standby), IFB will produce a -2% typical error in V OUT which may be eliminated at room temperature by trimming R 1. For better accuracy, choosing R2 = 100k reduces this error to 0.17% while increasing the resistor program current to 12µA. Since the AS29372 typically draws 100µA at no load with SHUTDOWN open-circuited, this is a negligible addition. Reducing Output Noise In reference applications it may be advantageous to reduce the AC noise present at the output. One method is to reduce the regulator bandwidth by increasing the size of the output capacitor. This is relatively inefficient, as increasing the capacitor from 1µF to 220µF only decreases the noise from 430µV to 160µV RMS for a 100kHz bandwidth at 5V output. Noise can be reduced by a factor of four with the adjustable regulators with a bypass capacitor across R 1, since it reduces the high frequency gain from 4 to unity. Pick CBYPASS z 1 2πR1 H 200 Hz or about 0.01µF. When doing this, the output capacitor must be increased to 10µF to maintain stability. These changes reduce the output noise from 430µV to 100µV RMS for a 100kHz bandwidth at 5V output. With the bypass capacitor added, noise no longer scales with output voltage so that improvements are more dramatic at higher output voltages.
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. Package Designator F MECHANICAL DEFINITIONS* *All measurements are in inches. Drawing is not to scale.
VVVVVoltaoltaoltaoltaoltaggggge Re Re Re Re R eeeeegulagulagulagulagulatortortortortor AS29372 Austin Semiconductor, Inc. AS29372 Rev. 2.0 3/03 Austin Semiconductor, Inc. reserves the right to change products or specifications without notice. *AVAILABLE PROCESSES *AVAILABLE PROCESSES IT = Industrial Temperature Range -40 oC to +85oC XT = Extended Temperature Range -55 oC to +125oC 883C = MIL/883 equivalent processing compliant to paragraph 1.2.2 -55 oC to +125oC EXAMPLE: AS29372F/883 Device Number Package Type Process AS29372 F /*