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LM317

3-TERMINAL ADJUSTABLE REGULATORS

LM317
DESCRIPTION
3-TERMINAL ADJUSTABLE REGULATORS
The LM317 are adjustable 3-terminal positive-voltage regulators capable of supplying 1.5A over a differential voltage range of 3V to 40V. They are exceptionally easy to use and require only two external resistors to set the output voltage. Both input and output regulation is better than standard fixed regulators. In addition to higher performance than fixed regulators, these regulators offer full overload protection available only in integrated circuits. Included on the chip are current limit, thermal overload protection, and safe-area protection. All overload protection circuit remains fully functional even if the adjustment terminal is disconnected. Normally, no capacitors are needed unless the device is situated far from the input filter capacitors in which case an input bypass is needed. An optional output capacitor can be added to improve transient response. The primary applications of each of these regulators is that of a programmable output regulator, but by connecting a fixed resistor between adjustment terminal and the output terminal, each device can be used as a precision current regulator. Even though the regulator is floating and sees only the input-to-output differential voltage, use of these devices to regulate output voltages that would cause the maximum-rated differential voltage to be exceeded if the output became shorted is not recommended
TO-220 PACKAGE LM317T
FEATURES
INPUT OUTPUT ADJUSTMENT
INPUT OUTPUT ADJ
TO-92
LM317LZ
ABSOLUTE MAXIMUM RATINGS
Input-Output Voltage Differential VI - VO Operating Junction Temperature Range Continuous total dissipation at 25 free-air temperature Continuous total dissipation at (or below ) 25 case temperature Storage Temperature Lead Temperature1.6 mm from case for 10 seconds
40V 0 to +125 2000mW 15W -65 to +150 260
RECOMMENDED OPERATING CONDITIONS
OUTPUT CURRENT, IO OPERATING VIRTUAL JUNCTION TEMPERATURE, TJ MIN MAX UNIT 10 1500 mA 0 70
Wing Shing Computer Components Co., (H.K.)Ltd. Homepage: http://www.wingshing.com
Tel:(852)2341 9276 Fax:(852)2797 8153 E-mail: wsccltd@hkstar.com
LM317
3-TERMINAL ADJUSTABLE REGULATORS
ELECTRICAL CHARACTERISTICS
PARAMETER
Input Regulation2 Ripple Rejection
TEST CONDITIONS
MIN TYP MAX
Output Regulation
All characteristics are measured with a 0.1-µF capacitor across the input and a 1-µF capacitor across the output. Input regulation is expressed here as the percentage change in output voltage per 1-V change at the input Pulse testing techniques are used to maintain the junction temperature as close to the ambient temperature as possible. Thermal effects must be taken into account separately. Since long-term drift cannot be measured on the individual devices prior to shipment. This specification is not intended to be a guarantee or warranty. It is an engineering estimate of the average drift to be expected from lot to lot.
TYPICAL APPLICATION DATA
IN ADJ
R1 240
See Note 3
See Note 1
See Note 2
Output voltage is calculated from
Use of an input bypass capacitor is recommended if regulator is far from filter capacitors. Use of an output capacitor improves transient response but is optional. VREF equals the difference between the output and adjustment terminal voltages.
LM317
3-TERMINAL ADJUSTABLE REGULATORS
POSITIVE ADJUSTABLE REGULATOR
Chip Size: 2.45X1.85mm
PAD LOCATION LM317
PAD N 1 2 3 4 PAD NAME ADJ OUTPUT INPUT OUTPUT COORDINATES µm X Y 2120 410 1730 1490 1120 950 90 100