LM317A 1% Accurate, 1.5A Adjustable Linear Regulator with Short Circuit Protection | TI.com

LM317A (ACTIVE) 1% Accurate, 1.5A Adjustable Linear Regulator with Short Circuit Protection

 

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Other devices and data sheet

Other device variants can also be found in the   LM317A-MIL product page

This data sheet applies to both   LM317A and   LM317A-MIL

Description

The LM317A adjustable 3-terminal, positive-voltage regulators are capable of supplying current in excess of 1.5 A over a 1.25-V to 37-V output range and provide 1% output-voltage accuracy. The LM317A device is available in an SOT-223 package, which makes it ideal for space-constrained applications that require high-performance regulation. The device is exceptionally easy to use and requires only two external resistors to set the output voltage. Both line regulation and load regulation are better achieved with the LM317A device than with standard fixed regulators.

The LM317A offers full overload protection such as current limit, thermal-overload protection, and safe-area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is disconnected.

Typically, no capacitors are needed unless the device is situated more than 6 inches 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 adjustment terminal can be bypassed to achieve very high ripple-rejection ratios that are difficult to achieve with standard 3-terminal regulators.

Because the LM317A regulator is and detects only the input-to-output differential voltage, supplies of several hundred volts can be regulated as long as the maximum input-to-output differential is not exceeded. Exceeding the maximum input-to-output deferential will result in short-circuiting the output.

By connecting a fixed resistor between the adjustment pin and output, the LM317A can be also used as a precision current regulator. Supplies with electronic shutdown can be achieved by clamping the adjustment terminal to ground, which programs the output to 1.25 V where most loads draw little current.

For applications requiring greater output current, see data sheets for LM150 series (3A), SNVS772, and LM138 series (5A), SNVS771. For the negative complement, see LM137 (SNVS778) series data sheet.

Features

  • Typical 0.005%/V Line Regulation
  • 1% Output Voltage Tolerance
  • 1.5-A Output Current
  • Adjustable Output Down to 1.25 V
  • Current Limit Constant with Temperature
  • 80-dB Ripple Rejection
  • Short-Circuit Protected Output
  • −40°C to 125°C Operating Temperature Range

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  Min   Max Range
Vin  V 4.2 to 40.0V
Vout  V 1.25 to 37V
Iout  A ≤ 1.5A
Ambient Temp  °C -40 to 125°C

Parametrics

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Part number Order Output options Iout (Max) (A) Vin (Max) (V) Vin (Min) (V) Vout (Max) (V) Vout (Min) (V) Package Group Features Regulated outputs (#) Operating temperature range (C) Thermal resistance θJA (°C/W) Noise (uVrms) Approx. price (US$) Rating Output capacitor type PSRR @ 100 KHz (dB) Accuracy (%) Vdo (Typ) (mV) Iq (Typ) (mA) Package size: mm2:W x L (PKG)
LM317A Order now Adjustable Output     1.5     40     4.2     37     1.2     SOT-223 | 4
TO-220 | 3
TO-252 | 3
TO | 3    
   
1     -40 to 125     24     38     0.61 | 1ku     Catalog     Non-Ceramic     40     5     2250     0.05     4SOT-223: 46 mm2: 7 x 6.5 (SOT-223 | 4)
3TO: 92 mm2: 9.14 x 10.03 (TO | 3)
See datasheet (TO-220)
3TO-252: 40 mm2: 6.1 x 6.58 (TO-252 | 3)    
LM117 Samples not available Adjustable Output     1.5     40     4.2     37     1.25     TO-3 | 2
TO | 3    
   
1     -55 to 125
-55 to 150    
39     75     7.52 | 1ku     Catalog     Non-Ceramic     40     4     1200     5     3TO: 92 mm2: 9.14 x 10.03 (TO | 3)
2TO-3: 969 mm2: 24.89 x 38.94 (TO-3 | 2)    
LM317-N Order now Adjustable Output     1.5     40     4.2     37     1.2     DDPAK/TO-263 | 3
SOT-223 | 4
TO-220 | 3
TO-252 | 3    
   
1     0 to 125     39     35     0.43 | 1ku     Catalog     Non-Ceramic     40     5     2250     3.5     3DDPAK/TO-263: 155 mm2: 15.24 x 10.16 (DDPAK/TO-263 | 3)
4SOT-223: 46 mm2: 7 x 6.5 (SOT-223 | 4)
See datasheet (TO-220)
3TO-252: 40 mm2: 6.1 x 6.58 (TO-252 | 3)    
LM317HV Order now Adjustable Output     1.5     60     4.2     57     1.25     TO-220 | 3    
   
1     0 to 125     23     1710     0.95 | 1ku     Catalog    
   
40     5     2250     0.05     See datasheet (TO-220)    
LM317L-N Order now Adjustable Output     0.1     40     4.2     38     1.2