LM317M_11 Datasheet, PDF (1/14 Pages) Fairchild Semiconductor – 3-Terminal 0.5A Positive Adjustable Regulator

LM317M, NCV317MAB,
NCV317MB
500 mA Adjustable Output,
Positive Voltage Regulator
The LM317M is an adjustable three−terminal positive voltage
regulator capable of supplying in excess of 500 mA over an output
voltage range of 1.2 V to 37 V. This voltage regulator is exceptionally
easy to use and requires only two external resistors to set the output
voltage. Further, it employs internal current limiting, thermal
shutdown and safe area compensation, making it essentially blow−out
proof.
The LM317M serves a wide variety of applications including local,
on−card regulation. This device also makes an especially simple
adjustable switching regulator, a programmable output regulator, or by
connecting a fixed resistor between the adjustment and output, the
LM317M can be used as a precision current regulator.
Features
• Output Current in Excess of 500 mA
• Output Adjustable between 1.2 V and 37 V
• Internal Thermal Overload Protection
• Internal Short Circuit Current Limiting
• Output Transistor Safe−Area Compensation
• Floating Operation for High Voltage Applications
• Eliminates Stocking Many Fixed Voltages
• NCV Prefix for Automotive and Other Applications Requiring Site
and Control Changes
• Pb−Free Packages are Available
V_in
V_in
V_out
LM317M
V_out
*
C_in
0.1mF
I_{Adj Adjust}
R₁
240
**
+ _CO
1.0mF
R₂
 * = C_in is required if regulator is located an appreciable distance from power supply filter.
** = C_O is not needed for stability, however, it does improve transient response.
ǒ Ǔ Vout + 1.25   V  
1
)
R2
R1
) IAdj  R2
Since I_Adj is controlled to less than 100 mA, the error associated with this
term is negligible in most applications.
Figure 1. Simplified Application
http://onsemi.com
Heatsink surface
connected to Pin 2
TO−220AB
T SUFFIX
CASE 221AB
SOT−223
ST SUFFIX
CASE 318E
1
2
3
1
23
DPAK
DT SUFFIX
CASE 369C
4
12
3
Heatsink Surface (shown as terminal 4 in
case outline drawing) is connected to Pin 2.
PIN ASSIGNMENT
1
Adjust
2
V_out
3
V_in
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 10 of this data sheet.
DEVICE MARKING INFORMATION
See general marking information in the device marking
section on page 11 of this data sheet.
© Semiconductor Components Industries, LLC, 2011
1
September, 2011 − Rev. 21
Publication Order Number:
LM317M/D