LM317 |
RFQ for LM317 Required Field |
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| Technical/Catalog Information | LM317AEMP/NOPB |
| Vendor | National Semiconductor (VA) |
| Category | Integrated Circuits (ICs) |
| Regulator Type | Single Output |
| Package / Case | SOT-223 (3 leads + Tab), SC-73, TO-261AA |
| Packaging | Digi-Reel? |
| Regulator Topology | Positive Adjustable |
| Current - Output | 1A |
| Voltage - Output | 1.2 ~ 37 V |
| Operating Temperature | -40°C ~ 125°C |
| Voltage - Input | 4.2 ~ 40 V |
| Number of Regulators | 1 |
| Current - Limit (Min) | 1.5A |
| Current Short Circuit (Isc) | - |
| Drawing Number | 14; MP04A; ; 4 |
| Lead Free Status | Lead Free |
| RoHS Status | RoHS Compliant |
| Other Names | LM317AEMP NOPB LM317AEMPNOPB LM317AEMPDKR ND LM317AEMPDKRND LM317AEMPDKR |
| Product | Manufacturers | Pack | D/C | |||||
| LM317 | National Semiconductor | - | - |
The optocoupler (as shown) provides load sensing for a 3-terminal regulator, such as the LM317 series. R1 sets a current of 5 mA through the optocoupler transistor and R3 is adjusted for 12 V across the load.
The LM117 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 1.5A over a 1.2V to 37V output range. They are exceptionally easy to use and require only two external resistors to set the output voltage. Further, both line and load regulation are better than standard fixed regulators. Also, the LM117 is packaged in standard transistor packages which are easily mounted and handled.
In addition to higher performance than fixed regulators, the LM117 series offers full overload protection available only in IC's. Included on the chip are current limit, thermal overload protection and safe area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is disconnected.
Normally, 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 which are difficult to achieve with standard 3-terminal regulators.
Besides replacing fixed regulators, the LM117 is useful in a wide variety of other applications. Since the regulator is “floating” and sees 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, i.e., avoid short-circuiting the output.
Also, it makes an especially simple adjustable switching regulator, a programmable output regulator, or by connecting a fixed resistor between the adjustment pin and output, the LM117 can be used as a precision current regulator. Supplies with electronic shutdown can be achieved by clamping the adjustment terminal to grou
| Product | Product status | Eco Status | Pricing* | Package type | Leads | Packing method | Package Drawing | Package Marking Convention** |
|---|---|---|---|---|---|---|---|---|
| LM317T | Full Production | RoHS Compliant | $0.396 | TO-220 | 3 | RAIL | T03B | Line 1: $Y (Fairchild logo) &Z (Asm. Plant Code) &3 (3-Digit Date Code) &K Line 3: LM317 |
| * Fairchild 1,000 piece Budgetary Pricing |
| ** A sample button will appear if the part is available through Fairchild's on-line samples program. If there is no sample button, please contact a Fairchild distributor to obtain samples |
Package marking information for product LM317 is available. Click here for more information . |
