LM317T
Voltage Regulator – Adjustable Output, Positive 1.5 A
Manufacturer
ti
Overview
Part: LM317, NCV317
Type: Adjustable 3-terminal positive voltage regulator
Key Specs:
- Output Current: In excess of 1.5 A
- Output Voltage Range: 1.2 V to 37 V
- Input-Output Voltage Differential: -0.3 V to 40 V
- Adjustment Pin Current (Typ): 50 µA
- Reference Voltage (Typ): 1.25 V
Features:
- Output Current in Excess of 1.5 A
- Output Adjustable between 1.2 V and 37 V
- Internal Thermal Overload Protection
- Internal Short Circuit Current Limiting Constant with Temperature
- Output Transistor Safe-Area Compensation
- Floating Operation for High Voltage Applications
- Eliminates Stocking many Fixed Voltages
- Available in Surface Mount D²PAK-3, and Standard 3-Lead Transistor Package
- NCV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC-Q100 Qualified and PPAP Capable
- These Devices are Pb-Free, Halogen Free/BFR Free and are RoHS Compliant
Applications:
- Local, on card regulation
- Programmable output regulator
- Precision current regulator
Package:
- D²PAK-3: Case 936
- Standard 3-Lead Transistor Package: Case 221A
Features
- Output Current in Excess of 1.5 A
- Output Adjustable between 1.2 V and 37 V
- Internal Thermal Overload Protection
- Internal Short Circuit Current Limiting Constant with Temperature
- Output Transistor Safe-Area Compensation
- Floating Operation for High Voltage Applications
- Eliminates Stocking many Fixed Voltages
- Available in Surface Mount D2PAK-3, and Standard 3-Lead Transistor Package
- NCV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements; AEC-Q100 Qualified and PPAP Capable
- These Devices are Pb-Free, Halogen Free/BFR Free and are RoHS Compliant
* Cin is required if regulator is located an appreciable distance from power supply filter.
** CO is not needed for stability, however, it does improve transient response.
$$V_{out} = 1.25 V \left( 1 + \frac{R_2}{R_1} \right) + I_{Adj} R_2$$
Since $I_{Adj}$ is controlled to less than 100 $\mu\text{A},$ the error associated with this term is negligible in most applications.
August, 2021 - Rev. 17
Figure 1. Standard Application
D2PAK-3 D2T SUFFIX CASE 936
Heatsink surface (shown as terminal 4 in case outline drawing) is connected to Pin 2.
Heatsink surface connected to Pin 2.
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 10 of this data sheet.
MAXIMUM RATINGS
| Rating | Symbol | Value | Unit |
|---|---|---|---|
| Input-Output Voltage Differential | V I -V O | -0.3 to 40 | Vdc |
| Power Dissipation | |||
| Case 221A | |||
| $T_A = +25^{\circ}C$ | P D | Internally Limited | W |
| Thermal Resistance, Junction-to-Ambient | $\theta_{\sf JA}$ | 65 | °C/W |
| Thermal Resistance, Junction-to-Case | θJC | 5.0 | °C/W |
| Case 936 (D 2 PAK-3) | |||
| $T_A = +25^{\circ}C$ | P D | Internally Limited | W |
| Thermal Resistance, Junction-to-Ambient | $\theta_{\sf JA}$ | 70 | °C/W |
| Thermal Resistance, Junction-to-Case | $\theta_{\sf JC}$ | 5.0 | °C/W |
| Operating Junction Temperature Range | T J | -55 to +150 | °C |
| Storage Temperature Range | T stg | -65 to +150 | °C |
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected.
Electrical Characteristics
$(V_I - V_O = 5.0 \text{ V}; I_O = 0.5 \text{ A for D2T and T packages}; T_J = T_{low} \text{ to } T_{high} \text{ (Note 1)}; I_{max} \text{ and P}_{max} \text{ (Note 2)}; unless otherwise noted.)}$
| Characteristics | Figure | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|---|
| Line Regulation (Note 3), $T_A = +25^{\circ}C$ , $3.0 \text{ V} \leq V_I - V_O \leq 40 \text{ V}$ | 1 | Reg line | - | 0.01 | 0.04 | %/V |
| Load Regulation (Note 3), $T_A = +25^{\circ}C$ , 10 mA $\leq I_O \leq I_{max}$ $V_O \leq 5.0 \text{ V}$ $V_O \geq 5.0 \text{ V}$ | 2 | Reg load | - - | 5.0 0.1 | 25 0.5 | mV % V O |
| Thermal Regulation, $T_A = +25^{\circ}C$ (Note 4), 20 ms Pulse | - | Reg therm | - | 0.03 | 0.07 | % V O /W |
| Adjustment Pin Current | 3 | $I_{Adj}$ | - | 50 | 100 | μΑ |
| Adjustment Pin Current Change, 2.5 V $\leq$ V I -V O $\leq$ 40 V, 10 mA $\leq$ I L $\leq$ I max , P D $\leq$ P max | 1, 2 | $\Delta I_{Adj}$ | - | 0.2 | 5.0 | μΑ |
| Reference Voltage, 3.0 V $\leq$ V I -V O $\leq$ 40 V, 10 mA $\leq$ I O $\leq$ I max , P D $\leq$ P max | 3 | $V_{ref}$ | 1.2 | 1.25 | 1.3 | V |
| Line Regulation (Note 3), 3.0 V $\leq$ V I -V O $\leq$ 40 V | 1 | Reg line | - | 0.02 | 0.07 | %/V |
| Load Regulation (Note 3), 10 mA $\leq$ $I_O \leq$ $I_{max}$ $V_O \leq$ 5.0 V $V_O \geq$ 5.0 V | 2 | Reg load | 20 0.3 | 70 1.5 | mV % V O | |
| Temperature Stability ( $T_{low} \le T_J \le T_{high}$ ) | 3 | T S | _ | 0.7 | _ | % V O |
| Minimum Load Current to Maintain Regulation (V I –V O = 40 V) | 3 | I Lmin | _ | 3.5 | 10 | mA |
| Maximum Output Current $V_{I} - V_{O} \leq 15 \text{ V, } P_{D} \leq P_{max}, \text{ T Package}$ $V_{I} - V_{O} = 40 \text{ V, } P_{D} \leq P_{max}, \text{ T}_{A} = +25^{\circ}\text{C, T Package}$ | 3 | I max | 1.5 0.15 | 2.2 0.4 | A | |
| RMS Noise, % of $V_0$ , $T_A = +25^{\circ}C$ , 10 Hz $\leq$ f $\leq$ 10 kHz | _ | N | _ | 0.003 | _ | % V O |
| Ripple Rejection, $V_O$ = 10 V, f = 120 Hz (Note 5) Without $C_{Adj}$ $C_{Adj}$ = 10 $\mu F$ | 4 | RR | - 66 | 65 80 | - - | dB |
| Thermal Shutdown (Note 6) | _ | - | - | 180 | _ | °C |
| Long-Term Stability, T J = T high (Note 7), T A = +25°C for Endpoint Measurements | 3 | S | - | 0.3 | 1.0 | %/1.0 kHrs. |
| Thermal Resistance Junction-to-Case, T Package | - | $R_{\theta JC}$ | - | 5.0 | _ | °C/W |
1. $T_{low}$ to $T_{high}$ = 0° to +125°C, for LM317T, D2T. $T_{low}$ to $T_{high}$ = -40° to +125°C, for LM317BT, BD2T, $T_{low}$ to $T_{high}$ = -55° to +150°C, for NCV317BT, BD2T.
Since Long-Term Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot.
2. $I_{max} = 1.5 A$ , $P_{max} = 20 W$
Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used.
Power dissipation within an IC voltage regulator produces a temperature gradient on the die, affecting individual IC components on the die. These effects can be minimized by proper integrated circuit design and layout techniques. Thermal Regulation is the effect of these temperature gradients on the output voltage and is expressed in percentage of output change per watt of power change in a specified time.
5. CAdj, when used, is connected between the adjustment pin and ground.
6. Thermal characteristics are not subject to production test.
This device contains 29 active transistors.
Figure 2. Representative Schematic Diagram
Figure 3. Line Regulation and $\Delta I_{\mbox{\scriptsize Adj}}/\mbox{\scriptsize Line}$ Test Circuit
Figure 4. Load Regulation and $\Delta I_{\mbox{Adj}}\mbox{/Load}$ Test Circuit
Figure 5. Standard Test Circuit
Figure 6. Ripple Rejection Test Circuit
Figure 7. Load Regulation
Figure 8. Current Limit
Figure 9. Adjustment Pin Current
Figure 10. Dropout Voltage
Figure 11. Temperature Stability
Figure 12. Minimum Operating Current
Figure 13. Ripple Rejection versus Output Voltage
Figure 14. Ripple Rejection versus Output Current
Figure 15. Ripple Rejection versus Frequency
Figure 16. Output Impedance
Figure 17. Line Transient Response
Figure 18. Load Transient Response
APPLICATIONS INFORMATION
Absolute Maximum Ratings
| Rating | Symbol | Value | Unit |
|---|---|---|---|
| Input-Output Voltage Differential | V I -V O | -0.3 to 40 | Vdc |
| Power Dissipation | |||
| Case 221A | |||
| $T_A = +25^{\circ}C$ | P D | Internally Limited | W |
| Thermal Resistance, Junction-to-Ambient | $\theta_{\sf JA}$ | 65 | °C/W |
| Thermal Resistance, Junction-to-Case | θJC | 5.0 | °C/W |
| Case 936 (D 2 PAK-3) | |||
| $T_A = +25^{\circ}C$ | P D | Internally Limited | W |
| Thermal Resistance, Junction-to-Ambient | $\theta_{\sf JA}$ | 70 | °C/W |
| Thermal Resistance, Junction-to-Case | $\theta_{\sf JC}$ | 5.0 | °C/W |
| Operating Junction Temperature Range | T J | -55 to +150 | °C |
| Storage Temperature Range | T stg | -65 to +150 | °C |
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected.
Get structured datasheet data via API
Get started free