Overview
The LM317D2TR4, produced by onsemi, is an adjustable 3-terminal positive voltage regulator. It is capable of supplying an output current in excess of 1.5 A over an output voltage range of 1.2 V to 37 V. This regulator is known for its ease of use, requiring only two external resistors to set the output voltage. The LM317D2TR4 also features internal current limiting, thermal shutdown, and safe area compensation, making it highly reliable and essentially blow-out proof.
Key Specifications
| Parameter | Symbol | Value | Unit |
|---|---|---|---|
| Input-Output Voltage Differential | VI - VO | -0.3 to 40 | Vdc |
| Output Current | IO | Internally Limited | A |
| Power Dissipation | PD | Internally Limited | W |
| Thermal Resistance, Junction-to-Ambient | θJA | 70 | °C/W |
| Thermal Resistance, Junction-to-Case | θJC | 5.0 | °C/W |
| Operating Junction Temperature Range | TJ | -40 to +125 | °C |
| Storage Temperature Range | Tstg | -65 to +150 | °C |
| Line Regulation | ΔVO | 0.01 to 0.05 %/V | |
| Load Regulation | ΔVO | 0.1 to 1.0 % | |
| Adjustment Pin Current | IADJ | 50 to 100 µA | |
| Reference Voltage | VREF | 1.2 to 1.3 V | |
| Minimum Load Current | IO(min) | 3.5 to 5 mA | |
| Maximum Load Current | IO(max) | 1.5 A |
Key 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
- Requires only two external resistors to set the output voltage
- Can be used as a programmable output regulator or precision current regulator
- High ripple rejection ratio (up to 80 dB with CAdj = 10 µF)
- Long-term stability and low output noise voltage
Applications
The LM317D2TR4 serves a wide variety of applications, including local, on-card regulation. It is suitable for use in:
- Local voltage regulation on PCBs
- Programmable output regulators
- Precision current regulators by connecting a fixed resistor between the adjustment and output terminals
- High-voltage applications where the voltage differential across the circuit is critical
Q & A
- What is the output voltage range of the LM317D2TR4?
The output voltage range of the LM317D2TR4 is from 1.2 V to 37 V.
- What is the maximum output current of the LM317D2TR4?
The maximum output current is internally limited but can exceed 1.5 A.
- What kind of protection does the LM317D2TR4 have?
The LM317D2TR4 features internal thermal overload protection and short circuit current limiting.
- How do you set the output voltage of the LM317D2TR4?
The output voltage is set using two external resistors connected between the output, adjustment, and ground terminals.
- What is the thermal shutdown temperature of the LM317D2TR4?
The thermal shutdown temperature is approximately 180°C.
- What is the minimum load current required for the LM317D2TR4?
The minimum load current is typically 3.5 to 5 mA.
- Can the LM317D2TR4 be used as a precision current regulator?
Yes, it can be used as a precision current regulator by connecting a fixed resistor between the adjustment and output terminals.
- What is the ripple rejection ratio of the LM317D2TR4?
The ripple rejection ratio is up to 80 dB with a 10 µF capacitor connected between the adjustment pin and ground.
- What are the common package types for the LM317D2TR4?
The LM317D2TR4 is available in D2PAK-3 and TO-220 packages.
- Is the LM317D2TR4 suitable for high-voltage applications?
Yes, it is suitable for high-voltage applications where the voltage differential across the circuit is critical.
