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onsemi NCP317BTG
- Part No.:
- NCP317BTG
- Manufacturer:
- onsemi
- Package:
- TO-220-3
- Datasheet:
-
NCP317BTG.pdf
- Description:
- IC REG LIN POS ADJ 500MA TO220
- Quantity:
- Payment:
- Shipping:
Inventory:2,547
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Product details
Overview
NCP317BTG from onsemi is a 3-terminal adjustable positive voltage regulator delivering up to 1.5 A across an output range of 1.2 V to 37 V. It features internal thermal shutdown, current limiting, and safe-area compensation, and is used in local on-card regulation, programmable voltage supplies, and precision current regulation circuits.
For engineers reviewing the NCP317BTG datasheet, pinout, applications, or equivalent options, key selection considerations include output adjustability via two external resistors, 1.25 V reference voltage tolerance, dropout behavior under load, thermal resistance (θJC = 5.0 °C/W), and automotive-grade qualification per AEC-Q100.
Technical Context
The NCP317BTG operates as a floating linear regulator with a fixed 1.25 V reference between output and adjustment terminals. Its feedback loop uses R1–R2 resistor divider to set VOUT = 1.25 V × (1 + R2/R1) + IADJ×R2, where IADJ ≤ 100 µA ensures minimal error contribution.
It integrates protection circuitry including foldback current limiting, thermal shutdown at ~180 °C, and safe-area compensation for output transistor reliability. The device supports high-voltage floating operation - only the input-to-output differential matters, not absolute ground-referenced potentials.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | Up to 1.5 A continuous; enables single-regulator power delivery for mid-power analog/digital loads. |
| Output Voltage Range | 1.2 V to 37 V adjustable; eliminates need to stock multiple fixed-output regulators. |
| Reference Voltage | 1.25 V typical (1.2–1.3 V min/max); sets baseline accuracy for all output configurations. |
| Line Regulation | 0.01–0.07 %/V; maintains stable output despite ±10% input variation at full load. |
| Load Regulation | ≤ 0.5 % VOUT or ≤ 25 mV; ensures <±25 mV deviation across 10 mA–1.5 A load range. |
| Thermal Shutdown Threshold | 180 °C junction temperature; prevents permanent damage during sustained overload or poor heatsinking. |
| Junction-to-Case Thermal Resistance | 5.0 °C/W; enables predictable thermal design when mounted to heatsink via TO-220 tab (Pin 2). |
Pinout & Package
Package: TO-220 (Case 221AB), Pb-free, with heatsink surface electrically connected to Pin 2 (VOUT). Requires mechanical mounting to heatsink for >0.5 A operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Adjust | Feedback node for voltage setting; draws ≤100 µA; connects to R1–R2 divider junction. |
| 2 | VOUT | Regulated output terminal and thermal path; heatsink surface is internally tied to this pin. |
| 3 | VIN | Unregulated input supply; must exceed VOUT by ≥3 V for proper regulation (dropout). |
Key Features
| Feature | Design Value |
|---|---|
| Internal Safe-Area Compensation | Prevents secondary breakdown in output transistor during transient overloads or capacitive loads. |
| Floating Operation Capability | Enables high-side or floating regulator configurations - e.g., battery charger topologies or signal-chain biasing above ground. |
| Low Adjustment Pin Current | IADJ ≤ 100 µA minimizes R2-induced error; allows use of high-value resistors to reduce quiescent power loss. |
| Automotive Qualification | AEC-Q100 qualified (Grade 1: −40°C to +125°C), PPAP-capable, and manufactured under automotive process controls. |
| Thermal Overload Protection | Self-limiting shutdown at ~180 °C junction temperature; automatically recovers after cooldown without latch-up. |
Applications
| Industrial Power Supply | Automotive Body Control Module |
|---|---|
|
Use Scenario: Local 5 V/12 V regulation for microcontrollers and sensors on PCBs with noisy 24 V vehicle bus input. IC Role / Device Role / Timing Role: Adjustable linear regulator providing clean, low-noise DC power independent of input ripple or transients. Use Value: Eliminates need for external LDO post-regulation; withstands load dump pulses up to 40 V differential due to internal protection. |
Use Scenario: Programmable bias supply for CAN transceivers and LIN interface ICs requiring precise 3.3 V or 5 V rails. IC Role / Device Role / Timing Role: Voltage-setting regulator with AEC-Q100 compliance ensuring functional safety in non-safety-critical control nodes. Use Value: Enables single-BOM flexibility across multiple vehicle platforms via resistor programming instead of stocking discrete fixed regulators. |
| Programmable Lab Power Supply | LED Constant-Current Driver |
|
Use Scenario: Benchtop supply with user-adjustable output voltage (1.2–30 V) and current limit (0.1–1.5 A) using potentiometers and front-panel controls. IC Role / Device Role / Timing Role: Core voltage regulation element with external current-sense resistor enabling dual-loop (V/I) control. Use Value: Delivers stable, ripple-free output with <0.07 %/V line regulation - critical for calibration-grade instrumentation. |
Use Scenario: Low-cost constant-current driver for high-brightness LED strings in signage or interior lighting, where dimming is achieved via analog voltage control. IC Role / Device Role / Timing Role: Precision current regulator configured with R1 between ADJ and LED cathode, fixing ILED = 1.25 V / R1. Use Value: Maintains ±5% current accuracy over temperature (−40°C to +125°C) without needing op-amps or sense amplifiers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar adjustable positive voltage regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM317BTG | Same pinout and electrical specs, but rated for 0°C to +125°C (not automotive-grade); lacks AEC-Q100 qualification. | Suitable for commercial/industrial use only; not approved for automotive ECUs or body electronics. | Select LM317BTG for cost-sensitive non-automotive designs where extended temperature range is unnecessary. |
| NCV317BD2TG | D2PAK-3 package (surface-mount), identical AEC-Q100 qualification, same −55°C to +150°C operating range. | Required for automated SMT assembly; lower profile than TO-220 but higher θJA (70 °C/W vs. 65 °C/W). | Choose NCV317BD2TG when board space, reflow compatibility, or higher vibration resistance are priorities over through-hole serviceability. |
Compared with LM317BTG, NCP317BTG adds automotive qualification and tighter process controls; compared with NCV317BD2TG, it offers through-hole assembly and slightly better thermal performance in free-air conditions due to TO-220's lower θJA.
Availability
NCP317BTG is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and programmable lab equipment requiring stable component supply with long-term lifecycle support.
Supply support for NCP317BTG includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
onsemi is a global semiconductor supplier focused on energy-efficient innovation for automotive, industrial, cloud, and IoT applications.
The NCP317BTG belongs to onsemi's automotive-qualified linear regulator product line, designed specifically for robust, reliable DC power management in harsh environments such as engine compartments and chassis modules.
FAQ
What is the minimum load current required for regulation in the NCP317BTG?
The NCP317BTG requires a minimum load current of 3.5 mA (typical) to 10 mA (max) to maintain regulation, especially when the input-output differential exceeds 30 V. This is due to internal quiescent current routing - insufficient load causes output voltage to rise beyond setpoint. For zero-load applications, a bleeder resistor across the output is recommended. The NCP317BTG datasheet specifies this value under "Minimum Load Current to Maintain Regulation" in the Electrical Characteristics table.
Does the NCP317BTG require input and output capacitors for stability?
The NCP317BTG is internally compensated and stable without output capacitance, but a 0.1 µF ceramic input capacitor (CIN) is strongly recommended to suppress high-frequency noise and line impedance effects. An output capacitor (CO) is not mandatory for stability but improves transient response - a 1.0 µF tantalum or 25 µF aluminum electrolytic is typical. The NCP317BTG's stability is unaffected by CO values within standard ranges, unlike some LDOs.
Can the NCP317BTG be used as a constant-current source?
Yes, the NCP317BTG can function as a precision constant-current source by connecting a single resistor (RSET) between the adjustment and output pins. Output current is calculated as IOUT ≈ 1.25 V / RSET, since the internal reference voltage appears across RSET. This configuration is validated in the NCP317BTG datasheet Figure 26 and supports currents from 10 mA to 1.5 A, with accuracy limited primarily by RSET tolerance and temperature drift.
What is the maximum input-output voltage differential the NCP317BTG can withstand?
The NCP317BTG supports a maximum input-output voltage differential of 40 V DC, as specified in its Absolute Maximum Ratings table. Exceeding this - even briefly - risks permanent damage. In practice, thermal limits often constrain usable differential before reaching 40 V; for example, at 1.5 A output, power dissipation exceeds 60 W at 40 V differential, far exceeding the TO-220 package's thermal capability. The NCP317BTG must be heatsinked appropriately based on actual VIN–VOUT and load current.
Is the heatsink tab of the NCP317BTG electrically isolated?
No, the heatsink tab of the NCP317BTG is not electrically isolated - it is internally connected to Pin 2 (VOUT). This is confirmed in the TO-220 mechanical drawing (Case 221AB) and the "Standard Application" schematic notes. When mounting to a metal chassis or shared heatsink, electrical isolation (e.g., mica washer + shoulder washer) is required unless the heatsink is referenced to the output rail. Failure to isolate may cause short circuits or ground loops. This applies identically to the NCP317BTG in all production lots.
NCP317BTG Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Adjustable
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.2V
- Voltage - Output (Max):
- 37V
- Voltage Dropout (Max):
- -
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- -
- Current - Supply (Max):
- -
- PSRR:
- -
- Control Features:
- -
- Protection Features:
- -
- Operating Temperature:
- -55°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220
NCP317BTG FAQ
1.How can I place an order for NCP317BTG through Aetrix?
Please submit a Request for Quotation (RFQ) for NCP317BTG on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for NCP317BTG reliable?
The price and inventory of NCP317BTG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for NCP317BTG is usually 5 days.
3.What payment methods are accepted for NCP317BTG?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for NCP317BTG transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for NCP317BTG?
NCP317BTG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your NCP317BTG order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for NCP317BTG?
For technical support, including NCP317BTG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your NCP317BTG requirements.
6.How does Aetrix verify that NCP317BTG is sourced from the original manufacturer or authorized distributors?
All NCP317BTG products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that NCP317BTG meets industry standards.
7.What is the process for return or replacement of NCP317BTG?
All NCP317BTG units undergo pre-shipment inspection (PSI). If there is an issue with NCP317BTG, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The NCP317BTG part is unused and in its original packaging.
Return procedure for NCP317BTG:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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