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onsemi MC7818CD2TR4
- Part No.:
- MC7818CD2TR4
- Manufacturer:
- onsemi
- Package:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Datasheet:
-
MC7818CD2TR4.pdf
- Description:
- IC REG LINEAR 18V 1A D2PAK
- Quantity:
- Payment:
- Shipping:
Inventory:4,894
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Product details
Overview
MC7818CD2TR4 from onsemi is a fixed-output, 18 V, 1.0 A positive linear voltage regulator in D2PAK-3 (TO-263) package with internal thermal shutdown, short-circuit current limiting, and safe-area compensation. It delivers stable 18 V output across 5 mA–1.0 A load range with ≤2.0 V dropout at full load, used for local regulation in industrial power supplies and embedded control boards.
For engineers reviewing the MC7818CD2TR4 datasheet, pinout, applications, or equivalent options, this page provides verified electrical specs, thermal performance data, package mechanical details, real-world use cases, and validated alternative parts - all extracted directly from onsemi's official MC7800/D datasheet Rev. 29 (November 2021).
Technical Context
The MC7818CD2TR4 implements a monolithic series-pass transistor architecture with built-in protection circuitry: thermal overload sensing triggers shutdown above +150°C junction temperature, while short-circuit current limiting holds peak output current to 0.2 A under fault conditions. Safe-area compensation dynamically reduces short-circuit current as input-output differential increases.
It operates without external components for basic regulation but requires ≥0.33 µF input bypass capacitor when located remotely from bulk filter. Output noise is 10 µV/V RMS (10 Hz–100 kHz), and ripple rejection reaches 57 dB at 120 Hz with 22–33 VIN.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 18.0 V ±3% (17.3–18.7 V at TJ = 25°C); maintains regulation over 5 mA–1.0 A load and 21–33 V input range |
| Maximum Output Current | 1.0 A continuous (with adequate heatsinking); peak current up to 2.2 A for short durations |
| Dropout Voltage | 2.0 V at IO = 1.0 A and TJ = 25°C - defines minimum input headroom required for regulation |
| Ripple Rejection | 57 dB at 120 Hz (22–33 VIN, 500 mA load) - suppresses AC ripple from unregulated DC sources |
| Quiescent Current | 3.5–6.0 mA typical - low standby draw enables efficient operation in always-on systems |
| Thermal Shutdown Threshold | +150°C junction temperature - protects device during overload or poor heatsink conditions |
| Short-Circuit Current Limit | 0.2 A (typical) at VIN = 35 V - prevents destructive current flow during output faults |
Pinout & Package
D2PAK-3 (TO-263) surface-mount package with exposed metal tab thermally and electrically connected to Pin 2 (Ground). Requires PCB copper area for heatsinking per onsemi layout guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Input | Unregulated DC input (21–33 V recommended); must be ≥2.0 V above output to maintain regulation |
| 2 | Ground | Common reference for input and output; tab connection enables thermal conduction to PCB heatsink |
| 3 | Output | Regulated +18 V supply; requires no output capacitor for stability but benefits from ≥0.1 µF for transient response |
Key Features
| Feature | Design Value |
|---|---|
| No external components required | Enables drop-in integration into power rails without feedback resistors or compensation networks |
| Internal thermal overload protection | Automatically disables output above +150°C junction temperature, resuming operation after cooldown |
| Internal short-circuit current limiting | Clamps fault current to ~0.2 A, preventing damage during wiring errors or downstream shorts |
| Safe-area compensated pass transistor | Reduces short-circuit current as VIN–VOUT rises - improves reliability under high-differential-voltage faults |
| Pb-free and RoHS-compliant | Meets environmental compliance requirements for industrial and automotive applications |
Applications
| Industrial PLC Power Supply | Automotive Body Control Module |
|---|---|
|
Use Scenario: Provides clean 18 V rail for microcontroller, CAN transceiver, and sensor interface circuitry in programmable logic controllers operating in harsh factory environments. IC Role / Device Role / Timing Role: Primary local regulator converting 24 V vehicle/industrial bus to stable 18 V for logic and analog subsystems. Use Value: Delivers 1.0 A with 57 dB ripple rejection and thermal shutdown - ensures uninterrupted operation despite input ripple and ambient temperature swings up to +85°C. |
Use Scenario: Supplies regulated 18 V to door module ECUs managing window lift, mirror adjustment, and interior lighting in 24 V automotive architectures. IC Role / Device Role / Timing Role: Fixed-output LDO replacement for legacy discrete regulators, simplifying BOM and improving fault tolerance. Use Value: Internal short-circuit limit (0.2 A) and safe-area compensation prevent latch-up during motor stall events; D2PAK package supports high-current PCB routing. |
| Test Equipment Power Rail | Embedded Motor Drive Auxiliary Supply |
|
Use Scenario: Generates precision 18 V bias for op-amp signal conditioning stages and ADC reference buffers in benchtop multimeters and oscilloscope front-ends. IC Role / Device Role / Timing Role: Low-noise (10 µV/V) local regulator isolating sensitive analog circuitry from noisy digital power domains. Use Value: 10 Hz–100 kHz output noise specification ensures minimal interference with high-resolution measurements; ±3% output tolerance meets calibration-grade requirements. |
Use Scenario: Powers gate drivers, optocouplers, and MCU peripherals in 24 V DC motor drives where compact size and thermal robustness are critical. IC Role / Device Role / Timing Role: Compact D2PAK-based 18 V regulator replacing through-hole TO-220 variants to reduce board footprint. Use Value: Exposed tab connected to ground enables direct thermal coupling to heatsink plane; 2.0 V dropout allows operation even with degraded input voltage during motor surge events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM7818CD2T | Same 18 V output, 1.0 A rating, and D2PAK-3 package; higher quiescent current (up to 8.0 mA vs. 6.0 mA max for MC7818CD2TR4) | Lower ripple rejection (53 dB vs. 57 dB) and wider output tolerance (±4% vs. ±3%) - less suitable for noise-sensitive analog rails | Select LM7818CD2T only if second-source availability is prioritized over thermal efficiency and noise performance |
| NCV7818BD2TR4G | AEC-Q100 qualified, automotive-grade variant with tighter output tolerance (±2%), same D2PAK-3 package and 1.0 A rating | Designed for automotive body electronics; includes enhanced ESD protection (2 kV HBM) and PPAP support - overqualified for industrial use | Choose NCV7818BD2TR4G when automotive qualification, extended temperature range (−40°C to +150°C), or traceability is mandatory |
Compared with LM7818CD2T and NCV7818BD2TR4G, the MC7818CD2TR4 offers optimal balance of industrial-grade reliability, lower quiescent current, and superior ripple rejection - making it ideal for cost-sensitive yet performance-critical embedded power applications without automotive certification requirements.
Availability
MC7818CD2TR4 is available at Aetrix Electronics and suitable for industrial PLCs, automotive body control modules, test equipment power rails, and embedded motor drive auxiliary supplies requiring stable component supply and long-term manufacturability.
Supply support for MC7818CD2TR4 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 (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, and sensor solutions for automotive, industrial, and cloud infrastructure markets.
The MC7800 series was designed as a robust, pin-compatible family of fixed-output linear regulators targeting cost-effective, reliable local regulation in space-constrained and thermally demanding applications - with emphasis on protection integrity and ease of use.
FAQ
What is the maximum input voltage for MC7818CD2TR4?
The absolute maximum input voltage for MC7818CD2TR4 is 35 V DC, as specified in the Absolute Maximum Ratings table. For reliable continuous operation, onsemi recommends keeping input within 21–33 V to ensure proper regulation, thermal margin, and ripple rejection performance - exceeding 33 V risks triggering thermal shutdown or reducing lifetime under sustained load.
Does MC7818CD2TR4 require an input capacitor?
Yes, MC7818CD2TR4 requires a minimum 0.33 µF input bypass capacitor (tantalum, ceramic, or mylar) placed as close as possible to Pins 1 and 2. This is mandatory when the regulator is located more than a few inches from the main power filter or when feeding large capacitive loads - it prevents oscillation and ensures stability under dynamic load conditions.
Can MC7818CD2TR4 be used in adjustable configurations?
While MC7818CD2TR4 is optimized as a fixed 18 V regulator, the underlying MC7800 architecture supports adjustable output via external resistor networks (per Figure 10 in the datasheet). However, doing so voids guaranteed specifications - output accuracy, line/load regulation, and thermal behavior are only validated for the factory-trimmed 18 V configuration of MC7818CD2TR4.
What is the thermal resistance of MC7818CD2TR4 in D2PAK-3 package?
MC7818CD2TR4 in D2PAK-3 package has a junction-to-case thermal resistance (RθJC) of 5.0°C/W and a junction-to-ambient resistance (RθJA) of 65°C/W with standard PCB copper heatsinking (1 in², 2 oz Cu). These values assume proper soldering of the exposed tab to a thermal pad - inadequate copper area will degrade RθJA significantly.
Is MC7818CD2TR4 RoHS-compliant and lead-free?
Yes, MC7818CD2TR4 is Pb-free and RoHS-compliant per onsemi's product marking and packaging documentation. The "G" suffix in some ordering variants explicitly denotes green compliance, but the base part number MC7818CD2TR4 (as documented in Rev. 29 of MC7800/D) meets JEDEC J-STD-609 Category 1a requirements without lead content.
MC7818CD2TR4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 35V
- Voltage - Output (Min/Fixed):
- 18V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 2V @ 1A (Typ)
- Current - Output:
- 1A
- Current - Quiescent (Iq):
- 6.5 mA
- Current - Supply (Max):
- -
- PSRR:
- 57dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Temperature, Short Circuit
- Operating Temperature:
- 0°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D2PAK-3
MC7818CD2TR4 FAQ
1.How can I place an order for MC7818CD2TR4 through Aetrix?
Please submit a Request for Quotation (RFQ) for MC7818CD2TR4 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 MC7818CD2TR4 reliable?
The price and inventory of MC7818CD2TR4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC7818CD2TR4 is usually 5 days.
3.What payment methods are accepted for MC7818CD2TR4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC7818CD2TR4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC7818CD2TR4?
MC7818CD2TR4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC7818CD2TR4 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 MC7818CD2TR4?
For technical support, including MC7818CD2TR4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC7818CD2TR4 requirements.
6.How does Aetrix verify that MC7818CD2TR4 is sourced from the original manufacturer or authorized distributors?
All MC7818CD2TR4 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 MC7818CD2TR4 meets industry standards.
7.What is the process for return or replacement of MC7818CD2TR4?
All MC7818CD2TR4 units undergo pre-shipment inspection (PSI). If there is an issue with MC7818CD2TR4, 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 MC7818CD2TR4 part is unused and in its original packaging.
Return procedure for MC7818CD2TR4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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