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onsemi MC78L09ACD
- Part No.:
- MC78L09ACD
- Manufacturer:
- onsemi
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MC78L09ACD.pdf
- Description:
- IC REG LINEAR 9V 100MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,556
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Product details
Overview
MC78L09ACD from onsemi is a 100 mA, fixed +9.0 V positive linear voltage regulator in SOIC-8 package, featuring internal short-circuit current limiting, thermal shutdown, and dropout voltage of 1.7 V at 25°C. It operates over 0°C to +125°C junction temperature and requires no external components for basic regulation in low-power embedded systems, sensor interfaces, and industrial control modules.
For engineers reviewing the MC78L09ACD datasheet, pinout, applications, or equivalent options, key selection considerations include its 9.0 V ±5% output tolerance at 40 mA, 37–57 dB ripple rejection at 120 Hz, 60 µV RMS output noise (10 Hz–100 kHz), and SOIC-8 thermal resistance dependency on PCB copper area per Figure 8.
Technical Context
The MC78L09ACD implements a monolithic series-pass transistor regulator with built-in protection circuitry: thermal overload shutdown activates when junction temperature exceeds ~150°C, and internal current limiting caps output at ~150 mA under short-circuit conditions. Its architecture eliminates need for external compensation capacitors in most applications, though input bypassing with ≥0.33 µF and output stabilization with ≥0.1 µF are recommended for transient response and long-trace stability.
It belongs to the MC78L00A family optimized for cost-sensitive, low-current (<100 mA) regulation where simplicity and ruggedness outweigh efficiency demands. Unlike switching regulators, it delivers low-noise DC with no EMI concerns but dissipates power as heat-thermal design must account for RJA = variable (see Figure 8) and maximum 625 mW at 25°C ambient in SOIC-8 with adequate copper.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | +9.0 V ±0.4 V (min/max) at 25°C, 40 mA load - ensures stable supply for 9 V logic rails and analog sensors requiring tight DC accuracy |
| Maximum Output Current | 100 mA continuous - supports microcontrollers, op-amps, and small displays without derating below 50 mA in typical SOIC-8 layouts |
| Dropout Voltage | 1.7 V typical at 25°C - mandates minimum 10.7 V input for regulated 9 V output, critical for battery-powered designs near end-of-life |
| Ripple Rejection | 37 dB min / 57 dB typ at 120 Hz - suppresses line-frequency artifacts from unregulated wall adapters or rectified AC supplies |
| Output Noise | 60 µV RMS (10 Hz–100 kHz) - suitable for low-noise analog front-ends where switching regulator noise would degrade SNR |
| Thermal Shutdown Threshold | Junction temperature >150°C - protects against sustained overload or inadequate heatsinking in enclosed enclosures |
| Operating Temperature | 0°C to +125°C junction - validated for commercial/industrial environments excluding automotive under-hood |
Pinout & Package
MC78L09ACD uses an SOIC-8 package (Case 751), internally modified so pins 2, 3, 6, and 7 are electrically common to the die attach flag-reducing thermal resistance and enabling higher power dissipation when mounted on sufficient PCB copper area (see Figure 8).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Output (VOUT) | Regulated +9.0 V supply rail; connects directly to load and output capacitor (0.1 µF recommended) |
| 2 | Ground (GND) | Common reference for input/output; electrically tied to die flag and pins 3, 6, 7-must be low-impedance PCB plane |
| 3 | Ground (GND) | Redundant ground terminal enhancing thermal path and reducing ground bounce in noisy systems |
| 4 | Input (VIN) | Unregulated DC input; requires ≥0.33 µF bypass capacitor close to pin to prevent oscillation under dynamic loads |
| 5 | Ground (GND) | Third ground connection reinforcing thermal conduction and minimizing voltage drop across package leads |
| 6 | Ground (GND) | Fourth ground tied to die flag-critical for achieving specified RJA; must connect to large copper pour |
| 7 | Ground (GND) | Fifth ground terminal completing low-resistance return path and improving thermal performance |
| 8 | No Connect (NC) | Internally unused; leave floating-no routing or soldering required |
Key Features
| Feature | Design Value |
|---|---|
| Fixed +9.0 V output | Eliminates external resistor network calibration, reducing BOM count and layout complexity for dedicated 9 V rails |
| Internal short-circuit limiting | Prevents catastrophic failure during output faults-no external current-sense resistor or shutdown logic needed |
| Thermal overload protection | Automatically disables output above 150°C junction, enabling safe operation in sealed enclosures without forced air |
| No external components required | Enables single-chip regulation in space-constrained PCBs-only input/output capacitors recommended for robustness |
| Pb-free SOIC-8 package | Complies with RoHS directives and supports lead-free reflow profiles without compromising thermal performance |
Applications
| Industrial Sensor Interface | Low-Power Microcontroller Supply |
|---|---|
Use Scenario: Powering analog-output temperature/humidity sensors (e.g., Honeywell HIH-4000) in factory-floor monitoring nodes. IC Role / Device Role / Timing Role: Provides clean, stable +9.0 V bias for sensor excitation and op-amp signal conditioning stages. Use Value: 60 µV RMS noise and 57 dB ripple rejection preserve sensor signal integrity, avoiding ADC quantization errors from supply-induced offsets. | Use Scenario: Supplying 8-bit microcontrollers (e.g., PIC16F1503) in battery-operated remote controls and smart switches. IC Role / Device Role / Timing Role: Delivers regulated 9 V to MCU VDD while supporting sleep-mode current draw <1 mA. Use Value: 3.0 mA typical input bias current minimizes quiescent drain on primary cells, extending shelf life beyond 2 years. |
| Legacy Industrial Control Module | Embedded Display Backlight Driver |
Use Scenario: Replacing aging 7809-based power supplies in PLC I/O modules with legacy 9 V relay coils and optocouplers. IC Role / Device Role / Timing Role: Serves as direct drop-in replacement for through-hole 7809 regulators in surface-mount retrofits. Use Value: SOIC-8 footprint enables automated assembly while maintaining compatibility with existing 9 V load requirements and thermal margins. | Use Scenario: Biasing white LED strings (3× LEDs @ 3.0 V each) in small LCD menu displays for HVAC controllers. IC Role / Device Role / Timing Role: Supplies constant 9 V to simple resistor-limited LED current paths. Use Value: 100 mA rating supports up to 20 mA per string (3 strings), and thermal shutdown prevents LED thermal runaway during ambient temperature spikes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-voltage linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC78L09ABD | Same SOIC-8 package but −40°C to +125°C operating range; higher temp grade with tighter initial output tolerance (±4% vs ±4.4%) | Suitable for extended-temperature industrial or outdoor deployments where cold-start reliability is critical | Select MC78L09ABD if ambient operating range includes sub-zero temperatures; otherwise MC78L09ACD suffices for commercial-grade equipment |
| LM78L09ACM | Pin-compatible SOIC-8, 100 mA, +9 V output-but higher dropout (2.0 V typ), lower ripple rejection (30 dB min), and no AEC-Q100 qualification | Acceptable for non-critical consumer electronics where thermal margin and noise are less constrained | Choose LM78L09ACM only when cost is primary driver and datasheet-confirmed 2.0 V dropout fits system headroom; verify thermal performance separately |
Compared with MC78L09ABD, the MC78L09ACD trades extended temperature capability for lower cost and standard commercial qualification; versus LM78L09ACM, it delivers superior ripple rejection and lower dropout-enabling more robust operation in margin-constrained power systems.
Availability
MC78L09ACD is available at Aetrix Electronics and suitable for industrial sensor interfaces, low-power microcontroller supply, legacy control module upgrades, and embedded display backlight drivers requiring stable component supply and RoHS-compliant packaging.
Supply support for MC78L09ACD 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 manufacturer specializing in energy-efficient power management, analog, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.
The MC78L00A series-including MC78L09ACD-is designed for cost-sensitive, low-current linear regulation in commercial and industrial equipment where simplicity, reliability, and minimal external components are prioritized over high efficiency.
FAQ
What is the maximum input voltage rating for the MC78L09ACD?
The MC78L09ACD has an absolute maximum input voltage of 35 Vdc for 12–18 V output variants, confirmed in the Absolute Maximum Ratings table. For the +9 V version specifically, the datasheet specifies 35 Vdc as the upper limit-exceeding this risks permanent damage even briefly. Designers must ensure transient suppression (e.g., TVS diode) if input sources may spike beyond 35 V.
Does the MC78L09ACD require input and output capacitors to function stably?
The MC78L09ACD does not require external capacitors for basic regulation, but the datasheet strongly recommends a 0.33 µF input capacitor (placed near pin 4) and 0.1 µF output capacitor (near pin 1) to ensure stability under dynamic loads and long PCB traces. Omitting them risks oscillation or poor transient response, especially with capacitive loads >1 µF.
How does the SOIC-8 package of the MC78L09ACD improve thermal performance compared to TO-92?
The MC78L09ACD's SOIC-8 package features internal modification where pins 2, 3, 6, and 7 connect to the die attach flag-creating multiple low-resistance thermal paths to the PCB. This reduces effective RJA significantly versus TO-92 (200°C/W), enabling higher continuous power dissipation when mounted on ≥10 mm × 10 mm 2-oz copper areas per Figure 8.
Can the MC78L09ACD be used in automotive applications?
The MC78L09ACD is rated for 0°C to +125°C junction temperature and is not AEC-Q100 qualified. For automotive use, the NCV78L09ABDR2G variant (−40°C to +125°C, AEC-Q100 Grade 1, PPAP-capable) is specified. Using MC78L09ACD in automotive contexts voids compliance and risks field failure due to unvalidated temperature cycling and ESD robustness.
What is the typical output voltage tolerance of the MC78L09ACD across its full operating temperature range?
The MC78L09ACD guarantees output voltage between +8.5 V and +9.5 V (±5.6%) across 0°C to +125°C junction temperature at 1.0–40 mA load, per the "Output Voltage" row in the Electrical Characteristics table for MC78L09AC. At 25°C only, tolerance tightens to +8.6 V to +9.4 V (±4.4%).
MC78L09ACD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 9V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- -
- Current - Output:
- 100mA
- Current - Quiescent (Iq):
- 6 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:
- 8-SOIC
MC78L09ACD FAQ
1.How can I place an order for MC78L09ACD through Aetrix?
Please submit a Request for Quotation (RFQ) for MC78L09ACD 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 MC78L09ACD reliable?
The price and inventory of MC78L09ACD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MC78L09ACD is usually 5 days.
3.What payment methods are accepted for MC78L09ACD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MC78L09ACD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MC78L09ACD?
MC78L09ACD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MC78L09ACD 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 MC78L09ACD?
For technical support, including MC78L09ACD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MC78L09ACD requirements.
6.How does Aetrix verify that MC78L09ACD is sourced from the original manufacturer or authorized distributors?
All MC78L09ACD 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 MC78L09ACD meets industry standards.
7.What is the process for return or replacement of MC78L09ACD?
All MC78L09ACD units undergo pre-shipment inspection (PSI). If there is an issue with MC78L09ACD, 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 MC78L09ACD part is unused and in its original packaging.
Return procedure for MC78L09ACD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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