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Texas Instruments ULN2803ADWG4
- Part No.:
- ULN2803ADWG4
- Manufacturer:
- Texas Instruments
- Package:
- 18-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
ULN2803ADWG4.pdf
- Description:
- TRANS 8NPN DARL 50V 0.5A 18SO
- Quantity:
- Payment:
- Shipping:
Inventory:4,676
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Product details
Overview
ULN2803ADWG4 from Texas Instruments is an 8-channel NPN Darlington transistor array optimized for high-voltage, high-current sinking applications. Each channel delivers 500 mA collector current with 50 V output voltage rating and integrated common-cathode clamp diodes. It operates directly from TTL or 5-V CMOS logic and is widely used in relay, lamp, and solenoid driver circuits.
For engineers reviewing the ULN2803ADWG4 datasheet, ULN2803ADWG4 pinout, ULN2803ADWG4 application, or ULN2803ADWG4 equivalent, key selection criteria include per-channel sink capability, input base resistor value (2.7 kΩ), thermal resistance (66.4 °C/W), COM pin functionality for inductive load suppression, and SOIC-18 package compatibility with industrial PCB layouts.
Technical Context
The ULN2803ADWG4 integrates eight independent Darlington pairs-each formed by cascaded NPN transistors-yielding current gain up to 10,000 A/A. Input signals pass through a dedicated 2.7 kΩ series base resistor per channel, enabling direct interface with 3.3 V or 5 V logic without external biasing.
Each output features an open-collector configuration with a shared cathode clamp diode network connected to the COM terminal. This architecture allows safe energy dissipation during turn-off of inductive loads (e.g., relays, solenoids) when COM is tied to the coil supply rail, eliminating need for external flyback diodes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Channel count | 8 independent Darlington sink outputs |
| Max collector current | 500 mA per channel-supports driving medium-power relays or lamps |
| Output voltage rating | 50 V-enables use with 24 V and 48 V industrial control rails |
| Input resistor | 2.7 kΩ per channel-allows direct TTL/CMOS drive without external components |
| VCE(sat) @ 200 mA | 1.0–1.3 V-low saturation voltage minimizes power loss and heat generation |
| Thermal resistance θJA | 66.4 °C/W (SOIC-18)-defines maximum power dissipation under natural convection |
| ESD rating (HBM) | ±2000 V-meets standard handling requirements for board assembly |
Pinout & Package
ULN2803ADWG4 is housed in a 18-pin SOIC (DW) package measuring 11.50 mm × 7.50 mm, with standard JEDEC MS-013 footprint and moisture sensitivity level (MSL) Level-2-260°C-1 year.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1B–8B | Input base terminals | Logic-level inputs (pins 1–8); each internally biased via 2.7 kΩ resistor to corresponding Darlington base |
| 1C–8C | Collector outputs | Open-collector outputs (pins 18–11); sink current to GND when active; require external pull-up for logic-high signaling |
| GND | Common emitter reference | Shared emitter connection for all Darlington pairs; must be tied to system ground |
| COM | Clamp diode common cathode | Connect to inductive load supply rail to enable internal flyback path; left floating for resistive loads |
Key Features
| Feature | Design Value |
|---|---|
| Integrated clamp diodes | Eliminates need for external flyback diodes when driving relays or solenoids-reduces BOM count and layout area |
| On-chip base resistors | 2.7 kΩ per channel enables direct interface with 3.3 V/5 V logic-no external bias network required |
| High current gain | β ≈ 10,000 enables 250 µA input to switch 200+ mA output-ideal for low-drive MCU GPIOs |
| Parallel output capability | Multiple channels can be wired in parallel to achieve >500 mA sink per load-extends drive capacity without redesign |
| Wide operating voltage | Supports VCC up to 50 V on outputs and logic inputs up to 30 V-suitable for mixed-voltage industrial interfaces |
Applications
| Industrial Relay Control | LED Display Multiplexing |
|---|---|
Use Scenario: Controlling 24 VDC electromechanical relays in PLC I/O modules or motor starter panels. IC Role / Device Role / Timing Role: High-side switched load driver-ULN2803ADWG4 sinks relay coil current while providing transient suppression via COM-connected clamp diodes. Use Value: Enables single-chip control of eight relays with no external protection components, reducing board space and assembly cost by ~30% vs discrete solutions. | Use Scenario: Driving common-anode 7-segment LED displays in HVAC controllers or instrumentation panels. IC Role / Device Role / Timing Role: Digit-select sink driver-ULN2803ADWG4 sequentially activates digit cathodes at multiplex rates ≥1 kHz to minimize visible flicker. Use Value: Delivers consistent 20–300 mA per segment across temperature, maintaining brightness uniformity without external current-setting resistors per channel. |
| Solenoid Actuation | Printer Hammer Driver |
Use Scenario: Operating 12–48 V DC linear solenoids in vending machines, fluid valves, or access control locks. IC Role / Device Role / Timing Role: Pulse-width modulated load switch-ULN2803ADWG4 handles repetitive 100 ms ON/OFF cycles with peak currents up to 500 mA per channel. Use Value: Internal thermal design supports sustained duty cycles without derating; COM pin routing simplifies PCB layout for multi-solenoid banks. | Use Scenario: Driving impact-type print hammers in legacy dot-matrix printers requiring fast turn-on/turn-off response. IC Role / Device Role / Timing Role: High-speed current sink-ULN2803ADWG4 achieves tPHL = 20 ns and tPLH = 130 ns into 15 pF loads, meeting timing budgets for 200 Hz hammer actuation. Use Value: Low VCE(sat) ensures minimal voltage drop across hammer coils, preserving magnetic force and print reliability over 10M+ operations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Darlington array applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ULN2803ADR | Same electrical specs; tape-and-reel packaging (2000 pcs/reel) vs ULN2803ADWG4's tube (40 pcs) | Identical functional behavior; preferred for automated SMT production | Select ULN2803ADR for high-volume manufacturing; ULN2803ADWG4 suits prototyping and low-volume builds |
| STMicroelectronics ULN2803A | Pin-compatible but higher VCE(sat) (1.9 V typ @ 350 mA) and lower ESD rating (±1000 V HBM) | Acceptable for non-critical 24 V relay control; not recommended for high-speed or ESD-prone environments | Choose ULN2803ADWG4 where low saturation loss, robust ESD immunity, or TI's long-term supply assurance are required |
Compared with ULN2803ADR and STMicro ULN2803A, the ULN2803ADWG4 offers optimal balance of proven reliability, tight VCE(sat) tolerance, and logistics flexibility-making it the preferred choice for industrial control designs requiring field longevity and consistent thermal performance.
Availability
ULN2803ADWG4 is available at Aetrix Electronics and suitable for industrial relay control, LED display multiplexing, solenoid actuation, and printer hammer driver applications requiring stable component supply and long-term manufacturability.
Supply support for ULN2803ADWG4 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies with over 50 years of industrial-grade component development.
The ULN2803ADWG4 belongs to TI's legacy power interface portfolio, engineered specifically for robust, low-cost, high-reliability switching of inductive and resistive loads in factory automation, building controls, and electro-mechanical systems.
FAQ
What is the maximum continuous current per channel for ULN2803ADWG4?
The ULN2803ADWG4 is rated for 500 mA continuous collector current per channel under recommended operating conditions (TJ ≤ 125°C). This rating assumes proper PCB copper area for heat dissipation and adherence to thermal limits specified in the datasheet. Derating is required above 25°C ambient, and simultaneous full-load operation across all eight channels demands careful thermal analysis using θJA = 66.4 °C/W.
Can ULN2803ADWG4 drive 12 V relays directly from a 3.3 V microcontroller?
Yes, ULN2803ADWG4 can drive 12 V relays directly from a 3.3 V microcontroller. Its integrated 2.7 kΩ input resistors allow sufficient base current (≈1.2 mA at 3.3 V) to saturate each Darlington pair. Ensure the relay coil current stays within the 500 mA per-channel limit and connect the COM pin to the 12 V supply to activate internal clamp diodes for back-EMF protection.
What is the function of the COM pin on ULN2803ADWG4?
The COM pin on ULN2803ADWG4 serves as the common cathode node for all eight internal clamp diodes. When driving inductive loads (e.g., relays, solenoids), COM must be connected to the positive supply rail of the load to provide a safe path for flyback current during turn-off. For purely resistive loads, COM may be left unconnected or tied to GND depending on circuit topology.
Is ULN2803ADWG4 RoHS compliant and lead-free?
Yes, ULN2803ADWG4 is RoHS compliant and lead-free. Per TI's packaging documentation, it carries a "Green (RoHS & no Sb/Br)" eco-plan designation, with CU NIPDAU lead finish and compliance to EU RoHS Directive 2011/65/EU. The device meets exemption 7a for lead in high-melting-temperature solder alloys and contains no intentionally added brominated or antimony-based flame retardants.
How does ULN2803ADWG4 differ from ULN2003A?
The ULN2803ADWG4 contains eight Darlington pairs versus seven in the ULN2003A, and features different pin assignments-specifically, ULN2803ADWG4 allocates pins 1–8 as inputs and pins 18–11 as outputs, whereas ULN2003A uses pins 1–7 as inputs and pins 18–12 as outputs. Both share identical electrical specs (500 mA/channel, 50 V, 2.7 kΩ input resistors), but ULN2803ADWG4's extra channel and pinout make it incompatible as a drop-in replacement without PCB revision.
ULN2803ADWG4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Package/Case:
- 18-SOIC (0.295", 7.50mm Width)
- Series:
- -
- Packaging:
- Tube
- Product Status:
- Discontinued at Digi-Key
- Switch Type:
- -
- Number of Outputs:
- -
- Ratio - Input:Output:
- -
- Output Configuration:
- -
- Output Type:
- -
- Interface:
- -
- Voltage - Load:
- -
- Voltage - Supply (Vcc/Vdd):
- -
- Current - Output (Max):
- -
- Rds On (Typ):
- -
- Input Type:
- -
- Features:
- -
- Fault Protection:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 18-SOIC
ULN2803ADWG4 FAQ
1.How can I place an order for ULN2803ADWG4 through Aetrix?
Please submit a Request for Quotation (RFQ) for ULN2803ADWG4 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 ULN2803ADWG4 reliable?
The price and inventory of ULN2803ADWG4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ULN2803ADWG4 is usually 5 days.
3.What payment methods are accepted for ULN2803ADWG4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ULN2803ADWG4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ULN2803ADWG4?
ULN2803ADWG4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ULN2803ADWG4 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 ULN2803ADWG4?
For technical support, including ULN2803ADWG4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ULN2803ADWG4 requirements.
6.How does Aetrix verify that ULN2803ADWG4 is sourced from the original manufacturer or authorized distributors?
All ULN2803ADWG4 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 ULN2803ADWG4 meets industry standards.
7.What is the process for return or replacement of ULN2803ADWG4?
All ULN2803ADWG4 units undergo pre-shipment inspection (PSI). If there is an issue with ULN2803ADWG4, 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 ULN2803ADWG4 part is unused and in its original packaging.
Return procedure for ULN2803ADWG4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ULN2803ADWG4 Tags
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TPS22919DCKR
Texas Instruments
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MIC2091-1YM5-TR
Microchip Technology
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MIC2090-1YM5-TR
Microchip Technology
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TPS22995RZFR
Texas Instruments
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TPS22975DSGR
Texas Instruments
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SIP32510DT-T1-GE3
Vishay Siliconix
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ULN2003D1013TR
STMicroelectronics
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MIC2005A-1YM5-TR
Microchip Technology
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MIC2005A-1YM6-TR
Microchip Technology
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TPS22916BYFPR
Texas Instruments
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TPS22917DBVR
Texas Instruments
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ULN2003APWR
Texas Instruments
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