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Texas Instruments ULN2803AN — Discrete Semiconductors

ULN2803AN 8 NPN Darlington Array, 50V 500mA, 18-DIP

MPNULN2803AN
Obsolete

ULN2803AN, 8 NPN Darlington array, 50V Vce breakdown, 500mA per channel collector current, 1.6V Vce sat @ 500µA Ib / 350mA Ic, 18-DIP through-hole package, -40°C to 85°C industrial temperature range.

$1.1900Ref. price · indicative, final on quote
Texas Instruments ULN2803AN datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

ULN2803AN specifications
ParameterValue
MountingThrough Hole
FET type8 NPN Darlington
Voltage - collector emitter breakdown50V
Current - collector (Ic)500mA
Operating temperature-40°C~85°C(TA)
PackageTube
Case18-DIP (0.300\", 7.62mm)
Vce saturation (Max) @ ib, ic1.6V @ 500µA, 350mA

Product details

The ULN2803AN contains eight NPN Darlington pairs in a through-hole package, each rated for 500 mA continuous collector current and a 50 V collector-emitter breakdown.

Obsolete — no factory orders, but still on the BOM of legacy PLC and relay boards

The manufacturer no longer accepts new orders; the only channel is independent distribution sourcing surplus or last-time-buy inventory. If your BOM still calls out ULN2803AN, you are looking at a broker buy for production fill or repair stock.

Does it need a heatsink? The 1.6 V saturation voltage tells the story

At 350 mA per channel with all eight outputs on, the total power dissipation is roughly 8 × 350 mA × 1.6 V = 4.5 W. In the 18-DIP plastic package with no airflow, that exceeds the free-air thermal capability — the die temperature climbs above 85°C ambient. For continuous duty above 200 mA per channel, a clip-on heatsink or forced air is necessary. For intermittent relay pulsing at 100 mA or less, the package handles it without extra cooling.

Frequently asked questions

Is ULN2803AN obsolete?

Yes, the product status is Obsolete. No new factory orders are accepted. The only supply channel is surplus or last-time-buy inventory from independent distributors.

What is the maximum current per channel of ULN2803AN?

500 mA continuous collector current per channel. At that level, derating for ambient temperature and the number of active channels is required to stay within the package thermal limits.

What is equivalent to ULN2803AN?

The ULN2804AN is a pin-compatible drop-in with a higher input threshold for CMOS logic. The ULN2802AN is also pin-compatible but designed for 14-25 V PMOS inputs.