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Texas Instruments SN74AS27D — Analog & Data Acquisition
Texas Instruments

SN74AS27D Texas Instruments 74AS NOR Gate, 3-Circuit

MPNSN74AS27D
End of Life

Texas Instruments 74AS series, NOR Gate, SN74AS27D, 3 circuits, 3 inputs per gate, 14-SOIC surface mount, 4.5V to 5.5V supply, 5.5ns propagation delay.

$1.64Ref. price · indicative, final on quote
SN74AS27D datasheet
Packaging14-SOIC (0.154", 3.90mm Width)
StockContact for availability
Lead timeIn Stock wk
MOQ1 pcs
  • 100% new & originalTraceable channels only — no refurbs, no pulls, no remarked parts.
  • Date & lot codes on quoteStated per line before you commit; label photos on request.
  • MSL-compliant ESD packingMoisture-sealed bags with indicator cards; reels photo-verified.
  • PayPal buyer protectionPay by T/T, PayPal or Payoneer — card payments covered end to end.

Specifications

SN74AS27D Technical Specifications
ParameterValue
Series74AS
Logic typeNOR Gate
Mounting typeSurface Mount
Voltage4.5V ~ 5.5V
Current - output high, low2mA, 20mA
Number of inputs3
Operating temperature0°C ~ 70°C
PackageTube
Case14-SOIC (0.154\", 3.90mm Width)
Number of circuits3
Input logic level - low0.8V
Input logic level - high2V
Max propagation delay @ v, max CL5.5ns @ 5V, 50pF

Product details

What the 5.5 ns propagation delay means for your timing budget

The SN74AS27D is a triple 3-input NOR gate from TI's 74AS family, packing three independent NOR functions into a single 14-SOIC package. The headline spec is the 5.5 ns max propagation delay at 5 V into a 50 pF load — that is the time from any input crossing the threshold to the output settling. In a 5 V logic system clocked at 50 MHz (20 ns period), this delay eats about 27% of the cycle, so the downstream register must account for the skew. The input thresholds are TTL-compatible: 0.8 V low, 2.0 V high. That means it will reliably interpret a 3.3 V signal as a logic high as long as the high-level voltage exceeds 2.0 V, but the low-level noise margin is only 0.8 V below a 1.2 V ground bounce.

Active production and compliance — no LTB pressure

No stock-holding claim; we quote per RFQ.

Frequently asked questions

How can I order the SN74AS27D or check availability?

The SN74AS27D is an active Texas Instruments part, sourced to order through independent distribution.

Will the SN74AS27D drop into a board designed for the SN74HC27APWR without rewiring?

Both are 14-SOIC triple 3-input NOR gates, so the footprint is the same — 14-SOIC, 1.27 mm pitch. But the supply voltage and speed class differ. The SN74HC27APWR runs on 2 V to 6 V and has a 15 ns propagation delay at 6 V, while the SN74AS27D needs a 5 V ±10 % rail and switches in 5.5 ns. If the board already has a regulated 5 V supply and the timing margin closes with the faster delay, the swap is pin-compatible. If the board uses a 3.3 V rail, the AS part will not work because its minimum supply is 4.5 V.