The SN74LS136D is a quad 2-input XOR gate from TI's 74LS family, but with open-collector outputs — that's the detail that changes how you use it. Each of the four gates pulls its output low when the XOR condition is true, and floats high when false. That open-drain structure lets you wire multiple outputs together for a wired-OR bus, or shift the logic-high level to a different voltage by pulling up to a separate rail. The 30 ns propagation delay at 5V, 15 pF is typical for the LS series — fast enough for most 5V TTL logic but not for high-speed synchronous buses. Supply range is 4.75V to 5.25V, and the operating temperature is 0°C to 70°C, so this is a commercial-grade part for indoor boards, not an industrial or automotive line.
Open-collector XOR — what it means for the bus
The open-collector output distinguishes this part from a standard 74LS XOR. With open-collector outputs, the SN74LS136D can drive a wired-OR connection — multiple gate outputs tied together through a single pull-up resistor.