74HC153D vs 74HC126D

The 74HC126D is a quad non-inverting buffer/line driver with 3-state outputs, while the 74HC153D is a dual 4-input multiplexer. The 74HC126D provides four independent buffer channels with active-HIGH output enable pins, whereas the 74HC153D selects one of four data inputs per multiplexer based on two select lines and provides non-inverted output.

No. They perform fundamentally different logic functions. The 74HC126D is a 3-state buffer intended for signal buffering and bus driving, while the 74HC153D is a multiplexer intended for data selection. Substitution requires a complete redesign of the surrounding circuitry and is not a direct replacement.

Both the 74HC126D and 74HC153D are typically offered in a 16-pin SOIC package (the "D" suffix in Nexperia and similar manufacturer naming conventions denotes SOIC-16). The 74HC126D uses 16 pins for four buffers with enable controls, VCC, and GND. The 74HC153D uses 16 pins for two 4-input multiplexers, shared select lines, and VCC/GND.

Both devices are members of the 74HC family and operate over a supply voltage range of 2.0 V to 6.0 V. They provide CMOS-level inputs and outputs compatible with standard 74HC logic thresholds. At VCC = 4.5 V, both devices typically exhibit a propagation delay in the range of 10 ns to 20 ns depending on load conditions, as specified in manufacturer datasheets.

Both devices are specified with standard 74HC output drive. At VCC = 4.5 V, each output typically sinks or sources up to 4 mA while maintaining valid logic levels, with absolute maximum output current ratings per pin defined in the manufacturer datasheet. The 74HC126D 3-state outputs are designed for bus driving, while the 74HC153D outputs are standard push-pull CMOS outputs.

On the 74HC126D, each buffer has an active-HIGH output enable pin (1OE through 4OE). When an enable pin is LOW, the corresponding output enters a high-impedance state. On the 74HC153D, the select pins (S0 and S1) are shared between both multiplexers and determine which of the four data inputs (I0 to I3) is routed to the corresponding output. The 74HC153D also has separate active-LOW enable pins (1E and 2E) for each multiplexer.

Both devices are 74HC CMOS devices with standard CMOS input thresholds. They are generally compatible with 74HCT and 74LS outputs when operated at the same supply voltage, but level compatibility must be verified against the specific datasheet parameters. Direct interfacing with 74LVC may require level shifting due to differing supply voltage ranges and input thresholds.

The 74HC126D is typically used for bus buffering, signal isolation, and driving capacitive or low-impedance loads where 3-state control is required. The 74HC153D is typically used for data selection, signal routing, and implementing combinational logic functions where one of several inputs must be selected based on control signals.