74HC253D,653

The 74HC253; 74HCT253 are high-speed Si-gate CMOS devices and are pin compatible with Low-power Schottky TTL (LSTTL). The 74HC253; 74HCT253 provides a dual 4-input multiplexer with 3-state outputs which selects 2 bits of data from up to four sources selected by common data select inputs (S0, S1). The two 4-input multiplexer circuits have individual active LOW output enable inputs (1OE, 2OE). The 74HC253 and 74HCT253 are the logic implementation of a 2-pole, 4-position switch, where the position of the switch is determined by the logic levels applied to S0 and S1. The outputs are forced to a high-impedance OFF-state when nOE is HIGH. The logic equations for the outputs are: 1Y = 1OE • (1I0 • S1 • S0 + 1I1 • S1 • S0 + 1I2 • S1 • S0 + 1I3 • S1 • S0) 2Y = 2OE • (2I0 • S1 • S0 + 2I1 • S1 • S0 + 2I2 • S1 • S0 + 2I3 • S1 • S0)

• Non-inverting data path
• 3-state outputs interface directly with system bus
• Complies with JEDEC standard no. 7A
• Common select inputs
• Separate output enable inputs
• Input levels:
  • For 74HC253: CMOS level
  • For 74HCT253: TTL level
• ESD protection:
  • HBM JESD22-A114F exceeds 2000 V
  • MM JESD22-A115-A exceeds 200 V
• Multiple package options
• Specified from –40 ? to +85 ? and from –40 ? to +125 ?