CD4555B and CD4556B are dual one-of-four decoders/demultiplexers. Each decoder has two select inputs (A and B), an Enable input (E\), and four mutually exclusive outputs. On the CD4555B the outputs are high on select; on the CD4556B the outputs are low on select.

When the enable input is high, the outputs of the CD4555B remain low and the outputs of the CD4556B remain high regardless of the state of the select inputs A and B. The CD4555B and CD4556B are similar to types MC14555 and MC14556, respectively.

The CD4555B and CD4556B types are supplied in 16-lead hermetic dual-in-line ceramic packages (F3A suffix), 16-lead dual-in-line plastics packages (E suffix), and 16-lead small-outline packages (M, M96, and MT suffixes). The CD4555B is also supplied in 16-lead small-outline packages (NSR suffix) and 16-lead thin shrink small-outline packages (PW and PWR suffixes.)

• Expandable with multiple packages
• Standard, symmetrical output characteristics
• 100% tested for quiescent current at 20 V
• Maximum input current of 1 µA at 18 V over full package temperature range; 100 na at 18 V and 25°C
• Noise margin (full package-temperature range): 1 V at VDD = 5 V 2 V at VDD = 10 V 2.5 V at VDD = 15 V
• 5-V, 10-V, and 15-V parametric ratings
• Meets all requirements of JEDEC Tentative Standard No. 13B, "Standard Specifications for Description of 'B' Series CMOS Devices"
• Applications:
  • Decoding
  • Code conversion
  • Demultiplexing (using Enable input as a data input)
  • Memory chip-enable selection
  • Function selection