Encoder 10-to-4 Priority CMOS 16-Pin SOIC Tube

The CD40147B CMOS encoder features priority encoding of the inputs to ensure that only the highest-order data line is encoded. Ten data input lines (0-9) are encoded to four-line (8, 4, 2, 1) BCD. The highest priority line is line 9. All four output lines are logic 1 (VSS) when all input lines are logic 0. All inputs and outputs are buffered, and each output can drive one TTL low-power Schottky load. The CD40147B is functionally similar to the TTL54/74147 if pin 15 is tied low. The CD40147B types are supplied in 16-lead dual-in-line plastic packages (E suffix), 16-lead small-outline packages (M, M96, MT and NSR suffixes), and 16-lead thin shrink small-outline packages (PW and PWR suffixes).

Encodes 10-line to 4-line BCD

Active low inputs and outputs

Standardized, symmetrical output characteristics

100% tested for quiescent current at 20 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"

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 V_DD = 5 V
     2 V at V_DD = 10 V
     2.5 V at V_DD = 15 V

Applications:

• Keyboard encoding
• 10-line to BCD encoding
• Range selection