CD4055 belongs to the 4000 Series CMOS Logic Family of Integrated Circuits (IC’s) constructed with N- and P-channel enhancement mode transistors. CD4055 has BCD to 7-segment decoder/LCD driver
CD4055 has a supply voltage range of 5V to 20V, which is much higher than any contemporary logic family. It has buffered output which improves transfer characteristics by providing very high gain. All inputs are protected against static discharge with diodes to VDD and VSS.

CD4055 Features
- Standard Symmetrical Output Characteristics
- 100% Tested for Maximum Quiescent Current at 20V
- 5V, 10V, and 15V Parametric Ratings
- Maximum Input Current of 1μA at 18V Over Full Package-
- Temperature Range; 100nA at 18V and +25oC
- Noise Margin (Over Full Package Temperature Range):
- 1V at VDD = 5V
- 2V at VDD = 10V
- 2.5V at VDD = 15V
CD4055 Specifications
Absolute Maximum Ratings
- DC Supply Voltage Range, (VDD): -0.5V to +20V (Voltage Referenced to VSS Terminals)
- Input Voltage Range, All Inputs: -0.5V to VDD +0.5V
- DC Input Current, Any One Input: ±10mA
- Storage Temperature Range (TSTG): -65oC to +150oC
- Lead Temperature (During Soldering): +265oC
- At Distance 1/16 ± 1/32 Inch (1.59mm ± 0.79mm) from case for 10s Maximum
CD4055 Pinout Diagram

CD4055 Pin Description
Pin No | Pin Name | Description |
1 | DISPLAY FREQ: OUT | Display Frequency Output Pin |
2 | 2^2 | BCD Input Pin |
3 | 2^1 | BCD Input Pin |
4 | 2^3 | BCD Input Pin |
5 | 2^0 | BCD Input Pin |
6 | DISPLAY FREQ: IN | Display Frequency Input Pin |
7 | VEE | Emitter Voltage |
8 | VSS | Supply Voltage |
9 | a | 7-Segment Output Pin a |
10 | b | 7-Segment Output Pin b |
11 | c | 7-Segment Output Pin c |
12 | d | 7-Segment Output Pin d |
13 | e | 7-Segment Output Pin (e) |
14 | g | 7-Segment Output Pin (g) |
15 | f | 7-Segment Output Pin f |
16 | VDD | Drain Voltage |
CD4055 Circuit
Applications
- General Purpose displays
- Calculators and Meters
- Wall and Table Clock
- Panel Meters
- Appliance Control panel
CD4055 Alternative Equivalent
CD4054, CD4056
Download CD4055 BCD to 7-segment decoder/LCD driver Datasheet from the link given below.