7485 4-bit Magnitude Comparator PDIP-16
The 7485 4-Bit Magnitude Comparator is a high-performance CMOS digital logic IC that compares two 4-bit binary words and outputs signals indicating whether one word is greater than, less than, or equal to the other. Packaged in a standard 16-pin PDIP, this comparator supports expandability for wider word lengths through cascade inputs and outputs, making it suitable for complex digital systems and microprocessor interfaces.
It is widely used in arithmetic units, sorting logic, state machines, and decision-making circuits where high-speed, reliable binary magnitude comparison is required. The robust CMOS design ensures low power consumption and high noise immunity, compatible with standard TTL and CMOS logic voltage levels.
Features
- Compares two 4-bit binary numbers (A and B) and produces magnitude outputs.
- Outputs for A > B, A < B, and A = B for clear decision logic.
- Cascade inputs for expandability to larger bit-width comparisons.
- Standard PDIP-16 through-hole package for easy PCB integration.
- CMOS logic with low power consumption and high noise immunity.
- Suitable for TTL and CMOS mixed logic systems.
PINOUT
| Pin No | Pin Name | Description |
| 1 | B3 | Data Input B3 |
| 2 | 1A<B | Cascading Output Pin if A<B |
| 3 | 1A=B | Cascading Output Pin if A=B |
| 4 | 1A>B | Cascading Output Pin if A>B |
| 5 | 0A>B | Output Pin if A>B |
| 6 | 0A=B | Output Pin if A=B |
| 7 | 0A<B | Output Pin if A<B |
| 8 | GND | Ground |
| 9 | B0 | Data Input B0 |
| 10 | A0 | Data Input A0 |
| 11 | B1 | Data Input B1 |
| 12 | A1 | Data Input A1 |
| 13 | A2 | Data Input A2 |
| 14 | B2 | Data Input B2 |
| 15 | A3 | Data Input A3 |
| 16 | VCC | Positive Supply |
Specifications
| Attribute | Value |
| Product Category: | Logic Comparators |
| Comparator Type: | Magnitude |
| Number of Bits: | 4 bit |
| Logic Function: | A < B, A = B, A > B |
| Output Type: | Active High |
| Package/Case: | PDIP-16 |
| Propagation Delay Time: | 24 ns, 27 ns |
| Supply Voltage – Min: | 4.75 V |
| Supply Voltage – Max: | 5.25 V |
| Supply Current – Max: | 20 mA |
| Minimum Operating Temperature: | 0 C |
| Maximum Operating Temperature: | + 70 C |
| Mounting Style: | Through Hole |
| High Level Output Current: | – 400 uA |
| Low Level Output Current: | 8 mA |
| Operating Supply Voltage: | 4.75 V to 5.25 V |
For more electrical and mechanical dimensions check the datasheet
How 7485 Comparator Works?
The make the IC workable we will need to connect the IC first with the power supply and further with a TTL device or microcontroller to use it. In other ICs like an adder, the IC starts working from LSB but in the comparator, the IC will start comparing from the MSB. The data will start comparing from MSB and it will go to the LSB. In this case, at any point, if data A is bigger than the data B or vice versa then the output will be decided.
In IC the input data will be of two parts with 4-bit each and output data will be of 3 bits. In input, the data can be any binary numbers but in output data, only one bit will be HIGH other will be LOW and all three bits will describe the output on the base of input. Here’s the circuit of IC as a 4-bit comparator.
The IC can be used to compare the data of more than 4 bits by using the input expander pins. In IC those pins are Pin 2,3 and 5.
Truth Table
Applications
- Digital systems requiring binary magnitude comparison.
- Arithmetic and logic units in microprocessor systems.
- Address decoding and sorting logic circuits.
- Digital decision and control logic applications.
- Embedded systems and logic expansion modules.
Package Contents
- 1x 7485 4-Bit Magnitude Comparator PDIP-16.
Documents
| Datasheet | 7485 |