74LS398 Quadruple 2-Port Register IC | Datasheet

74LS398 is a Quad 2-Port Register. They are the logical equivalent of a quad 2-input multiplexer followed by a quad 4-bit edge-triggered register. A Common Select input selects between two 4-bit input ports (data sources). The selected data is transferred to the output register on the LOW-to-HIGH transition of the Clock input. The 74LS399 IC has a wide range of working voltage, a wide range of working conditions, offers a wide variety of features such as ESD protection & thermal overload protection and directly interfaces with CMOS, NMOS, and TTL.

What is a Register?

Registers are digital memory circuitry found in devices such as calculators, computers, and data processing systems. With a register, data or bits are entered into the system in a serial or parallel manner. data entry is done from one direction, and as more data is added, it shifts positions until the data gets to the output end. The two ends are referred to as the left and right end. Movement of data can be from left to right, from right to left, or in both directions to make a bidirectional register.

74LS398 Key Features & Specifications

• Technology Family: LS
• VCC (Min) (V): 4.75
• VCC (Max) (V): 5.25
• Input type: TTL
• Output type: TTL
• IOL (Max) (mA): 24
• IOH (Max) (mA): -2.6
• Select From Two Data Sources
• Fully Positive Edge-Triggered Operation
• Both True and Complemented Outputs on SN54/74LS398
• Input Clamp Diodes Limit High-Speed Termination Effects

74LS398 Pinout

Pin No.	Pin Name	Description
1	S	Common Select Input Pin
2	Qa	Register True Output Qa
3	Qa’	Register Complementary Output Qa’
4	I0a	Data Input From Source 0
5	I1a	Data Input From Source 1
6	I1b	Data Input From Source 1
7	I0b	Data Input From Source 0
8	Qb’	Register Complementary Output Qb’
9	Qb	Register True Output Qb
10	GND	Ground Pin
11	CP	Clock Pulse Input
12	Qc	Register True Output Qc
13	Qc’	Register Complementary Output Qc’
14	I0c	Data Input From Source 0
15	I1c	Data Input From Source 1
16	I1d	Data Input From Source 1
17	I0d	Data Input From Source 0
18	Qd’	Register Complementary Output Qd’
19	Qd	Register True Output Qd
20	Vcc	Chip Supply Volyage

Applications

The 74LS398 has a wide array of applications. A few of them are mentioned down below:

• Their function lies in many different memory defragmentation circuits used in system repair.

74LS398 Datasheet

You can download the datasheet for 74LS398 Quadruple 2-Port Register IC from the link given below:

See Also: 74LS157 Quad 2 To 1 Line Multiplexer IC – Datasheet | 74LS139 Dual 1-Of-4 Decoder/Demultiplexer IC – Datasheet | 74LS132 Quad 2-Input Schmitt trigger NAND Gate IC – Datasheet