Overview
The CD74HC194M is a 4-bit bidirectional universal shift register produced by Texas Instruments (previously Harris Semiconductor). It is part of the high-speed CMOS logic family and offers versatile operation modes. The device can operate in four different modes: shift right, shift left, hold, and reset, making it suitable for a variety of digital circuit applications.
Key Specifications
| Parameter | Value | Units | Conditions |
|---|---|---|---|
| Operating Voltage Range | 2 to 6 | V | HC Types |
| Operating Voltage Range | 4.5 to 5.5 | V | HCT Types |
| Maximum Clock Frequency | 60 MHz (at VCC = 5V, CL = 15pF, TA = 25°C) | MHz | |
| Operating Temperature Range | -55°C to 125°C | °C | |
| Fanout (Over Temperature Range) | 10 LSTTL Loads (Standard Outputs), 15 LSTTL Loads (Bus Driver Outputs) | ||
| Input Voltage Levels | VIL = 0.8V (Max), VIH = 2V (Min) for HCT Types | V | |
| Noise Immunity | NIL = 30%, NIH = 30% of VCC at VCC = 5V | % | HC Types |
| Package Types | PDIP, SOIC, SOP, TSSOP |
Key Features
- Four operating modes: shift right, shift left, hold, and reset.
- Synchronous parallel or serial operation.
- Asynchronous Master Reset (MR).
- Wide operating temperature range: -55°C to 125°C.
- Balanced propagation delay and transition times.
- Significant power reduction compared to LSTTL logic ICs.
- HC types: 2V to 6V operation, high noise immunity.
- HCT types: 4.5V to 5.5V operation, direct LSTTL input logic compatibility.
- CMOS input compatibility, IL ≤ 1μA at VOL, VOH.
Applications
The CD74HC194M is suitable for various digital circuit applications, including:
- Serial and parallel data processing.
- Shift register applications in digital systems.
- Data storage and retrieval in microprocessor systems.
- Counters and timers.
- General-purpose digital logic circuits.
Q & A
- What are the operating modes of the CD74HC194M?
The CD74HC194M operates in four modes: shift right, shift left, hold, and reset.
- What is the maximum clock frequency of the CD74HC194M?
The maximum clock frequency is 60 MHz at VCC = 5V, CL = 15pF, and TA = 25°C.
- What is the operating voltage range for the HC types of CD74HC194M?
The operating voltage range for HC types is 2V to 6V.
- What is the operating temperature range of the CD74HC194M?
The operating temperature range is -55°C to 125°C.
- How does the asynchronous Master Reset (MR) work?
The asynchronous Master Reset (MR) clears the register by applying a low voltage to the MR pin.
- What is the fanout capability of the CD74HC194M?
The fanout capability is 10 LSTTL loads for standard outputs and 15 LSTTL loads for bus driver outputs.
- Is the CD74HC194M compatible with CMOS inputs?
- What are the package types available for the CD74HC194M?
The available package types are PDIP, SOIC, SOP, and TSSOP.
- Is the CD74HC194M still in production?
No, the CD74HC194M is obsolete and new designs should consider an alternate product.
- What is the significance of balanced propagation delay and transition times in the CD74HC194M?
It ensures consistent and reliable operation by minimizing timing discrepancies.
