SN74LS194AD
| Parameters | |
|---|---|
| Series | 74LS |
| Moisture Sensitivity Level (MSL) | 1 (Unlimited) |
| RoHS Status | ROHS3 Compliant |
| Package / Case | 16-SOIC (0.154", 3.90mm Width) |
| Mfr | Texas Instruments |
| Mounting Type | Surface Mount |
| Operating Temperature | 0°C ~ 70°C |
| Output Type | Push-Pull |
| Number of Elements | 1 |
| Supplier Device Package | 16-SOIC |
| Number of Bits per Element | 4 |
| Function | Universal |
| Voltage - Supply | 4.75V ~ 5.25V |
| Logic Type | Register, Bidirectional |
| Package | Tube |
| Product Status | Active |
| Base Product Number | 74LS194 |
| REACH Status | REACH Unaffected |
| Standard Package | 40 |
| ECCN | EAR99 |
| HTSUS | 8542.39.0001 |
SN74LS194AD 4-Bit Bidirectional Universal Shift Register
The SN74LS194AD is a high-performance, low-power Schottky TTL (Transistor-Transistor Logic) integrated circuit designed as a 4-bit bidirectional universal shift register. Engineered for versatility, it supports four operational modes: synchronous parallel loading, right shift, left shift, and hold (no operation), controlled via mode-select inputs (S0, S1). Data is loaded into four D-type flip-flops and synchronized to the positive edge of the clock input (CP), ensuring precise timing. The device features parallel inputs (P0–P3) and outputs (Q0–Q3), along with dedicated serial data inputs for right (DSR) and left (DSL) shifts. An asynchronous master reset (MR) clears all outputs to low, enabling immediate system initialization. With a typical propagation delay of 26 ns and a maximum clock frequency of 25 MHz, the SN74LS194A is ideal for applications requiring rapid data manipulation, such as digital signal processing, communication protocols, and sequential logic systems.
SN74LS194AD Universal Shift Register Applications
The SN74LS194AD is widely utilized in digital systems requiring flexible data movement and storage. Key applications include serial-to-parallel and parallel-to-serial data conversion in communication interfaces, sequence generation for LED displays or motor control, and state machine implementations in embedded systems. Its bidirectional shifting capability simplifies the design of data buffers, counters, and pattern recognizers, while the synchronous operation ensures reliable timing in high-speed environments. Additionally, it serves as a core component in educational kits for demonstrating shift register functionality and in legacy industrial equipment where TTL compatibility is critical.
Alternative Shift Register Solutions
● Motorola MC74LS194N: A 4-bit bidirectional shift register offers identical pinouts and functionality, with a 36 MHz maximum clock frequency and compatibility with Motorola's TTL family.
● NXP HEF40194BT: A 4-bit universal shift register with a 12 MHz maximum clock frequency, designed for low-voltage applications (3–15 V) and offering enhanced noise immunity via CMOS technology.
● Fairchild Semiconductor DM74LS194N: Featuring the same 4-bit architecture and mode controls, with a 25 MHz maximum clock frequency and industrial-grade temperature tolerance.
