Overview
The 74HC595D is a high-speed 8-bit shift register/latch fabricated with silicon gate C2MOS technology. It achieves high-speed operation similar to equivalent LSTTL while maintaining the low power dissipation characteristic of CMOS technology. This device contains an 8-bit static shift register that feeds an 8-bit storage register. The shift operation is accomplished on the positive going transition of the SCK input, and the output register is loaded with the contents of the shift register on the positive going transition of the RCK input. The independent RCK and SCK signals allow parallel outputs to be held stable during the shift operation, and the 3-state parallel outputs can be directly connected to an 8-bit bus.
Key Specifications
| Parameter | Value | Unit | Conditions |
|---|---|---|---|
| Supply Voltage (VCC) | 2.0 to 6.0 | V | Operating Range |
| Input Voltage (VIN) | 0 to VCC | V | Operating Range |
| Output Voltage (VOUT) | 0 to VCC | V | Operating Range |
| Operating Temperature (Topr) | -40 to 125 | °C | Operating Range |
| Maximum Clock Frequency (fMAX) | 55 MHz | Hz | At VCC = 5 V |
| Quiescent Supply Current (ICC) | 4.0 µA | A | At Ta = 25 °C |
| High-Level Input Voltage (VIH) | 2.0 V | V | Minimum |
| Low-Level Input Voltage (VIL) | 0.8 V | V | Maximum |
| High-Level Output Voltage (VOH) | 3.15 V | V | Minimum at VCC = 5 V |
| Low-Level Output Voltage (VOL) | 0.33 V | V | Maximum at VCC = 5 V |
Key Features
- High speed operation: up to 55 MHz at VCC = 5 V.
- Low power dissipation: ICC = 4.0 µA (max) at Ta = 25 °C.
- Balanced propagation delays: tPLH ≈ tPHL.
- Wide operating voltage range: VCC(opr) = 2.0 V to 6.0 V.
- 3-state parallel outputs for direct connection to an 8-bit bus.
- Independent RCK and SCK signals for stable parallel outputs during shift operation.
- Protection circuits against static discharge and transient excess voltage.
Applications
- Serial-to-parallel data conversion.
- Data receivers and remote control holding registers.
- Controlling LED boards and matrices.
- Interfacing with LCD screens to supply basic data bits.
- Controlling 5V loads like relays through a 3.3V microcontroller.[
- Home automation systems and robotics for managing higher voltage components from lower voltage logic circuits.[
- Programmable logic controllers (PLCs) and other industrial automation systems.[
Q & A
- What is the 74HC595D?
The 74HC595D is an 8-bit shift register/latch with a storage register and 3-state outputs, fabricated with silicon gate C2MOS technology.
- How does the 74HC595D work?
The 74HC595D works on a Serial-In Parallel-Out (SIPO) protocol, receiving data serially and outputting it through parallel pins. It shifts data on the positive going transition of the SCK input and loads the output register on the positive going transition of the RCK input.
- What is the difference between 74HC595 and 74HC595D?
The suffix 'D' typically indicates a specific packaging or temperature range. In this case, it denotes the SOIC package.
- What are the key features of the 74HC595D?
Key features include high-speed operation, low power dissipation, balanced propagation delays, wide operating voltage range, and 3-state parallel outputs.
- What are the typical applications of the 74HC595D?
Typical applications include serial-to-parallel data conversion, data receivers, LED boards, LCD screens, and controlling 5V loads through a 3.3V microcontroller.
- How does the 74HC595D handle voltage levels?
The 74HC595D can handle a wide operating voltage range of 2.0 V to 6.0 V and can control 5V loads through a 3.3V microcontroller due to its 3.15V high-level voltage capability.
- What kind of protection does the 74HC595D have?
The 74HC595D is equipped with protection circuits against static discharge and transient excess voltage.
- Can multiple 74HC595D chips be connected?
Yes, multiple 74HC595D chips can be connected in a daisy-chain configuration to increase the potential output pins.[
- What is the significance of the RCK and SCK signals?
The independent RCK and SCK signals allow parallel outputs to be held stable during the shift operation, ensuring data integrity.
- How does the 74HC595D benefit industrial automation systems?
The 74HC595D benefits industrial automation systems by acting as a holding register, enhancing reliability and reducing the need for continuous data transmission, thus lowering power consumption and improving system efficiency.[
