Overview
The SN74HC374NSR is an octal edge-triggered D-type flip-flop integrated circuit produced by Texas Instruments. This component features eight D-type flip-flops in a single package, making it highly suitable for various digital logic applications. The flip-flops are edge-triggered, meaning they capture the data at the positive transition of the clock (CLK) input. The device also includes 3-state outputs, which can be placed in a high-impedance state, allowing for bus driving without the need for interface or pullup components.
Key Specifications
| Parameter | Unit | Min | Max | |
|---|---|---|---|---|
| VCC (Supply Voltage) | V | 2 | 5 | 6 |
| VIH (High-level Input Voltage) | V | 1.5 (VCC=2V), 3.15 (VCC=4.5V), 4.2 (VCC=6V) | ||
| VIL (Low-level Input Voltage) | V | 0.5 (VCC=2V), 1.35 (VCC=4.5V), 1.8 (VCC=6V) | ||
| ICC (Quiescent Current) | µA | 80 | 160 | |
| fclock (Clock Frequency) | MHz | 6 (VCC=2V), 30 (VCC=4.5V), 35 (VCC=6V) | ||
| tpd (Propagation Delay, CLK to Q) | ns | 80 (VCC=2V), 22 (VCC=4.5V), 19 (VCC=6V) | ||
| ten (Enable Time, OE to Q) | ns | 70 (VCC=2V), 25 (VCC=4.5V), 22 (VCC=6V) | ||
| TA (Operating Free-Air Temperature) | °C | -40 | 85 | |
| RθJA (Junction-to-Ambient Thermal Resistance) | °C/W | 113.4 (NS package) |
Key Features
- Wide operating voltage range of 2 V to 6 V
- High-current 3-state true outputs can drive up to 15 LSTTL loads
- Eight D-type flip-flops in a single package
- Full parallel access for loading
- Low power consumption, 80-µA max ICC
- Typical propagation delay (tpd) of 14 ns
- ±6-mA output drive at 5 V
- Low input current of 1 µA max
- Output-enable (OE) input for high-impedance state control
Applications
The SN74HC374NSR is particularly suitable for implementing:
- Buffer registers
- I/O ports
- Bidirectional bus drivers
- Working registers
These applications benefit from the device's ability to drive highly capacitive or relatively low-impedance loads and its 3-state output capability.
Q & A
- What is the operating voltage range of the SN74HC374NSR?
The operating voltage range is from 2 V to 6 V.
- How many D-type flip-flops are included in the SN74HC374NSR?
The device includes eight D-type flip-flops in a single package.
- What is the maximum propagation delay (tpd) at 5 V?
The typical propagation delay (tpd) at 5 V is around 14 ns, but it can range up to 49 ns.
- What is the purpose of the output-enable (OE) input?
The OE input places the eight outputs in either a normal logic state or the high-impedance state.
- What are the typical applications of the SN74HC374NSR?
It is used for buffer registers, I/O ports, bidirectional bus drivers, and working registers.
- What is the maximum output drive current at 5 V?
The device can drive ±6 mA at 5 V.
- How does the device handle power-up and power-down to ensure the high-impedance state?
OE should be tied to VCC through a pullup resistor to ensure the high-impedance state during power-up or power-down.
- What is the thermal resistance (RθJA) for the NS package?
The junction-to-ambient thermal resistance (RθJA) for the NS package is 113.4 °C/W.
- What is the maximum quiescent current (ICC) at 6 V?
The maximum quiescent current (ICC) at 6 V is 160 µA.
- What is the recommended operating free-air temperature range?
The recommended operating free-air temperature range is from -40°C to 85°C.
