Overview
The SN74HC688NG4 is an 8-bit identity comparator produced by Texas Instruments. This component is designed to compare two 8-bit binary or BCD words and provide an output based on the comparison. It features an output-enable (OE) input that can force the output to a high level. The SN74HC688NG4 is part of the HC688 series, known for its wide operating voltage range and low power consumption, making it suitable for various digital logic applications.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage Range (VCC) | 2 | 5 | 6 | V |
| Operating Free-Air Temperature (TA) | -40 | 85 | °C | |
| High-Level Input Voltage (VIH) | 1.5 (VCC=2V), 3.15 (VCC=4.5V), 4.2 (VCC=6V) | V | ||
| Low-Level Input Voltage (VIL) | 0.5 (VCC=2V), 1.35 (VCC=4.5V), 1.8 (VCC=6V) | V | ||
| Output Voltage (VOH) at IOH = -20 μA | 1.9 (VCC=2V), 4.4 (VCC=4.5V), 5.9 (VCC=6V) | V | ||
| Output Voltage (VOL) at IOL = 20 μA | 0.1 | 0.1 | V | |
| Propagation Delay Time (tpd) | 113 ns (VCC=2V), 30 ns (VCC=4.5V), 24 ns (VCC=6V) | ns | ||
| Input Transition Time (tt) | 1000 ns (VCC=2V), 500 ns (VCC=4.5V), 400 ns (VCC=6V) | ns | ||
| Power Dissipation Capacitance (Cpd) | 40 | pF | ||
| Continuous Output Current (IO) | ±25 | mA | ||
| Continuous Current through VCC or GND | ±50 | mA |
Key Features
- Wide operating voltage range of 2 V to 6 V
- High-current outputs drive up to 10 LSTTL loads
- Low power consumption, 80-μA max ICC
- Typical propagation delay time (tpd) of 14 ns at VCC = 6 V
- ±4-mA output drive at 5 V
- Low input current of 1 μA max
- CMOS input levels
- CMOS low power dissipation
- Output-enable (OE) input to force the output to a high level
Applications
The SN74HC688NG4 is suitable for various digital logic applications where the comparison of two 8-bit binary or BCD words is necessary. This includes:
- Digital logic circuits in computing and communication systems
- Data processing and storage systems
- Automated control systems
- Embedded systems requiring low power consumption and high reliability
Q & A
- What is the primary function of the SN74HC688NG4?
The primary function is to compare two 8-bit binary or BCD words and provide an output based on the comparison.
- What is the operating voltage range of the SN74HC688NG4?
The operating voltage range is from 2 V to 6 V.
- What is the maximum propagation delay time at VCC = 6 V?
The typical propagation delay time (tpd) at VCC = 6 V is 24 ns.
- How much current can the outputs drive?
The outputs can drive up to 10 LSTTL loads and provide ±4-mA output drive at 5 V.
- What is the maximum input current?
The maximum input current is 1 μA.
- What is the purpose of the output-enable (OE) input?
The output-enable (OE) input can be used to force the output to a high level.
- What are the typical operating temperatures for the SN74HC688NG4?
The operating free-air temperature range is from -40°C to 85°C.
- What is the power dissipation capacitance of the SN74HC688NG4?
The power dissipation capacitance (Cpd) is typically 40 pF.
- Can the SN74HC688NG4 be used in safety-critical applications?
No, it is not recommended for use in safety-critical applications without proper evaluation and validation.
- What are the available package types for the SN74HC688NG4?
The available package types include SOIC, PDIP, TSSOP, CDIP, and LCCC.
