Overview
The 74HCT123DB,112 is a dual retriggerable monostable multivibrator with reset, produced by NXP Semiconductors (now part of Nexperia). This integrated circuit is designed to generate a single pulse of a fixed duration in response to a trigger signal. The device is highly versatile and can be used in a variety of applications requiring precise timing and pulse generation.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage (VCC) | 2.0 | 6.0 | V | ||
| Input Voltage (VIH) | VCC = 6.0 V | 4.2 | 3.2 | 4.2 | V |
| Propagation Delay (tPLH) | VCC = 5 V; CL = 15 pF | 23 | 46 | ns | |
| Transition Time | VCC = 4.5 V | 7 | 22 | ns | |
| Pulse Width (tW) | CEXT = 100 nF; REXT = 10 kΩ | 450 | μs | ||
| External Timing Resistor (REXT) | VCC = 5.0 V | 2 | 1000 | kΩ | |
| External Timing Capacitor (CEXT) | VCC = 5.0 V | pF | |||
| Operating Temperature | -40 | +125 | °C |
Key Features
- Wide supply voltage range from 2.0 V to 6.0 V
- CMOS low power dissipation
- High noise immunity
- Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
- Complies with JEDEC standards: JESD8C (2.7 V to 3.6 V) and JESD7A (2.0 V to 6.0 V)
- Input levels: TTL level for 74HCT123
- DC triggered from active HIGH or active LOW inputs
- Retriggerable for very long pulses up to 100% duty factor
- Direct reset terminates output pulse
- Schmitt-trigger action on all inputs except for the reset input
- ESD protection: HBM exceeds 2000 V and CDM exceeds 1000 V
- Multiple package options
Applications
The 74HCT123DB,112 is suitable for a variety of applications requiring precise timing and pulse generation. These include:
- Timing circuits in digital systems
- Pulse generators in test and measurement equipment
- Delay circuits in communication systems
- Trigger circuits in industrial control systems
- Frequency counters and digital signal processors
Q & A
- What is the primary function of the 74HCT123DB,112?
The primary function is to act as a dual retriggerable monostable multivibrator with reset, generating a single pulse of a fixed duration in response to a trigger signal. - What is the supply voltage range for the 74HCT123DB,112?
The supply voltage range is from 2.0 V to 6.0 V. - What are the input levels for the 74HCT123DB,112?
The input levels are TTL level. - Can the output pulse be extended or terminated?
Yes, the output pulse can be extended by retriggering either of the edge-triggered inputs, and it can be terminated at any time by a LOW-going edge on the reset input. - What is the operating temperature range for the 74HCT123DB,112?
The operating temperature range is from -40°C to +125°C. - Does the 74HCT123DB,112 have ESD protection?
Yes, it has ESD protection: HBM exceeds 2000 V and CDM exceeds 1000 V. - How is the pulse width programmed for the 74HCT123DB,112?
The pulse width is programmed by the selection of external components (REXT and CEXT). - Is the 74HCT123DB,112 retriggerable?
Yes, it is retriggerable for very long pulses up to 100% duty factor. - What are some common applications for the 74HCT123DB,112?
Common applications include timing circuits, pulse generators, delay circuits, and trigger circuits in various digital and industrial systems. - Does the 74HCT123DB,112 comply with any specific standards?
Yes, it complies with JEDEC standards: JESD8C (2.7 V to 3.6 V) and JESD7A (2.0 V to 6.0 V).
