Overview
The MC74HC4538ADR2, produced by onsemi, is a dual precision monostable multivibrator that is retriggerable and resettable. This device is part of the 74HC series and is known for its versatility in generating precise output pulses. It is identical in pinout to the MC14538B and is compatible with standard CMOS outputs, as well as LSTTL outputs with pull-up resistors. The device can be triggered by either the positive or negative edge of an input pulse and produces output pulses with widths determined by external timing components, Rx and Cx. Although this device is discontinued and not recommended for new designs, it remains relevant for existing applications and maintenance.
Key Specifications
| Symbol | Parameter | Conditions | Unit | Min | Typ | Max |
|---|---|---|---|---|---|---|
| VCC | DC Supply Voltage | - | V | -0.5 | - | 7.0 |
| VI | DC Input Voltage | -0.5 ≤ VI ≤ VCC + 0.5 | V | -0.5 | - | VCC + 0.5 |
| VO | DC Output Voltage | -0.5 ≤ VO ≤ VCC + 0.5 | V | -0.5 | - | VCC + 0.5 |
| IIK | DC Input Diode Current | A, B, Reset | mA | ±20 | - | ±30 |
| IOK | DC Output Diode Current | - | mA | ±25 | - | - |
| ICC | DC Supply Current per Supply Pin | Vin = VCC or GND | mA | - | 100 | - |
| TSTG | Storage Temperature Range | - | °C | -55 | - | 125 |
| tPLH | Maximum Propagation Delay Input A or B to Q | VCC = 2.0 V to 6.0 V, CL = 50 pF, tr = tf = 6.0 ns | ns | 175 | - | 265 |
| tw | Minimum Pulse Width, Input A or B | VCC = 2.0 V to 6.0 V | ns | 60 | - | 90 |
Key Features
- Triggering from Positive or Negative Edge: The device can be triggered by either the positive or negative edge of an input pulse.
- Retriggerable and Resettable: The multivibrator can be retriggered and reset, allowing for flexible control over the output pulse.
- Conditioned Trigger Inputs: There are no restrictions on the rise and fall times of the trigger inputs, making it tolerant of slow trigger rise and fall times.
- Precision Output Pulse Width: The output pulse width is determined by external timing components, Rx and Cx, allowing for precise control over the pulse width.
- ESD Protection: The device features ESD protection, with HBM exceeding 2000 V and MM exceeding 200 V.
- Multiple Package Options: Available in various package types, including SOIC-16 and TSSOP-16.
- Compliance with Standards: Complies with JEDEC standard no. 7A and is AEC-Q100 qualified for automotive applications.
Applications
The MC74HC4538ADR2 is suitable for a variety of applications where precise timing and pulse generation are required. These include:
- Timing and Pulse Generation: In circuits where precise timing and pulse widths are necessary, such as in digital counters, sequencers, and timing circuits.
- Automotive Systems: Given its AEC-Q100 qualification, it is suitable for use in automotive electronics where reliability and precision are critical.
- Industrial Control Systems: In industrial control systems that require accurate timing and pulse generation for various control functions.
- Communication Systems: In communication systems where precise timing is essential for data transmission and reception.
Q & A
- What is the MC74HC4538ADR2?
The MC74HC4538ADR2 is a dual precision monostable multivibrator that is retriggerable and resettable, produced by onsemi.
- What are the key features of the MC74HC4538ADR2?
Key features include triggering from positive or negative edges, retriggerable and resettable capabilities, conditioned trigger inputs, and precision output pulse width determined by external components.
- What are the input voltage levels for the MC74HC4538ADR2?
The input voltage levels are compatible with CMOS outputs and can be compatible with LSTTL outputs using pull-up resistors. The input voltage range is from 0 to VCC.
- What is the maximum propagation delay for the MC74HC4538ADR2?
The maximum propagation delay from input A or B to Q is between 175 ns and 265 ns, depending on the VCC and load conditions.
- What is the minimum pulse width for the MC74HC4538ADR2?
The minimum pulse width for input A or B is between 60 ns and 90 ns, depending on the VCC.
- Is the MC74HC4538ADR2 suitable for automotive applications?
Yes, it is AEC-Q100 qualified and PPAP capable, making it suitable for automotive and other applications requiring unique site and control change requirements.
- What are the storage temperature range and operating temperature range for the MC74HC4538ADR2?
The storage temperature range is from -55°C to 125°C, and the operating temperature range is from -40°C to 125°C.
- What is the ESD protection level for the MC74HC4538ADR2?
The device features ESD protection with HBM exceeding 2000 V and MM exceeding 200 V.
- Why is the MC74HC4538ADR2 not recommended for new designs?
The MC74HC4538ADR2 is discontinued and not recommended for new designs. Users should contact onsemi representatives for information on alternative components.
- In what package types is the MC74HC4538ADR2 available?
The device is available in SOIC-16 and TSSOP-16 package types.
