Overview
The AD654JRZ-REEL7, produced by Analog Devices Inc., is a monolithic voltage-to-frequency (V/F) converter. This device integrates an input amplifier, a precision oscillator system, and a high current output stage, making it versatile for various applications. It can operate with a single supply voltage ranging from 4.5V to 36V and supports dual supply voltages from ±5V to ±18V. The AD654 is known for its high accuracy and stability, with a linearity error of only 0.03% for a 250 kHz full-scale frequency and an overall temperature coefficient of ±50 ppm/°C.
Key Specifications
| Parameter | Min | Typ | Max | Units |
|---|---|---|---|---|
| Frequency Range | 0 | - | 500 kHz | kHz |
| Nonlinearity (fMAX = 250 kHz) | 0.06 | 0.1 | - | % |
| Output Sink Current in Logic “0” | 10 | 20 | - | mA |
| Output Leakage Current in Logic “1” | 10 | 100 | - | nA |
| Logic Common Level Range | -VS | - | +VS – 4 | V |
| Supply Voltage (Single Supply) | 4.5 | - | 36 | V |
| Quiescent Current (VS = 5 V) | 1.5 | 2.5 | - | mA |
| Operating Temperature Range | -40 | - | 85 | °C |
| Package | - | - | 8-SOIC (0.154, 3.90mm Width) | - |
Key Features
- High Accuracy and Linearity: The AD654 offers a linearity error of only 0.03% for a 250 kHz full-scale frequency, ensuring high precision in voltage-to-frequency conversion.
- Wide Operating Range: The device can operate with a single supply voltage from 4.5V to 36V and supports dual supply voltages from ±5V to ±18V.
- Low Drift Input Amplifier: The input amplifier has a low drift of 4 µV/°C, allowing operation directly from small signals such as thermocouples or strain gauges.
- High Input Resistance: The device features a high input resistance of 250 MΩ, making it suitable for a variety of input sources.
- Versatile Output Stage: The open-collector output stage can sink more than 10 mA and drive up to 12 TTL loads, optocouplers, or long cables.
- Temperature Stability: The overall temperature coefficient is typically ±50 ppm/°C, ensuring stable operation over a wide temperature range.
Applications
- Analog-to-Digital Conversion: The AD654 can be used as an analog-to-digital converter when paired with a microcomputer having an interval timer/event counter.
- Industrial Automation: Suitable for applications involving thermocouples, strain gauges, and other small signal sources in industrial automation.
- Medical Devices: Can be used in medical devices requiring precise voltage-to-frequency conversion, such as in patient monitoring systems.
- Remote Sensing: The device's ability to transmit frequency data over long cables makes it ideal for remote sensing applications.
- Process Control: Used in process control systems where accurate and stable voltage-to-frequency conversion is critical.
Q & A
- What is the maximum frequency range of the AD654?
The AD654 can operate up to a maximum frequency of 500 kHz.
- What is the linearity error of the AD654 at 250 kHz full-scale frequency?
The linearity error is only 0.03% at 250 kHz full-scale frequency.
- What is the input resistance of the AD654?
The input resistance is 250 MΩ, making it suitable for small signal sources.
- What is the operating temperature range of the AD654?
The device operates over a temperature range of -40°C to 85°C.
- Can the AD654 drive TTL loads directly?
Yes, the AD654 can drive up to 12 TTL loads, optocouplers, or long cables.
- What is the quiescent current of the AD654 at 5V supply voltage?
The quiescent current is typically 2.5 mA at 5V supply voltage.
- What package type is the AD654JRZ-REEL7 available in?
The AD654JRZ-REEL7 is available in an 8-SOIC (0.154, 3.90mm Width) package.
- Can the AD654 be used with dual supply voltages?
Yes, the AD654 supports dual supply voltages from ±5V to ±18V.
- How does the AD654 handle temperature variations?
The device has a temperature coefficient of typically ±50 ppm/°C, ensuring stable operation over a wide temperature range.
- What is the typical drift of the input amplifier in the AD654?
The input amplifier has a low drift of 4 µV/°C.
