AD694BQ - 4-20 mA Current Transmitter | Analog Devices
부품 번호: AD694BQ ✓ 활성AD694BQ 개요
A current transmitter is an industrial interface IC that converts a control or sensor voltage into a standardized current signal for transmission over long cables. In the signal-chain hierarchy, it belongs to interface ICs, industrial signal-conditioning ICs, and power-management-aware measurement components. The standardized 4-20 mA output allows a controller or receiver to distinguish a live zero reading from a broken wire, improving system diagnostics.
The AD694BQ includes a precalibrated 10 V input range and a programmable 10.000 V precision voltage reference. It also provides an input buffer amplifier, open-loop alarm capability, and wide output compliance for driving process-control loops. These functions make it suitable for conditioning signals from pressure, temperature, level, and flow transmitters where a regulated current output is required.
Its monolithic architecture consolidates the amplifier, reference, output stage, and alarm functions into one device. This can reduce the component count compared with discrete transmitter designs, while the hermetically sealed CERDIP construction supports use in environments where package integrity and long-term reliability are important. The industrial temperature option is specified over -40°C to +85°C.
Typical applications include process-control valve and actuator interfaces, factory-automation monitoring, system-level current-loop generation, industrial sensor transmitters, and 4-20 mA instrumentation. In these systems, the AD694BQ can convert a controller command or conditioned sensor signal into a current that remains usable over long cable runs and through industrial electrical-noise environments.
When designing around the AD694BQ, verify the available input range, supply configuration, output compliance, alarm state, and loop resistance against the manufacturer datasheet. Place the loop output and supply connections so that voltage drops in long cables do not exceed the available compliance voltage. Request the current stock position and lead time through the Request a Quote form on this page.
This page consolidates the manufacturer product information, distributor listings, drop-in replacement findings, and practical application guidance for the AD694BQ. It also organizes comparison and design notes so engineers can evaluate the hermetically sealed 16-pin CERDIP option before releasing a new industrial or process-control design.
드롭인 대체품: AD694BQ — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
AD694AQ
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
AD694BQ 사양
| Product Type | Monolithic current transmitter IC |
| Input Signal Type | High-level voltage input |
| Output Signal Type | 4-20 mA or 0-20 mA current output |
| Precalibrated Input Range | 10 V |
| Precision Voltage Reference | Programmable 10.000 V |
| Supply Configuration | Single or dual supply operation |
| Maximum Supply Voltage | 36 V |
| Wide Output Compliance | Supported |
| Input Buffer Amplifier | Integrated |
| Open-Loop Alarm | Supported |
| 패키지 | 16-pin CERDIP, hermetically sealed |
| Package Type | Through-hole ceramic dual in-line package |
| Industrial Temperature Range | -40°C to +85°C |
| Application Area | Industrial process control and factory automation |
| Controlled Devices | Valves, actuators, and process-control instruments |
| MSL 레벨 | 1 (Unlimited) |
AD694BQ through-hole ceramic dual in-line package 핀 구성 가이드
AD694BQ(through-hole ceramic dual in-line package 패키지)의 핀 구성입니다. 핀 번호, 기능, 연결 다이어그램은 제조사 데이터시트에 정의되어 있습니다. 정확한 풋프린트와 솔더링 지침은 해당 문서를 참조하십시오.
다음에 대한 상세 핀아웃 데이터 없음: AD694BQ.
다음을 참조하십시오: 데이터시트 전체 핀 구성은 다음을 참조하십시오.
일반적인 애플리케이션
AD694BQ 적합 용도: 6 애플리케이션s: Industrial Process-Control Valve Interfaces, Factory Automation Sensor Conditioning, 4-20 mA Loop Generator for Remote Instrumentation, Actuator and Valve Command Systems, Industrial System Monitoring, High-Impedance Industrial Signal Interfaces.
Industrial Process-Control Valve Interfaces
The AD694BQ fits controller-to-valve interfaces that require a 4-20 mA current instead of a low-level voltage. Its monolithic transmitter architecture combines a 10 V precalibrated input range, a programmable 10.000 V reference, and an integrated input buffer. Placing the device at a remote actuator reduces the risk that cable noise corrupts a control command. The 36 V supply capability also provides headroom for industrial installations, although the actual loop voltage and output compliance must be verified against the cable resistance and receiver impedance before the output stage is approved.
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Factory Automation Sensor Conditioning
The AD694BQ can convert a conditioned voltage from industrial pressure, temperature, level, or flow sensors into a standard current-loop signal. The precalibrated 10 V input path and integrated input buffer reduce the external conditioning required for a transmitter stage. A 4-20 mA output is especially useful when the remote sensor is connected to a controller through a long cable. Designers should confirm the AD694BQ input configuration, calibration tolerance, and output compliance against the sensor's transfer function and the total resistance of the field wiring.
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4-20 mA Loop Generator for Remote Instrumentation
The AD694BQ is useful where a remote instrument must receive a current proportional to a control voltage rather than a fragile millivolt-level signal. Its monolithic construction integrates the input amplifier, precision reference, current-output stage, and open-loop alarm function in a 16-pin CERDIP package. The 4-20 mA range permits the receiver to distinguish a valid zero measurement from a broken field connection. Check the available supply voltage, allowable loop resistance, and receiver input impedance so that the transmitter retains output-control capability across the complete installation distance.
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Actuator and Valve Command Systems
The AD694BQ suits actuator and valve-control systems that benefit from a current-loop command because current transmission is robust over long industrial cable runs. The device supports both 4-20 mA and 0-20 mA operating ranges, allowing it to match existing controller conventions. Its single or dual supply operation can simplify adaptation across different field-wiring architectures, while the integrated open-loop alarm provides a diagnostic path for a broken connection. The final design must account for the actuator's load, loop resistance, isolation requirements, and the AD694BQ's specified output-compliance limits.
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Industrial System Monitoring
The AD694BQ can serve as the transmitter element in a monitoring system that distributes analog measurements over standard 4-20 mA loops. Its high-level voltage input, integrated buffer, and programmable 10.000 V reference provide a compact way to create the current output required by monitoring receivers. The open-loop alarm feature helps distinguish normal operation from a transmitter or wiring failure. For reliable monitoring, calibrate the input scaling at the transmitter and verify that supply variation, cable resistance, and receiver loading remain within the manufacturer's operating limits.
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High-Impedance Industrial Signal Interfaces
The AD694BQ is appropriate when a low-level control signal must be protected from noise before entering a remote current-loop receiver. The integrated input buffer accepts a high-level voltage input and drives the standard 4-20 mA output while the 36 V power-supply capability supports higher-voltage field environments. This arrangement is useful in automated test equipment, process monitoring, and data-acquisition installations where analog commands travel across long cables. Validate the analog-common arrangement, isolation strategy, loop-return connection, and output compliance in the completed circuit schematic.
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추천 제품 요약
엔지니어링 참조 데이터: AD694BQ — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | AD694AQ |
|---|---|---|
| Package | 16-pin CERDIP | 16-pin CERDIP |
| Brand | Analog Devices | Analog Devices |
| Product Function | Monolithic voltage-to-current transmitter | Monolithic voltage-to-current transmitter |
| Output Range | 4-20 mA or 0-20 mA | 4-20 mA or 0-20 mA |
| Precalibrated Input Range | 10 V | 10 V |
| Precision Reference | Programmable 10.000 V | Programmable 10.000 V |
| Maximum Supply Voltage | 36 V | 36 V |
| Supply Configuration | Single or dual supply operation | Single or dual supply operation |
| Open-Loop Alarm | Supported | Supported |
주요 차별점
- Monolithic integration reduces external transmitter-circuit complexity (vs AD694AQ)
- Supports both 4-20 mA and 0-20 mA loop configurations (vs AD694AQ)
- Wide supply capability suits industrial field wiring (vs AD694AQ)
설계 노트
Confirm that the field supply remains within the AD694BQ's 36 V maximum under transient conditions, and select the single- or dual-supply configuration from the manufacturer datasheet for the intended topology. Decouple the supply pins with the capacitance and placement specified by Analog Devices. For a remote loop, calculate the maximum supply voltage as the receiver drop plus the IR drop across the entire cable and load before committing to the power design.
Use the 16-pin CERDIP pin-description table in the manufacturer datasheet to assign every connection, particularly the analog-common and loop-return pins. Place the current-loop output and supply components near the relevant device pins, and route the high-current output path away from sensitive input and reference nodes. Through-hole ceramic construction also requires a mechanically suitable socket or plated-through-hole footprint with adequate spacing.
Do not assume that a 4-20 mA receiver can operate from the same voltage as the transmitter. Verify the full loop resistance, receiver burden voltage, output compliance, and minimum supply voltage at the AD694BQ. Also avoid confusing the 0-20 mA option with a live-zero 4-20 mA system: 0-20 mA cannot distinguish zero current from a disconnected loop, so it is appropriate only where that diagnostic distinction is not required.
규정 준수 정보
The AD694 is an industrial interface IC rather than an automotive-qualified device, so AEC-Q100 is not applicable. RoHS, REACH, lead-free, halogen-free, and conflict-minerals declarations should be confirmed from current manufacturer or distributor documentation before a compliance-controlled release.
