ISO124P - 8-Pin DIP Isolation Amplifier, 1.5kV | Texas Instruments
부품 번호: ISO124P ✓ 활성| 수량 | 단가 | 합계 |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $12.95 | $129.50 |
| 100 | $11.4 | $1,140.00 |
| 500 | $9.95 | $4,975.00 |
| 1,000 | $8.75 | $8,750.00 |
ISO124P 개요
An isolation amplifier is a specialized analog IC that transmits an analog signal across a galvanic isolation barrier - typically required for safety, ground-loop elimination, or high common-mode voltage rejection - while preserving DC accuracy and bandwidth. The ISO124P belongs to the instrumentation amplifier family and is further categorized as an isolation amplifier, sitting within the broader analog signal-chain and data-acquisition hierarchies. It is one of the lowest-cost precision isolation solutions in the industry and is widely used where optical, transformer, or digital isolators are unsuitable for the analog accuracy required.
The device features ±4.5 V to ±18 V dual supply operation on both sides of the barrier, ±5 mA quiescent current on V_S1 and ±5.5 mA on V_S2, and a fixed unity-gain configuration that eliminates external gain-setting resistors and removes a common source of drift. Its high common-mode rejection (140 dB typical) makes it tolerant of large ground potential differences and switching transients on industrial buses, while the capacitive digital modulation scheme avoids the LED aging and linearity limitations of opto-isolated solutions.
Typical applications include motor control current sensing, biomedical signal acquisition with patient-isolated inputs, industrial process-control analog front-ends with 4-20 mA loop isolation, and power-supply feedback isolation in high-side current monitors. The PDIP-8 form factor is well-suited to through-hole designs and is preferred where mechanical robustness and ease of prototyping outweigh the area advantage of surface-mount variants.
When designing with this part, ensure the supplies on each side of the barrier are truly isolated and that bypass capacitors (typically 0.1 uF plus 1 uF) are placed close to each supply pin to handle the high-frequency switching of the modulator. Because the signal path includes a 500 kHz modulator running continuously, allow adequate ground-plane stitching on both isolated sections to avoid contaminating the rest of the analog chain.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet. It targets engineers searching for a complete engineering reference on ISO124P selection, replacement, and PCB integration.
드롭인 대체품: ISO124P — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:
ISO122P
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
ISO124P 최대 정격 & 전기적 특성
| Isolation Voltage (Rated) | 1500 Vrms |
| Isolation Barrier Type | Capacitive (matched 1 pF differential) |
| Modulation Technique | Duty-cycle modulation/demodulation |
| Number of Channels | 1 |
| 입력 전압 범위 | ±10 V (bipolar) |
| Supply Voltage Range (each side) | ±4.5 V to ±18 V |
| Quiescent Current (V_S1) | ±5 mA |
| Quiescent Current (V_S2) | ±5.5 mA |
| Bandwidth (Small Signal) | 50 kHz |
| Nonlinearity (Max) | 0.010% max |
| Input Offset Voltage Drift | 200 uV/°C max |
| Common-Mode Rejection (CMR) | 140 dB typical |
| Gain Configuration | Fixed unity gain (1 V/V) |
| 패키지 | 8-pin PDIP (P) |
| 실장 유형 | Through-hole |
| 동작 온도 | -25°C to +85°C |
| RoHS 상태 | Compliant (lead-free finish) |
ISO124P 핀 구성
| 핀 1 | V_IN — Analog input signal (input-side, isolated) |
| 핀 2 | V_S1 — Input-side positive supply |
| 핀 3 | GND_1 — Input-side ground (isolated from output-side ground) |
| 핀 4 | NC — Not connected (per datasheet) |
| 핀 5 | NC — Not connected (per datasheet) |
| 핀 6 | GND_2 — Output-side ground (isolated from input-side ground) |
| 핀 7 | V_S2 — Output-side positive supply |
| 핀 8 | V_OUT — Isolated analog output signal (output-side) |
일반적인 애플리케이션
ISO124P 적합 용도: 6 애플리케이션s: Industrial Motor Current Sensing, Biomedical Patient-Isolated Signal Acquisition, 4-20 mA Industrial Process Control Loop Isolation, Switch-Mode Power Supply Feedback Isolation, High-Voltage Analog Data Acquisition Front End, Ground-Loop-Free Audio Signal Routing.
Industrial Motor Current Sensing
The ISO124P's 1500 Vrms isolation and 50 kHz bandwidth make it ideal for shunt-resistor based motor phase current measurement in variable-frequency drives. Placed between a low-side shunt and the controller ADC, the device's 140 dB common-mode rejection rejects the high dV/dt switching transients on the motor bus while its duty-cycle modulation preserves DC accuracy for closed-loop torque control. Compared with opto-isolated amplifiers, the ISO124P avoids LED aging drift and maintains linearity over the full -25°C to +85°C industrial temperature range. Pair with the INA240 current-sense amplifier or AMC1301 reinforced isolator for higher-bandwidth or higher-isolation variants.
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Biomedical Patient-Isolated Signal Acquisition
The ISO124P provides the required patient-protection isolation barrier for ECG, EEG, EMG, and patient-monitoring front-ends that demand leakage currents below IEC 60601 limits. Its ±10 V bipolar input accommodates the full-scale bioelectric signals and its ±4.5 V to ±18 V dual supply range permits operation from medical-grade isolated DC-DC modules. The 0.010% nonlinearity preserves diagnostic signal fidelity, while 140 dB common-mode rejection rejects 50/60 Hz mains interference from the hospital environment. Pair with the INA128 instrumentation amplifier on the patient side and an ADS1298 24-bit ADC for full diagnostic-channel signal chains.
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4-20 mA Industrial Process Control Loop Isolation
The ISO124P is well suited to isolating the analog I/O channels of PLCs, distributed control systems, and smart process transmitters that need to break ground loops between field wiring and the controller. Its 1.5 kVrms rating covers most process-plant common-mode voltages, and its 50 kHz bandwidth handles the dynamic response of pressure, flow, and temperature loops. Compared with discrete opto-isolator + op-amp solutions, the ISO124P provides a single-chip precision isolation path with 0.010% max nonlinearity, simplifying loop calibration and reducing long-term drift in installed systems.
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Switch-Mode Power Supply Feedback Isolation
The ISO124P isolates the primary-side feedback path in offline switch-mode power supplies, enabling primary-side regulation while keeping the secondary-side feedback loop safe for low-voltage control circuitry. Its capacitive isolation barrier handles the high dV/dt of the primary switching node, while the ±10 V input range accommodates typical optocoupler-replacement feedback voltages. Compared with traditional opto-isolator TL431 feedback paths, it eliminates the CTR aging and temperature drift issues that historically limited supply accuracy. Pair with the UCC28C42 PWM controller and TL431 secondary reference for a complete isolated feedback chain.
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High-Voltage Analog Data Acquisition Front End
The ISO124P is used as the analog isolation element in multi-channel data-acquisition systems that digitize high common-mode voltages from power inverters, traction motor controllers, and renewable-energy converters. Its 8-pin PDIP package and unity configuration minimize board area, while its 140 dB CMR cleanly rejects the PWM switching noise present at the measurement node. Compared with digital isolator + ADC architectures, the analog-output ISO124P preserves the analog signal all the way to a safely-grounded ADC, simplifying clock-routing and avoiding the latency of modulator-based digital isolators.
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Ground-Loop-Free Audio Signal Routing
The ISO124P's 50 kHz small-signal bandwidth and 0.010% nonlinearity make it suitable for breaking ground loops in professional audio systems, broadcast equipment, and inter-rack signal routing. Placed between a sending and receiving device with separate grounds, it eliminates the 50/60 Hz hum and DC offset caused by ground-potential differences while preserving audio-bandwidth and dynamic range. Compared with transformer-based audio isolators, the ISO124P is smaller, cheaper, and has flatter frequency response across the audio band.
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추천 제품 요약
엔지니어링 참조 데이터: ISO124P — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | ISO122P | ISO124U |
|---|---|---|---|
| Package | 8-pin PDIP | 8-pin PDIP - same | SOIC-16 - different (NOT drop-in) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Nonlinearity (Max) | 0.010% | 0.020% | 0.010% |
| Bandwidth | 50 kHz | 50 kHz | 50 kHz |
| Input Voltage Range | ±10 V | ±10 V | ±10 V |
| Supply Voltage Range | ±4.5 V to ±18 V | ±4.5 V to ±18 V | ±4.5 V to ±18 V |
| Gain Configuration | Fixed unity (1 V/V) | Fixed unity (1 V/V) | Fixed unity (1 V/V) |
주요 차별점
- Higher precision than ISO122P within same family (vs ISO122P)
- PDIP-8 package preferred for through-hole and high-voltage creepage designs (vs ISO124U (SOIC-16))
- Capacitive isolation barrier avoids opto-coupler aging (vs Discrete opto-isolator + op-amp solutions)
설계 노트
Each side of the ISO124P isolation barrier requires its own isolated supply rail. Use a DC-DC converter such as the SN6501 with a transformer isolation barrier, or a small isolated module like the DCP010505DBP. Place 0.1 uF plus 1 uF ceramic bypass capacitors within 5 mm of each V_S1 and V_S2 pin; this is critical because the internal 500 kHz modulator draws fast transient currents that will inject switching noise into the analog path if not properly bypassed. The ±5 mA / ±5.5 mA quiescent currents are nominal; the device draws additional current during signal transitions.
The 8-pin PDIP ISO124P provides a minimum 4 mm package-body clearance to the isolation barrier. On a 2-layer board, route all input-side signals (pins 1-4) on the left side and all output-side signals (pins 5-8) on the right side, with a keep-out region under the package body. For higher surge-withstand capability (such as IEC 61000-4-5), increase the creepage by milling a slot between input and output sections of the PCB. Avoid placing any copper trace, via, or component within the package-body footprint on either layer to maintain the rated isolation voltage.
Do not connect input-side and output-side grounds together - they are galvanically isolated by design and connecting them defeats the isolation. The internal unity-gain configuration is laser-trimmed; do not add external gain-setting resistors, as this will introduce gain error and drift. Avoid using the ISO124P for signals above 50 kHz, as the small-signal bandwidth rolls off rapidly above this point. Per datasheet, the input common-mode voltage range is limited to ±10 V - signals outside this range will saturate the input modulator and cause output distortion.
규정 준수 정보
RoHS compliant per Texas Instruments product page. Not AEC-Q100 qualified - ISO124P is not intended for automotive applications. Halogen-free per TI package materials declaration.
