THS4531A - Ultra-Low-Power Fully Differential Amplifier | TI
MPN： THS4531A ✓ 啟用中THS4531A 概覽
A fully differential amplifier (FDA) is an operational amplifier with differential inputs and differential outputs, providing both the signal and its complement. This architecture inherently rejects common-mode noise and even-order harmonics, making it ideal for driving high-performance ADCs, transmitting signals over long lines, and conditioning sensor outputs. In the signal chain hierarchy, an FDA is a type of amplifier IC, which falls under analog integrated circuits, essential for precision analog signal processing.
Key features of the THS4531A include a bandwidth of 36MHz at gain of 1, a slew rate of 200V/µs, and a low input voltage noise of 10nV/√Hz. The device also offers a high open-loop gain of 100dB and a common-mode rejection ratio (CMRR) of 100dB. Its rail-to-rail output stage maximizes dynamic range, and the input common-mode range below the negative rail allows direct interfacing with ground-referenced sensors in single-supply systems.
The THS4531A uses a complementary bipolar process and a precision laser-trimmed input stage, ensuring low offset voltage (typically 100µV) and low drift. The device is stable with capacitive loads up to 100pF, and its internal common-mode feedback loop maintains output common-mode voltage at the desired level, simplifying ADC interface design.
Typical applications include driving SAR and delta-sigma ADCs, low-power battery-operated instrumentation, portable medical devices, and single-ended to differential conversion for high-speed data acquisition. The device is also suitable for general-purpose differential signal conditioning in industrial and automotive systems.
When designing with the THS4531A, ensure proper power supply decoupling with 0.1µF capacitors close to the supply pins. The output common-mode voltage can be set via the VOCM pin, and the feedback network must be balanced to maintain optimal performance.
直接替換替代品，適用於 THS4531A — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： THS4531A （相同外形與佔位） — 差異在於 Number of Channels, Package.
THS4531
✅ 直接替換📋 參考替代品（不在目錄中）
THS4551
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
THS4521
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
ADA4932-1
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LMH6550
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
THS4531A 最大額定值與電氣特性
| Number of Channels | 1 |
| Supply Voltage - Single | 2.5 V to 5.5 V |
| Supply Voltage - Dual | ±1.25 V to ±2.75 V |
| 靜態電流 | 250 µA |
| Bandwidth | 36 MHz (G=1) |
| Slew Rate | 200 V/µs |
| Input Voltage Noise | 10 nV/√Hz |
| Open-Loop Gain | 100 dB |
| CMRR | 100 dB |
| Offset Voltage | 100 µV (typical) |
| 輸出類型 | Rail-to-Rail |
| Input Common-Mode Range | Below negative rail |
| 工作溫度範圍 | -40°C to +125°C |
| 封裝 | 8-SOIC |
| RoHS | Compliant |
THS4531A 腳位配置
| 腳位 1 | OUT- — Inverting output |
| 腳位 2 | V- — Negative supply |
| 腳位 3 | IN+ — Non-inverting input |
| 腳位 4 | IN- — Inverting input |
| 腳位 5 | VOCM — Output common-mode voltage control |
| 腳位 6 | V+ — Positive supply |
| 腳位 7 | OUT+ — Non-inverting output |
| 腳位 8 | PD — Power down (active low) |
典型應用
THS4531A 適用於 6 應用s: ADC Driver, Battery-Powered Instrumentation, Portable Medical Devices, Single-Ended to Differential Conversion, High-Speed Data Acquisition, Industrial Sensor Conditioning.
ADC Driver
The THS4531A is ideal for driving high-resolution ADCs due to its fully differential output, which provides common-mode rejection and doubles the dynamic range. Its low noise (10nV/√Hz) and 36MHz bandwidth ensure accurate signal conversion. The output common-mode voltage can be set via the VOCM pin to match the ADC input range, simplifying interface design. In a typical SAR ADC application, the THS4531A converts a single-ended sensor signal to differential, improving noise immunity and reducing even-order harmonics.
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Battery-Powered Instrumentation
With a quiescent current of only 250µA, the THS4531A is perfect for battery-powered instruments such as portable multimeters, data loggers, and field transmitters. It operates from a 2.5V supply, allowing direct connection to a 3V battery. The rail-to-rail output maximizes dynamic range, and the input common-mode range below the negative rail enables ground-referenced sensor interfacing. This low power consumption extends battery life, making it ideal for remote monitoring applications.
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Portable Medical Devices
The THS4531A's low power and small footprint make it suitable for portable medical devices like ECG monitors, pulse oximeters, and glucose meters. Its low noise (10nV/√Hz) ensures accurate biopotential signal amplification. The fully differential output rejects common-mode interference from the body, improving signal quality. The device operates from a single 3.3V supply, simplifying power design in battery-operated medical equipment.
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Single-Ended to Differential Conversion
The THS4531A can convert a single-ended signal to a differential output, which is useful for driving differential ADCs or transmitting signals over twisted-pair cables. Its input common-mode range below the negative rail allows direct connection to ground-referenced sensors. The device provides a balanced output that rejects common-mode noise, improving signal integrity in noisy industrial environments. This application is common in motor control and power monitoring systems.
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High-Speed Data Acquisition
With a 36MHz bandwidth and 200V/µs slew rate, the THS4531A is suitable for high-speed data acquisition systems, such as those used in test and measurement equipment. It can drive high-speed ADCs with minimal settling time, ensuring accurate capture of fast transients. The low power consumption allows high channel density in multi-channel systems. The device's rail-to-rail output maximizes the ADC input range, improving resolution.
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Industrial Sensor Conditioning
The THS4531A is used in industrial sensor conditioning, such as pressure, temperature, and strain gauge interfaces. Its low offset voltage (100µV) and high CMRR (100dB) ensure accurate measurement of small sensor signals. The input common-mode range below the negative rail allows direct connection to sensors referenced to ground. The device operates over -40°C to +125°C, making it suitable for harsh industrial environments.
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推薦產品摘要
工程參考資料，適用於 THS4531A — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | THS4531 | THS4551 | THS4521 | ADA4932-1 |
|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Supply Voltage Range | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 3V to 5V |
| Quiescent Current | 250 µA | 250 µA | 1.35 mA | 1.1 mA | 1.4 mA |
| Bandwidth | 36 MHz | 36 MHz | 150 MHz | 95 MHz | 560 MHz |
| Slew Rate | 200 V/µs | 200 V/µs | 220 V/µs | 490 V/µs | 2800 V/µs |
| Input Voltage Noise | 10 nV/√Hz | 10 nV/√Hz | 3.3 nV/√Hz | 4.6 nV/√Hz | 1.6 nV/√Hz |
| Offset Voltage | 100 µV | 100 µV | 50 µV | 100 µV | 100 µV |
主要差異化特點
- Ultra-low quiescent current of 250µA (對比THS4551)
- Input common-mode range below negative rail (對比ADA4932-1)
- Rail-to-rail output (對比THS4521)
設計說明
The THS4531A operates from 2.5V to 5.5V single supply or ±1.25V to ±2.75V dual supply. Ensure adequate decoupling with 0.1µF capacitors close to the V+ and V- pins. For single-supply operation, the input common-mode range below the negative rail allows direct connection to ground-referenced sensors, but the output swing is limited by the rail-to-rail output stage.
For optimal performance, place the THS4531A close to the ADC it drives to minimize trace length and parasitic capacitance. Use a solid ground plane and route differential traces symmetrically. The feedback resistors should be matched to 1% tolerance to maintain CMRR. Add a small capacitor (e.g., 10pF) across the feedback resistors to limit bandwidth and reduce noise.
Do not leave the PD (power down) pin floating; connect it to V+ for normal operation or to ground to disable the device. The VOCM pin sets the output common-mode voltage; if left floating, it defaults to mid-supply. Ensure the feedback network is balanced to avoid common-mode errors. Also, avoid driving capacitive loads greater than 100pF without a series resistor to prevent oscillation.
合規資訊
RoHS compliant per TI product page. Not AEC-Q100 qualified.
