Описание

The OPAx333 series of CMOS operational amplifiers use a proprietary auto-calibration technique to simultaneously provide very low offset voltage (10μV, maximum) and near-zero drift over time and temperature. These miniature, high-precision, low quiescent current amplifiers offer high-impedance inputs that have a common-mode range 100 mV beyond the rails, and rail-to-rail output that swings within 50 mV of the rails. Single or dual supplies as low as 1.8 V (±0.9 V) and up to 5.5 V (±2.75 V) can be used. These devices are optimized for lowvoltage, single-supply operation.
The OPAx333 family offers excellent CMRR without the crossover associated with traditional complementary input stages. This design results in superior performance for driving analog-to-digital converters (ADCs) without degradation of differential linearity.
The OPA333 (single version) is available in the 5-pin SOT-23, SOT, and 8-pin SOIC packages, while the OPA2333 (dual version) is available in the 8-pin VSON, SOIC, and VSSOP packages. All versions are specified for operation from–40°C to 125°C.

 

Характеристики

• Low Offset Voltage: 10 μV (Maximum)
• Zero Drift: 0.05 μV/°C (Maximum)
• 0.01-Hz to 10-Hz Noise: 1.1 μVPP
• Quiescent Current: 17 μA
• Single-Supply Operation
• Supply Voltage: 1.8 V to 5.5 V
• Rail-to-Rail Input/Output
• microSize Packages: SC70 and SOT23

 

Приложения

• Transducers
• Temperature Measurements
- Электронные весы
- Медицинское оборудование
• Battery-Powered Instruments
• Handheld Test Equipment

 

Характеристика Описание

The OPA333 and OPA2333 are unity-gain stable and free from unexpected output phase reversal. These devices use a proprietary auto-calibration technique to provide low offset voltage and very low drift over time and temperature. For lowest offset voltage and precision performance, optimize circuit layout and mechanical conditions. Avoid temperature gradients that create thermoelectric (Seebeck) effects in the thermocouple junctions formed from connecting dissimilar conductors. Cancel these thermally-generated potentials by assuring they are equal on both input terminals. Other layout and design considerations include:
• Uselow thermoelectric-coefficient conditions (avoid dissimilar metals).
- Термоизолируйте компоненты от источников питания или других источников тепла.
- Экранируйте операционный усилитель и входные цепи от воздушных потоков, например, от вентиляторов охлаждения.
Following these guidelines reduces the likelihood of junctions being at different temperatures, which can cause thermoelectric voltages of 0.1 μV/°C or higher, depending on materials used.

Operating Voltage

The OPA333 and OPA2333 operational amplifiers operate over a power-supply range of 1.8 V to 5.5 V (±0.9 V to ±2.75 V). Parameters that vary over supply voltage or temperature are shown in the Typical Characteristics section.

Input Voltage

The OPA333 and OPA2333 input common-mode voltage range extends 0.1 V beyond the supply rails. The OPA333 is designed to cover the full range without the troublesome transition region found in some other rail-to-rail amplifiers.
Typically, input bias current is approximately 70 pA; however, input voltages that exceed the power supplies can cause excessive current to flow into or out of the input pins. Momentary voltages greater than the power supply can be tolerated if the input current is limited to 10 mA. This limitation is easily accomplished with an input Resistor.

Internal Offset Correction

The OPA333 and OPA2333 operational amplifiers use an auto-calibration technique with a time-continuous 350-kHz operational amplifier in the signal path. This amplifier is zero-corrected every 8 μs using a proprietary technique. Upon power up, the amplifier requires approximately 100 μs to achieve specified VOS accuracy. This design has no aliasing or flicker noise.

Описание характеристик (продолжение)

The OPA333 and OPA2333 have an output stage that allows the output voltage to be pulled to the negative supply rail, or slightly below, using the technique previously described. This technique only works with some types of output stages. The OPA333 and OPA2333 are characterized to perform with this technique; the recommended resistor value is approximately 20 kΩ.