Overview
The INA317IDGKR from Texas Instruments is a micro-power, zero-drift instrumentation amplifier designed for high accuracy and low power consumption. This device is based on the precision zero-drift OPA333 operational amplifier core and integrates laser-trimmed resistors to ensure excellent common-mode rejection and low gain error. The INA317 is suitable for a wide range of portable and industrial applications due to its small size, low quiescent current of 50 µA, and operation over a supply voltage range of 1.8 V to 5.5 V.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Offset Voltage, RTI | ±10 | ±25 | ±75 | µV |
| Offset Voltage Drift | ±0.3 | ±0.5 | µV/°C | |
| Noise Density | 50 | nV/√Hz | ||
| Common-Mode Rejection Ratio (CMRR) | 100 | dB (G ≥ 10) | ||
| Input Bias Current | 200 | pA | ||
| Supply Voltage Range | 1.8 | 5.5 | V | |
| Quiescent Current | 50 | 80 | µA | |
| Operating Temperature Range | -40 | 125 | °C | |
| Bandwidth (–3 dB) | 150 | kHz (G = 1) | ||
| Slew Rate | 0.16 | V/μs (VS = 5 V, G = 1) |
Key Features
- Low offset voltage: 75 µV (maximum) for G ≥ 100
- Low drift: 0.3 µV/°C for G ≥ 100
- Low noise: 50 nV/√Hz for G ≥ 100
- High CMRR: 100 dB (minimum) for G ≥ 10
- Low input bias current: 200 pA (maximum)
- Supply range: 1.8 V to 5.5 V
- Low quiescent current: 50 µA
- Operating temperature: –40°C to +125°C
- RFI filtered inputs
- 8-pin VSSOP package
- Single external resistor sets gain from 1 to 1000
Applications
- Bridge amplifiers
- ECG amplifiers
- Pressure sensors
- Medical instrumentation
- Portable instrumentation
- Weigh scales
- Thermocouple amplifiers
- RTD sensor amplifiers
- Data acquisition
Q & A
- What is the minimum and maximum supply voltage for the INA317?
The INA317 operates with a supply voltage range of 1.8 V to 5.5 V.
- What is the quiescent current of the INA317?
The quiescent current of the INA317 is 50 µA.
- What is the typical noise density of the INA317?
The typical noise density is 50 nV/√Hz for G ≥ 100.
- How is the gain of the INA317 set?
The gain is set by a single external resistor (RG) using the equation G = 1 + (100 kΩ / RG).
- What is the common-mode rejection ratio (CMRR) of the INA317?
The CMRR is 100 dB (minimum) for G ≥ 10.
- What is the operating temperature range of the INA317?
The operating temperature range is –40°C to +125°C.
- What package type is the INA317 available in?
The INA317 is available in an 8-pin VSSOP surface-mount package.
- How does the INA317 handle input bias current?
The INA317 requires a path for the input bias current, which is typically ±70 pA. High-input impedance means this current changes very little with varying input voltage.
- What are some common applications of the INA317?
Common applications include bridge amplifiers, ECG amplifiers, pressure sensors, medical instrumentation, and data acquisition.
- How does the autocalibration technique in the INA317 affect its performance?
The autocalibration technique reduces low-frequency noise and ensures precision over the extended industrial temperature range without aliasing or flicker noise.
