Overview
The INA116PA from Texas Instruments is a high-performance, ultra-low input bias current instrumentation amplifier. This monolithic FET-input amplifier is designed for applications requiring extremely low input bias currents and high common-mode rejection. The INA116PA is available in 16-pin plastic DIP and SOL-16 surface-mount packages and is specified for a temperature range of –40°C to +85°C. It features a 3-op amp topology, allowing gains to be set from 1 to 1000 using a single external resistor. The device is particularly suited for laboratory instrumentation, pH measurement, ion-specific probes, and leakage current measurement due to its low offset voltage, high common-mode rejection, and low quiescent current.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Input Offset Voltage, RTI | TA = +25°C | ±0.5 | ±2 | ±6 | mV |
| Input Bias Current | TA = +25°C | ±3 | ±25 | ±100 | fA |
| Common-Mode Rejection | VCM = ±11V, ∆RS = 1kΩ, G = 10 | 84 | 92 | 78 | dB |
| Quiescent Current | VIN = 0V | ±1 | ±1.4 | ±6 | mA |
| Safe Input Voltage | ±40 | V | |||
| Bandwidth, –3dB | G = 1 | 800 | kHz | ||
| Slew Rate | G = 10 to 200 | 0.8 | V/µs | ||
| Power Supply Voltage Range | ±4.5 | ±15 | ±18 | V | |
| Temperature Range | Specification | –40 | 85 | °C |
Key Features
- Ultra Low Input Bias Current: 3fA typical at 25°C and 25fA at 85°C.
- Buffered Guard Drive Pins: Helps maintain low input bias current by driving circuit board and input cable guards.
- Low Offset Voltage: ±2mV maximum.
- High Common-Mode Rejection: Up to 94dB at G = 1000.
- Low Quiescent Current: 1.4mA typical.
- Input Over-Voltage Protection: ±40V safe input voltage.
- Gain Setting: Gain can be set from 1 to 1000 using a single external resistor.
Applications
- Laboratory Instrumentation: Suitable for precise measurement applications.
- pH Measurement: Ideal for high-accuracy pH sensing.
- Ion-Specific Probes: Used in various ion-specific sensing applications.
- Leakage Current Measurement: High sensitivity for detecting low leakage currents.
Q & A
- What is the typical input bias current of the INA116PA at 25°C?
The typical input bias current is 3fA at 25°C. - How can the gain of the INA116PA be set?
The gain can be set from 1 to 1000 using a single external resistor, RG. - What is the common-mode rejection ratio (CMRR) of the INA116PA?
The CMRR is up to 94dB at G = 1000. - What is the safe input voltage range for the INA116PA?
The safe input voltage range is ±40V. - What are the typical quiescent current and slew rate of the INA116PA?
The typical quiescent current is 1.4mA, and the slew rate is 0.8V/µs for gains between 10 and 200. - What are the package options for the INA116PA?
The INA116PA is available in 16-pin plastic DIP and SOL-16 surface-mount packages. - What is the operating temperature range of the INA116PA?
The operating temperature range is –40°C to +85°C. - How does the INA116PA protect against input over-voltage?
The INA116PA has built-in input over-voltage protection up to ±40V. - What are some common applications of the INA116PA?
Common applications include laboratory instrumentation, pH measurement, ion-specific probes, and leakage current measurement. - How important is circuit board layout for the INA116PA?
Careful circuit board layout and assembly techniques are crucial to achieve the exceptionally low input bias current performance of the INA116PA.
