Overview
The INA117KU, produced by Texas Instruments, is a precision unity-gain difference amplifier known for its high common-mode input voltage range. This single monolithic IC integrates a precision op amp and a thin-film resistor network, enabling it to accurately measure small differential voltages in the presence of common-mode signals up to ±200V. The device is particularly useful in applications where galvanic isolation is not essential, allowing it to replace isolation amplifiers and eliminate the need for costly isolated input-side power supplies and their associated noise and quiescent current. The INA117KU is available in 8-pin plastic mini-DIP and SO-8 surface-mount packages, with a specified temperature range of –40°C to +85°C.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Gain | Initial | 1 | V/V | ||
| Gain Error | 0.01 | 0.05 | 0.02 | % | |
| Gain Error vs Temperature | 2 | 10 | ppm/°C | ||
| Nonlinearity | 0.0002 | 0.001 | % | ||
| Output Rated Voltage | IO = +20mA, –5mA | 10 | 12 | V | |
| Output Rated Current | VO = 10V | +20, –5 | mA | ||
| Output Impedance | 0.01 | Ω | |||
| Common-Mode Input Range | VS = ±15V | ±200 | V | ||
| Protected Inputs | ±500 | V (Common-Mode/Differential) | |||
| CMRR | 86 | dB |
Key Features
- High Common-Mode Input Range: Up to ±200V (VS = ±15V).
- Protected Inputs: Momentary common-mode or differential overloads up to ±500V.
- Unity Gain: 0.05% gain error maximum.
- Nonlinearity: 0.001% maximum.
- CMRR: Minimum of 86dB.
- Packaging: Available in 8-pin plastic mini-DIP and SO-8 surface-mount packages.
- Temperature Range: Specified for –40°C to +85°C.
Applications
- Current Monitoring: Measuring current by sensing voltage drop across a series resistor.
- Battery Cell-Voltage Monitoring: Accurate measurement of battery cell voltages.
- Ground Breaker: Detecting ground faults in various systems.
- Input Protection: Protecting against common-mode and differential overloads.
- Signal Acquisition in Noisy Environments: Accurate signal measurement in noisy environments.
- Factory Automation: Used in various factory automation applications where precise signal measurement is required.
Q & A
- What is the common-mode input range of the INA117KU?
The common-mode input range of the INA117KU is up to ±200V (VS = ±15V).
- What is the maximum gain error of the INA117KU?
The maximum gain error of the INA117KU is 0.05%.
- How is the nonlinearity of the INA117KU specified?
The nonlinearity of the INA117KU is specified as 0.001% maximum.
- What is the CMRR of the INA117KU?
The CMRR (Common Mode Rejection Ratio) of the INA117KU is a minimum of 86dB.
- What types of packaging are available for the INA117KU?
The INA117KU is available in 8-pin plastic mini-DIP and SO-8 surface-mount packages.
- What is the operating temperature range of the INA117KU?
The operating temperature range of the INA117KU is –40°C to +85°C.
- Can the INA117KU replace isolation amplifiers in some applications?
Yes, the INA117KU can replace isolation amplifiers in applications where galvanic isolation is not essential, eliminating the need for costly isolated input-side power supplies.
- How does the INA117KU protect against overloads?
The INA117KU inputs are protected from momentary common-mode or differential overloads up to ±500V.
- What are some common applications of the INA117KU?
Common applications include current monitoring, battery cell-voltage monitoring, ground breaker, input protection, signal acquisition in noisy environments, and factory automation.
- How does the INA117KU handle noisy environments?
The INA117KU is designed to accurately measure signals in noisy environments due to its high CMRR and nonlinearity specifications.
