INA146UA - 100V/V High-Voltage Difference Amplifier | TI
MPN: INA146UA ✓ ActiveINA146UA Overview
A difference amplifier is a voltage-feedback amplifier that amplifies the voltage difference between two inputs while rejecting voltage common to both inputs. The INA146 belongs to the precision difference-amplifier family within instrumentation amplifiers and signal-conditioning ICs. Its differential input architecture supports accurate attenuation of high differential voltages, rejection of high common-mode voltages, and compatibility with common signal-processing voltage levels.
Key features include a ±15 V high common-mode voltage range, differential gain up to 100 V/V set by external resistors, and a 570 µA low quiescent current. The input common-mode range extends beyond both supply rails, providing inherent input protection and allowing the amplifier to operate when its inputs exceed the local supply voltages. The 5 mV offset and 550 kHz bandwidth balance precision and response speed.
Technically, the INA146 uses external gain-setting resistors, allowing the gain to be programmed according to application requirements. This resistor-programmed architecture makes it suitable for measurement systems in which gain must be adjusted across multiple input ranges. The operating temperature range of −40 °C to +125 °C supports industrial equipment, while the single-circuit 8-SOIC package simplifies PCB layout and replacement.
Typical applications include high-side current sensing, precision bridge and transducer excitation, industrial process measurement, battery monitoring, and instrumentation where inputs may exceed the amplifier supply rails. The common-mode rejection capability is especially useful when a small sensor signal is superimposed on a larger system voltage.
Designers should verify input and output voltage limits, power dissipation, gain-resistor tolerance, and stability across the intended frequency range. Because the common-mode input range extends beyond the rails, PCB creepage, protection, and grounding remain important even though the device offers inherent input protection. External input protection may still be required for sustained overvoltage conditions.
This page combines verified manufacturer and distributor information with a parameter comparison, drop-in alternatives, application guidance, and practical design notes to support faster component selection and implementation.
Drop-in alternatives for INA146UA — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
INA146UA/2K5
✅ Drop-In📋 Reference alternative (not in catalog)
INA146UAE4
✅ Drop-In📋 Reference alternative (not in catalog)
INA149UA
✅ Drop-In📋 Reference alternative (not in catalog)
INA148UA/2K5G4
✅ Drop-In📋 Reference alternative (not in catalog)
AD8271
✅ Drop-In📋 Reference alternative (not in catalog)
INA146UA Maximum Ratings & Electrical Characteristics
| Product Type | Precision high-voltage programmable-gain difference amplifier (1 circuit) |
| Maximum Differential Gain | 100 V/V |
| Gain Configuration | Set with external resistors |
| Small-Signal Bandwidth | 550 kHz |
| Input Offset Voltage | 5 mV |
| Input Common-Mode Voltage Range | ±15 V |
| Supply Voltage Range, Single | 4.5 V to 36 V |
| Supply Voltage Range, Dual | ±2.25 V to ±18 V |
| Quiescent Current | 570 µA |
| Output Current | 15 mA |
| Operating Temperature Range | −40 °C to +125 °C |
| Package | 8-pin SOIC (D), 3.9 mm nominal width |
| Pin Count | 8 pins |
| Mounting Type | Surface mount |
| Input Protection | High-voltage capability with inherent input protection |
| Halogen-Free Status | Compliant |
| Country of Origin | Malaysia |
| Export Control Classification Number | EAR99 |
INA146UA 8-pin soic (d), 3.9 mm nominal width Pin Configuration Guide
Pin configuration for INA146UA (8-pin soic (d), 3.9 mm nominal width package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for INA146UA.
Refer to the datasheet for full pin configuration.
Typical Applications
INA146UA is suitable for 6 applications: High-Side Current Sensing, Industrial Bridge and Transducer Measurement, Battery and Power-System Monitoring, Precision Test and Measurement Front End, Process-Control Signal Conditioning, High-Voltage Input-Protected Data Acquisition.
High-Side Current Sensing
The INA146UA fits high-side current measurement because its input common-mode range extends beyond the supply rails and reaches ±15 V, allowing a small shunt differential voltage to be measured above a larger bus potential. The external-resistor gain network supports gains up to 100 V/V, while 550 kHz bandwidth accommodates current transients beyond a dc-only measurement. The 570 µA quiescent current helps limit standing losses in portable or distributed systems. In implementation, keep the shunt and amplifier input loop compact, connect the amplifier to the same ground reference as the shunt, and verify that the common-mode voltage and output swing remain within the selected INA146 operating region. External clamping may be necessary if the bus can exceed the absolute maximum input rating.
Recommended
Industrial Bridge and Transducer Measurement
The INA146UA is appropriate for bridge or transducer front ends where the wanted differential signal is small relative to the common-mode voltage. Its precision-difference-amplifier architecture rejects common voltage while the external gain resistors scale the output to the next-stage input range. A bandwidth of 550 kHz provides useful response for controlled industrial signals without requiring a high-speed amplifier, and the 5 mV offset specification supports reasonably accurate measurements. The 4.5 V to 36 V single-supply option simplifies higher-voltage industrial systems, but the output must remain within the supply rails. Use precision gain resistors and verify input and output limits against the official datasheet.
Recommended
Battery and Power-System Monitoring
The INA146UA can monitor battery or power-rail voltage when the measurement benefits from rejection of a substantial common-mode potential. Its single-supply operating range of 4.5 V to 36 V covers many industrial and energy-storage measurement points, while 570 µA quiescent current limits the amplifier's continuous overhead. Programmable differential gain up to 100 V/V permits direct attenuation of high differential voltages. In a battery-management circuit, use the amplifier as a measurement element rather than as the protection device itself, and account for output saturation near the positive supply rail. A scaled output or level-shifting stage may be required when the next controller operates from a lower voltage.
Recommended
Precision Test and Measurement Front End
The INA146UA is suitable as the differential input stage of an instrumentation system when test signals require common-mode rejection and programmable attenuation. Its 550 kHz bandwidth supports measurements beyond static dc, and gain up to 100 V/V can be established with external resistors. The single-circuit 8-pin SOIC package keeps the analog front end compact while leaving a straightforward layout for feedback, reference, and gain components. Engineers should evaluate resistor tolerance, input bias-current effects, and output settling for the shortest intended measurement interval. Because the verified data does not include the complete pin map, the circuit must be drawn directly from the official Texas Instruments datasheet rather than from a secondary pinout image.
Recommended
Process-Control Signal Conditioning
The INA146UA can condition the differential output of sensors used in process-control loops where the physical measurement is superimposed on a substantial common-mode voltage. The ±15 V common-mode specification and beyond-rail input capability help reject unwanted system voltage, while programmable gain adapts the signal to an analog or digital acquisition stage. Its 550 kHz bandwidth is more than adequate for many slow process variables and supports diagnostic signals that change rapidly enough to require measurement. Place input and gain components close to the amplifier, maintain a quiet return path, and avoid routing sensitive differential traces beside switching nodes. The output reference should be established in a way that preserves the required headroom for bipolar signals.
Recommended
High-Voltage Input-Protected Data Acquisition
The INA146UA is appropriate for data-acquisition inputs that can carry high common-mode voltage relative to the local electronics. Its high-voltage capability provides inherent input protection, and the common-mode range extending beyond both supply rails allows a small differential sensor output to be measured even when the input sits outside the amplifier's supply voltage. Gain can be adjusted from 1 V/V upward through external resistors, up to 100 V/V. The 570 µA quiescent current is useful in remote or battery-operated acquisition nodes. Designers must still distinguish permitted common-mode operation from absolute-maximum stress, add external protection for severe transients, and ensure that the attenuated output remains inside the input range of the converter or controller.
Recommended
Recommended Products Summary
Engineering reference data for INA146UA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | INA146UA/2K5 | INA146UAE4 | INA149UA | INA148UA/2K5G4 | AD8271 |
|---|---|---|---|---|---|---|
| Package | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC (D) | 8-pin SOIC |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Product Type | High-voltage programmable-gain difference amplifier | High-voltage programmable-gain difference amplifier | INA146-family difference amplifier | High-voltage high-precision difference amplifier | High-voltage difference amplifier | High-precision difference amplifier |
Key Differentiators
- High common-mode operation supports measurement above the local supply rails (vs AD8271)
- Programmable differential gain reaches 100 V/V (vs INA149UA)
- Low 570 µA quiescent current supports portable measurement nodes (vs AD8271)
- 550 kHz bandwidth covers a broader range of industrial dynamic signals (vs INA146UA/2K5)
Design Notes
Do not equate the extended input common-mode range with unlimited input voltage. The verified operating specification identifies ±15 V common-mode capability and inputs that may extend beyond the supply rails, but the official datasheet absolute-maximum limits must still control the design. Add series resistance or dedicated clamps where a fault can apply sustained voltage beyond those limits, and verify that every external gain resistor remains within its working voltage rating.
Route the two differential inputs as a compact, tightly coupled pair and connect the external gain-setting network close to the amplifier. Keep the loop small to minimize conversion of common-mode noise into differential error and to reduce sensitivity to parasitic capacitance. Maintain a low-impedance return for the reference and supply connections, and avoid placing the input pair beneath switching nodes, inductors, or high-current traces.
The INA146UA can operate from a single 4.5 V to 36 V supply or from dual ±2.25 V to ±18 V rails, but the output must remain within the selected rail arrangement. Check the output swing at the worst input combination and load before assuming a downstream device has adequate headroom. Because the device supports high-voltage inputs, include the INA146 supply current and any output-drive loss when estimating system power, while avoiding excessive dissipation in surrounding components.
Programmed gain depends on the accuracy and matching of the external resistors rather than on a fixed internal gain control. Use the gain equation and resistor values in the official INA146 datasheet, account for resistor tolerance and temperature coefficient, and confirm that the selected network remains stable at the intended gain. A board layout that works for one gain ratio may not preserve the same bandwidth or settling behavior at another ratio.
Compliance Information
The supplied GlobalSpec-derived result states that INA146UA is halogen-free compliant and manufactured in Malaysia under EAR99. The supplied excerpts did not provide explicit RoHS, REACH, lead-free, or conflict-minerals statements for the exact ordering code.
