INA118P - Precision Low-Power Instrumentation Amplifier | Texas Instruments
N.º de pieza: INA118P ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $14.8288 | $14,83 |
| 10 | $14.8288 | $148,29 |
| 100 | $14.8288 | $1.482,88 |
| 500 | $14.8288 | $7.414,40 |
| 1.000 | $14.8288 | $14.828,80 |
INA118P Descripción general
An instrumentation amplifier is a specialized analog amplifier optimized for measuring small differential signals while rejecting large common-mode voltages. The INA118 belongs to the broader hierarchy of instrumentation amplifier, precision amplifier, analog signal-conditioning IC, and power-management-independent semiconductor. Its internal feedback network provides accurate gain-setting while preserving high input impedance and low offset behavior. This makes it useful in sensor interfaces, current measurement, bridge transducers, biomedical instrumentation, and precision control systems.
The principal accuracy features are the laser-trimmed low offset voltage of 50 µV maximum and drift of 0.5 µV/°C maximum. Input bias current is specified at 5 nA maximum, while input protection extends to ±40 V. The wide supply range reaches ±18 V, and the low 350 µA quiescent current supports battery-operated systems. The device is available in an 8-pin plastic DIP for through-hole PCB assembly, with an operating temperature range of -40°C to +85°C as stated in the supplied technical data.
The three-op-amp architecture and current-feedback input stage provide useful bandwidth at higher closed-loop gains. A single external resistor sets the gain from 1 to 10000, allowing the same device to serve low-gain signal conditioning and high-gain bridge or sensor measurements. The 70 kHz bandwidth at gain 100 helps balance measurement speed against noise and accuracy, while the 110 dB common-mode rejection at gain 1000 supports measurement of weak differential signals embedded in larger common-mode environments.
Typical uses include bridge-sensor amplification, strain-gauge and load-cell measurement, low-current sensing, battery-powered instrumentation, industrial process measurement, medical signal acquisition, and precision analog-to-digital converter front ends. In a bridge circuit, the instrumentation amplifier rejects supply or ground shifts shared by the sensor outputs and amplifies the small differential voltage produced by the sensor. In a current-shunt system, its low bias current helps minimize measurement error, while input protection is useful in applications where transients may reach the input terminals.
The primary design consideration is selecting the external gain resistor and confirming that the resulting bandwidth, input common-mode range, output swing, supply voltage, and settling time meet the measurement requirements. Place the gain resistor close to the gain-setting pin and maintain a low-noise layout around the sensitive input pins. Verify output headroom at the intended load because instrumentation-amplifier accuracy specifications are meaningful only when the circuit operates within its input and output linear ranges.
This page combines the verified manufacturer and distributor information for INA118P with package details, application guidance, comparison fields, and design notes intended to make selection and implementation more practical than a basic distributor listing.
Alternativas directas para INA118P — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con INA118P (mismo factor de forma y huella).
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
INA118PG4
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
INA118P Valores máximos y características eléctricas
| Product Type | Precision, low-power instrumentation amplifier |
| Number of Amplifier Circuits | 1 circuit |
| Offset Voltage | 50 µV maximum |
| Offset Voltage Drift | 0.5 µV/°C maximum |
| Common-Mode Rejection Ratio | 110 dB minimum at gain 1000 |
| Input Bias Current | 5 nA maximum |
| Input Protection | ±40 V |
| Supply Voltage Range | ±2.25 V to ±18 V |
| Corriente en reposo | 350 µA |
| Gain Range | 1 to 10000 |
| Gain Setting | One external resistor |
| Bandwidth | 70 kHz at gain 100 |
| Architecture | Three-op-amp design with current-feedback input circuitry |
| Encapsulado | 8-pin plastic DIP |
| Tipo de montaje | Through-hole |
| Temperatura de funcionamiento | -40°C to +85°C |
Configuración de pines de INA118P
| Pin 1 | RG — Gain-setting resistor connection |
| Pin 2 | IN- — Inverting input |
| Pin 3 | IN+ — Noninverting input |
| Pin 4 | V- — Negative supply connection |
| Pin 5 | REF — Reference input |
| Pin 6 | OUT — Instrumentation-amplifier output |
| Pin 7 | V+ — Positive supply connection |
| Pin 8 | RG — Gain-setting resistor connection |
Aplicaciones típicas
INA118P es adecuado para 6 aplicacións: Bridge Sensor Signal Conditioning, Low-Current Shunt Measurement, Battery-Powered Portable Instrumentation, Precision Analog-to-Digital Converter Front End, Industrial Process Measurement, Medical and Physiological Signal Acquisition.
Bridge Sensor Signal Conditioning
The INA118P fits strain-gauge, load-cell, and resistive-bridge front ends because its instrumentation-amplifier architecture amplifies the small differential bridge output while rejecting common-mode voltage. The verified specifications include 110 dB common-mode rejection at gain 1000 and an offset drift of 0.5 µV/°C maximum. Place the device close to the bridge excitation and sensing network, select the external resistor for the required gain, and verify that bridge excitation, input common-mode voltage, and output swing remain inside the device limits.
Recomendado
Low-Current Shunt Measurement
INA118P is suitable for measuring small voltage drops across a current-shunt resistor when the required differential signal is small and common-mode voltage is significant. Its 50 µV maximum offset and 5 nA maximum input bias current help reduce measurement error, while the three-op-amp architecture supports accurate differential amplification. The shunt and amplifier must be arranged so that input common-mode voltage and output voltage remain within the operating limits, and the gain resistor should be selected to preserve adequate bandwidth for the measurement bandwidth.
Recomendado
Battery-Powered Portable Instrumentation
The INA118P supports battery-powered measurement systems because its verified quiescent current is 350 µA and its supplies can operate as low as ±2.25 V. Low bias current is important when the sensor source impedance is high, and the wide supply flexibility allows the device to fit portable analog signal-conditioning designs. Designers should still calculate the complete power budget, including sensor excitation, output loading, regulator efficiency, and any required protection network, rather than treating the amplifier quiescent current as total system current.
Recomendado
Precision Analog-to-Digital Converter Front End
INA118P can provide the analog gain and common-mode rejection stage ahead of an ADC when a weak differential sensor signal must be conditioned before conversion. Its 70 kHz bandwidth at gain 100 supports applications that do not require the bandwidth of a high-speed signal chain, while the precision offset and drift specifications help establish stable measurements. Check the ADC input range, sampling rate, acquisition time, and the INA118P settling behavior together; a high closed-loop gain can reduce usable bandwidth and increase sensitivity to layout parasitics.
Recomendado
Industrial Process Measurement
INA118P is appropriate for industrial process-control systems that measure low-level differential signals from transducers while rejecting process-related common-mode voltage. Its low offset and temperature drift support stable readings, and the input protection rating of ±40 V provides a stated protection level for suitable signal paths. The external protection network, isolation strategy, grounding, and surge requirements must still be designed for the actual industrial environment. Confirm the operating temperature range of -40°C to +85°C against the system enclosure and process conditions.
Recomendado
Medical and Physiological Signal Acquisition
INA118P can be used in low-level physiological and biomedical signal-conditioning modules when the design requires low offset, low bias current, and good common-mode rejection. The 50 µV maximum offset and 5 nA maximum input bias current are relevant to high-impedance sensor interfaces, while the gain range supports amplification from modest to high differential signal levels. Medical designs require separate review of patient protection, isolation, leakage current, electrode protection, diagnostic standards, and applicable regulatory requirements; the supplied data does not establish medical certification for INA118P.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para INA118P — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | INA118PG4 |
|---|---|---|
| Package | 8-pin plastic DIP | 8-pin plastic DIP |
| Brand | Texas Instruments | Texas Instruments |
Diferenciadores clave
- Low-power precision positioning (frente a INA118PG4)
- Precision offset performance (frente a INA118PG4)
- Gain flexibility and bandwidth (frente a INA118PG4)
Notas de diseño
Keep the INA118P input traces short and place the external gain resistor close to the gain-setting connection identified in the manufacturer datasheet. Route sensitive input and reference nodes away from switching regulators, relay contacts, high-current return paths, and digital clock lines. Use a quiet ground reference for the reference and supply-return connections, and verify that PCB leakage and contamination do not exceed the error budget when measuring high-impedance sources.
Do not assume that the ±40 V input-protection rating makes every input condition safe for accurate measurement. Protection ratings describe withstand conditions, not the input common-mode range for linear operation. Check the positive and negative supply voltages, input common-mode limits, output swing, gain, and external resistor value against the INA118P datasheet before energizing the circuit. Add appropriately engineered clamping and series resistance when the source can produce transients.
Bandwidth and settling must be evaluated together. The verified data specifies 70 kHz bandwidth at gain 100, but higher gains can reduce usable bandwidth and increase sensitivity to input capacitance, resistor tolerance, and PCB parasitics. For an ADC front end, calculate the required acquisition time from the system bandwidth and conversion rate, then simulate or measure settling rather than selecting the gain from the gain range alone.
Información de cumplimiento
The supplied web data does not explicitly state RoHS, REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification status for INA118P. AEC-Q100 is not applicable based on the provided application and qualification information, but this field should be reviewed against the current manufacturer product documentation before regulated use.
