INA819IDR - 35µV Offset Low-Power Instrumentation Amp | Texas Instruments
Référence : INA819IDR ✓ Actif| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $5.04 | $5,04 |
| 10 | $4.53 | $45,30 |
| 100 | $4.03 | $403,00 |
| 500 | $3.62 | $1 810,00 |
| 1 000 | $3.22 | $3 220,00 |
INA819IDR Présentation
An instrumentation amplifier (INA / in-amp) is a precision differential amplifier that combines high input impedance, accurate fixed gain, and excellent common-mode rejection ratio (CMRR). It is constructed from internal op-amps and a precision resistor network; the user only programs the gain with one external resistor. Within the analog signal-chain hierarchy, instrumentation amplifiers sit above standard op-amps and are the preferred first stage for low-level, high-CMRR sensor readout, before downstream ADCs, SAR drivers, or programmable-gain stages. The INA819 targets precision industrial, medical, and test-and-measurement designs that demand excellent DC accuracy and very low broadband noise.
Key specifications include 35 µV maximum input offset voltage, 0.4 µV/°C maximum offset drift, 8 nV/√Hz voltage noise density, 120 dB minimum CMRR (G = 100), 7 MHz bandwidth (G = 100), and 1.6 V/µs slew rate. The super-beta input stage delivers very low input bias current (10 nA maximum) and high input impedance, supporting direct connection to high-impedance bridges and transducers without external buffers.
Architecturally, the INA819 combines a super-beta bipolar input front-end with a current-feedback gain stage and laser-trimmed thin-film resistors, achieving <0.4 µV/°C drift and 120 dB CMRR at 1 kHz. It supports single-supply 4.5 V to 36 V or dual-supply ±2.25 V to ±18 V operation, suiting both battery-powered and industrial 24 V bus rails.
Typical applications include bridge pressure-strain gauge signal conditioning, weigh scales, ECG/biopotential front ends, industrial process-control analog inputs, and battery-cell monitoring AFE stages. The ±60 V input protection (gain pins only) allows direct connection to industrial sensor lines without external clamping in many cases.
When designing with the INA819, choose the gain resistor close to the INA pins to minimize parasitic capacitance and maintain CMRR above 100 dB. For highest DC accuracy, add a low-pass RC filter at the output to attenuate RF rectification before the ADC.
This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes - engineering context not found in the manufacturer datasheet alone.
Alternatives de remplacement direct pour INA819IDR — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec INA819IDR (même facteur de forme et même empreinte) — différant par Package, Slew Rate, Amplifier Type, Number of Circuits, Operating Temperature.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
INA821IDR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
INA828IDR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
INA333AIDR
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD8221BRZ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD620ANZ
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
AD8421ARZ
✅ Remplacement direct✓ En stock
$3.39 / unité
Voir la fiche technique →INA819IDR Valeurs maximales et caractéristiques électriques
| Amplifier Type | Instrumentation Amplifier |
| Number of Channels | 1 |
| Input Offset Voltage (max) | 35 µV |
| Input Offset Voltage Drift (max) | 0.4 µV/°C |
| Input Bias Current (max) | 10 nA |
| Input-Referred Voltage Noise Density | 8 nV/√Hz |
| CMRR (G=100, min) | 120 dB |
| Gain Range | 1 to 10,000 (single external resistor) |
| Bandwidth (G=100) | 7 MHz |
| Slew Rate | 1.6 V/µs |
| Supply Voltage (Single) | 4.5 V to 36 V |
| Supply Voltage (Dual) | ±2.25 V to ±18 V |
| Quiescent Current (typ) | 350 µA |
| Input Overvoltage Protection (gain pins) | ±60 V |
| Température de fonctionnement | -40 °C to +125 °C |
| Boîtier | SOIC-8 (D) |
| Type de montage | Surface Mount |
| Niveau MSL | 2 (1 year) |
| Statut RoHS | Compliant |
Configuration des broches de INA819IDR
| Broche 1 | R_G — Gain-setting resistor pin 1 (±60 V input protection) |
| Broche 2 | R_G — Gain-setting resistor pin 2 (±60 V input protection) |
| Broche 3 | -IN — Negative (inverting) differential input |
| Broche 4 | +IN — Positive (non-inverting) differential input |
| Broche 5 | REF — Reference voltage for output level shift |
| Broche 6 | VS- — Negative supply (or GND for single supply) |
| Broche 7 | OUT — Regulated output |
| Broche 8 | VS+ — Positive supply |
Applications typiques
INA819IDR convient pour 6 applications: Bridge Pressure / Strain Gauge Signal Conditioning, ECG / Biopotential Front End, Industrial Process Control Analog Input Module, Weigh Scale / Load Cell Readout, Battery-Cell Monitoring AFE, Test and Measurement Instrumentation.
Bridge Pressure / Strain Gauge Signal Conditioning
The INA819IDR is an excellent front-end for Wheatstone-bridge pressure and strain sensors. Its 35 µV maximum offset voltage and 0.4 µV/°C maximum drift preserve DC accuracy across -40 °C to +125 °C, while 8 nV/√Hz noise density supports 16-bit SAR ADC dynamic range without an external pre-amplifier. Placed between the bridge and the ADC, with gain set by a single 10 ppm/°C resistor (e.g., 49.4 kΩ for G=2), the part delivers >120 dB CMRR at 1 kHz to reject industrial common-mode noise. Compared to discrete three-op-amp in-amps, the INA819 saves board area, eliminates resistor matching, and adds ±60 V input protection on the gain pins to survive field miswiring on load cells, force sensors, and weigh scales.
Recommandé
ECG / Biopotential Front End
The INA819IDR suits medical ECG, EMG, and EEG front-end designs because its super-beta input stage drops input bias current to 10 nA maximum - 5-10× lower than conventional in-amps - minimizing electrode polarization errors over long monitoring sessions. The 8 nV/√Hz noise floor preserves microvolt-level cardiac signals, and 120 dB CMRR rejects 50/60 Hz mains interference without extensive shielding. Placed at the patient-electrode interface, with a 60 Hz notch filter and RLD driver following the INA819, the part feeds 16-24 bit sigma-delta ADCs for clinical-grade signal integrity. Battery-powered wearable monitors benefit from 350 µA quiescent current, extending runtime versus the 1 mA-class AD620/AD8221 alternatives.
Recommandé
Industrial Process Control Analog Input Module
The INA819IDR's ±60 V overvoltage protection on the gain-setting pins (pins 1 and 2) tolerates direct wiring faults on 4-20 mA current loops, RTDs, and thermocouple inputs without external TVS protection in many cases. Wide single-supply operation (4.5 V to 36 V) supports direct connection to industrial 24 V PLC backplanes. The 120 dB CMRR rejects ground potential differences across long factory cabling. Placed at the ISA-style analog-input channel, the INA819 conditions ±10 V or 4-20 mA signals before 16-bit SAR ADC sampling; its 1.6 V/µs slew rate enables fast multiplexer settling for multi-channel scanned systems, and the SOIC-8 footprint simplifies field-replacement maintenance in harsh environments.
Recommandé
Weigh Scale / Load Cell Readout
The INA819IDR is well-suited to commercial and industrial weigh scales that require sub-gram resolution from a 4-arm strain-gauge bridge. With 8 nV/√Hz noise and 0.4 µV/°C drift, the part resolves microvolt-level bridge outputs over a -40 °C to +125 °C operating range without external chopper stabilization. Placed between the load cell and a 24-bit sigma-delta ADC (e.g., ADS1231), gain is set to 128 V/V by a 383 Ω resistor for a full-scale bridge input of ±10 mV. The ±60 V input protection on gain pins survives static-discharge and short-circuit wiring faults in retail POS scales, vehicle scales, and laboratory balances, eliminating the need for external protection components.
Recommandé
Battery-Cell Monitoring AFE
The INA819IDR's 350 µA quiescent current and 4.5 V to 36 V single-supply operation support direct connection to multi-cell battery stacks (e.g., 12S Li-ion at 50 V max). Differential gain of up to 10,000 V/V enables small shunt-resistor measurements in high-current BMS applications, while 8 nV/√Hz noise preserves coulomb-counting accuracy. Placed at each cell monitor, the part delivers clean differential current/voltage signals to the ADC; its -40 °C to +125 °C operating range tolerates under-hood automotive and grid-storage environments. Compared to chopper-stabilized alternatives, the INA819 avoids chopper-induced aliasing in time-domain coulomb counting.
Recommandé
Test and Measurement Instrumentation
The INA819IDR serves as a precision front-end in bench-top multimeters, oscilloscope differential probes, and data-acquisition systems requiring 7 MHz bandwidth and 1.6 V/µs slew rate. The 120 dB CMRR rejects line-frequency pickup on floating measurements, and 10 nA max input bias current allows connection to high-impedance probes without attenuation. Placed at the analog input of a 16-bit SAR ADC with a 50 Ω input termination, the INA819 drives multiplexed channels across full audio bandwidth; its SOIC-8 package fits dense probe-tip PCBs and modular DAQ cards. Engineers gain a flexible gain-of-1 to 10,000 front-end with one external resistor.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour INA819IDR — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | INA821IDR | INA828IDR | INA333AIDR | AD8221BRZ | AD620ANZ | AD8421ARZ |
|---|---|---|---|---|---|---|---|
| Package | SOIC-8 (D) | SOIC-8 (D) - same | SOIC-8 (D) - same | SOIC-8 (D) - same | SOIC-8 (D) - same | SOIC-8 (D) - same | SOIC-8 (D) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Analog Devices | Analog Devices |
| Input Offset Voltage (max) | 35 µV | 35 µV | 50 µV | 25 µV (chopper) | 60 µV | 50 µV | 25 µV |
| Input-Referred Noise Density | 8 nV/√Hz | 7 nV/√Hz | 7 nV/√Hz | 50 nV/√Hz (chopper) | 8 nV/√Hz | 9 nV/√Hz | 10 nV/√Hz |
| Bandwidth (G=100) | 7 MHz | 4.7 MHz | 1 MHz | 3.5 MHz | 825 kHz | 120 kHz | 10 MHz |
| Slew Rate | 1.6 V/µs | 1.0 V/µs | 1.5 V/µs | 0.3 V/µs | 2.0 V/µs | 1.3 V/µs | 35 V/µs |
| Quiescent Current (typ) | 350 µA | 350 µA | 750 µA | 50 µA | 1.0 mA | 1.3 mA | 2.3 mA |
| Input Overvoltage Protection | ±60 V (gain pins) | ±40 V | ±40 V | ±40 V | ±40 V | ±25 V | ±25 V |
| CMRR (G=100, min) | 120 dB | 120 dB | 130 dB | 100 dB | 120 dB | 130 dB | 130 dB |
Principaux différenciateurs
- ±60 V overvoltage protection on gain pins (vs AD620ANZ)
- Super-beta input stage for low bias current (vs AD8221BRZ)
- 7 MHz bandwidth at G=100 (vs AD620ANZ)
Notes de conception
Place the gain-setting resistor (R_G) directly between pins 1 and 2 with traces as short as possible - ideally under 5 mm. Parasitic capacitance between these pins and ground degrades CMRR at high frequencies (>1 kHz). According to Texas Instruments INA819 datasheet, use a 10 ppm/°C low-drift resistor (e.g., Susumu RG2010 series) for best gain accuracy across temperature. Route the input traces as a differential pair with 100 Ω characteristic impedance if bandwidth above 1 MHz is required, and guard both inputs with a ground or driven-low ring to absorb leakage.
Decouple VS+ (pin 8) and VS- (pin 6) with 100 nF X7R ceramic capacitors placed within 2 mm of the supply pins, plus a 10 µF bulk tantalum or ceramic capacitor on the same rail. The INA819 draws 350 µA quiescent plus load current, so PSRR rejection above 100 kHz depends on local decoupling. According to the Texas Instruments datasheet, add a small ferrite bead (e.g., BLM18PG221SN1) on the supply trace when the INA819 shares a rail with digital switching noise, to prevent RF rectification at the super-beta inputs.
Add a 2-pole RC low-pass filter at the output (REF and OUT pins) with corner at the target signal bandwidth (e.g., 100 kHz for strain-gauge bandwidth) to attenuate RF rectification at the super-beta inputs. According to Texas Instruments instrumentation amplifier design guidance, even non-conducting RF (10 V/m at 100 MHz) can be rectified by input ESD structures, producing DC errors of hundreds of microvolts. Use a common-mode choke (e.g., Würth Elektronik WE-CMBNC) on the differential input pair when source impedances exceed 10 kΩ to preserve CMRR above 100 dB at 1 kHz.
Do not exceed ±60 V on the gain-setting pins (1 and 2), even though the differential inputs (3, 4) tolerate only ±VS+; the gain pin protection is independent and adds ESD margin for load-cell wiring faults. According to the Texas Instruments datasheet, REF pin (5) must be driven to mid-supply for single-supply operation or to true ground for dual ±15 V operation - floating the REF pin causes asymmetric output swing and degrades DC linearity. Use the REF pin to level-shift the output within the ADC input range, not as a low-impedance bias point.
Informations de conformité
RoHS compliant per Texas Instruments product page. Industrial-grade operating temperature -40 °C to +125 °C; not AEC-Q100 qualified - use INA819IDR-Q1 or INA819-Q1 variant for automotive designs.
