HI7191IB - 24-Bit Sigma-Delta ADC, 20-SOIC | Renesas Electronics
Référence : HI7191IB ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $12.45 | $12,45 |
| 10 | $11.3 | $113,00 |
| 100 | $10.05 | $1 005,00 |
| 500 | $8.95 | $4 475,00 |
| 1 000 | $7.9 | $7 900,00 |
HI7191IB Présentation
A sigma-delta (Σ-Δ) ADC is a type of analog-to-digital converter that oversamples the input signal and uses noise shaping to push quantization noise out of the baseband. Within the broader taxonomy, sigma-delta ADCs sit under successive-approximation and integrating ADCs as part of the data-converter family, which in turn belongs to the data acquisition IC category and ultimately to the broader power and signal-chain semiconductor hierarchy. They are the preferred architecture for precision DC measurement applications where high effective resolution and excellent linearity outweigh the need for high absolute sampling rates.
Key features of the HI7191IB include 24-bit resolution, internal digital calibration, an on-chip PGIA providing 1x to 128x input gain, and flexible serial communication. The PGIA eliminates the need for external pre-amplifiers in most applications, simplifying front-end design and reducing board area. The on-demand calibration mechanism removes offset and gain errors at any time, including immediately after power-up or after operating-condition changes, ensuring repeatable conversion accuracy across production units.
The HI7191IB architecture uses a switched-capacitor modulator followed by a digital decimation filter, with separate calibration registers that the user can read and write. This decoupled modulator/filter design allows the user to trade off output word rate against effective noise-free resolution, while the calibration registers give the system designer visibility into error sources. The serial interface supports both SPI and SSR protocols, enabling direct connection to most microcontrollers and DSPs without external glue logic.
Typical applications for the HI7191IB include industrial weigh scales, pressure and strain-gauge transducer readouts, precision temperature measurement with thermocouple or RTD front-ends, process-control instrumentation, and portable analytical instruments such as blood-glucose meters and multi-meters. It is also widely used in the field of smart sensors and 4-20 mA loop-powered transmitters that require a wide dynamic range and low-noise conversion of small differential sensor outputs. When integrating the HI7191IB into a multi-channel system, the serial-interface architecture lets multiple parts share the same bus with individual chip-select lines.
Designers should pay attention to the analog supply bypassing on both the +5V and -5V rails, as the sigma-delta modulator is sensitive to high-frequency supply noise; place 10 uF tantalum and 0.1 uF ceramic capacitors as close to the supply pins as possible, with the 0.1 uF capacitor leading to a low-impedance ground plane. Common-mode input voltage range and reference voltage range must both stay within the supply rails to avoid linearity degradation at the converter's full-scale output.
This page synthesizes distributor pricing, drop-in SOIC-20 alternatives, and practical design notes for the HI7191IB that go beyond what is found in the manufacturer datasheet.
Alternatives de remplacement direct pour HI7191IB — 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 HI7191IB (même facteur de forme et même empreinte) — différant par Supply Voltage, Resolution, Operating Temperature Range, Package, Reference Input Type.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
HI7191IBZ
✅ Remplacement direct✓ En stock
$21.1 / unité
Voir la fiche technique →HI7191IB-T
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
HI7190IB
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
HI7190IB-T
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
HI7191IBZ-T
✅ Remplacement direct✓ En stock
$17.4 / unité
Voir la fiche technique →HI7191IB Valeurs maximales et caractéristiques électriques
| Résolution | 24 bits |
| Architecture | Sigma-Delta |
| Number of Inputs | 1 differential input |
| Tension d'alimentation | +/-5 V (dual supply) |
| Signal Input Type | Differential |
| Reference Input Type | Differential |
| On-chip PGIA Gain Range | 1 to 128 (programmable) |
| On-chip Calibration | On-demand auto-calibration |
| Digital Interface | Serial (SPI-compatible / SSR-compatible) |
| Boîtier | 20-SOIC (Wide) |
| Pins | 20 |
| Plage de température de fonctionnement | -40 C to +85 C (Industrial) |
| Screening Level | Industrial |
| Type de montage | Surface Mount |
Configuration des broches de HI7191IB
| Broche 1 | AIN+ — Positive analog differential input |
| Broche 2 | AIN- — Negative analog differential input |
| Broche 3 | REF+ — Positive reference input |
| Broche 4 | REF- — Negative reference input |
| Broche 5 | AVDD — +5V analog supply |
| Broche 6 | AVSS — -5V analog supply |
| Broche 7 | AGND — Analog ground |
| Broche 8 | XIN — Crystal oscillator input (or external clock) |
| Broche 9 | XOUT — Crystal oscillator output |
| Broche 10 | DGND — Digital ground |
| Broche 11 | DVDD — +5V digital supply |
| Broche 12 | CAL — Calibration control / start conversion |
| Broche 13 | SCLK — Serial interface clock |
| Broche 14 | SDATA — Serial data input/output |
| Broche 15 | SYNC — Serial frame synchronization |
| Broche 16 | CS — Chip-select (active low) |
| Broche 17 | MODE — SPI/SSR protocol mode select |
| Broche 18 | STBY — Standby mode control (active low) |
| Broche 19 | G1 — PGIA gain select bit 1 |
| Broche 20 | G0 — PGIA gain select bit 0 |
Applications typiques
HI7191IB convient pour 6 applications: Industrial Weigh Scales, Pressure and Strain-Gauge Transducer Readout, Precision Temperature Measurement (RTD / Thermocouple), Process-Control Instrumentation (4-20 mA Loop), Portable Analytical Instruments (Multi-meter, Blood-Glucose Meter), Smart Sensor Front End.
Industrial Weigh Scales
The HI7191IB fits industrial weigh-scale front ends because its 24-bit sigma-delta resolution and built-in PGIA (1x-128x gain) directly digitize low-level load-cell outputs without external instrumentation amplifiers. Placed between the load-cell bridge and the microcontroller, the HI7191IB delivers noise-free resolution suitable for kg-scale commercial weighing. The on-demand calibration removes offset and gain drift over temperature, which is critical for legal-for-trade scales where recalibration between weighings must be reliable. The SPI/SSR serial port connects directly to most scale-indicator MCUs, eliminating glue logic.
Recommandé
Pressure and Strain-Gauge Transducer Readout
The HI7191IB is well matched to pressure-transducer and strain-gauge readouts because of its fully differential signal and reference inputs combined with PGIA gain up to 128x, which suppresses common-mode noise from long sensor cables. Placed at the transducer output, the converter digitizes millivolt-level bridge outputs at industrial accuracy. The bipolar +/-5V supplies accommodate bi-directional strain signals, and the on-demand calibration corrects offset drift that would otherwise dominate accuracy in field-installed sensors.
Recommandé
Precision Temperature Measurement (RTD / Thermocouple)
The HI7191IB serves precision temperature-measurement front ends by digitizing RTD bridge or thermocouple outputs with 24-bit noise-free resolution. Placed downstream of the sensor signal-conditioning network, it resolves microvolt-level thermocouple signals directly, removing the need for a dedicated chopper amplifier. The PGIA gain of 128x covers the full mV range of common thermocouples, while the on-demand calibration tracks cold-junction compensation drift. SPI/SSR output streams cleanly into a small Cortex-M0/M4 MCU for linearization.
Recommandé
Process-Control Instrumentation (4-20 mA Loop)
The HI7191IB is suitable for 4-20 mA smart-loop transmitters because the high effective resolution and small package simplify designs targeting HART or wireless HART protocols. Placed in the loop-powered transmitter, it digitizes the sensor signal at the head of the analog chain with 1x-128x PGIA gain. The on-demand calibration supports periodic recalibration in the field, which extends maintenance intervals. Dual +/-5V supplies can be derived from a small isolated DC-DC module for intrinsic-safe applications.
Recommandé
Portable Analytical Instruments (Multi-meter, Blood-Glucose Meter)
The HI7191IB fits portable analytical instruments because its 24-bit resolution combined with PGIA gain up to 128x gives the dynamic range required for multi-range hand-held multi-meters and clinical analyzers. Placed in the meter's measurement channel, it digitizes both low-ohm and high-impedance inputs directly, simplifying the analog front end. The on-demand calibration is invoked at each measurement to suppress battery-voltage drift. The 20-SOIC wide-body package is hand-solderable for prototype builds and supports low-volume production.
Recommandé
Smart Sensor Front End
The HI7191IB is well suited as the front-end converter for smart sensors (gas, flow, optical) that need a wide dynamic range and on-demand calibration. Placed between the analog signal conditioning chain and the host MCU, it provides the 24-bit noise floor required for ppm-level gas detection and similar low-amplitude sensor outputs. The differential reference input allows ratiometric measurement off an external precision reference, eliminating absolute-reference drift. SPI/SSR allows multiple HI7191IB parts to share a single MCU bus for multi-sensor modules.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour HI7191IB — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | HI7191IBZ | HI7191IB-T | HI7190IB | HI7190IB-T | HI7191IBZ-T |
|---|---|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Package | 20-SOIC (Wide) | 20-SOIC (Wide) - same | 20-SOIC (Wide) - same | 20-SOIC (Wide) - same | 20-SOIC (Wide) - same | 20-SOIC (Wide) - same |
| Resolution | 24 bit | 24 bit | 24 bit | 24 bit | 24 bit | 24 bit |
| Architecture | Sigma-Delta | Sigma-Delta | Sigma-Delta | Sigma-Delta | Sigma-Delta | Sigma-Delta |
| Precision Grade | High precision | High precision | High precision | Standard precision | Standard precision | High precision |
| Lead-Free / RoHS | Tin-lead (Pb) finish | Lead-free / RoHS compliant | Tin-lead (Pb) finish | Tin-lead (Pb) finish | Tin-lead (Pb) finish | Lead-free / RoHS compliant |
| Packaging Form | Tube | Tube | Tape & Reel | Tube | Tape & Reel | Tape & Reel |
| On-chip PGIA Gain Range | 1x to 128x | 1x to 128x | 1x to 128x | Limited range (lower precision variant) | Limited range (lower precision variant) | 1x to 128x |
Principaux différenciateurs
- RoHS-compliant variant available as true drop-in (vs HI7191IBZ)
- Tape-and-reel packaging option for high-volume assembly (vs HI7191IB-T)
- Lower-precision family member shares footprint (vs HI7190IB)
Notes de conception
The HI7191IB operates from dual +/-5V analog supplies. Decouple AVDD, AVSS, DVDD, and DGND with a 10 uF tantalum in parallel with a 0.1 uF ceramic capacitor placed as close to the IC pins as possible, and tie both ground pins to a low-impedance ground plane. The 0.1 uF capacitor should be the closest to the IC. Avoid sharing analog and digital ground returns to prevent digital switching noise from coupling into the modulator.
Common-mode input and reference voltages must stay within the +/-5V supply rails. Driving the inputs outside the rails will degrade linearity and may permanently damage the device. Both the signal (AIN+/AIN-) and reference (REF+/REF-) inputs are fully differential, so use true differential drive and not single-ended-to-ground when high common-mode rejection is required. For thermocouple or strain-gauge use, ensure the bridge excitation is ratiometric with the reference input to cancel excitation drift.
Route analog and digital traces on separate layers and keep digital lines (SCLK, SDATA, SYNC, CS) away from AIN+/AIN- and REF+/REF- traces to avoid digital-to-analog coupling. The crystal or external clock on XIN/XOUT should be placed close to the IC with short traces and a guard ground trace. Use a star-ground topology for the AGND/DGND tie point and place the bulk decoupling capacitor near that point to suppress ground bounce during calibration pulses.
Informations de conformité
The HI7191IB uses tin-lead (Pb) terminal finish; the HI7191IBZ variant is the RoHS-compliant lead-free version. Hi7191IB is not AEC-Q100 qualified (industrial grade only).
