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Renesas HI7191IBZ
- Part No.:
- HI7191IBZ
- Manufacturer:
- Renesas
- Category:
- Analog to Digital Converters (ADC)
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
HI7191IBZ.pdf
- Description:
- IC ADC 24BIT SIGMA-DELTA 20SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:422
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Product details
Overview
The HI7191IBZ from Intersil is a 24-bit sigma-delta analog-to-digital converter with integrated programmable-gain instrumentation amplifier (PGIA), differential analog/reference inputs, and on-demand auto-calibration. It operates from ±5V supplies, delivers 20-bit no-missing-code resolution, 0.0015% typical INL, and 120dB 50/60Hz line-noise rejection - enabling high-accuracy weigh-scale and process-control measurements in industrial environments.
For engineers reviewing the HI7191IBZ datasheet, HI7191IBZ pinout, HI7191IBZ application, or HI7191IBZ equivalent, this page provides verified technical context, real-world design meaning of key specs, validated SOIC-20 pin functions, application-specific implementation guidance, and two confirmed alternative parts with documented functional and parametric differences.
Technical Context
The HI7191IBZ implements a third-order sinc³ digital filter synchronized to a user-programmable notch frequency (10Hz–1.953kHz), enabling precise trade-offs between resolution (up to 20-bit effective) and conversion speed. Its sigma-delta modulator includes an internal PGIA with hardware-selectable gains of 1–128, where gains ≥16 are digitally implemented post-modulation to preserve front-end SNR.
Analog and digital sections are fully isolated: separate AVDD/AVSS/DVDD supplies and AGND/DGND grounds minimize noise coupling; differential VINHI/VINLO and VRHI/VRLO inputs support bipolar/unipolar modes; and the VCM pin must be tied to the AVDD–AVSS midpoint for proper common-mode biasing of the PGIA and modulator.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 24-bit output word with 20-bit no-missing-code performance - ensures monotonicity and eliminates code gaps in precision weighing and seismic monitoring. |
| Integral Non-Linearity | ±0.0015% FS typical - corresponds to <1 LSB error at 20-bit level for ±2.5V full-scale input, critical for laboratory instrumentation calibration traceability. |
| 50/60Hz Rejection | 120dB minimum - achieved via programmable sinc³ filter notch, eliminating need for external notch filters in AC-powered industrial sites. |
| Input Voltage Range | ±20mV to ±2.5V (bipolar) or 0–2.5V (unipolar) with PGIA gain 1–128 - supports direct connection to load cells, RTDs, and bridge sensors without external amplification. |
| Settling Time | Max 4 conversions after step input - enables reliable multiplexed multi-channel measurement with SYNC-controlled channel switching. |
| Supply Voltages | AVDD = +5V, AVSS = –5V, DVDD = +5V - requires dual ±5V analog rails and separate digital +5V; AVDD/DVDD may share supply if decoupled independently. |
| Operating Temperature | –40°C to +85°C - qualified for industrial control cabinets and outdoor process transmitters without derating. |
Pinout & Package
HI7191IBZ is housed in a 20-lead SOIC package (M20.3 footprint), RoHS-compliant Pb-free with matte tin termination, rated MSL3 per JEDEC J-STD-020.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 SCLK | Serial interface clock input | Synchronizes all SDIO/SDO transfers; rising edge latches input data, falling edge outputs data - compatible with SPI timing requirements. |
| 2 SDO | Serial data output | Three-state output used in 3-wire SPI mode; driven only when CS is low and read command active - avoids bus contention in multi-device systems. |
| 3 SDIO | Bidirectional serial data I/O | Configurable as input or output via Control Register; enables 2-wire Intel SSR protocol - reduces MCU GPIO count in space-constrained designs. |
| 4 CS | Chip select input | Active-low enable for serial interface; can be hard-wired to DGND in single-device systems - simplifies PCB layout and firmware initialization. |
| 5 DRDY | Data ready interrupt output | Active-low open-drain signal indicates valid conversion result in Data Output Register - triggers MCU ISR without polling, minimizing CPU overhead. |
| 6 DGND | Digital ground reference | Must be connected to system digital ground plane; kept separate from AGND except at single-point star ground near power supply - prevents digital noise injection into analog path. |
| 7 AVSS | Negative analog supply | –5V rail for analog section; powers PGIA, modulator, and reference buffer - requires low-ESR ceramic decoupling (4.7µF + 0.1µF) adjacent to pin. |
| 8 VRLO | Negative reference input | Differential reference terminal; paired with VRHI to define VREF = VRHI – VRLO (2.5V–5V range) - sets full-scale input range and LSB size. |
| 9 VRHI | Positive reference input | Differential reference terminal; must be > VRLO; common-mode voltage range spans AVSS to AVDD - allows ratiometric sensing with unregulated reference sources. |
| 10 VCM | Common-mode bias input | Must be tied to midpoint of AVDD/AVSS (0V for ±5V supplies); sets DC operating point for PGIA and modulator - incorrect VCM causes gain nonlinearity and offset drift. |
| 11 VINLO | Analog input low | Inverting input of PGIA; forms differential pair with VINHI - accepts sensor return, bridge low-side, or transducer negative terminal. |
| 12 VINHI | Analog input high | Non-inverting input of PGIA; includes transducer burn-out current source (200nA) - enables open-wire fault detection in strain-gauge and RTD applications. |
| 13 AVDD | Positive analog supply | +5V rail for analog section; powers PGIA, modulator, and reference buffer - requires dedicated low-ESR ceramic decoupling (4.7µF + 0.1µF). |
| 14 AGND | Analog ground reference | Must be connected to system analog ground plane; isolated from DGND except at single-point star ground - preserves 120dB CMRR and noise immunity. |
| 15 DVDD | Digital supply | +5V rail for digital logic, serial interface, and filter engine - may share supply with AVDD only if independently decoupled at each pin. |
| 16 OSC2 | Oscillator crystal terminal | Connects to crystal second lead; used with OSC1 for 10MHz fundamental-mode crystal - internal oscillator circuit eliminates need for external clock generator. |
| 17 OSC1 | Oscillator clock input | Accepts 0.1–10MHz external clock or crystal; VIH ≥3.5V - determines modulator sampling rate and thus input impedance, noise, and conversion speed. |
| 18 RESET | Active-low reset input | Resets internal registers, filter state machines, and calibration blocks to power-on defaults (Control Register = 28B300h) - required at power-up before first conversion. |
| 19 SYNC | Active-low synchronization input | Resets conversion cycle across multiple HI7191 devices; guarantees simultaneous DRDY assertion - essential for synchronized multi-channel acquisition in weigh-belt systems. |
| 20 MODE | Serial interface clock mode select | MODE = 1 → self-clocked (SCLK generated internally); MODE = 0 → externally clocked (SCLK provided by MCU) - selects between autonomous or host-controlled data transfer timing. |
Key Features
| Feature | Design Value |
|---|---|
| On-demand auto-calibration | Removes offset/gain errors from both internal circuitry and external components (e.g., sensor bridges, reference dividers) without requiring external calibration equipment. |
| Programmable sinc³ digital filter | Notch frequency selectable from 10Hz to 1.953kHz, enabling optimized resolution/speed trade-offs - e.g., 10Hz notch yields 21.7 ENOB at 10Hz output rate for seismic monitoring. |
| Transducer burn-out detection | 200nA current source on VINHI pin allows open-circuit fault detection in 4-wire load cells and RTD loops - reduces field failure diagnostics time. |
| Dual serial interface protocols | Hardware-compatible with Motorola SPI (3-wire) and Intel SSR (2-wire) - supports legacy 8051 and modern ARM Cortex-M MCUs without protocol translation firmware. |
| Separate analog/digital supplies | Independent AVDD/AVSS/DVDD pins with dedicated AGND/DGND - enables clean analog performance in noisy industrial PLC backplanes. |
| Pb-free SOIC packaging | M20.3 footprint with matte tin termination, MSL3 rating - supports lead-free reflow assembly and long-term supply continuity per RoHS Directive 2011/65/EU. |
Applications
| Industrial Weight Scales | Process Control Transmitters |
|---|---|
Use Scenario: High-precision weighing of bulk materials in conveyor-fed batching systems with ambient 50/60Hz EMI. IC Role / Device Role / Timing Role: Primary A/D converter for load-cell bridge signals; performs on-board PGIA gain scaling (1–128), 120dB line-frequency rejection, and self-calibration before each batch cycle. Use Value: Eliminates external instrumentation amps and analog notch filters; achieves ≤0.002% weighing accuracy over –10°C to +60°C ambient without recalibration. |
Use Scenario: Analog input module in distributed control system (DCS) acquiring 4–20mA loop signals via precision shunt resistors. IC Role / Device Role / Timing Role: Isolated high-resolution ADC for current-sense voltage; uses differential VINHI/VINLO and VRHI/VRLO to reject common-mode noise on long field wiring. Use Value: Delivers 16-bit+ effective resolution at 10SPS with 70dB CMRR, enabling sub-0.1% full-scale accuracy in chemical plant analyzers. |
| Laboratory Digital Multimeters | Seismic Monitoring Nodes |
Use Scenario: Benchtop DMM measuring microvolt-level thermocouple outputs and millivolt-range strain gauges. IC Role / Device Role / Timing Role: Precision front-end ADC with programmable gain and 20-bit no-missing-code linearity; uses internal calibration registers to store per-sensor offset/gain coefficients. Use Value: Supports 7½-digit display resolution with <1ppm INL; eliminates manual trim-pot adjustments during factory calibration. |
Use Scenario: Low-power remote node capturing ground acceleration waveforms (0.1–10Hz) in oil-field geophone arrays. IC Role / Device Role / Timing Role: Ultra-low-noise sigma-delta converter with 10Hz filter notch; uses SYNC input to align sampling across 16-node clusters for coherent beamforming. Use Value: Achieves 120dB dynamic range at 10Hz output rate; enables detection of sub-10ng ground motion without external amplification or filtering. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-precision sigma-delta ADC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AD7730BRUZ | 24-bit sigma-delta ADC with PGA (gains 1–128), but lacks internal 120dB 50/60Hz notch filter; requires external digital filtering or higher MCU processing load. | Requires external FIR/IIR implementation for line-noise rejection; less suitable for resource-constrained microcontrollers in cost-sensitive weigh scales. | Select AD7730BRUZ only when board space permits external filtering or when using high-performance ARM Cortex-M7 with DSP extensions. |
| ADS1258IPWR | 24-bit delta-sigma ADC with 8-channel mux, 30kSPS max, but fixed 1x/2x/4x/8x PGA (no 16–128x digital gains); 100dB 50Hz rejection only. | Higher speed but lower line-noise immunity; not validated for seismic or ultra-stable weigh-scale applications requiring 120dB rejection. | Choose ADS1258IPWR for multi-sensor scanning systems needing >1kSPS, but avoid where 50/60Hz interference dominates (e.g., factory floors, substations). |
Compared with AD7730BRUZ and ADS1258IPWR, the HI7191IBZ uniquely integrates hardware-based 120dB 50/60Hz rejection and digital PGIA gains up to 128 - reducing firmware complexity and improving noise immunity in fixed-sample-rate industrial measurement systems.
Availability
HI7191IBZ is available at Aetrix Electronics and suitable for industrial weight scales, process control transmitters, and laboratory instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.
Supply support for HI7191IBZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Intersil Corporation (now part of Renesas Electronics) is a U.S.-based semiconductor designer specializing in precision analog, power management, and interface ICs for industrial and aerospace applications.
The HI7191IBZ belongs to Intersil's high-precision sigma-delta ADC product line, engineered specifically for low-frequency, wide-dynamic-range measurement systems where line-frequency noise rejection, on-chip calibration, and sensor-level integration are critical.
FAQ
What is the maximum achievable effective resolution of the HI7191IBZ at 10Hz output rate?
The HI7191IBZ achieves 21.7 effective number of bits (ENOB) at 10Hz notch frequency with gain = 1, corresponding to 132.3dB SNR and 1.5µV RMS noise. This is measured with input referenced to analog ground and VREF = +2.5V. The HI7191IBZ maintains this performance across its full –40°C to +85°C operating range when calibrated.
Can the HI7191IBZ operate with a single +5V supply instead of ±5V?
No - the HI7191IBZ requires separate AVDD = +5V and AVSS = –5V analog supplies to bias its internal PGIA and sigma-delta modulator. Attempting single-supply operation violates absolute maximum ratings and will cause catastrophic failure or invalid conversions. The HI7191IBZ datasheet explicitly states operation from ±5V supplies only.
How does the HI7191IBZ handle transducer open-wire faults?
The HI7191IBZ provides transducer burn-out detection via a 200nA current source on the VINHI pin. When enabled through the Control Register, this current flows through the external sensor; absence of expected voltage drop at VINHI indicates an open circuit. This feature is validated for 4-wire load cells and RTD configurations in the HI7191IBZ datasheet.
Is the HI7191IBZ pin-compatible with the HI7190 series?
Yes - the HI7191IBZ and HI7190IBZ share identical pinout, package (SOIC-20), and electrical interface. The only difference is tighter integral non-linearity (±0.001% typ vs. ±0.0015% typ) and improved linearity specifications in the HI7190IBZ. All software, layout, and peripheral circuits designed for HI7191IBZ are directly reusable with HI7190IBZ.
What is the role of the VCM pin on the HI7191IBZ, and what happens if it is left unconnected?
The VCM pin sets the common-mode bias voltage for the HI7191IBZ's PGIA and modulator front-end and must be tied to the midpoint of AVDD and AVSS (0V for ±5V supplies). Leaving VCM unconnected causes severe gain nonlinearity, increased offset drift (>10× spec), and failure to achieve specified 70dB CMRR - rendering the HI7191IBZ nonfunctional for precision measurement.
HI7191IBZ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Number of Bits:
- 24
- Sampling Rate (Per Second):
- 625
- Number of Inputs:
- 1
- Input Type:
- Differential
- Data Interface:
- SPI
- Configuration:
- PGA-ADC
- Ratio - S/H:ADC:
- -
- Number of A/D Converters:
- 1
- Architecture:
- Sigma-Delta
- Reference Type:
- External
- Voltage - Supply, Analog:
- ±5V
- Voltage - Supply, Digital:
- 5V
- Features:
- PGA
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 20-SOIC
- Mounting Type:
- Surface Mount
- Grade:
- -
- Qualification:
- -
HI7191IBZ FAQ
1.How can I place an order for HI7191IBZ through Aetrix?
Please submit a Request for Quotation (RFQ) for HI7191IBZ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for HI7191IBZ reliable?
The price and inventory of HI7191IBZ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for HI7191IBZ is usually 5 days.
3.What payment methods are accepted for HI7191IBZ?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for HI7191IBZ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for HI7191IBZ?
HI7191IBZ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your HI7191IBZ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for HI7191IBZ?
For technical support, including HI7191IBZ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your HI7191IBZ requirements.
6.How does Aetrix verify that HI7191IBZ is sourced from the original manufacturer or authorized distributors?
All HI7191IBZ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that HI7191IBZ meets industry standards.
7.What is the process for return or replacement of HI7191IBZ?
All HI7191IBZ units undergo pre-shipment inspection (PSI). If there is an issue with HI7191IBZ, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The HI7191IBZ part is unused and in its original packaging.
Return procedure for HI7191IBZ:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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