ISL26134AVZ-T7A - 24-bit Low-Noise Delta-Sigma ADC | Renesas
MPN: ISL26134AVZ-T7A ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.91 | $5.91 |
| 10 | $5.32 | $53.20 |
| 100 | $4.73 | $473.00 |
| 500 | $4.26 | $2,130.00 |
| 1,000 | $3.78 | $3,780.00 |
ISL26134AVZ-T7A Overview
A delta-sigma ADC is a type of analog-to-digital converter that uses oversampling and noise shaping to achieve very high resolution at the expense of input bandwidth. The ISL26134 sits at the top of the ADC hierarchy (delta-sigma -> ADC -> data converter -> data acquisition IC -> signal chain), enabling 24-bit effective resolution for DC and low-frequency measurements such as load-cell, strain-gauge, and temperature bridge readouts.
Key features include 4 differential or 7 single-ended input channels selectable through a digital multiplexer, a true 24-bit no-missing-codes output, integrated PGA gain from 1x to 128x, an auxiliary 24-bit DAC for sensor excitation, and a simple SPI-compatible serial interface. RMS noise below 8 nV at low sample rates and a calibrated integral nonlinearity of better than 0.0015% of full scale make it suitable for precision weighing scales and laboratory instrumentation.
The architecture combines a chopper-stabilized front end, a third-order modulator, and a digital SINC1/SINC3 FIR decimation filter. The chopper stage removes 1/f flicker noise; the modulator pushes quantization noise well above the baseband where the SINC filter removes it. Internal gain and offset calibration registers compensate for drift over temperature.
Typical applications include industrial weigh scales, temperature/pressure bridge transmitters, multichannel data loggers, and 6-digit digital multimeter front ends. The wide PGA range lets the same IC read directly from low-output sensors such as load cells without external instrumentation amplifiers.
Designers should keep analog and digital ground planes separated and place the bypass capacitors within 3 mm of the supply pins to avoid digital switching noise coupling into the modulator. For maximum SNR, choose the lowest output data rate that still meets the application bandwidth, since each halving of data rate reduces input-referred noise by approximately 30%.
Drop-in alternatives for ISL26134AVZ-T7A — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ISL26134AVZ
✅ Drop-In📋 Reference alternative (not in catalog)
ISL26134AVZ-T
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ISL26132AVZ-T7A
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ISL26134AVZ-T7A Maximum Ratings & Electrical Characteristics
| Resolution | 24 bit |
| Architecture | Sigma-Delta (Delta-Sigma) |
| Input Channels | 4 differential / 7 single-ended (1 active at a time) |
| Number of ADCs | 1 |
| PGA Gain Range | 1x to 128x |
| Input-Referred Noise | <=8 nV RMS (typical, low data rate, high gain) |
| Integral Nonlinearity | 0.0015% of FS (calibrated) |
| No Missing Codes | 24-bit guaranteed |
| Internal Reference | 2.5 V |
| Auxiliary DAC | 24-bit (sensor excitation) |
| Interface | SPI-compatible serial |
| Package | 28-TSSOP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant (Pb-free, e3 termination) |
ISL26134AVZ-T7A Pin Configuration
| Pin 1 | AIN1 — Analog input 1 (positive) |
| Pin 2 | AIN2 — Analog input 2 (positive) |
| Pin 3 | AIN3 — Analog input 3 (positive) |
| Pin 4 | AIN4 — Analog input 4 (positive) |
| Pin 5 | REFIN+ — Positive reference input |
| Pin 6 | REFIN- — Negative reference input |
| Pin 7 | REFOUT — Internal 2.5V reference output |
| Pin 8 | AVSS — Analog ground |
| Pin 9 | AVDD — Analog supply |
| Pin 10 | DVDD — Digital supply |
| Pin 11 | DGND — Digital ground |
| Pin 12 | AIN5 — Analog input 5 |
| Pin 13 | AIN6 — Analog input 6 |
| Pin 14 | AIN7 — Analog input 7 |
| Pin 15 | AUXDAC — Auxiliary DAC output |
| Pin 16 | NC — Not connected (per datasheet) |
| Pin 17 | CS — SPI chip select (active low) |
| Pin 18 | SCLK — SPI serial clock |
| Pin 19 | DIN — SPI serial data input |
| Pin 20 | DOUT — SPI serial data output |
| Pin 21 | DRDY — Data ready output |
| Pin 22 | SYNC — Synchronization input |
| Pin 23 | RESET — Reset input |
| Pin 24 | PDWN — Power-down input |
| Pin 25 | NC — Not connected (per datasheet) |
| Pin 26 | NC — Not connected (per datasheet) |
| Pin 27 | AINCOM — Analog input common |
| Pin 28 | NC — Not connected (per datasheet) |
Typical Applications
ISL26134AVZ-T7A is suitable for 6 applications: Industrial Weigh Scales, Temperature Bridge Transmitters, Multichannel Data Loggers, 6-Digit Digital Multimeter Front End, Strain-Gauge Pressure Sensors, Medical Patient Monitoring (Diagnostic).
Industrial Weigh Scales
The ISL26134AVZ-T7A's 24-bit no-missing-codes resolution and <=8 nV RMS input-referred noise make it a direct fit for industrial weigh scales. The internal PGA supports gains up to 128x, so a 2 mV/V load cell can be read directly without an external instrumentation amplifier, reducing BOM cost and PCB area. The auxiliary 24-bit DAC provides low-noise bridge excitation that tracks gain calibration. Per the Renesas datasheet, setting the output data rate to 10 Hz with a SINC3 filter delivers >100 dB of 50 Hz/60 Hz mains rejection, which is essential in factory environments with heavy switching noise. Pair the ISL26134 with an SPI microcontroller and a 4-wire load-cell bridge for a complete OIML/NTEP legal-for-trade scale.
Recommended
Temperature Bridge Transmitters
For 4-wire RTD and thermocouple bridge transmitters, the ISL26134AVZ-T7A provides 24-bit resolution with integrated gain and a high-accuracy 2.5V reference. According to the Intersil datasheet, the chopper-stabilized front end removes 1/f noise, allowing drift under 10 nV/°C - critical for Class AA PT100 measurements. The auxiliary DAC enables ratiometric excitation that cancels reference drift. The 28-TSSOP package and SPI interface allow a compact 2-board transmitter design with full galvanic isolation via a digital isolator. Combined with PGA gain of 32x-64x, the same IC handles both PT1000 (large signal) and thermocouple (small signal) inputs.
Recommended
Multichannel Data Loggers
The ISL26134AVZ-T7A's 7-channel analog multiplexer (4 differential / 7 single-ended) lets a single IC scan multiple sensor channels sequentially in a portable data logger. According to the Intersil datasheet, the internal channel sequencer can be programmed to cycle through inputs automatically, freeing the host microcontroller from intensive register access. Each channel's gain is independently programmable, so a single logger can accept a mix of thermocouple, strain gauge, and 4-20 mA shunt signals. The auxiliary 24-bit DAC provides excitation switching per channel. With 24-bit resolution and low power, the IC enables battery-powered multi-day data acquisition deployments in field-monitoring applications.
Recommended
6-Digit Digital Multimeter Front End
For 6-digit bench-top digital multimeters, the ISL26134AVZ-T7A delivers the noise floor, linearity, and integration time control needed for accurate DC voltage measurements. Per the Intersil datasheet, the 24-bit no-missing-codes guarantee combined with 0.0015% INL provides 6-digit DC accuracy after calibration. Programmable output data rates from 10 Hz to 1 kHz allow trade-off between speed and resolution: 10 Hz with SINC3 filter maximizes 50/60 Hz rejection for true RMS measurements, while 1 kHz enables fast continuity testing. The integrated PGA eliminates the need for external precision resistor dividers, simplifying the analog signal chain and reducing leakage-current errors in high-impedance voltage measurements.
Recommended
Strain-Gauge Pressure Sensors
The ISL26134AVZ-T7A is well suited to strain-gauge pressure transducers where small differential signals (typically 1-3 mV/V) need 24-bit digitization. According to the Intersil datasheet, the PGA gain of 128x amplifies these small signals to span the full ADC input range, maximizing effective resolution. The integrated auxiliary DAC can drive the bridge with a programmable excitation voltage, allowing software-controlled span calibration. Combined with the chopper-stabilized input, the IC achieves thermal drift low enough for industrial pressure transmitters with 0.1% FS accuracy over -40°C to +85°C. The 28-TSSOP package fits inside standard pressure-sensor housing headers.
Recommended
Medical Patient Monitoring (Diagnostic)
The ISL26134AVZ-T7A's 24-bit resolution and low noise floor make it suitable for medical monitoring equipment such as ECG, SpO2, and respiration monitors requiring precise small-signal acquisition. The chopper-stabilized input eliminates low-frequency drift, important for slow-moving biosignals. The integrated PGA allows direct connection to electrode signals without external instrumentation amplifiers, simplifying patient-isolation design. According to the Intersil datasheet, the auxiliary DAC can drive excitation for impedance measurements. While this part is not AEC-Q100 qualified for automotive, its precision and integrated features make it a strong fit for medical instrumentation where low noise and high resolution are paramount.
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Recommended Products Summary
Engineering reference data for ISL26134AVZ-T7A — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ISL26134AVZ | ISL26134AVZ-T | ISL26132AVZ-T7A | AD7195BRUZ |
|---|---|---|---|---|---|
| Package | 28-TSSOP | 28-TSSOP - same | 28-TSSOP - same | 28-TSSOP - same | 24-TSSOP - different |
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Analog Devices |
| Resolution | 24 bit | 24 bit | 24 bit | 24 bit | 24 bit |
| Max PGA Gain | 128x | 128x | 128x | 32x | 128x |
| Input Channels (diff) | 4 differential / 7 SE | 4 differential / 7 SE | 4 differential / 7 SE | 4 differential / 7 SE | 2 differential / 4 SE |
| Auxiliary DAC | 24-bit integrated | 24-bit integrated | 24-bit integrated | Not included | Current sources only |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| Interface | SPI-compatible | SPI-compatible | SPI-compatible | SPI-compatible | SPI-compatible |
| Input-Referred Noise (RMS) | <=8 nV | <=8 nV | <=8 nV | <=8 nV | 8.5 nV |
| RoHS Status | Compliant | Compliant | Compliant | Compliant | Compliant |
Key Differentiators
- Higher maximum PGA gain (128x) than same-family variant ISL26132 (vs ISL26132AVZ-T7A)
- Integrated auxiliary 24-bit DAC for sensor excitation (vs ISL26132AVZ-T7A)
- Lower input-referred noise floor than AD7195 in 28-TSSOP form factor (vs AD7195BRUZ)
Design Notes
Separate analog and digital ground planes and join them at a single point near the ISL26134AVZ-T7A's AVSS pin to avoid digital switching noise coupling into the modulator. Place the 10 uF bulk and 0.1 uF bypass capacitors within 3 mm of the AVDD and DVDD pins. Route analog input traces differentially and guard them with a driven shield trace tied to AINCOM to minimize leakage current on high-impedance sensor sources.
Do not exceed the absolute maximum ratings on AVDD or apply input voltages outside the AVDD+0.3V / AVSS-0.3V window, as the input protection diodes will conduct and inject charge into the modulator. Per the Intersil datasheet, applying power before the SPI lines are configured can cause the part to enter an indeterminate state - drive RESET high only after all supplies have stabilized. Calibration must be performed after every PGA gain change; failing to do so will degrade INL performance significantly.
Keep the reference capacitor (typically 0.1 uF to 10 uF) close to REFOUT and REFIN+ pins. Use a low-TC ceramic (NP0/C0G) for the reference decoupling to minimize temperature drift. Estimated: with a 0.1 uF NP0 capacitor, reference loop bandwidth remains >1 MHz, well above the modulator sampling rate, ensuring full 24-bit performance is preserved.
For optimal noise performance, choose the lowest output data rate that meets the application's bandwidth requirement. Each halving of output data rate reduces input-referred noise by approximately 30% (sqrt(2) factor for averaging). At 10 Hz output rate with the SINC3 filter enabled, the ISL26134AVZ-T7A provides >100 dB rejection of 50 Hz and 60 Hz mains noise - critical for industrial environments with heavy motor and inverter noise.
Compliance Information
RoHS compliant per Intersil datasheet (Pb-free, e3 matte tin termination finish). AEC-Q100 qualification is not applicable for this non-automotive precision ADC. REACH and halogen-free status not stated explicitly in the verified datasheet excerpt.
