CS5531-ASZ - 16-Bit Sigma-Delta ADC with PGIA | Cirrus Logic
MPN: CS5531-ASZ β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.2 | $6.20 |
| 10 | $5.58 | $55.80 |
| 100 | $4.96 | $496.00 |
| 500 | $4.47 | $2,235.00 |
| 1,000 | $3.98 | $3,980.00 |
CS5531-ASZ Overview
A sigma-delta ADC is a type of analog-to-digital converter that oversamples the input signal and applies digital filtering and decimation to achieve high resolution, making it the dominant architecture within the data-conversion hierarchy (ADC -> data converter -> mixed-signal IC) for precision, low-frequency measurements. The charge-balance technique used in the CS5531 family delivers 16-bit performance with very low noise, which is essential when the input signal spans only a few millivolts.
Key differentiating features include the on-chip PGIA with multiple gain settings, which allows direct connection of low-level bridge and thermocouple signals without external amplification; a serial SPI-compatible interface for simple host connectivity; and a high level of integration that reduces board area, component count, and overall signal-chain error budget.
Architecturally, the CS5531 combines a charge-balance sigma-delta modulator with an on-board digital filter and calibration functions. System calibration options allow offset and gain errors to be minimized in the end application, supporting stable, repeatable measurements over time and temperature. The ultra-low-noise analog front end preserves the effective resolution of the 16-bit converter even at high PGIA gain settings.
Typical applications include electronic weigh scales and bridge-transducer measurement, industrial process control transmitters measuring pressure or flow, and portable instrumentation requiring a compact, low-noise data-acquisition front end. The integrated PGIA makes the part especially well suited to load-cell interfaces where full-scale signals are small.
When designing with the CS5531-ASZ, pay careful attention to the analog supply and reference layout: keep the analog ground return clean, decouple VA+ and the voltage reference close to the pins, and route digital lines away from the analog inputs to preserve the low-noise floor.
This page synthesizes distributor pricing context, drop-in family alternatives, pinout guidance, and practical design notes not found in the manufacturer datasheet, providing engineers with a single reference for evaluating the CS5531-ASZ against CS5532/33/34 family variants.
Drop-in alternatives for CS5531-ASZ β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with CS5531-ASZ (same form factor and footprint) β differing in Number of Input Channels, Package, Interface, Calibration, Input Type.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
CS5533-ASZ
β Drop-Inβ In Stock
$2.25 / Unit
View Datasheet βCS5532-ASZ
β Drop-Inβ In Stock
$9.85 / Unit
View Datasheet βCS5534-ASZR
β Drop-Inβ In Stock
$3.55 / Unit
View Datasheet βCS5534-BSZ
β Drop-Inβ In Stock
Contact for price
View Datasheet βCS5534-BSZR
β Drop-Inβ In Stock
$8.5 / Unit
View Datasheet βCS5531-ASZ Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Number of Input Channels | 2 (differential) |
| Architecture | Sigma-Delta (charge-balance) |
| Front End | Ultra-low-noise PGIA (programmable gain instrumentation amplifier) |
| Analog Input Type | Differential |
| Interface | Serial (SPI-compatible) |
| Package | 20-SSOP |
| Mounting Type | Surface Mount |
| Calibration | System offset and gain calibration |
| Typical Application | Bridge transducers, weigh scales, process control |
CS5531-ASZ 20-ssop Pin Configuration Guide
Pin configuration for CS5531-ASZ (20-ssop package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for CS5531-ASZ.
Refer to the datasheet for full pin configuration.
Typical Applications
CS5531-ASZ is suitable for 6 applications: Electronic Weigh Scales, Industrial Process Control Transmitters, Medical Instrumentation, Data Acquisition Systems, Battery Testing and Monitoring, Temperature and Pressure Transducer Measurement.
Electronic Weigh Scales
The CS5531-ASZ is a natural fit for electronic weigh scales because its integrated ultra-low-noise PGIA can amplify the small full-scale output of a load-cell bridge (typically 2 mV/V) directly, without an external instrumentation amplifier. The 16-bit charge-balance sigma-delta converter with system offset and gain calibration delivers the stable, repeatable counts required for commercial weighing. In a typical design, the load-cell differential output connects to the AIN differential inputs, a precision reference tracks the bridge excitation for ratiometric operation, and the SPI interface streams conversion results to the scale MCU. The 20-SSOP package keeps the analog front end compact on the scale PCB.
Recommended
Industrial Process Control Transmitters
In 4-20 mA transmitters and process-control heads, the CS5531-ASZ digitizes low-level signals from pressure, flow, and level transducers with the accuracy that industrial loops demand. The PGIA gain settings allow a single design to cover multiple transducer sensitivities, while system calibration corrects offset and gain drift in the field. The differential inputs reject ground noise common on factory floors, and the sigma-delta architecture provides strong line rejection at low data rates. Its 20-SSOP surface-mount package and serial interface reduce transmitter PCB area and support loop-powered designs where every milliwatt of the signal-chain budget counts.
Recommended
Medical Instrumentation
Diagnostic and monitoring instruments that measure slow, small biophysical signals benefit from the CS5531-ASZ combination of low noise and integrated gain. The ultra-low-noise PGIA preserves signal fidelity for sensors producing millivolt-level outputs, and the 16-bit converter provides sufficient dynamic range for many clinical measurement channels. System calibration supports the periodic recalibration routines required by medical device quality systems. Because the CS5531 family was designed specifically for low-level unipolar and bipolar measurements, it integrates cleanly with resistive-bridge and resistive-temperature sensors found in patient-connected and laboratory equipment.
Recommended
Data Acquisition Systems
The CS5531-ASZ serves as a compact, low-noise front end for general-purpose data acquisition modules that digitize a small number of differential sensor channels. The SPI-compatible serial interface connects directly to microcontrollers or FPGAs, and the sigma-delta converter's digital filtering reduces the anti-aliasing burden on the analog side, simplifying filter design. With two differential inputs and programmable gain, one CS5531-ASZ replaces an amplifier-plus-ADC cascade, cutting board area and calibration complexity. For modules needing more channels or resolution, same-footprint CS5533/5534 variants allow a shared PCB layout to scale without redesign.
Recommended
Battery Testing and Monitoring
Battery test equipment and monitoring circuits require accurate measurement of small differential voltages across sense elements, and the CS5531-ASZ delivers this with its differential inputs and ultra-low-noise PGIA. The sigma-delta converter's line rejection and system calibration support accurate coulomb-counting and cell-voltage measurements over long test durations. The low integration level of the 20-SSOP device keeps multi-channel battery analyzers compact. Designs that later require finer resolution can migrate to the pin-compatible 24-bit CS5532/5534 family members, preserving firmware structure and layout while improving measurement granularity.
Recommended
Temperature and Pressure Transducer Measurement
Thermocouples, RTDs, and piezoresistive pressure sensors all produce low-level differential signals, which is precisely the measurement case the CS5531/32/33/34 family targets. The PGIA provides the gain to map these small signals onto the converter's input range, while differential inputs reject ground-loop noise common in industrial installations. Ratiometric operation with the sensor excitation reference minimizes drift terms. Because the CS5531-ASZ integrates amplification, conversion, and calibration in one 20-SSOP package, a temperature or pressure channel can occupy minimal PCB area, and CS5533/5534 variants add channels on the same footprint for multi-sensor probes.
Recommended
Recommended Products Summary
Engineering reference data for CS5531-ASZ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CS5533-ASZ | CS5532-ASZ | CS5534-ASZR | CS5534-BSZ | CS5534-BSZR |
|---|---|---|---|---|---|---|
| Package | 20-SSOP | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same | 20-SSOP - same |
| Brand | Cirrus Logic | Cirrus Logic | Cirrus Logic | Cirrus Logic | Cirrus Logic | Cirrus Logic |
| Resolution | 16 bit | 16 bit | 24 bit | 24 bit | 24 bit | 24 bit |
| Differential Input Channels | 2 | 4 | 2 | 4 | 4 | 4 |
| Architecture | Sigma-Delta (charge-balance) with PGIA | Sigma-Delta with PGIA | Sigma-Delta with PGIA | Sigma-Delta with PGIA | Sigma-Delta with PGIA | Sigma-Delta with PGIA |
| Front End | Ultra-low-noise PGIA | Ultra-low-noise PGIA | Ultra-low-noise PGIA | Ultra-low-noise PGIA | Ultra-low-noise PGIA | Ultra-low-noise PGIA |
| Primary Use Case | 2-channel low-level bridge measurement | Multi-channel 16-bit measurement | High-resolution 2-channel measurement | High-resolution multi-channel measurement | High-resolution multi-channel measurement | High-resolution multi-channel measurement |
Key Differentiators
- Right-sized 16-bit resolution at lower cost (vs CS5532-ASZ)
- Sufficient two-channel coverage for single-sensor designs (vs CS5533-ASZ)
- Lower-spec family option versus 24-bit parts (vs CS5534-BSZ)
Design Notes
Follow the CS5531/32/33/34 datasheet typical application circuit: decouple the analog supply and the voltage reference with ceramic capacitors placed as close to the pins as possible, and return analog ground through a quiet ground plane. Keep the differential input traces short, matched, and guarded by ground. Route SCLK, SDI, SDO, and CS away from analog input and reference traces; if crossing is unavoidable, use a ground guard trace between digital and analog regions to protect the low-noise floor.
Use ratiometric measurement wherever the sensor and ADC can share a common reference (for example, a load cell whose excitation also drives the ADC reference). Ratiometric operation cancels reference drift and excitation variation from the measurement, substantially improving long-term accuracy without additional components. When the reference must be independent, choose a low-noise precision reference and filter its output; the sigma-delta modulator will faithfully convert reference noise into output noise.
The CS5531 is a 16-bit part in a family that also includes 24-bit members (CS5532/CS5534); firmware word-length and conversion timing assumptions written for a CS5532 will not translate directly, and vice versa. Similarly, two-channel (CS5531/32) and four-channel (CS5533/34) variants multiplex differently. Verify calibration register sequencing against the Cirrus Logic datasheet before switching variants, and confirm gain settings in the PGIA match the transducer full-scale output.
Compliance Information
Compliance status not stated in retrieved web data; verify RoHS/REACH certificates on the Cirrus Logic product page or DigiKey listing before procurement.
