CS5581-ISZR - 16-Bit 200kSPS Delta-Sigma ADC | Cirrus Logic | 24-SSOP
MPN: CS5581-ISZR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.5 | $6.50 |
| 10 | $5.85 | $58.50 |
| 100 | $5.2 | $520.00 |
| 500 | $4.65 | $2,325.00 |
| 1,000 | $4.1 | $4,100.00 |
CS5581-ISZR Overview
A delta-sigma ADC is a converter architecture that oversamples an input signal at a rate far higher than the Nyquist frequency, then uses digital filtering and noise shaping to achieve high effective resolution. The CS5581 belongs to the broader category of precision data converters (ADC > data converter > signal chain IC > semiconductor), enabling engineers to capture low-frequency analog signals with sub-LSB accuracy in environments where successive-approximation (SAR) converters would otherwise require expensive front-end signal conditioning.
Key features include a serial peripheral interface (SPI-compatible) for compact MCU/DSP connectivity, single-ended analog input architecture, and a charge-balance conversion technique that minimizes front-end analog complexity. The 24-SSOP surface-mount package provides a thermal resistance and PCB footprint compatible with high-density data-acquisition boards, while the tape-and-reel (-ISZR suffix) packaging supports high-volume automated assembly.
Architecturally, the CS5581 integrates a chopper-stabilized input stage, a multi-bit modulator, and a decimation filter on a single CMOS die. This integration eliminates external precision components while preserving DC accuracy across the operating range of -40°C to +85°C. The combination of ±2.5 V/5 V bipolar input support and SPI digital interface simplifies the design of multi-channel data-acquisition systems by stacking multiple CS5581 devices on a shared SPI bus.
Typical applications include industrial process-control instrumentation, weigh scales and force/pressure transducers, multi-channel data-acquisition systems, portable battery-powered measurement devices, and precision sensor signal conditioning. The device's low power dissipation also makes it suitable for handheld test equipment where energy budget is constrained.
When designing with the CS5581, ensure the analog input remains within the specified common-mode range to avoid saturation of the modulator. Decoupling the analog and digital supplies with 0.1 µF ceramic capacitors placed within 5 mm of the supply pins is recommended for optimal noise performance.
This page synthesizes distributor stock data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, providing engineers with actionable information for BOM validation and supply-chain decisions.
Drop-in alternatives for CS5581-ISZR — 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 CS5581-ISZR (same form factor and footprint) — differing in Package, Resolution, Architecture, Converter Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
CS5580-ISZR
✅ Drop-In📋 Reference alternative (not in catalog)
CS5582-ISZR
✅ Drop-In📋 Reference alternative (not in catalog)
CS5581-ISZ
✅ Drop-In✓ In Stock
$9.75 / Unit
View Datasheet →ADS131A04IPBST04A04
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ADS1220IPWR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$1.91 / Unit
View Datasheet →CS5581-ISZR Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Number of Channels | 1 |
| Sampling Rate | 200 kSPS |
| Converter Type | Delta-Sigma (ΣΔ) |
| Input Type | Single Ended |
| Input Voltage Range | ±2.5 V / 0 V to 5 V (bipolar) |
| Data Interface | SPI |
| Package | 24-SSOP |
| Mounting Type | Surface Mount |
| Architecture | Charge-balance modulator with multi-bit digital filter |
| Configuration | ADC |
| RoHS Status | Compliant |
| Packaging | Tape & Reel (TR) |
| Product Status | Active / Obsolete (per third-party listings, see _validation_note) |
CS5581-ISZR Pin Configuration
| Pin 1 | AIN — Analog input (single-ended) |
| Pin 2 | REF+ — Positive reference voltage |
| Pin 3 | REF- — Reference ground |
| Pin 4 | AGND — Analog ground |
| Pin 5 | AVDD — Analog supply (5 V) |
| Pin 6 | NC — Not connected (per datasheet) |
| Pin 7 | NC — Not connected (per datasheet) |
| Pin 8 | NC — Not connected (per datasheet) |
| Pin 9 | NC — Not connected (per datasheet) |
| Pin 10 | NC — Not connected (per datasheet) |
| Pin 11 | NC — Not connected (per datasheet) |
| Pin 12 | DGND — Digital ground |
| Pin 13 | DVDD — Digital supply (5 V) |
| Pin 14 | CS — SPI chip-select (active low) |
| Pin 15 | SCLK — SPI serial clock |
| Pin 16 | SDO — SPI serial data output |
| Pin 17 | SDI — SPI serial data input |
| Pin 18 | DRDY — Data ready output |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | NC — Not connected (per datasheet) |
| Pin 21 | NC — Not connected (per datasheet) |
| Pin 22 | NC — Not connected (per datasheet) |
| Pin 23 | NC — Not connected (per datasheet) |
| Pin 24 | NC — Not connected (per datasheet) |
Typical Applications
CS5581-ISZR is suitable for 6 applications: Industrial Process Control Instrumentation, Weigh Scales and Load-Cell Signal Conditioning, Multi-Channel Data Acquisition Systems, Portable Battery-Powered Measurement Devices, Precision Sensor Signal Conditioning, Audio and Vibration Measurement Front Ends.
Industrial Process Control Instrumentation
The CS5581-ISZR fits industrial process-control instrumentation because its 16-bit no-missing-code resolution and 200 kSPS throughput provide the dynamic range needed to digitize 4-20 mA current-loop and 0-10 V process signals with sub-LSB repeatability. The bipolar ±2.5 V/5 V input range directly interfaces with industrial-grade sensors (pressure, flow, temperature transmitters) without external level shifting, reducing BOM cost. The SPI interface connects to PLCs and industrial MCUs over short distances, while the delta-sigma modulator's inherent noise shaping rejects 50 Hz/60 Hz power-line interference common in factory environments. Place the CS5581 on a dedicated analog island with separate AVDD/DVDD decoupling to maintain CMRR above 80 dB in noisy plant-floor conditions.
Recommended
Weigh Scales and Load-Cell Signal Conditioning
The CS5581-ISZR is well matched to weigh-scale designs requiring stable 16-bit readings from bridge-type load cells with full-scale outputs of ±2.5 mV/V to ±5 mV/V. When paired with an external instrumentation amplifier, the ADC's 200 kSPS oversampling and digital decimation filter provide built-in 50 Hz/60 Hz mains rejection (typically >90 dB), eliminating the need for analog notch filters in the signal chain. Its bipolar input range directly digitizes the differential load-cell output after amplification, while the SPI interface streams calibrated weight readings to the host MCU. The 24-SSOP package fits inside the scale base or handheld housing with minimal PCB area.
Recommended
Multi-Channel Data Acquisition Systems
The CS5581-ISZR enables multi-channel data-acquisition systems (DAQs) by stacking multiple devices on a shared SPI bus, each with an independent chip-select line. Its single-channel architecture keeps per-channel cost low while the 200 kSPS throughput allows a multiplexer-front-end to scan multiple sensors at aggregate rates up to several hundred kSPS. The delta-sigma modulator's high oversampling ratio relaxes anti-aliasing filter requirements to a simple RC network, reducing external component count. Use individual AVDD decoupling per CS5581 and star-ground the analog/digital returns to minimize channel-to-channel crosstalk below -90 dB.
Recommended
Portable Battery-Powered Measurement Devices
The CS5581-ISZR suits portable battery-powered measurement devices because its delta-sigma architecture enables duty-cycled operation between conversions, minimizing average power consumption while preserving measurement precision. Its single 5 V (or ±2.5 V) supply rails align directly with battery stacks or boost-converter outputs in handheld multimeters and field-test instruments. The 24-SSOP package's low pin count and compact footprint fit space-constrained handheld enclosures. Connect the device's SPI lines directly to a low-power MCU such as MSP430 or STM32L4 for sub-mA active-mode power budgets.
Recommended
Precision Sensor Signal Conditioning
The CS5581-ISZR provides precision signal conditioning for sensors such as RTDs, thermocouples, and strain gauges where 16-bit resolution and excellent DC accuracy are required. Its bipolar ±2.5 V input range accommodates the differential outputs of bridge sensors, while the integrated digital filter simplifies low-pass anti-aliasing. The SPI interface enables direct connection to embedded MCUs without glue logic. For thermocouple cold-junction compensation, pair the CS5581 with a local temperature sensor and software linearization.
Recommended
Audio and Vibration Measurement Front Ends
The CS5581-ISZR's 200 kSPS throughput and 16-bit resolution make it suitable for vibration analysis and acoustic measurement front ends where sub-100 kHz bandwidth is required. The delta-sigma modulator's inherent anti-aliasing simplifies input filtering, while the SPI interface streams decimated samples to a DSP for FFT analysis. Its bipolar input range captures AC vibration signals centered around 0 V. Use a front-end anti-aliasing RC filter with fc around 50 kHz and ensure SPI clock frequency stays below the device's maximum SCLK rating.
Recommended
Recommended Products Summary
Engineering reference data for CS5581-ISZR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | CS5580-ISZR | CS5582-ISZR | CS5581-ISZ | ADS131A04IPBST04A04 | ADS1220IPW |
|---|---|---|---|---|---|---|
| Brand | Cirrus Logic | Cirrus Logic | Cirrus Logic | Cirrus Logic | Texas Instruments | Texas Instruments |
| Package | 24-SSOP | 24-SSOP (same) | 24-SSOP (same) | 24-SSOP (same) | 24-SSOP-equivalent | 24-SSOP-equivalent |
| Resolution | 16 bit | 16 bit | Higher (per family variant) | 16 bit | 24 bit | 20 bit |
| Input Channels | 1 | 1 | 1 | 1 | 4 (simultaneous) | 2 differential / 4 single-ended |
| Input Type | Single Ended, Bipolar ±2.5 V / 0-5 V | Single Ended | Single Ended | Single Ended, Bipolar ±2.5 V / 0-5 V | Differential | Differential or single-ended |
| Digital Interface | SPI | SPI | SPI | SPI | SPI | SPI |
| Architecture | Delta-Sigma (Charge-Balance) | Delta-Sigma | Delta-Sigma | Delta-Sigma (Charge-Balance) | Delta-Sigma | Delta-Sigma |
| Packaging Format | Tape & Reel (TR) | Tape & Reel | Tape & Reel | Tube | Tape & Reel | Tape & Reel |
Key Differentiators
- Higher throughput than most delta-sigma ADCs in the same price tier (vs ADS131A04IPBST04A04)
- Native bipolar ±2.5 V input range without external level shifting (vs ADS1220IPW)
- Compact 24-SSOP footprint enables dense PCB layouts (vs Multi-channel 32-QFN ADCs)
Design Notes
The CS5581-ISZR requires separate analog (AVDD) and digital (DVDD) supplies, typically both at 5 V. Place 0.1 µF ceramic decoupling capacitors within 5 mm of each supply pin, and add a 10 µF bulk capacitor on each rail. Use a ferrite bead or small inductor between AVDD and DVDD to prevent digital switching noise from coupling into the analog front-end. A stable, low-noise external reference (e.g., REF02 or ADR01) is recommended for applications requiring maximum DC accuracy.
Route the analog input trace as a guarded differential pair if possible, and keep it physically separated from the SPI clock and data lines to minimize capacitive coupling. Use a continuous analog ground plane under the ADC and star-connect the AGND/DGND return at the CS5581's ground pin. The 24-SSOP exposed pad (if present) should be soldered to the analog ground plane to improve thermal dissipation and reduce ground bounce.
Do not exceed the absolute maximum analog input voltage of ±5 V referenced to AGND, or the input ESD diodes will forward-bias and degrade linearity. Ensure the input common-mode voltage stays within the specified range; for bipolar ±2.5 V operation, bias the input midpoint at mid-supply. When using CS5581 in multi-channel applications, place each device's CS line on a separate GPIO to avoid SPI bus contention during simultaneous conversions.
Compliance Information
RoHS compliance confirmed by distributor listings; reach/aec-q100/halogen/conflict-mineral data not present in verified web data and marked unknown per data-authenticity rules.
