CS5520-BSZ - 20-bit Bridge Transducer Sigma-Delta ADC | Cirrus Logic
料号： CS5520-BSZ ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $32.5 | $32.50 |
| 10 | $29.2 | $292.00 |
| 100 | $25.85 | $2,585.00 |
| 500 | $23.4 | $11,700.00 |
| 1,000 | $21.1 | $21,100.00 |
CS5520-BSZ 概述
A sigma-delta (Σ-Δ) ADC is a converter that oversamples an input signal at a much higher rate than the Nyquist frequency and uses noise-shaping feedback to push quantization noise out of the signal band. In the bridge-sensor hierarchy, the CS5520-BSZ belongs to the precision transducer ADC class, which sits between general-purpose ADCs and dedicated strain-gauge signal conditioners, sharing the role of power management ICs and amplifiers in the broader mixed-signal IC family. By integrating excitation-current sources and instrumentation gain on-chip, the CS5520-BSZ replaces what would otherwise be a multi-chip front-end (sensor + INA + 24-bit ADC + MCU interface logic).
Key differentiating features include four software-selectable differential analog input ranges (±25 mV, ±55 mV, ±100 mV, and ±250 mV referenced to the on-chip common-mode voltage), a programmable-gain instrumentation amplifier with gains of 1, 2, 4, 8, 16, 32, 64, and 128, an integrated constant-voltage or constant-current bridge excitation block, and a low-noise chopper-stabilized front-end with digital filter options (sinc³ or sinc¹). The CS5520 also supports DC or AC bridge excitation, allowing ratiometric measurement configurations that cancel 1/f noise and lead/drift over the bridge line.
Architecturally, the device uses a second-order sigma-delta modulator whose bit-stream is decimated by an on-chip digital filter, with calibration coefficients stored in on-chip registers to correct gain and offset drift. According to the manufacturer datasheet, the part achieves ±0.0007 %FS nonlinearity (INL) and 20-bit effective resolution at the 60 Sps output word rate, with a noise floor below 1 µVrms at the lowest output rate. The hardware interface is a four-wire synchronous serial port (SCLK, SDO, SDI, CS) reading conversion data after an end-of-conversion flag.
Typical applications include weigh scales, force and load-cell instrumentation, process-control pressure transmitters, industrial weighing platforms, and torque/stress measurement systems. The wide input range and high common-mode rejection also make it suitable for battery-cell voltage and strain-bridge temperature compensation in-line monitoring.
When designing with this device, ensure that the analog and digital grounds are joined at a single star point and that the bridge excitation traces are routed away from the digital SPI lines to preserve CMRR. Calibration should be performed at the same output word rate as the measurement to avoid scale-shift errors.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single consolidated reference for the CS5520-BSZ.
直接替换替代料： CS5520-BSZ ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
CS5520-BS
✅ 直接替换📋 参考替代料（不在目录中）
CS5520-BSZR
✅ 直接替换📋 参考替代料（不在目录中）
CS5516-ASZ
✅ 直接替换📋 参考替代料（不在目录中）
CS5516-BS
✅ 直接替换📋 参考替代料（不在目录中）
CS5520-BSZ 最大额定值与电气特性
| 分辨率 | 20 bits |
| Number of Channels | 1 input, 1 sigma-delta channel |
| Conversion Rate (max) | 60 Sps |
| Architecture | Sigma-Delta (Δ-Σ) modulator with digital decimation filter |
| Differential Input Ranges | ±25 mV, ±55 mV, ±100 mV, ±250 mV |
| PGA Gain | 1, 2, 4, 8, 16, 32, 64, 128 (software-selectable) |
| Analog Supply Voltage | +5 V |
| Digital Supply Voltage | +3 V to +5 V |
| 静态电流 | 6.7 mA (typical) |
| Integral Nonlinearity (INL) | ±0.0007 %FS |
| Effective Resolution | 20 bits at 60 Sps |
| Digital Filter | Sinc³ (programmable) |
| Bridge Excitation | On-chip constant-voltage / constant-current source |
| Serial Interface | 4-wire SPI-compatible synchronous serial |
| 封装 | 24-pin SOIC (SO-24) |
| 工作温度 | -40 °C to +85 °C |
| 安装类型 | Surface Mount |
| MSL 等级 | 1 (unlimited floor life at ≤30 °C / 85 % RH) |
| RoHS 状态 | Compliant |
| Bridge Mode | DC or AC excitation (software-selectable) |
CS5520-BSZ 引脚配置
| 引脚 1 | VA+ — Analog supply voltage (+5 V) |
| 引脚 2 | VA- — Analog ground reference |
| 引脚 3 | VD+ — Digital supply voltage (+3 V to +5 V) |
| 引脚 4 | VD- — Digital ground |
| 引脚 5 | REF+ — Positive reference input |
| 引脚 6 | REF- — Negative reference input |
| 引脚 7 | AIN1+ — Differential analog input, positive |
| 引脚 8 | AIN1- — Differential analog input, negative |
| 引脚 9 | REFOUT — Reference voltage output (common-mode) |
| 引脚 10 | VA- — Analog ground (substrate) |
| 引脚 11 | NC — Not connected (per datasheet) |
| 引脚 12 | NC — Not connected (per datasheet) |
| 引脚 13 | EXC+ — Bridge excitation, positive terminal |
| 引脚 14 | EXC- — Bridge excitation, negative terminal |
| 引脚 15 | SDO — Serial data output (SPI) |
| 引脚 16 | SDI — Serial data input (SPI) |
| 引脚 17 | SCLK — Serial clock input |
| 引脚 18 | CS — Chip select (active low) |
| 引脚 19 | DRDY — Data ready output flag |
| 引脚 20 | XIN — Crystal oscillator input |
| 引脚 21 | XOUT — Crystal oscillator output |
| 引脚 22 | TEST — Factory test pin (tie low in application) |
| 引脚 23 | RESET — Hardware reset, active low |
| 引脚 24 | VA- — Analog ground (supply return) |
典型应用
CS5520-BSZ 适用于 6 应用s: Weigh Scales and Load-Cell Instrumentation, Process-Control Pressure Transmitters, Force and Strain Measurement Systems, Industrial Weighing Platforms, Battery-Cell Voltage Monitoring, Embedded Instrumentation and Data Acquisition Modules.
Weigh Scales and Load-Cell Instrumentation
The CS5520-BSZ is purpose-built for direct digitization of low-level bridge outputs in weigh scales. With four software-selectable differential ranges (±25 mV to ±250 mV) and PGA gains up to 128, the part accepts strain-gauge outputs directly without external amplification, achieving 20-bit effective resolution at 60 Sps. Its on-chip DC or AC bridge excitation eliminates the need for separate constant-current regulators. In a typical 4-wire load-cell platform, the CS5520-BSZ replaces both an instrumentation amplifier and a standalone ADC, reducing BOM cost and PCB area by 30-40 %.
推荐
Process-Control Pressure Transmitters
Industrial pressure transmitters using piezoresistive or strain-gauge sensors benefit from the CS5520-BSZ's high common-mode rejection (>120 dB at DC) and integrated excitation. The 24-pin SOIC package supports industrial temperature ranges (-40 °C to +85 °C) and the chopper-stabilized front-end cancels 1/f noise over long integration periods. The on-chip digital calibration registers allow end-of-line gain and offset correction without external potentiometers, simplifying factory calibration of 4-20 mA transmitter modules.
推荐
Force and Strain Measurement Systems
Force-measurement systems such as load pins, dynamometers, and torque transducers rely on the CS5520-BSZ's low-noise chopper front-end, with effective resolution of 20 bits at 60 Sps and a noise floor below 1 µVrms at the lowest output word rate. The programmable PGA lets the same hardware handle full-scale ranges from ±25 mV to ±250 mV, eliminating manual range-switching hardware. Its SPI-compatible four-wire serial interface simplifies isolation to high-voltage drive electronics in dynamometer rigs.
推荐
Industrial Weighing Platforms
Multi-cell industrial weighing platforms benefit from the CS5520-BSZ's ratiometric AC excitation mode, which eliminates thermoelectric offsets in long cable runs. The sinc³ digital filter provides simultaneous 50 Hz and 60 Hz line-frequency rejection at the appropriate output word rate, critical for global-market scales. With on-chip PGA gains of 1, 4, 16, and 64, the part adapts to platforms ranging from 5 kg laboratory balances to 50,000 kg truck scales with a single calibration profile per range.
推荐
Battery-Cell Voltage Monitoring
Although primarily marketed for bridge sensors, the CS5520-BSZ's ±25 mV to ±250 mV input and on-chip PGA make it well-suited to monitor individual battery-cell voltages in stacked Li-ion or lead-acid battery management systems. The chopper-stabilized front-end eliminates drift over long measurement periods, while the 6.7 mA quiescent current is acceptable in always-on battery-monitoring ICs. Use of the ratiometric reference eliminates gain error from cell-load transients.
推荐
Embedded Instrumentation and Data Acquisition Modules
Embedded DAQ modules and handheld instrumentation integrate the CS5520-BSZ for direct sensor-to-digital conversion without bulky signal conditioning. The 24-pin SOIC package is hand-solderable, simplifying prototype work, while the SPI interface drops into any microcontroller with a hardware SPI peripheral. Calibration data can be stored in the on-chip registers and the device is software-configurable to support DC excitation, AC excitation, or external sensor power, allowing one hardware platform to serve strain-gauge, load-cell, and thermocouple-cold-junction measurement tasks.
推荐
推荐产品汇总
工程参考数据： CS5520-BSZ ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | CS5520-BS | CS5520-BSZR | CS5516-ASZ | CS5516-BS | ADS1231IPWR | AD7799BRUZ |
|---|---|---|---|---|---|---|---|
| Brand | Cirrus Logic | Cirrus Logic | Cirrus Logic | Cirrus Logic | Cirrus Logic | Texas Instruments | Analog Devices |
| Package | SOIC-24 | SOIC-24 - same | SOIC-24 - same | SOIC-24 - same | SOIC-24 - same | TSSOP-16 - cross-package | TSSOP-16 - cross-package |
| Resolution | 20 bits | 20 bits | 20 bits | 16 bits | 16 bits | 24 bits | 24 bits |
| Max Output Rate | 60 Sps | 60 Sps | 60 Sps | 60 Sps | 60 Sps | 80 Sps | 470 Sps |
| Differential Input Ranges | ±25 mV to ±250 mV (4 ranges) | Same | Same | Same | Same | ±19.5 mV / ±39 mV / ±78 mV (3 ranges) | ±40 mV to ±4.7 V (5 ranges, configurable) |
| On-Chip Bridge Excitation | Yes (constant-V / constant-I) | Yes | Yes | Yes | Yes | No - external required | Yes - constant current source only |
| On-Chip PGA | 1, 2, 4, 8, 16, 32, 64, 128 | Same | Same | Same | Same | 1, 2, 64, 128 (fixed gains) | 1 to 128 (configurable) |
| Analog Supply | +5 V | +5 V | +5 V | +5 V | +5 V | +3 V to +5.3 V | +2.7 V to +5.25 V |
| Quiescent Current | 6.7 mA | 6.7 mA | 6.7 mA | 6.7 mA | 6.7 mA | 1.3 mA (typ) | 1.5 mA (typ) |
关键差异点
- Integrated on-chip bridge excitation (constant-voltage / constant-current) （对比 ADS1231IPWR (Texas Instruments))
- Four software-selectable differential input ranges with 8 gain steps （对比 ADS1231IPWR (Texas Instruments))
- Pin-compatible upgrade path within the CS5520 family （对比 CS5516-ASZ (Cirrus Logic 16-bit member))
设计说明
Use separate analog and digital supplies for the CS5520-BSZ (VA+ = +5 V, VD+ = +3 V to +5 V). Tie VA- and VD- together at a single star point under the IC to avoid ground loops. Place 100 nF ceramic decoupling close to each supply pin, plus a 10 µF tantalum bulk capacitor at the analog supply entry. Power-supply rejection of the modulator degrades above 10 kHz, so LC filtering on the analog rail is recommended for industrial environments with switching converters nearby.
Route the analog input traces (AIN1+, AIN1-) as a true differential pair with matching lengths and impedance. Keep the bridge excitation traces (EXC+, EXC-) physically separated from the analog input traces by at least 1 mm to minimize crosstalk and thermoelectric coupling. Use a ground plane on layer 2 beneath the analog section; do not route digital SPI signals (SDO, SDI, SCLK, CS, DRDY) over the analog ground plane area. Estimated: with a 24-pin SOIC and 1 oz copper, this routing achieves <0.5 mm trace-length mismatch.
Do not connect unused analog inputs to ground; the CS5520-BSZ inputs are fully differential and floating inputs will inject noise. Do not exceed the +5 V analog supply - even a 6 V transient on VA+ can damage the chopper input stage. When using AC bridge excitation, ensure the EXC+ and EXC- pins drive the bridge with the polarity expected by the calibration firmware; reversed polarity produces a sign-inverted result that is not corrected by gain calibration. Calibration coefficients stored in the on-chip registers must be re-loaded if the device is reset or loses power.
For best CMRR, drive the bridge from the EXC+/EXC- pins using the on-chip constant-voltage mode and route the AIN1+/AIN1- traces together with a guard trace tied to VA-. Avoid tying AIN1+ or AIN1- to system ground. The CS5520-BSZ's chopper stabilization cancels low-frequency 1/f noise, so DC performance improves with lower output word rates - select the lowest word rate that meets the application's bandwidth requirement. Estimated: dropping from 60 Sps to 10 Sps reduces effective noise floor by ~3.5x.
合规信息
RoHS-compliant per Cirrus Logic ordering code suffix 'Z'. Standard commercial grade - not AEC-Q100 qualified for automotive applications. Reach compliance status confirmed by distributor listing.
