AD7942BCPZ - 14-Bit 250kSPS PulSAR ADC | Analog Devices
MPN: AD7942BCPZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.8 | $78.00 |
| 100 | $6.95 | $695.00 |
| 500 | $6.2 | $3,100.00 |
| 1,000 | $5.6 | $5,600.00 |
AD7942BCPZ Overview
An ADC (analog-to-digital converter) is an electronic component that converts continuous analog signals into discrete digital values. The AD7942 is a SAR ADC, which uses a binary search algorithm through a charge redistribution capacitor array to achieve high-speed, high-resolution conversion with low power consumption. SAR ADCs are widely used in data acquisition systems, industrial process control, and medical instrumentation where a balance of speed, resolution, and power efficiency is required. The AD7942 belongs to the PulSAR family, known for its no missing codes guarantee and excellent linearity.
Key features of the AD7942BCPZ include 14-bit resolution with no missing codes, a maximum sampling rate of 250 kSPS, and a pseudo-differential input that rejects common-mode noise. The reference voltage (VREF) is applied externally and can be set up to the supply voltage, allowing flexible full-scale range selection. The device's power consumption scales linearly with throughput, making it ideal for battery-powered applications. The SPI interface includes an SDI input for daisy-chaining and an optional busy indicator, simplifying multi-channel systems.
Technically, the AD7942 uses a charge redistribution architecture with an internal capacitor array, achieving excellent INL and DNL performance. The device operates over a temperature range of -40°C to +125°C, ensuring reliability in harsh environments. The MSOP-10 package has a thermal resistance of approximately 150°C/W, and the device is RoHS compliant. The external reference allows the user to optimize the full-scale range for specific applications, and the power dissipation is typically 4.5 mW at 250 kSPS with a 5V supply.
Typical applications include battery-powered data acquisition systems, portable medical devices, industrial process control, and instrumentation. The AD7942's low power and high speed make it suitable for multi-channel systems where multiple ADCs are daisy-chained. The pseudo-differential input rejects common-mode noise, improving signal integrity in noisy industrial environments.
When designing with the AD7942, ensure that the reference voltage is stable and properly decoupled, as it directly affects conversion accuracy. The SPI interface should be kept short to minimize parasitic capacitance, and the analog input should be driven by a low-impedance source to avoid sampling errors.
Drop-in alternatives for AD7942BCPZ — 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 AD7942BCPZ (same form factor and footprint) — differing in Resolution, Operating Temperature Range, Package, Power Dissipation, Sampling Rate.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD7942BCPZRL
✅ Drop-In📋 Reference alternative (not in catalog)
AD7942BCPZ-RL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7680BRMZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD7682BRMZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD7942BRMZ
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD7942BCPZ-RL7
✅ Drop-In📋 Reference alternative (not in catalog)
AD7942BCPZ Maximum Ratings & Electrical Characteristics
| Resolution | 14 bits |
| Sampling Rate | 250 kSPS |
| Number of Inputs | 1 |
| Input Type | Pseudo-Differential |
| Data Interface | SPI, DSP |
| Number of A/D Converters | 1 |
| Reference Type | External |
| Supply Voltage | 2.3 V to 5.5 V |
| Power Dissipation | 4.5 mW at 250 kSPS (5V) |
| Operating Temperature Range | -40°C to +125°C |
| Package | 10-Lead MSOP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Configuration | S/H-ADC |
| Marking Code | C4S |
AD7942BCPZ Pin Configuration
| Pin 1 | IN+ — Positive analog input |
| Pin 2 | IN- — Negative analog input (pseudo-differential) |
| Pin 3 | GND — Ground |
| Pin 4 | VREF — External reference voltage input |
| Pin 5 | VDD — Power supply (2.3V to 5.5V) |
| Pin 6 | SDO — Serial data output |
| Pin 7 | SDI — Serial data input (for daisy-chaining) |
| Pin 8 | SCK — Serial clock input |
| Pin 9 | CNV — Convert input (start conversion) |
| Pin 10 | BUSY — Busy indicator (optional) |
Typical Applications
AD7942BCPZ is suitable for 6 applications: Battery-Powered Data Acquisition, Industrial Process Control, Portable Medical Devices, Instrumentation and Test Equipment, Multi-Channel Data Acquisition Systems, Automotive Battery Monitoring.
Battery-Powered Data Acquisition
The AD7942BCPZ's low power consumption (4.5 mW at 250 kSPS) and wide supply range (2.3V-5.5V) make it ideal for portable data loggers and wireless sensors. Its power scales linearly with throughput, allowing designers to optimize battery life by reducing sampling rate when full speed is not needed. The pseudo-differential input rejects common-mode noise, ensuring accurate readings in electrically noisy field environments. With a compact MSOP-10 package, it fits easily into space-constrained designs.
Recommended
Industrial Process Control
In industrial automation, the AD7942BCPZ provides 14-bit resolution at 250 kSPS, enabling precise monitoring of analog signals such as temperature, pressure, and flow. Its -40°C to +125°C operating range ensures reliable operation in harsh factory environments. The SPI interface with daisy-chain capability simplifies wiring in multi-channel control systems, reducing connector count and cost. The external reference allows calibration to match specific transducer full-scale outputs, improving measurement accuracy.
Recommended
Portable Medical Devices
The AD7942BCPZ is well-suited for portable medical devices such as glucose monitors and pulse oximeters, where low power and high accuracy are critical. Its 14-bit resolution provides fine granularity for physiological signals, while the 250 kSPS sampling rate captures fast transients. The device operates from a single 3.3V supply, simplifying battery management. The pseudo-differential input helps reject interference from motors and displays, ensuring clean signal acquisition. Its small MSOP-10 package enables miniaturized device designs.
Recommended
Instrumentation and Test Equipment
For benchtop multimeters and data loggers, the AD7942BCPZ offers a balance of speed and resolution. Its 250 kSPS throughput allows fast waveform capture, while 14-bit resolution ensures accurate DC measurements. The external reference enables users to set precise full-scale ranges, and the SPI interface connects easily to microcontrollers or FPGAs. The device's low power dissipation reduces thermal drift in precision instruments, improving long-term stability. The MSOP-10 package is compatible with standard PCB layouts.
Recommended
Multi-Channel Data Acquisition Systems
The AD7942BCPZ's daisy-chain capability allows multiple ADCs to share a single SPI bus, reducing I/O requirements in multi-channel systems. Each ADC can sample simultaneously, and the SDI/SDO chain shifts data out sequentially. This is ideal for applications like vibration monitoring or phased array sensing, where many channels must be sampled synchronously. The 250 kSPS per channel provides adequate throughput for most industrial sensors. The pseudo-differential input reduces crosstalk between channels.
Recommended
Automotive Battery Monitoring
In automotive battery management systems, the AD7942BCPZ monitors cell voltages and temperatures with 14-bit accuracy. Its wide supply range (2.3V-5.5V) accommodates varying battery voltages, and the -40°C to +125°C range meets automotive temperature requirements. The SPI interface allows direct connection to a BMS microcontroller, and the low power consumption minimizes drain on the battery. The pseudo-differential input rejects common-mode noise from high-current switching, ensuring accurate measurements.
Recommended
Recommended Products Summary
Engineering reference data for AD7942BCPZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD7942BCPZRL | AD7680BRMZ | AD7682BRMZ |
|---|---|---|---|---|
| Package | 10-Lead MSOP | 10-Lead MSOP | 10-Lead MSOP | 10-Lead MSOP |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 14 bits | 14 bits | 16 bits | 16 bits |
| Sampling Rate | 250 kSPS | 250 kSPS | 100 kSPS | 250 kSPS |
| Number of Inputs | 1 | 1 | 1 | 4 |
| Input Type | Pseudo-Differential | Pseudo-Differential | Pseudo-Differential | Pseudo-Differential |
| Supply Voltage | 2.3V to 5.5V | 2.3V to 5.5V | 2.3V to 5.5V | 2.3V to 5.5V |
| Data Interface | SPI, DSP | SPI, DSP | SPI, DSP | SPI, DSP |
Key Differentiators
- 14-bit resolution with no missing codes (vs AD7680BRMZ (16-bit))
- 250 kSPS sampling rate (vs AD7680BRMZ (100 kSPS))
- Daisy-chain capability (vs AD7682BRMZ (4-channel))
Design Notes
Decouple the VDD pin with a 10uF ceramic capacitor and a 0.1uF capacitor placed as close to the pin as possible. The reference voltage (VREF) should be decoupled with a 10uF capacitor to ensure stability. Use a low-noise LDO like the ADP150 to supply VDD, as switching noise can degrade ADC performance.
Keep the analog input traces short and shielded from digital signals. Use a ground plane under the ADC to minimize noise. The SPI lines (SCK, SDO, SDI) should be routed away from the analog input to avoid crosstalk. Place the ADC close to the signal source to reduce parasitic capacitance.
Ensure the reference voltage is stable and within the specified range (up to VDD). An unstable reference will cause conversion errors. Also, avoid driving the analog input with a high-impedance source, as the sampling capacitor may not charge fully, leading to inaccurate readings. Use a buffer amplifier if necessary.
Compliance Information
RoHS compliant per Analog Devices product page. No AEC-Q100 qualification indicated for this part.
