AD4691BCPZ - 16-Channel 16-Bit SAR ADC | Analog Devices
MPN: AD4691BCPZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $10 | $1,000.00 |
| 500 | $9 | $4,500.00 |
| 1,000 | $8 | $8,000.00 |
AD4691BCPZ Overview
An ADC (analog-to-digital converter) is a device that converts continuous analog signals into discrete digital numbers. The AD4691 is a SAR ADC, which uses a successive approximation register algorithm to perform conversions with high speed and accuracy. SAR ADCs are widely used in data acquisition systems, industrial process control, and medical instrumentation due to their excellent balance of speed, resolution, and power consumption. The AD4691 belongs to the family of multiplexed SAR ADCs, which allow multiple input channels to share a single conversion core, reducing cost and board space.
Key features of the AD4691BCPZ include 16 single-ended or 8 differential input channels, a 16-bit resolution with no missing codes, and a maximum sample rate of 500 kSPS. The Easy Drive technology reduces input current and voltage transients, simplifying the external driver requirements. The device also includes per-channel averaging filters, which can improve noise performance and reduce the digital filter burden on the host processor. The LFCSP package offers a compact footprint suitable for space-constrained designs.
Technically, the AD4691 uses a charge redistribution SAR architecture with an internal reference buffer. The precharge buffers are the key innovation, as they isolate the input from the sampling capacitor, allowing the use of lower-bandwidth amplifiers and reducing power consumption. The device supports both SPI and QSPI interfaces for communication with microcontrollers and DSPs. The per-channel averaging filters can be configured to average up to 128 samples, providing trade-offs between noise reduction and throughput.
Typical applications include industrial process control, data acquisition systems, battery-powered instrumentation, and medical monitoring equipment. The AD4691 is particularly suited for multi-channel sensor monitoring where low power and small size are critical. Its Easy Drive feature makes it ideal for direct connection to sensors without complex front-end circuitry.
When designing with the AD4691, ensure that the reference voltage is stable and well-decoupled. The input signal range should be within the specified common-mode range to avoid distortion. The SPI interface should be configured for the correct clock polarity and phase as per the datasheet.
Drop-in alternatives for AD4691BCPZ — 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 AD4691BCPZ (same form factor and footprint) — differing in Supply Voltage, Input Type, Package, Sampling Rate, Number of Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD4692BCPZ
✅ Drop-In✓ In Stock
$5.9 / Unit
View Datasheet →AD4693BCPZ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$8.1 / Unit
View Datasheet →AD4694BCPZ
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$8.1 / Unit
View Datasheet →MAX11166
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
MAX11167
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
ADS8688
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
AD4691BCPZ Maximum Ratings & Electrical Characteristics
| Resolution | 16 Bit |
| Number of Channels | 16 Input |
| Sampling Rate | 500 kSPS |
| Input Type | Single-Ended / Differential |
| Interface | SPI / QSPI |
| Architecture | SAR |
| Package | 32-LFCSP (5x5 mm) |
| Operating Temperature Range | -40°C to +125°C |
| Supply Voltage | 1.8 V to 5.5 V |
| Reference Voltage | 2.5 V to 5 V |
| Easy Drive | Yes |
| Averaging Filters | Per Channel |
| RoHS | Compliant |
AD4691BCPZ Pin Configuration
| Pin 1 | VIN0 — Analog input channel 0 |
| Pin 2 | VIN1 — Analog input channel 1 |
| Pin 3 | VIN2 — Analog input channel 2 |
| Pin 4 | VIN3 — Analog input channel 3 |
| Pin 5 | VIN4 — Analog input channel 4 |
| Pin 6 | VIN5 — Analog input channel 5 |
| Pin 7 | VIN6 — Analog input channel 6 |
| Pin 8 | VIN7 — Analog input channel 7 |
| Pin 9 | VIN8 — Analog input channel 8 |
| Pin 10 | VIN9 — Analog input channel 9 |
| Pin 11 | VIN10 — Analog input channel 10 |
| Pin 12 | VIN11 — Analog input channel 11 |
| Pin 13 | VIN12 — Analog input channel 12 |
| Pin 14 | VIN13 — Analog input channel 13 |
| Pin 15 | VIN14 — Analog input channel 14 |
| Pin 16 | VIN15 — Analog input channel 15 |
| Pin 17 | GND — Ground |
| Pin 18 | VREF — Reference voltage input |
| Pin 19 | AVDD — Analog supply voltage |
| Pin 20 | DVDD — Digital supply voltage |
| Pin 21 | SCLK — Serial clock input |
| Pin 22 | SDI — Serial data input |
| Pin 23 | SDO — Serial data output |
| Pin 24 | CS — Chip select (active low) |
| Pin 25 | CNV — Convert input |
| Pin 26 | BUSY — Busy output |
| Pin 27 | GPIO0 — General purpose I/O 0 |
| Pin 28 | GPIO1 — General purpose I/O 1 |
| Pin 29 | GPIO2 — General purpose I/O 2 |
| Pin 30 | GPIO3 — General purpose I/O 3 |
| Pin 31 | RESET — Reset input (active low) |
| Pin 32 | PD — Power-down input |
Typical Applications
AD4691BCPZ is suitable for 6 applications: Industrial Process Control, Data Acquisition Systems, Battery-Powered Instrumentation, Medical Monitoring Equipment, Multi-Channel Sensor Monitoring, Audio and Vibration Analysis.
Industrial Process Control
The AD4691BCPZ is ideal for industrial process control systems that monitor multiple analog signals such as temperature, pressure, and flow. Its 16 input channels allow direct connection to various sensors without complex front-end circuitry. The Easy Drive technology reduces input transients, enabling the use of lower-bandwidth amplifiers, which lowers system cost and power. The 500 kSPS sampling rate is sufficient for real-time monitoring of process variables. The device's SPI interface simplifies integration with industrial microcontrollers. Its wide operating temperature range (-40°C to +125°C) ensures reliable operation in harsh industrial environments.
Recommended
Data Acquisition Systems
The AD4691BCPZ is well-suited for general-purpose data acquisition systems requiring high resolution and multiple channels. Its 16-bit resolution and 500 kSPS throughput allow accurate digitization of a wide range of signals. The per-channel averaging filters can reduce noise and improve effective resolution, making it ideal for precision measurements. The device's low power consumption is beneficial for portable data loggers. The Easy Drive feature simplifies the analog front-end, reducing component count and board space. The SPI interface is compatible with most microcontrollers and DSPs, enabling quick integration.
Recommended
Battery-Powered Instrumentation
The AD4691BCPZ is an excellent choice for battery-powered instrumentation due to its low power consumption and wide supply voltage range (1.8V to 5.5V). It can operate directly from a battery or a low-voltage regulator, reducing system complexity. The 16 input channels allow monitoring of multiple battery cells or sensor outputs. The Easy Drive technology reduces input current, which is critical for preserving battery life. The device's small LFCSP package is ideal for compact handheld devices. Its SPI interface enables low-power sleep modes when not converting, further extending battery life.
Recommended
Medical Monitoring Equipment
The AD4691BCPZ is suitable for medical monitoring equipment such as patient monitors and diagnostic devices. Its 16-bit resolution ensures accurate measurement of physiological signals like ECG, EEG, and temperature. The multiple input channels can acquire several signals simultaneously. The Easy Drive technology reduces input transients, which is important for high-impedance sources like bio-potential electrodes. The device's low power consumption is advantageous for portable medical devices. The SPI interface allows easy connection to medical-grade microcontrollers. The wide temperature range ensures reliable operation in clinical environments.
Recommended
Multi-Channel Sensor Monitoring
The AD4691BCPZ is perfect for multi-channel sensor monitoring in applications like environmental monitoring, structural health monitoring, and smart agriculture. Its 16 input channels can interface with a variety of sensors, including temperature, humidity, and strain gauges. The Easy Drive feature allows direct connection to high-impedance sensors without additional buffer amplifiers. The per-channel averaging filters help reduce noise from sensor outputs. The device's low power consumption is ideal for remote sensor nodes powered by batteries or energy harvesting. The SPI interface enables daisy-chaining multiple ADCs for even more channels.
Recommended
Audio and Vibration Analysis
The AD4691BCPZ can be used in audio and vibration analysis systems where multiple channels of high-resolution data are required. Its 16-bit resolution and 500 kSPS sampling rate are adequate for capturing audio signals up to 250 kHz. The multiple input channels allow simultaneous acquisition of multiple microphones or accelerometers. The Easy Drive technology reduces input transients, preserving signal fidelity. The device's low noise performance is critical for accurate analysis. The SPI interface enables high-speed data transfer to DSPs for real-time processing. The compact package is suitable for portable analyzers.
Recommended
Recommended Products Summary
Engineering reference data for AD4691BCPZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD4692BCPZ | MAX11166 | ADS8688 |
|---|---|---|---|---|
| Package | 32-LFCSP (5x5 mm) | 32-LFCSP (5x5 mm) | 32-TQFN (5x5 mm) | 32-TQFP (5x5 mm) |
| Brand | Analog Devices | Analog Devices | Maxim Integrated | Texas Instruments |
| Resolution | 16 Bit | 16 Bit | 16 Bit | 16 Bit |
| Sampling Rate | 500 kSPS | 1 MSPS | 500 kSPS | 500 kSPS |
| Number of Channels | 16 | 16 | 16 | 16 |
| Interface | SPI/QSPI | SPI/QSPI | SPI | SPI |
| Easy Drive | Yes | Yes | No | No |
| Averaging Filters | Per Channel | Per Channel | No | No |
Key Differentiators
- Easy Drive technology reduces input transients (vs MAX11166)
- Per-channel averaging filters (vs ADS8688)
- Higher sampling rate option in same family (vs AD4692BCPZ)
Design Notes
The AD4691BCPZ operates from a single supply voltage ranging from 1.8V to 5.5V. It is crucial to decouple the AVDD and DVDD pins with 0.1uF and 10uF capacitors placed close to the device. The reference voltage (VREF) should be decoupled with a 10uF capacitor to ensure stability. For optimal performance, use a low-noise LDO to supply the ADC, as switching regulators can introduce noise that degrades SNR.
For best performance, place the AD4691BCPZ on a PCB with a solid ground plane. Keep analog input traces short and shielded from digital signals to minimize crosstalk. The LFCSP package has an exposed pad that should be soldered to the ground plane for thermal and electrical grounding. Use a 4-layer PCB with dedicated power and ground planes to reduce noise.
A common mistake is driving the analog inputs with high-impedance sources without considering the input current. The Easy Drive feature reduces input transients, but it is still recommended to use a buffer amplifier if the source impedance exceeds 1kΩ. Also, ensure that the input voltage does not exceed the reference voltage to avoid clipping. The SPI interface must be configured with the correct clock polarity and phase as specified in the datasheet.
Compliance Information
RoHS compliance is indicated by the 'Z' suffix in the part number. Other compliance details are not provided in the verified data.
