Part A
AD7685BCPZRL7
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4541 PCS
- Package
- LFCSP-10
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7683BCPZRL is a strong functional replacement candidate for the AD7683BCPZRL7, sharing the same 16-bit SAR architecture, 100 kSPS throughput, pseudo-differential input, and 8-lead LFCSP package. The primary distinction is the interface configuration: the AD7683BCPZRL7 provides a 3-wire SPI/QSPI/MICROWIRE/DSP-compatible serial interface, while the AD7683BCPZRL uses a 4-wire interface with a separate CS and RD configuration. Designers should validate the digital interface timing and host controller compatibility before substituting, but the core analog performance and footprint remain aligned.
Resolution and Throughput
High match
Package and Footprint
High match
Digital Interface Type
Validation required
Analog Input Configuration
High match
Parts at a glance
Part B
AD7683BCPZRL
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4315 PCS
- Package
- VDFN-8
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7685BCPZRL7 | AD7683BCPZRL | Why it matters |
|---|---|---|---|
| Resolution (bits) | 16 | 16 | Both are 16-bit ADCs, so nominal resolution is identical and does not differentiate substitutability. |
| Sampling Rate (max) | 250 kSPS | 100 kSPS | The AD7685 supports a higher throughput, which matters if the application requires faster sampling than 100 kSPS. |
| Architecture | SAR | SAR | Both use successive-approximation register architecture, giving similar latency and no pipeline delay behavior. |
| Input Type | Pseudo-differential, single-ended | Pseudo-differential, single-ended | Matching input configuration allows similar analog front-end design and signal conditioning. |
| Supply Voltage (analog) | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Identical analog supply range means both can operate from the same system rails. |
| Interface | SPI / QSPI / MICROWIRE / DSP compatible | SPI / QSPI / MICROWIRE / DSP compatible | Same serial interface compatibility simplifies digital host connection and firmware reuse. |
| Package | 10-Lead LFCSP (3 mm x 3 mm) | 8-Lead LFCSP (3 mm x 3 mm) | Different pin count and footprint affect PCB layout and may require board redesign for substitution. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings mean both suit the same industrial operating environments. |
| Power Consumption (typical) | 3.5 mW at 5 V, 250 kSPS | 1.4 mW at 5 V, 100 kSPS | Lower power per conversion in the AD7683 matters for battery-powered or thermally constrained designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7685BCPZRL7 | AD7683BCPZRL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 250k | 100k |
| Number of Inputs | 1 | 1 |
| Input Type | Pseudo-Differential | Pseudo-Differential |
| Data Interface | SPI, DSP | SPI, DSP |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External | External |
| Voltage - Supply, Analog | 2.3V ~ 5.5V | 2.7V ~ 5.5V |
| Voltage - Supply, Digital | 2.3V ~ 5.5V | 2.7V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD7685BCPZRL7 and the AD7683BCPZRL?
The AD7685BCPZRL7 is a 16-bit, 250 kSPS PulSAR analog-to-digital converter, while the AD7683BCPZRL is a 16-bit, 100 kSPS PulSAR ADC. Both are single-channel, successive-approximation ADCs in a 10-lead LFCSP package, but they differ in throughput rate and digital interface timing characteristics.
Are the AD7685BCPZRL7 and AD7683BCPZRL pin-compatible?
Both devices are offered in a 10-lead LFCSP (CP-10) package with the same pin count and footprint. However, designers should verify the pin function assignments against the respective manufacturer datasheets, as the serial interface and control pin behavior may differ between the two parts.
What is the maximum sampling rate of each device?
The AD7685BCPZRL7 supports a maximum throughput of 250 kSPS, whereas the AD7683BCPZRL supports a maximum throughput of 100 kSPS. The higher sampling rate of the AD7685 makes it suitable for faster signal acquisition applications.
Do both ADCs use the same serial interface?
Both devices provide a serial digital output compatible with SPI/QSPI/MICROWIRE/DSP interfaces. However, the AD7685 uses a CS- and SCLK-based serial interface with a busy indicator, while the AD7683 uses a simpler 3-wire interface. The timing and readback protocol should be reviewed in each datasheet before interchange.
What is the resolution and architecture of these ADCs?
Both the AD7685BCPZRL7 and AD7683BCPZRL are 16-bit, charge-redistribution successive-approximation register (SAR) ADCs. They provide no missing codes at 16 bits and are designed for high-accuracy, low-power data acquisition.
Can the AD7683BCPZRL directly replace the AD7685BCPZRL7 in an existing design?
Direct replacement is not recommended without validation. Although both are 16-bit SAR ADCs in the same package, the AD7685 offers a higher throughput rate (250 kSPS vs 100 kSPS) and different serial interface timing. The system timing, firmware, and sampling requirements must be verified against the AD7683 datasheet before substitution.
What are the typical supply and reference requirements for these devices?
Both devices operate from a single 2.7 V to 5.5 V supply and use an external reference voltage. The reference input range and analog input span should be confirmed from the respective datasheets, as the allowable reference and input configurations may differ between the AD7685 and AD7683.