Part A
AD7705BRZ-REEL
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 7181 PCS
- Package
- SOIC-16
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Not a drop-in replacement
The AD7705BRZ-REEL and AD7707BR are not drop-in replacements for one another. Although both are 16-bit sigma-delta ADCs from Analog Devices, they differ in input channel configuration, analog input range and front-end architecture, package and pinout, and supply voltage requirements. Each of these differences affects board-level compatibility, so the AD7707BR cannot be substituted directly for the AD7705BRZ-REEL without design validation and layout changes.
Different input channel configuration
Different analog input range
Different package and pinout
Different supply voltage requirements
Parts at a glance
Part B
AD7707BR
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 8441 PCS
- Package
- SOIC-20
- 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 | AD7705BRZ-REEL | AD7707BR | Why it matters |
|---|---|---|---|
| Number of Input Channels | 2 differential | 3 (2 differential + 1 single-ended high-level) | Channel count determines how many signal sources can be connected; the AD7707 adds a high-level input path not present on the AD7705. |
| Input Type / Signal Range | Low-level differential (analog front end for small signals) | Low-level differential plus high-level single-ended input | The AD7707 can directly accept larger single-ended signals, while the AD7705 is limited to low-level differential inputs, affecting sensor interface flexibility. |
| Resolution | 16-bit | 16-bit | Both provide 16-bit resolution, so precision is comparable; resolution alone does not differentiate them. |
| Package | 16-lead SOIC | 20-lead SOIC | Different package footprints and pin counts mean the parts are not drop-in replacements on an existing PCB. |
| Supply Voltage | 2.7 V to 3.3 V (single supply) | 2.7 V to 3.3 V (single supply) | Matching supply requirements allow both to operate from the same low-voltage rail, simplifying power design. |
| Interface | SPI-compatible serial (3-wire) | SPI-compatible serial (3-wire) | Identical serial interface protocol enables similar microcontroller firmware and bus connections. |
| PGA / Gain | On-chip PGA, gain 1 to 128 | On-chip PGA, gain 1 to 128 | Programmable gain allows both to amplify small sensor signals, supporting similar low-level measurement applications. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent industrial temperature range means both suit the same environmental conditions. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7705BRZ-REEL | AD7707BR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 500 | 500 |
| Number of Inputs | 2 | 1, 2 |
| Input Type | Differential | Pseudo-Differential, Single Ended |
| Data Interface | SPI, DSP | SPI, DSP |
| Configuration | MUX-PGA-ADC | MUX-PGA-ADC |
| Number of A/D Converters | 1 | 1 |
| Architecture | Sigma-Delta | Sigma-Delta |
| Reference Type | External | External |
| Voltage - Supply, Analog | 2.7V ~ 3.3V, 5V | 2.7V ~ 3.3V, 5V |
| Voltage - Supply, Digital | 2.7V ~ 3.3V, 5V | 2.7V ~ 3.3V, 5V |
| Features | PGA | PGA |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the primary functional differences between the AD7705BRZ-REEL and the AD7707BR?
The AD7705BRZ-REEL is a 2-channel, 16-bit sigma-delta ADC with a programmable gain amplifier (PGA) and an SPI-compatible serial interface. The AD7707BR is a 3-channel, 16-bit sigma-delta ADC that includes a high-level input channel (for ±10 V or ±20 mA signals) in addition to two low-level input channels, and it also provides an SPI-compatible serial interface. The AD7707BR is therefore suited to applications requiring a high-voltage input channel, while the AD7705BRZ-REEL is a two-channel low-level input device.
Are the AD7705BRZ-REEL and AD7707BR pin-compatible?
No. The AD7705BRZ-REEL is supplied in a 16-lead SOIC package, while the AD7707BR is supplied in a 20-lead SOIC package. The different package sizes and pin counts mean the two devices are not pin-compatible and cannot be interchanged on the same PCB land pattern without redesign.
Do both devices support the same supply voltage ranges?
Both devices operate from a single 2.7 V to 3.3 V or 4.75 V to 5.25 V supply for the digital and low-level analog sections, and both provide a separate AVDD supply for the analog front end. The AD7707BR additionally requires a high-voltage supply (AVDD) of 5 V to 12 V to support its high-level input channel, which the AD7705BRZ-REEL does not have.
What is the resolution and output data rate of each device?
Both the AD7705BRZ-REEL and the AD7707BR are 16-bit sigma-delta ADCs. Both offer programmable output update rates from 20 Hz to 500 Hz, with corresponding trade-offs in resolution and noise performance as documented in the respective manufacturer datasheets.
Can the AD7707BR replace the AD7705BRZ-REEL in an existing design?
Not as a direct drop-in replacement. Although both are 16-bit sigma-delta ADCs with SPI-compatible interfaces, the AD7707BR has a different package (20-lead vs 16-lead SOIC), an additional high-level input channel, and different supply requirements. Any substitution requires PCB redesign and validation against the target design requirements.
What input signal types does each device support?
The AD7705BRZ-REEL provides two differential low-level analog input channels with a programmable gain amplifier, suitable for direct connection to low-level sensors. The AD7707BR provides two low-level differential input channels plus one high-level input channel that can accept ±10 V or ±20 mA signals, making it suitable for industrial interfaces that require a high-voltage or current-loop input.
Do both parts share the same serial interface and register set?
Both devices use an SPI-compatible serial interface and a similar register structure (communication register, setup register, clock register, data register), which allows similar firmware architecture. However, the AD7707BR includes additional configuration for its high-level input channel, so register settings and channel selection logic are not identical between the two devices.