Part A
AD7709ARU
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1879 Stückzahl
- Package
- TSSOP-24
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7709ARU and AD7708BRU-REEL are both multichannel sigma-delta ADCs from the same Analog Devices family, sharing a common TSSOP-28 footprint and similar core architecture, making them a viable functional replacement candidate. However, the AD7708BRU-REEL offers a higher resolution grade and a wider specified temperature range, so the AD7709ARU should be validated against the target system's accuracy and thermal requirements before substitution.
Resolution
High match
Package Type
High match
Operating Temperature Range
Validation required
Input Channel Configuration
Validation required
Parts at a glance
Part B
AD7708BRU-REEL
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5374 Stückzahl
- Package
- TSSOP-28
- Series
- Datenerfassung mit Analog to Digital Converters (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 | AD7709ARU | AD7708BRU-REEL | Why it matters |
|---|---|---|---|
| Resolution (bits) | 16 | 16 | Both are 16-bit sigma-delta ADCs, so resolution is equivalent for precision measurement applications. |
| Number of ADC Input Channels | 4 differential / 8 single-ended | 4 differential / 8 single-ended | Channel count determines how many sensor signals can be multiplexed into a single converter. |
| Interface Type | SPI / QSPI / MICROWIRE / DSP-compatible serial | SPI / QSPI / MICROWIRE / DSP-compatible serial | Serial interface compatibility affects how easily the part drops into an existing digital host design. |
| Supply Voltage (Analog) | 2.7 V to 3.6 V | 2.7 V to 3.6 V | Analog supply range must match the system rail to avoid level shifting or additional regulators. |
| Package / Mounting | 24-TSSOP (Surface Mount) | 28-TSSOP (Surface Mount) | Different pin counts and package footprints mean the PCB layout must be redesigned for substitution. |
| On-Chip PGA | Yes (gain 1 to 128) | Yes (gain 1 to 128) | A programmable gain amplifier allows direct connection of low-level sensors without external front-end circuitry. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range suitability is critical for reliable operation in harsh environments. |
| Number of Digital I/O / GPIO | 2 (P1, P2) | 2 (P1, P2) | Auxiliary GPIO pins can be used for control signals or status outputs, reducing external component count. |
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 | AD7709ARU | AD7708BRU-REEL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Obsolete | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 105 | 1.37k |
| Number of Inputs | 2, 4 | 4, 8 |
| Input Type | Differential, Pseudo-Differential | 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 key differences between the AD7709ARU and the AD7708BRU-REEL?
The AD7709ARU is a 16-bit sigma-delta ADC with a maximum output rate of 105 kSPS, housed in a 24-lead TSSOP package. The AD7708BRU-REEL is a 16-bit sigma-delta ADC with a maximum output rate of 19.79 kSPS, supplied in a 28-lead TSSOP package on tape and reel. The AD7708 offers more analog input channels and a higher-resolution PGA, while the AD7709 provides a faster maximum output rate.
Are the AD7709ARU and AD7708BRU-REEL pin-compatible?
No. The AD7709ARU uses a 24-lead TSSOP package, while the AD7708BRU-REEL uses a 28-lead TSSOP package. The different pin counts and pin assignments mean they are not drop-in replacements for each other.
How do the analog input configurations compare between the two devices?
The AD7709ARU provides 4 differential or 8 pseudo-differential analog input channels. The AD7708BRU-REEL provides 8 differential or 10 pseudo-differential input channels, offering more flexibility for multi-channel measurement systems.
What are the maximum output data rates of the AD7709ARU and AD7708BRU-REEL?
The AD7709ARU supports a maximum output data rate of 105 kSPS. The AD7708BRU-REEL supports a maximum output data rate of 19.79 kSPS. The AD7709 is therefore better suited for higher-speed signal acquisition.
Do both parts include a programmable gain amplifier (PGA)?
Yes. Both the AD7709ARU and the AD7708BRU-REEL integrate a programmable gain amplifier. The AD7708 provides a PGA gain range of 1 to 128, while the AD7709 provides a PGA gain range of 1 to 128 as well, allowing direct interfacing with low-level sensors.
What are the supply voltage requirements for the AD7709ARU and AD7708BRU-REEL?
Both devices operate from a single 3 V or 5 V supply. The AD7709ARU and AD7708BRU-REEL each include an on-chip reference and support ratiometric measurement configurations, making them suitable for low-power industrial and instrumentation applications.
Which part is more suitable for high-channel-count, low-speed precision measurement?
The AD7708BRU-REEL is more suitable for high-channel-count, low-speed precision measurement because it offers 8 differential or 10 pseudo-differential input channels and a maximum output rate of 19.79 kSPS. The AD7709ARU offers fewer input channels but a higher maximum output rate of 105 kSPS.
Are the AD7709ARU and AD7708BRU-REEL available in tape and reel packaging?
The AD7708BRU-REEL is explicitly supplied in tape and reel packaging, as indicated by the "-REEL" suffix. The AD7709ARU is specified in a 24-lead TSSOP tube or tray format; tape and reel availability should be confirmed against the manufacturer's ordering guide before production planning.