Part A
AD7709ARUZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 1974 Stückzahl
- Package
- TSSOP-24
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7708BRU-REEL is a functionally compatible alternative to the AD7709ARUZ, sharing the same signal chain architecture, TSSOP-28 footprint, and industrial temperature range, though the AD7709ARUZ offers a higher programmable gain range and additional analog input configuration flexibility that should be validated against the target application requirements.
Package Type
High match
Resolution
High match
Programmable Gain Range
Validation required
Operating Temperature Range
High match
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 | AD7709ARUZ | 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 pseudo-differential | 4 differential / 8 pseudo-differential | Channel count determines how many sensor inputs can be multiplexed into a single converter. |
| Interface Type | SPI / QSPI / MICROWIRE / DSP-compatible | SPI / QSPI / MICROWIRE / DSP-compatible | Serial interface compatibility affects how easily the part integrates with a host microcontroller. |
| 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 package pin counts and footprints affect PCB layout and drop-in substitutability. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Industrial temperature range ensures reliable operation across harsh environments. |
| On-Chip PGA | Yes (gain 1 to 128) | Yes (gain 1 to 128) | Programmable gain allows direct connection of low-level sensors without external amplification. |
| Data Output Rate | Up to 105 Hz (19.79 Hz to 105 Hz) | Up to 105 Hz (19.79 Hz to 105 Hz) | Output rate determines the trade-off between noise performance and measurement speed. |
| On-Chip Reference | No (external reference required) | No (external reference required) | Reference configuration affects accuracy and external component count in the design. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7709ARUZ | AD7708BRU-REEL |
|---|---|---|
| Supplier | - | Analog Devices Inc. |
| Part Status | Active | 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 AD7709ARUZ and the AD7708BRU-REEL?
The AD7709ARUZ is a 16-bit sigma-delta ADC with a 4-channel input multiplexer, while the AD7708BRU-REEL is a 16-bit sigma-delta ADC with an 8-channel input multiplexer. Both are part of the AD7708/AD7709 family and share the same core architecture, but the AD7709 offers 4 differential input channels and the AD7708 offers 8 differential input channels. The AD7709ARUZ is supplied in a 24-lead TSSOP, and the AD7708BRU-REEL is supplied in a 28-lead TSSOP in tape-and-reel packaging.
Are the AD7709ARUZ and AD7708BRU-REEL pin-compatible?
No. The AD7709ARUZ 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, and the PCB footprint must be designed accordingly.
What is the resolution and architecture of these ADCs?
Both the AD7709ARUZ and AD7708BRU-REEL are 16-bit sigma-delta (Σ-Δ) analog-to-digital converters. They use a sigma-delta modulation architecture with on-chip digital filtering, suitable for low-frequency, high-resolution measurement applications such as industrial process control and instrumentation.
What input channel configuration does each device support?
The AD7709ARUZ provides a 4-channel input multiplexer, while the AD7708BRU-REEL provides an 8-channel input multiplexer. Both support differential input configurations, allowing multiple sensor or signal sources to be connected to a single ADC.
Do both devices support the same serial interface?
Yes. Both the AD7709ARUZ and AD7708BRU-REEL feature a serial interface compatible with SPI and QSPI protocols, allowing direct connection to microcontrollers and DSPs. The interface supports read and write operations for configuration and data retrieval.
What are the typical applications for the AD7709ARUZ and AD7708BRU-REEL?
Both devices are intended for low-bandwidth, high-resolution measurement applications, including industrial process control, instrumentation, weigh scales, pressure sensors, and temperature measurement systems. The AD7708BRU-REEL with its 8-channel multiplexer is suited to systems requiring more input channels, while the AD7709ARUZ with 4 channels fits more compact designs.
What packaging options are available for these two parts?
The AD7709ARUZ is supplied in a 24-lead TSSOP package. The AD7708BRU-REEL is supplied in a 28-lead TSSOP package in tape-and-reel format, which is suitable for automated surface-mount assembly. The "REEL" suffix indicates tape-and-reel packaging for high-volume production.
Can the AD7709ARUZ be used as a substitute for the AD7708BRU-REEL in an existing design?
Not directly. Because the two devices differ in package size (24-lead vs 28-lead TSSOP) and input channel count (4 vs 8 channels), a direct substitution is not possible without PCB redesign and verification of the channel requirements. Designers should consult the respective datasheets and validate all electrical and mechanical parameters before considering any substitution.