Part A
AD7738BRUZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 5636 PCS
- Package
- TSSOP-28
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7738BRUZ and AD7732BRU are both multichannel sigma-delta ADCs from the same family, sharing a common TSSOP-28 footprint and similar digital interface architecture, but they differ in channel count, resolution, and input configuration. The AD7738BRUZ offers eight single-ended or four differential channels at 24-bit resolution, while the AD7732BRU provides two differential channels at 24-bit resolution. Because the channel count and input topology differ, the AD7732BRU is not a direct drop-in substitute for the AD7738BRUZ in applications requiring the full channel set, but it can serve as a functional replacement where fewer channels are acceptable and the board layout is adapted accordingly.
Channel Count
Validation required
Resolution
High match
Package Type
High match
Input Configuration
Validation required
Parts at a glance
Part B
AD7732BRU
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4642 PCS
- Package
- TSSOP-28
- 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 | AD7738BRUZ | AD7732BRU | Why it matters |
|---|---|---|---|
| Number of Input Channels | 8 (differential) | 2 (differential) | Channel count determines how many independent analog signals can be measured; a 2-channel part cannot replace an 8-channel part in multi-sensor systems. |
| Resolution | 24-bit | 24-bit | Both provide 24-bit sigma-delta conversion, so resolution alone does not differentiate them for high-precision measurement applications. |
| Maximum Output Data Rate | 15.4 kSPS | 19.2 kSPS | Data rate affects throughput and settling time; the higher rate of the AD7732BRU may be needed for faster-sampling applications. |
| Package / Pin Count | 28-lead TSSOP | 28-lead TSSOP | Matching package and pin count simplifies PCB layout compatibility, though pin functions may still differ between the two devices. |
| Supply Voltage (Analog) | 5 V | 5 V | Identical analog supply requirements mean both can operate from the same power rail in a shared design. |
| Interface Type | SPI / Serial | SPI / Serial | Both use a serial SPI-compatible interface, allowing connection to the same microcontroller bus architecture. |
| Operating Temperature Range | -40°C to +105°C | -40°C to +105°C | Identical temperature ratings ensure both parts suit the same industrial and harsh-environment applications. |
| Internal PGA Gain Range | 1 to 128 | 1 to 128 | Programmable gain allows direct connection of low-level sensors; matching ranges preserve signal-conditioning flexibility. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7738BRUZ | AD7732BRU |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 24 | 24 |
| Sampling Rate(Per Second) | 15.4k | 15.4k |
| Number of Inputs | 4, 8 | 2 |
| Input Type | Differential, Single Ended | Differential |
| Data Interface | SPI, DSP | SPI, DSP |
| Configuration | MUX-ADC | MUX-ADC |
| Number of A/D Converters | 1 | 1 |
| Architecture | Sigma-Delta | Sigma-Delta |
| Reference Type | External | External |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 2.7V ~ 3.6V, 5V | 2.7V ~ 3.6V, 5V |
| Operating Temperature | -40°C ~ 105°C | -40°C ~ 105°C |
| Features | True Bipolar | - |
Frequently asked questions
What are the key differences between the AD7738BRUZ and the AD7732BRU?
The AD7738BRUZ is an 8-channel, 24-bit sigma-delta ADC with a maximum throughput of 15.4 kSPS, while the AD7732BRU is a 2-channel, 24-bit sigma-delta ADC with a maximum throughput of 15.4 kSPS. The AD7738BRUZ provides eight single-ended or four differential input channels, whereas the AD7732BRU provides two differential input channels. Both devices are specified for operation from a 5 V analog supply and a 2.7 V to 3.6 V digital supply, and both are offered in a 28-lead TSSOP package.
Are the AD7738BRUZ and AD7732BRU pin-compatible?
No. Although both devices are housed in a 28-lead TSSOP package, they are not pin-compatible. The AD7738BRUZ uses its 28 pins to support eight input channels plus the associated multiplexer control and interface signals, while the AD7732BRU uses its pins for two differential input channels and its own interface configuration. The pin functions and PCB land patterns differ, so a direct drop-in replacement is not possible without design changes.
Can the AD7732BRU be used as a direct substitute for the AD7738BRUZ in an existing design?
No. The AD7732BRU cannot be used as a direct substitute for the AD7738BRUZ. The AD7738BRUZ provides eight input channels, while the AD7732BRU provides only two differential channels, so any design requiring more than two input channels cannot use the AD7732BRU. In addition, the two devices are not pin-compatible despite sharing the same 28-lead TSSOP package, so substituting one for the other requires PCB and firmware changes validated against the respective manufacturer datasheets.
What is the maximum throughput rate of each device?
Both the AD7738BRUZ and the AD7732BRU are specified with a maximum throughput of 15.4 kSPS. The actual output data rate is programmable through the on-chip registers, allowing lower rates for higher resolution and noise rejection. Designers should confirm the exact programmable rate range and filter settings in the respective Analog Devices datasheets for their target configuration.
What supply voltages do the AD7738BRUZ and AD7732BRU require?
Both devices operate from a 5 V analog supply (AVDD) and a separate digital supply (DVDD) in the 2.7 V to 3.6 V range, with an additional 5 V supply for the reference and signal conditioning as specified in the datasheets. The dual-supply arrangement allows the analog front end to interface with higher-voltage sensors while the digital interface remains compatible with 3 V logic. Exact supply tolerances and sequencing requirements should be verified in the Analog Devices datasheets.
How many input channels does each device support?
The AD7738BRUZ supports eight single-ended input channels or four fully differential input channels through its on-chip multiplexer. The AD7732BRU supports two differential input channels. This difference in channel count is the primary selection criterion between the two parts: the AD7738BRUZ suits multi-channel data acquisition, while the AD7732BRU suits lower-channel-count, higher-per-channel applications.
Do both devices include an on-chip programmable gain amplifier (PGA)?
Yes. Both the AD7738BRUZ and the AD7732BRU integrate a programmable gain amplifier ahead of the sigma-delta modulator, allowing direct interfacing with low-level signals such as thermocouples, RTDs, and bridge sensors. The available gain settings and their associated input ranges should be confirmed in the respective Analog Devices datasheets, as the exact gain options and input voltage ranges are defined per device.
What package do the AD7738BRUZ and AD7732BRU use, and are they RoHS compliant?
Both devices are offered in a 28-lead TSSOP package. The AD7738BRUZ suffix indicates a RoHS-compliant, lead-free (Pb-free) version per Analog Devices ordering nomenclature. Designers should verify the RoHS and Pb-free status of the specific AD7732BRU ordering variant against the Analog Devices product page or an authorized distributor such as DigiKey or Mouser before finalizing a bill of materials.