Part A
AD7490BRUZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 2333 PCS
- Package
- TSSOP-28
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Not a drop-in replacement
The AD7490BRUZ and AD7492BRU are not drop-in replacements for one another. Although both are 12-bit successive-approximation ADCs from Analog Devices, they differ in channel count, package footprint, and digital interface, so a direct board-level substitution is not possible without redesign.
Different channel count
Different package footprint
Different digital interface
Different conversion architecture
Parts at a glance
Part B
AD7492BRU
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 9446 PCS
- Package
- TSSOP-24
- 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 | AD7490BRUZ | AD7492BRU | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both converters provide 12-bit resolution, so measurement precision is equivalent. |
| Number of ADC Inputs / Channels | 16 single-ended (multiplexed) | 1 single-ended | The AD7490 offers a 16-channel multiplexer while the AD7492 is a single-channel device, which fundamentally changes system architecture and channel count. |
| Sampling Rate | 1 MSPS | 1.25 MSPS | Maximum throughput differs; the AD7492 can sample faster, affecting achievable signal bandwidth and timing margins. |
| Interface Type | SPI / QSPI / MICROWIRE / DSP compatible serial | Parallel (byte/word) | Serial versus parallel interface affects pin count, board routing, and the host controller interface required for substitution. |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Both operate over the same supply range, so power supply compatibility is maintained. |
| Package | 28-lead TSSOP | 24-lead TSSOP | Different package pin counts and footprints mean the parts are not drop-in replacements on an existing PCB. |
| Input Type | Single-ended | Single-ended | Both accept single-ended inputs, so signal conditioning topology can remain similar. |
| Reference Type | External | External | Both require an external reference, so reference design considerations are comparable. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings mean environmental operating limits are the same. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7490BRUZ | AD7492BRU |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 1M | 1M |
| Number of Inputs | 16 | 1 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI, DSP | Parallel |
| Configuration | MUX-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 | Internal |
| Voltage - Supply, Analog | 2.7V ~ 5.25V | 2.7V ~ 5.25V |
| Voltage - Supply, Digital | 2.7V ~ 5.25V | 2.7V ~ 5.25V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key architectural differences between the AD7490BRUZ and the AD7492BRU?
The AD7490BRUZ is a 12-bit, 16-channel successive approximation ADC with a serial SPI/QSPI/MICROWIRE/DSP-compatible interface, housed in a 28-lead TSSOP. The AD7492BRU is a 12-bit, 4-channel (2 single-ended plus 1 differential pair configurable) ADC with a parallel interface, housed in a 24-lead TSSOP. The AD7490BRUZ offers more input channels and a serial interface, while the AD7492BRU provides a parallel interface and fewer channels.
Are the AD7490BRUZ and AD7492BRU pin-to-pin compatible?
No. The AD7490BRUZ is supplied in a 28-lead TSSOP, while the AD7492BRU is supplied in a 24-lead TSSOP. The differing package sizes and pin counts mean the two devices are not pin-to-pin compatible and cannot be interchanged on the same PCB land pattern without redesign.
Do the AD7490BRUZ and AD7492BRU have the same resolution and throughput rate?
Both devices are 12-bit successive approximation ADCs. The AD7490BRUZ offers a throughput rate of up to 1 MSPS. The AD7492BRU offers a throughput rate of up to 1.25 MSPS. Designers should confirm the exact grade-specific timing from the respective manufacturer datasheets before finalizing throughput budgets.
What interface differences should be considered when choosing between the AD7490BRUZ and AD7492BRU?
The AD7490BRUZ uses a serial interface compatible with SPI, QSPI, MICROWIRE, and DSP host ports, which reduces pin count and suits isolated or space-constrained designs. The AD7492BRU uses a parallel microprocessor interface, which can simplify connection to parallel-bus hosts and may offer higher aggregate data transfer for multi-channel reads. The choice depends on the host controller's available bus and the number of channels required.
How do the input channel configurations of the AD7490BRUZ and AD7492BRU differ?
The AD7490BRUZ provides 16 analog input channels, configurable as single-ended inputs, with channel selection programmed over the serial interface. The AD7492BRU provides 4 analog input channels arranged as 2 single-ended inputs plus 1 differential input pair (or 4 single-ended, depending on configuration). Systems requiring many single-ended sensors favor the AD7490BRUZ, while the AD7492BRU suits lower-channel-count designs that benefit from a differential input.
Can the AD7490BRUZ and AD7492BRU operate from the same supply voltage?
Both devices are specified for a single 2.7 V to 5.25 V supply, making them compatible with common 3 V and 5 V system rails. Designers should still verify the exact supply range and any interface voltage requirements against the manufacturer datasheet for the specific grade ordered.
Which device is better suited for a design that needs many single-ended sensor inputs over a serial bus?
The AD7490BRUZ is the more suitable choice because it provides 16 single-ended input channels and a serial SPI/QSPI/MICROWIRE-compatible interface, reducing host pin count while accommodating a high channel count. The AD7492BRU, with 4 channels and a parallel interface, is better matched to lower-channel-count designs using a parallel host bus.
What package and mounting considerations apply when comparing the AD7490BRUZ and AD7492BRU?
Both devices are offered in TSSOP packages, but with different lead counts: 28 leads for the AD7490BRUZ and 24 leads for the AD7492BRU. PCB designers must use the correct land pattern and thermal/assembly guidelines for each package. Because the pin counts differ, a board designed for one device cannot accept the other without layout changes.