Part A
AD7490BRU
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2930 PCS
- Package
- TSSOP-28
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Not a drop-in replacement
The AD7490BRU and AD7492ARU-5 are not drop-in replacements for one another. Although both are 12-bit successive-approximation ADCs from Analog Devices in a TSSOP package, they differ in channel count, digital interface, conversion throughput, and analog input architecture, so substituting one for the other requires board-level and firmware redesign.
Different channel count
Different digital interface
Different throughput
Different input architecture
Parts at a glance
Part B
AD7492ARU-5
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7983 PCS
- Package
- TSSOP-24
- Series
- Data Acquisition - 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 | AD7490BRU | AD7492ARU-5 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so quantization resolution is equivalent for signal acquisition. |
| Number of Input Channels | 16 (single-ended) | 1 (single-ended) | The AD7490 is a multiplexed 16-channel device while the AD7492 is a single-channel part, which fundamentally changes system architecture and channel count. |
| Sampling Rate | 1 MSPS | 1.25 MSPS | Maximum throughput affects the highest signal bandwidth that can be digitized without aliasing. |
| Supply Voltage | 2.7 V to 5.25 V | 5 V | The AD7490 supports a wider supply range including 3 V systems, while the AD7492 requires a 5 V supply, affecting power rail compatibility. |
| Interface Type | SPI / QSPI / MICROWIRE / DSP compatible serial | Parallel (byte/word) | Serial versus parallel interface determines pin count, host controller requirements, and board routing complexity. |
| Package | 24-lead TSSOP | 24-lead TSSOP | Matching package footprint allows potential board-level drop-in compatibility if pin functions align. |
| Input Type | Single-ended | Single-ended | Both accept single-ended inputs, so signal conditioning front-ends can be similar in topology. |
| Reference | External | Internal 2.5 V reference | The AD7492 includes an on-chip reference while the AD7490 requires an external reference, affecting accuracy budget and external component count. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature ratings mean both suit the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7490BRU | AD7492ARU-5 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Obsolete | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 1M | 1.25M |
| Data Interface | SPI, DSP | Parallel |
| Number of A/D Converters | 1 | 1 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Number of Inputs | 16 | - |
| Input Type | Single Ended | - |
| Configuration | MUX-S/H-ADC | - |
| Ratio - S / H: ADC | 1:1 | - |
| Architecture | SAR | - |
| Reference Type | External | - |
| Voltage - Supply, Analog | 2.7V ~ 5.25V | - |
| Voltage - Supply, Digital | 2.7V ~ 5.25V | - |
Frequently asked questions
What are the key architectural differences between the AD7490BRU and AD7492ARU-5?
The AD7490BRU 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 AD7492ARU-5 is a 12-bit, 4-channel successive approximation ADC with a parallel interface, housed in a 24-lead TSSOP. The AD7490 offers more input channels and a serial interface, while the AD7492ARU-5 provides fewer channels with a parallel data bus.
Do the AD7490BRU and AD7492ARU-5 have the same resolution and sampling rate?
Both devices are 12-bit successive approximation ADCs. The AD7490BRU offers a throughput rate of up to 1 MSPS. The AD7492ARU-5 offers a throughput rate of up to 1.25 MSPS. The sampling rates differ, so timing budgets must be recalculated if substituting one for the other.
Are the AD7490BRU and AD7492ARU-5 pin-compatible?
No. The AD7490BRU is supplied in a 28-lead TSSOP, while the AD7492ARU-5 is supplied in a 24-lead TSSOP. The package sizes, pin counts, and pin functions differ, so they are not drop-in replacements and require different PCB land patterns.
What supply voltage and reference requirements apply to each device?
The AD7490BRU operates from a single 2.7 V to 5.25 V supply and uses an external reference (REF IN) with a range of 2.5 V to VDD. The AD7492ARU-5 operates from a single 5 V supply and includes an internal 2.5 V reference, while also allowing an external reference. Reference configuration and decoupling must be reviewed when comparing the two.
How do the digital interfaces of the AD7490BRU and AD7492ARU-5 differ?
The AD7490BRU uses a serial interface compatible with SPI, QSPI, MICROWIRE, and DSP standards, which reduces pin count and suits isolated or space-constrained designs. The AD7492ARU-5 uses a parallel interface with a 12-bit data bus, which can provide higher aggregate data throughput to a host processor but requires more I/O pins.
Can the AD7490BRU and AD7492ARU-5 be used interchangeably in an existing design?
No. Differences in package pinout, channel count (16 vs 4), interface type (serial vs parallel), supply voltage range, and reference architecture mean the two devices are not interchangeable without redesigning the PCB, firmware, and analog front end. Each substitution must be validated against the respective manufacturer datasheets.
What are the typical applications for each converter?
The AD7490BRU, with 16 channels and a serial interface, is suited to multi-channel data acquisition, industrial monitoring, and systems where board space and pin count are constrained. The AD7492ARU-5, with 4 channels and a parallel interface, is suited to applications requiring fast parallel data transfer to a processor, such as motor control and instrumentation. Application suitability should be confirmed against the manufacturer datasheets.