Part A
AD7490BRU
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2930 Stückzahl
- Package
- TSSOP-28
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7492BRU-5 is not a direct drop-in replacement for the AD7490BRU. While both are 12-bit successive-approximation ADCs in a TSSOP-24 package, they differ in channel count, throughput, and serial interface framing, so the AD7492BRU-5 can only serve as a functional substitute where a single-channel converter and adjusted digital timing are acceptable.
Channel Count
Not compatible
Sample Rate
Validation required
Package Type
High match
Digital Interface
Validation required
Parts at a glance
Part B
AD7492BRU-5
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7623 Stückzahl
- Package
- TSSOP-24
- 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 | AD7490BRU | AD7492BRU-5 | Why it matters |
|---|---|---|---|
| Number of ADC Channels | 16 | 1 | Determines how many analog signals can be sampled; a 16-channel multiplexed ADC versus a single-channel ADC fundamentally changes system architecture and cannot be directly substituted. |
| Resolution | 12 bits | 12 bits | Both provide 12-bit resolution, so quantization accuracy is equivalent, but resolution alone does not guarantee substitutability given the channel count difference. |
| Sampling Rate | 1 MSPS | 1.25 MSPS | Maximum throughput affects the highest signal frequency that can be captured; the AD7492BRU-5 offers a slightly higher conversion rate. |
| Input Type | Single-ended | Single-ended | Both accept single-ended inputs, so signal conditioning requirements are similar, though channel count still differs. |
| Supply Voltage | 2.7 V to 5.25 V | 5 V | The AD7490BRU supports a wider supply range including 3 V systems, while the AD7492BRU-5 is fixed at 5 V, affecting compatibility with low-voltage logic. |
| Interface | SPI / QSPI / MICROWIRE / DSP compatible | Parallel | Serial versus parallel interface changes the host connection, pin count, and firmware; these parts are not pin- or protocol-compatible. |
| Package | 24-lead TSSOP | 24-lead TSSOP | Same package footprint aids board-level layout, but differing pin functions prevent direct drop-in replacement. |
| Power Consumption | Approx. 2.5 mW at 1 MSPS (5 V) | Approx. 15 mW at 1.25 MSPS (5 V) | Lower power is important for portable and thermally constrained designs; the AD7490BRU is significantly more power-efficient. |
| Internal Reference | No (external reference required) | Yes (2.5 V internal reference) | An internal reference simplifies the analog front end and reduces external component count, whereas the AD7490BRU requires an external reference. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7490BRU | AD7492BRU-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 AD7492BRU-5?
The AD7490BRU is a 12-bit, 16-channel successive approximation ADC with a serial interface, housed in a 28-lead TSSOP. The AD7492BRU-5 is a 12-bit, 4-channel ADC with a parallel interface and an internal 2.5 V reference, also in a 28-lead TSSOP. The AD7490 offers more input channels and a serial SPI/QSPI/MICROWIRE/DSP-compatible interface, while the AD7492-5 provides a parallel interface and a faster throughput rate.
What are the maximum throughput rates of the AD7490BRU and AD7492BRU-5?
The AD7490BRU has a maximum throughput rate of 1 MSPS. The AD7492BRU-5 has a maximum throughput rate of 1.25 MSPS. Both are specified for a 5 V supply.
How do the input channel configurations differ between the two devices?
The AD7490BRU provides 16 single-ended input channels, configurable via a sequencer, and can also be operated in differential or pseudo-differential modes on selected channel pairs. The AD7492BRU-5 provides 4 single-ended input channels. Designs requiring more analog inputs should select the AD7490, while the AD7492-5 suits applications with fewer channels.
Do the AD7490BRU and AD7492BRU-5 use the same digital interface?
No. The AD7490BRU uses a serial interface compatible with SPI, QSPI, MICROWIRE, and DSP interfaces. The AD7492BRU-5 uses a parallel interface with a 12-bit wide data bus. The interface choice affects PCB routing, pin count utilization, and microcontroller or DSP selection.
Are the AD7490BRU and AD7492BRU-5 pin-compatible or directly interchangeable?
No. Although both are 12-bit ADCs in 28-lead TSSOP packages, their pin functions differ because one uses a serial interface and the other a parallel interface, and their channel counts and reference configurations differ. They are not direct drop-in replacements; a redesign of the digital interface and analog input routing is required.
What reference voltage options are available on each device?
The AD7490BRU can operate with an external reference voltage applied to the REF IN pin; it does not include an internal reference. The AD7492BRU-5 includes an internal 2.5 V reference, and it can also be configured to use an external reference. Designs requiring a self-contained reference may favor the AD7492-5.
What are the power supply requirements for the AD7490BRU and AD7492BRU-5?
Both devices operate from a single 5 V analog supply (VDD). The AD7490BRU also requires a separate digital supply pin (VDRIVE) that sets the digital interface voltage, allowing operation with 3 V or 5 V logic. The AD7492BRU-5 operates with a 5 V supply for both analog and digital sections. Designers should verify the exact supply and VDRIVE requirements against the respective manufacturer datasheets.
Which device is better suited for multi-channel data acquisition systems?
The AD7490BRU is better suited for multi-channel data acquisition because it provides 16 input channels with a programmable sequencer, allowing scanning of multiple signals with a single converter. The AD7492BRU-5, with only 4 channels, is more appropriate for lower-channel-count applications requiring a parallel interface and higher throughput.