Part A
AD7328BRUZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7432 PCS
- Package
- TSSOP-20
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7321BRUZ and AD7328BRUZ share the same TSSOP-20 footprint, 12-bit SAR architecture, and software-selectable input ranges, making them functionally interchangeable in many designs. However, the AD7328BRUZ provides eight analog input channels versus four on the AD7321BRUZ, and its higher throughput and power envelope require validation against the target application's timing and thermal budget before substitution.
Package Type
High match
Resolution
High match
Channel Count
Validation required
Throughput Rate
Validation required
Parts at a glance
Part B
AD7321BRUZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7731 PCS
- Package
- TSSOP-14
- 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 | AD7321BRUZ | AD7328BRUZ | Why it matters |
|---|---|---|---|
| Number of ADC Channels | 2 (single-ended) / 2 (differential) | 8 (single-ended) / 4 (differential) | Channel count determines how many analog signals can be monitored; a 2-channel part cannot replace an 8-channel part in multi-sensor systems. |
| Resolution | 12 bits plus sign (13-bit) | 12 bits plus sign (13-bit) | Resolution sets the smallest measurable signal step; both offer 13-bit signed output, so measurement granularity is equivalent. |
| Throughput Rate | 500 kSPS | 1 MSPS | Maximum sampling rate limits the bandwidth of signals that can be digitized; the AD7328 supports twice the conversion speed. |
| Input Voltage Range | ±10 V, ±5 V, ±2.5 V, 0 to +10 V (software selectable) | ±10 V, ±5 V, ±2.5 V, 0 to +10 V (software selectable) | Selectable bipolar/unipolar ranges allow direct interfacing to industrial signals without external conditioning; both parts match here. |
| Interface Type | SPI / QSPI / MICROWIRE / DSP compatible serial | SPI / QSPI / MICROWIRE / DSP compatible serial | Serial interface compatibility determines whether the part can drop into an existing digital bus; both use the same serial protocol. |
| Supply Voltage | VDD 2.7 V to 16.5 V, VSS ±2.7 V to ±16.5 V, VCC 2.7 V to 5.25 V | VDD 2.7 V to 16.5 V, VSS ±2.7 V to ±16.5 V, VCC 2.7 V to 5.25 V | Supply requirements dictate power rail design; identical rails mean the same power architecture can be reused. |
| Package | 20-lead TSSOP | 20-lead TSSOP | Package footprint affects PCB layout and assembly; matching TSSOP packages allow the same land pattern. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range defines the environments where the part is reliable; identical ratings mean equivalent environmental tolerance. |
| Power Consumption | Typically 17 mW at 500 kSPS | Typically 30 mW at 1 MSPS | Power draw impacts thermal budget and supply sizing; the higher-throughput AD7328 consumes more power, which may affect low-power designs. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7328BRUZ | AD7321BRUZ |
|---|---|---|
| Series | iCMOS® | iCMOS® |
| Part Status | Active | Active |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 1M | 500k |
| Number of Inputs | 4, 7, 8 | 1, 2 |
| Input Type | Differential, Pseudo-Differential, Single Ended | Differential, Pseudo-Differential, Single Ended |
| Data Interface | SPI, DSP | SPI, DSP |
| Configuration | MUX-S/H-ADC | MUX-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 | External, Internal |
| Voltage - Supply, Analog | ±12V ~ 16.5V | ±12V ~ 16.5V |
| Voltage - Supply, Digital | 2.7V ~ 5.25V | 2.7V ~ 5.25V |
| Features | Temperature Sensor, True Bipolar | True Bipolar |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD7321BRUZ and AD7328BRUZ?
The AD7321BRUZ is a 2-channel, 12-bit plus sign successive approximation ADC, while the AD7328BRUZ is an 8-channel, 12-bit plus sign successive approximation ADC. Both are bipolar input ADCs from Analog Devices in a 20-lead TSSOP (RUZ) package, but they differ in channel count and correspondingly in internal multiplexer configuration and throughput-related specifications.
Do the AD7321BRUZ and AD7328BRUZ share the same package and pinout?
Both devices are offered in a 20-lead TSSOP package (RUZ suffix). However, because the AD7328BRUZ provides 8 input channels versus 2 on the AD7321BRUZ, the pin functions and multiplexer-related pin assignments differ. They are not pin-for-pin drop-in replacements and PCB layouts must be verified against each device's datasheet.
What is the resolution and input type of these ADCs?
Both the AD7321BRUZ and AD7328BRUZ are 12-bit plus sign successive approximation ADCs with bipolar input ranges. They accept true bipolar analog input signals and provide a sign bit in addition to 12 bits of resolution, allowing conversion of negative and positive input voltages without external level shifting.
What analog input voltage ranges do the AD7321BRUZ and AD7328BRUZ support?
Both devices support software-selectable bipolar input ranges of ±10 V, ±5 V, and ±2.5 V, as well as a 0 V to +10 V unipolar range, configured through the on-chip control register. The range selection is programmable per channel on the AD7328BRUZ and applies to the available channels on the AD7321BRUZ.
What is the maximum throughput rate of the AD7321BRUZ and AD7328BRUZ?
Both the AD7321BRUZ and AD7328BRUZ offer a maximum throughput rate of 1 MSPS. The achievable rate depends on the selected input range and the serial clock frequency used with the SPI-compatible interface.
What digital interface do the AD7321BRUZ and AD7328BRUZ use?
Both devices use an SPI-compatible serial interface for configuration and data readback, supporting standard serial clock, chip select, and data input/output signals. This allows direct connection to most microcontrollers and DSPs without external glue logic.
Can the AD7321BRUZ be substituted for the AD7328BRUZ in an existing design?
No, they are not directly interchangeable. The AD7328BRUZ provides 8 input channels while the AD7321BRUZ provides only 2, and their pin functions differ despite sharing the same 20-lead TSSOP package. A substitution requires redesign of the analog input routing, multiplexer control, and verification of the PCB layout against the respective datasheets.
What are the typical applications for the AD7321BRUZ and AD7328BRUZ?
These bipolar-input ADCs are suited for applications requiring true bipolar signal conversion, such as industrial process control, instrumentation, data acquisition systems, and motor control. The AD7328BRUZ's 8 channels suit multi-channel monitoring, while the AD7321BRUZ's 2 channels suit compact designs with fewer analog inputs.