Part A
AD7684BRMZRL7
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 6195 PCS
- Package
- MSOP-8
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7685ARMZRL7 and AD7684BRMZRL7 are both 16-bit successive-approximation ADCs in the same MSOP-8 package and share a compatible serial interface, making them a viable functional replacement candidate. However, they differ in input architecture and throughput, so the AD7684BRMZRL7 should be validated against the system's signal chain and timing requirements before substitution.
Resolution and ADC Architecture
High match
Package and Pin Configuration
High match
Input Type
Validation required
Throughput Rate
Validation required
Parts at a glance
Part B
AD7685ARMZRL7
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 1265 PCS
- Package
- MSOP-10
- 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 | AD7685ARMZRL7 | AD7684BRMZRL7 | Why it matters |
|---|---|---|---|
| Resolution (bits) | 16 | 16 | Both are 16-bit ADCs, so resolution is equivalent and not a differentiator for substitutability. |
| Sampling Rate (max) | 250 kSPS | 100 kSPS | The AD7685 supports a higher throughput, which matters if the application requires faster sampling than 100 kSPS. |
| Number of Input Channels | 1 (single-ended) | 1 (fully differential) | Input configuration differs: single-ended versus fully differential affects signal conditioning and noise performance requirements. |
| Input Type | Single-ended | Differential | Differential inputs offer better common-mode rejection; single-ended is simpler to drive, so the choice impacts the analog front end. |
| Supply Voltage (analog) | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Identical supply range means both can operate from the same rails, easing power-supply compatibility. |
| Interface | SPI / QSPI / MICROWIRE / DSP compatible | SPI / QSPI / MICROWIRE / DSP compatible | Same serial interface simplifies digital-side redesign when swapping parts. |
| Package | 10-lead MSOP (RM) | 10-lead MSOP (RM) | Identical package footprint allows drop-in PCB compatibility without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Same temperature range ensures both meet the same environmental requirements. |
| Power Consumption (typical) | ~4 mW at 5 V, 250 kSPS | ~3.5 mW at 5 V, 100 kSPS | Lower power per conversion in the AD7684 may matter for battery-powered or thermally constrained designs. |
Need help validating a replacement?
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7684BRMZRL7 | AD7685ARMZRL7 |
|---|---|---|
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 100k | 250k |
| Number of Inputs | 1 | 1 |
| Input Type | Differential | Pseudo-Differential |
| Data Interface | SPI, DSP | SPI, DSP |
| Configuration | 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 | External |
| Voltage - Supply, Analog | 2.7V ~ 5.5V | 2.3V ~ 5.5V |
| Voltage - Supply, Digital | 2.7V ~ 5.5V | 2.3V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD7685ARMZRL7 and AD7684BRMZRL7?
The AD7685ARMZRL7 is a 16-bit, 250 kSPS PulSAR ADC with a pseudo-differential input, while the AD7684BRMZRL7 is a 16-bit, 100 kSPS PulSAR ADC with a fully differential input. Both are offered in a 10-lead MSOP (RM) package and operate from a 2.7 V to 5.5 V single supply, but they differ in throughput, input configuration, and serial interface behavior.
Are the AD7685ARMZRL7 and AD7684BRMZRL7 pin-compatible?
Both devices are supplied in the same 10-lead MSOP (RM) package, but pin compatibility must be confirmed against the respective manufacturer pinouts, because the analog input configuration (pseudo-differential vs. fully differential) and interface details differ between the two parts.
What is the maximum sampling rate of each device?
The AD7685ARMZRL7 supports a maximum throughput of 250 kSPS, whereas the AD7684BRMZRL7 supports a maximum throughput of 100 kSPS. The higher throughput of the AD7685 makes it preferable for faster acquisition requirements.
How do the analog input configurations differ?
The AD7685ARMZRL7 uses a pseudo-differential input structure, while the AD7684BRMZRL7 uses a fully differential input structure. This affects signal conditioning, common-mode handling, and the external driver amplifier requirements in the target design.
Do both parts use the same serial interface?
Both devices provide a serial digital output compatible with SPI/QSPI/MICROWIRE/DSP interfaces, but the AD7685ARMZRL7 and AD7684BRMZRL7 differ in their interface timing and configuration options. The interface timing must be verified against each device's datasheet before reusing a layout or firmware.
Can the AD7684BRMZRL7 directly replace the AD7685ARMZRL7 in an existing design?
A direct replacement is not recommended without validation. The lower 100 kSPS throughput of the AD7684BRMZRL7, its fully differential input, and its different interface timing can affect system performance, so the design must be re-verified against the AD7684 datasheet before substitution.
What supply voltage range do these ADCs support?
Both the AD7685ARMZRL7 and AD7684BRMZRL7 operate from a single 2.7 V to 5.5 V supply, allowing them to interface with common 3 V and 5 V logic systems. The reference voltage and analog input range should still be configured per each device's datasheet.