Part A
AD7685ARMZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 5296 個数
- Package
- MSOP-10
- Series
- データ取得 - アナログ/デジタルコンバータ (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7685BRMZRL7 and AD7685ARMZ are functionally compatible 16-bit PulSAR ADCs sharing the same core architecture, resolution, and interface, making them viable substitutes in most designs. The primary distinction lies in their operating temperature range and package finish, so the AD7685ARMZ is a suitable replacement for the AD7685BRMZRL7 where the wider industrial temperature grade and tube packaging are acceptable.
Resolution and Architecture
High match
Package Type
High match
Operating Temperature Range
Validation required
Interface and Supply Voltage
High match
Parts at a glance
Part B
AD7685BRMZRL7
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 4839 個数
- Package
- MSOP-10
- Series
- データ取得 - アナログ/デジタルコンバータ (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 | AD7685BRMZRL7 | AD7685ARMZ | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit ADCs, so resolution is identical and not a differentiator for substitutability. |
| Sampling Rate | 250 kSPS | 250 kSPS | Identical throughput means either part can meet the same acquisition timing requirements. |
| Number of Inputs / Channels | 1 single-ended | 1 single-ended | Same channel configuration allows direct replacement in single-channel signal chains. |
| Input Type | Pseudo-differential | Pseudo-differential | Matching input topology ensures the same analog front-end design can be reused. |
| Supply Voltage (Analog & Digital) | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Identical supply range means both parts operate in the same system power domain. |
| Interface | SPI / QSPI / MICROWIRE / DSP compatible | SPI / QSPI / MICROWIRE / DSP compatible | Same serial interface allows drop-in compatibility with existing digital hosts. |
| Package / Mounting | 10-Lead MSOP, Surface Mount | 10-Lead MSOP, Surface Mount | Identical package and footprint enable direct PCB replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Same temperature rating ensures equivalent environmental performance in the application. |
| Reference Type | External | External | Both require an external reference, so the same reference circuit can be shared. |
| Packaging / Ordering | Tape & Reel (RL7) | Tube / Tray | Different packaging affects assembly line handling and inventory form, though the die is functionally equivalent. |
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 | AD7685ARMZ | AD7685BRMZRL7 |
|---|---|---|
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 250k | 250k |
| Number of Inputs | 1 | 1 |
| Input Type | Pseudo-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 | 2.3V ~ 5.5V | 2.3V ~ 5.5V |
| Voltage - Supply, Digital | 2.3V ~ 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 AD7685BRMZRL7 and the AD7685ARMZ?
Both devices are 16-bit, 250 kSPS PulSAR analog-to-digital converters from Analog Devices in a 10-lead MSOP package. The primary difference is the grade: the AD7685BRMZRL7 is the B-grade version, while the AD7685ARMZ is the A-grade version. The B-grade offers tighter specifications, notably ±1.5 LSB INL maximum versus ±2.5 LSB for the A-grade, and a lower zero-scale error specification. The "RL7" suffix on the B-grade part indicates tape-and-reel packaging, whereas the AD7685ARMZ is supplied in tube form.
Are the AD7685BRMZRL7 and AD7685ARMZ pin-compatible and functionally interchangeable?
Yes. Both parts share the same 10-lead MSOP package, identical pinout, and the same core 16-bit SAR ADC architecture with a 250 kSPS throughput rate. They are functionally interchangeable in terms of pinout and interface. However, because the B-grade has tighter linearity specifications, substituting the A-grade for the B-grade in a design that relies on the B-grade's ±1.5 LSB INL limit may not meet the original performance requirements.
What are the INL specifications for the AD7685BRMZRL7 and AD7685ARMZ?
Per Analog Devices datasheet specifications, the AD7685B (AD7685BRMZRL7) has a maximum integral nonlinearity of ±1.5 LSB, while the AD7685A (AD7685ARMZ) has a maximum INL of ±2.5 LSB. Both are specified as 16-bit no-missing-codes devices. The tighter INL of the B-grade makes it preferable for applications requiring higher DC accuracy.
Do both parts support the same supply voltage and reference configuration?
Yes. Both the AD7685BRMZRL7 and AD7685ARMZ operate from a single 2.7 V to 5.5 V supply (VDD) with a separate VIO supply for the digital interface, and both use an external reference applied to the REF pin. The analog input range is 0 V to VREF, and both support the same SPI-/QSPI-/MICROWIRE-compatible serial interface. The supply and reference requirements are identical across both grades.
What is the difference in packaging between the AD7685BRMZRL7 and AD7685ARMZ?
The AD7685BRMZRL7 is supplied in tape-and-reel packaging (the "RL7" suffix denotes a 7-inch reel), which is suited to automated high-volume assembly. The AD7685ARMZ is supplied in standard tube packaging. Both use the same 10-lead MSOP (RM) package, so the PCB footprint and land pattern are identical regardless of the packaging option chosen.
Which grade should be selected for a design requiring the tightest DC linearity?
For designs requiring the tightest DC linearity, the AD7685BRMZRL7 (B-grade) should be selected, as it guarantees a maximum INL of ±1.5 LSB compared with ±2.5 LSB for the AD7685ARMZ (A-grade). If the application can tolerate the wider A-grade limits, the AD7685ARMZ may be used, but the B-grade provides the higher guaranteed accuracy margin.
Are both parts specified over the same operating temperature range?
Yes. Both the AD7685BRMZRL7 and AD7685ARMZ are specified over the industrial temperature range of −40°C to +85°C, consistent with the AD7685 family datasheet. Their AC and DC performance specifications are guaranteed across this same temperature range, so the grade difference is in linearity limits rather than temperature coverage.