Part A
ADN2850BCPZ250
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7397 PCS
- Package
- LFCSP-16
- Series
- Data Acquisition - Digital Potentiometers
Replacement verdict
Not a drop-in replacement
The ADN2850BCPZ250 and ADN2811ACP-CML serve fundamentally different functions and cannot be treated as interchangeable. The ADN2850BCPZ250 is a dual-channel digital potentiometer, while the ADN2811ACP-CML is a clock and data recovery IC, so their electrical roles, signal interfaces, and application domains do not overlap. Substitution is not feasible without a complete redesign of the surrounding circuit.
Different device function
Different signal interface
Different package type
Different application domain
Parts at a glance
Part B
ADN2811ACP-CML
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 9484 PCS
- Package
- WFQFN-48
- Series
- Clock-Timing - Application Specific
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADN2850BCPZ250 | ADN2811ACP-CML | Why it matters |
|---|---|---|---|
| Function / Device Type | Dual-channel, nonvolatile digital potentiometer (256-position) | Clock and data recovery (CDR) IC with limiting amplifier | These are fundamentally different device classes, so they are not functionally substitutable in any design. |
| Primary Signal Domain | Analog resistive (potentiometer wiper) | High-speed serial digital (clock/data) | The signal type each part processes determines whether it can be used in an analog bias/trim path or a serial data path. |
| Supply Voltage | 2.7 V to 5.5 V (single supply) | 3.3 V nominal (3.0 V to 3.6 V) | Supply compatibility is a basic requirement for board-level interchangeability. |
| Package | 24-lead LFCSP (CP-24) | 32-lead LFCSP (CP-32) | Different package footprints and pin counts prevent drop-in replacement on an existing PCB. |
| Interface / Control | SPI-compatible serial interface | No digital control interface; analog/differential I/O | The control method dictates how the host system configures or communicates with the device. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching temperature ratings confirm both parts suit the same environmental conditions. |
| Data Rate / Bandwidth | Not applicable (analog resistive device) | Up to 2.7 Gbps serial data rate | The CDR's data rate capability is central to its role, while the potentiometer has no comparable metric. |
| Nonvolatile Memory | Yes (EEPROM wiper setting retention) | No | Nonvolatile storage lets the potentiometer retain its setting at power-up, a function the CDR does not provide. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADN2850BCPZ250 | ADN2811ACP-CML |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| PLL | - | Yes |
| Main Purpose | - | SONET/SDH, STM |
| Input | - | CML |
| Output | - | CML |
| Ratio - Input: Output | - | 1:2 |
| Differential - Input: Output | - | Yes/Yes |
| Frequency - Max | - | 2.66GHz |
| Voltage - Supply | - | 3V ~ 3.6V |
| Operating Temperature | - | -40°C ~ 85°C |
| Mounting Type | - | Surface Mount |
Frequently asked questions
Are the ADN2850BCPZ250 and ADN2811ACP-CML functionally interchangeable?
No. The ADN2850BCPZ250 is a dual-channel, 250 kΩ digital potentiometer (nonvolatile memory, SPI-compatible interface) in a 5 mm × 5 mm LFCSP package, while the ADN2811ACP-CML is a clock and data recovery IC (SONET/SDH OC-48/STM-16, 2.488 Gbps) in a 7 mm × 7 mm LFCSP package. They serve entirely different functions and are not interchangeable.
What are the primary functions of each device?
The ADN2850BCPZ250 provides digitally controlled variable resistance for applications such as gain adjustment, offset trimming, and calibration, with 250 kΩ end-to-end resistance and 1024-position resolution per channel. The ADN2811ACP-CML performs clock and data recovery for 2.488 Gbps SONET/SDH OC-48/STM-16 optical links, extracting a recovered clock and retiming incoming serial data.
Do the two parts share the same package footprint?
No. The ADN2850BCPZ250 uses a 5 mm × 5 mm, 32-lead LFCSP, while the ADN2811ACP-CML uses a 7 mm × 7 mm, 48-lead LFCSP. The package sizes, pin counts, and pin assignments differ, so PCB land patterns are not compatible.
What supply voltages do these devices require?
The ADN2850BCPZ250 operates from a single 2.7 V to 5.5 V supply (dual-supply operation is also supported for extended voltage range). The ADN2811ACP-CML operates from a 3.3 V supply (3.0 V to 3.6 V). The supply requirements are not interchangeable.
What communication interfaces does each device use?
The ADN2850BCPZ250 uses an SPI-compatible 3-wire serial interface for programming wiper positions and storing settings in nonvolatile EEPROM. The ADN2811ACP-CML provides a serial data output, a recovered clock output, and a 2-wire I²C-compatible interface for configuration and status monitoring.
Are these devices suited for the same target applications?
No. The ADN2850BCPZ250 targets analog signal-chain trimming, instrumentation, and calibration applications requiring programmable resistance. The ADN2811ACP-CML targets optical networking equipment such as SONET/SDH add-drop multiplexers, repeaters, and line cards operating at OC-48/STM-16 rates.
Can either device be used as a drop-in replacement for the other in an existing design?
No. Because the two parts differ in function, package, pinout, supply voltage, and interface, neither can serve as a drop-in replacement for the other. Any substitution would require a complete redesign of the surrounding circuitry and PCB layout.