Part A
AD7849BRZ
Công ty Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5626 PCS
- Package
- SOIC-20
- Series
- Data Acquisition - Digital to Analog Converters (DAC)
Replacement verdict
Not a drop-in replacement
The AD7849BRZ and AD7845BR are not drop-in replacements for one another. Although both are Analog Devices 12-bit voltage-output DACs in a 24-lead SOIC package, they differ in resolution architecture, reference configuration, interface timing, and output amplifier characteristics, so a direct board-level substitution is not supported without design validation.
Different DAC architecture
Different reference configuration
Different interface timing
Different output amplifier
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7849BRZ | AD7845BR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Higher resolution provides finer output steps and lower quantization error, which is critical for precision control applications. |
| Number of DAC Channels | 1 | 1 | Channel count determines how many independent analog outputs the device can drive in a system. |
| Interface Type | Serial (SPI-compatible) | Parallel | The digital interface must match the host controller; serial reduces pin count while parallel offers higher throughput. |
| Output Voltage Range | ±10 V (bipolar) | ±10 V (bipolar) | The output span must match the actuator or measurement system's expected input range. |
| Supply Voltage | ±12 V to ±15 V (dual) | ±12 V to ±15 V (dual) | Supply requirements determine power rail compatibility and overall system power design. |
| Package Type | 20-Lead SOIC (Wide) | 24-Lead PDIP | Package footprint and mounting style affect PCB layout and assembly compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range must cover the application's environmental conditions for reliable operation. |
| Settling Time | 10 µs (typical) | 5 µs (typical) | Settling time affects the maximum update rate and dynamic accuracy in closed-loop control systems. |
| Integral Nonlinearity (INL) | ±1 LSB (max) | ±0.5 LSB (max) | INL defines the deviation from an ideal transfer function and directly impacts absolute accuracy. |
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 | AD7849BRZ | AD7845BR |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | - |
| Number of D/A Converters | 1 | - |
| Settling Time | 10µs (Typ) | - |
| Output Type | Voltage - Buffered | - |
| Differential Output | No | - |
| Data Interface | SPI | - |
| Reference Type | External | - |
| Voltage - Supply, Analog | ±14.25V ~ 15.75V | - |
| Voltage - Supply, Digital | 5V | - |
| INL / DNL(LSB) | ±16 (Max), ±0.9 (Max) | - |
| Architecture | String DAC | - |
| Operating Temperature | -40°C ~ 85°C | - |
Frequently asked questions
What are the key architectural differences between the AD7849BRZ and the AD7845BR?
The AD7849BRZ is a 16-bit voltage-output DAC with a serial interface, while the AD7845BR is a 12-bit multiplying DAC with a parallel interface. The AD7849BRZ integrates an output amplifier and operates from ±12 V to ±15 V supplies, whereas the AD7845BR is a current-output multiplying DAC requiring an external op-amp for voltage output.
Are the AD7849BRZ and AD7845BR pin-compatible?
No. The AD7849BRZ is offered in a 24-lead SOIC (RW-24) package, while the AD7845BR is supplied in a 24-lead PDIP (N-24) or 24-lead SOIC (R-24) package with a different pinout. Pin functions and assignments differ, so they are not drop-in replacements.
What are the resolution and accuracy specifications of each device?
The AD7849BRZ provides 16-bit resolution with ±1 LSB integral nonlinearity (INL) and ±1 LSB differential nonlinearity (DNL) at the B grade. The AD7845BR provides 12-bit resolution with ±1/2 LSB INL and ±1 LSB DNL at the B grade.
How do the digital interfaces of the AD7849BRZ and AD7845BR differ?
The AD7849BRZ uses a serial interface compatible with SPI, QSPI, and MICROWIRE, allowing daisy-chaining of multiple devices. The AD7845BR uses a parallel 12-bit interface with standard CS, WR, and data bus lines, requiring more I/O pins from the host controller.
What are the supply voltage and reference requirements for each part?
The AD7849BRZ operates from dual supplies of ±12 V to ±15 V and requires an external voltage reference (typically +5 V or +10 V). The AD7845BR operates from ±10 V to ±15 V dual supplies and uses an external reference to set the multiplying input range; it does not include an internal reference.
Can the AD7849BRZ and AD7845BR be used in the same application interchangeably?
No. The AD7849BRZ is a voltage-output DAC suited for precision setpoint and control applications, while the AD7845BR is a current-output multiplying DAC intended for signal multiplication, attenuation, and waveform generation. Differences in resolution, interface, output type, and package prevent direct interchange without redesign.
What are the operating temperature ranges for the AD7849BRZ and AD7845BR?
Both the AD7849BRZ and AD7845BR are specified for the industrial temperature range of −40 °C to +85 °C, making them suitable for industrial control and instrumentation environments.