Part A
AD7849BRZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5626 PCS
- Package
- SOIC-20
- Series
- Acquisição de dados - Convertedores digitais para analógicos (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD7849BRZ and AD7845BRZ are both 12-bit voltage-output DACs from Analog Devices in a 24-lead SOIC package, sharing a comparable digital interface and supply architecture. However, they differ in reference architecture and output amplifier configuration, so the AD7849BRZ can serve as a functional replacement candidate for the AD7845BRZ only after the reference and output-stage requirements of the target design are validated.
Resolution
High match
Package Type
High match
Reference Architecture
Validation required
Output Amplifier Configuration
Validation required
Parts at a glance
Part B
AD7845BRZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3535 PCS
- Package
- SOIC-24
- Series
- Acquisição de dados - Convertedores digitais para analógicos (DAC)
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 | AD7845BRZ | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Resolution determines the smallest output step and overall precision; a 16-bit DAC offers 16 times finer granularity than a 12-bit DAC, which is critical for high-accuracy control loops. |
| Number of DAC Channels | 1 | 1 | Both are single-channel DACs, so channel count does not differentiate them for multi-channel system designs. |
| Output Type | Voltage output | Voltage output | Both provide voltage outputs, so the interface to downstream circuitry is functionally similar. |
| Digital Interface | Serial (SPI-compatible) | Parallel | The interface type dictates the host connection and pin count; serial reduces board routing while parallel offers faster update rates and simpler timing. |
| Supply Voltage | ±12 V to ±15 V (dual supply) | ±12 V to ±15 V (dual supply) | Matching supply requirements means both can operate in the same analog power domain without redesign. |
| Package | 20-lead SOIC (R-20) | 24-lead SOIC (R-24) | Different package footprints affect PCB layout and may require board redesign when substituting one part for the other. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings confirm both are suitable for the same industrial-grade environments. |
| Integral Nonlinearity (INL) | ±1 LSB (max) | ±1/2 LSB (max) | INL defines deviation from an ideal transfer function; tighter INL improves absolute accuracy in precision applications. |
| Settling Time | 10 µs (to ±1/2 LSB) | 5 µs (to ±1/2 LSB) | Settling time limits the maximum update rate; faster settling enables higher-speed control and waveform generation. |
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 | AD7845BRZ |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,Analog Devices Inc. |
| Part Status | Active | Active |
| Number of Bits | 16 | 12 |
| Number of D/A Converters | 1 | 1 |
| Settling Time | 10µs (Typ) | 5µs |
| Output Type | Voltage - Buffered | Voltage - Buffered |
| Differential Output | No | No |
| Data Interface | SPI | Parallel |
| Reference Type | External | External |
| Voltage - Supply, Analog | ±14.25V ~ 15.75V | ±14.25V ~ 15.75V |
| INL / DNL(LSB) | ±16 (Max), ±0.9 (Max) | ±0.75 (Max), ±1 (Max) |
| Architecture | String DAC | R-2R |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Voltage - Supply, Digital | 5V | - |
Frequently asked questions
What are the key architectural differences between the AD7849BRZ and AD7845BRZ?
The AD7849BRZ is a 16-bit voltage-output DAC with a serial interface, while the AD7845BRZ is a 12-bit multiplying DAC with a parallel interface and current output. The AD7849BRZ integrates an output amplifier and reference, whereas the AD7845BRZ requires an external op-amp and reference for voltage-mode operation.
Are the AD7849BRZ and AD7845BRZ pin-compatible?
No. The AD7849BRZ is offered in a 20-lead SOIC (RW-20) package, and the AD7845BRZ is offered in a 24-lead SOIC (R-24) package. Their pin counts, pin functions, and footprints 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 ±2 LSB INL (B grade) and ±1 LSB DNL. The AD7845BRZ provides 12-bit resolution with ±1/2 LSB INL and ±1 LSB DNL (B grade). The AD7849BRZ therefore offers four times the resolution of the AD7845BRZ.
How do the digital interfaces of the AD7849BRZ and AD7845BRZ differ?
The AD7849BRZ uses a serial interface compatible with SPI, QSPI, and MICROWIRE, operating at clock rates up to 5 MHz. The AD7845BRZ uses a 12-bit parallel interface with standard CS, WR, and data bus control signals. The interface choice affects microcontroller pin count and firmware architecture.
What are the output configuration differences between the two DACs?
The AD7849BRZ provides a buffered voltage output (0 V to VREF or ±VREF depending on configuration) with an on-chip output amplifier. The AD7845BRZ is a current-output multiplying DAC that requires an external operational amplifier to convert the current output to a voltage, but this allows four-quadrant multiplication.
Do the AD7849BRZ and AD7845BRZ have the same reference requirements?
No. The AD7849BRZ includes an on-chip reference and can also operate from an external reference. The AD7845BRZ requires an external reference voltage for operation. Designs migrating between the two must account for this difference in reference architecture.
What are the supply voltage and power consumption differences?
The AD7849BRZ operates from ±12 V to ±15 V dual supplies (or +5 V single supply in some configurations) and typically consumes about 10 mW. The AD7845BRZ operates from ±12 V to ±15 V dual supplies and typically consumes about 30 mW. Power budgeting and supply rail design must be reviewed when comparing the two.
Can the AD7849BRZ directly replace the AD7845BRZ in an existing design?
No. The devices differ in resolution (16-bit vs 12-bit), interface (serial vs parallel), package (20-lead vs 24-lead SOIC), output type (voltage vs current), and reference architecture. A direct replacement is not possible without redesigning the interface, output stage, and PCB layout.