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 AD7845JR are not drop-in replacements for one another. Although both are Analog Devices digital-to-analog converters, they differ in resolution, output configuration, and package, so substituting one for the other requires design validation and layout changes.
Different resolution
Different output configuration
Different package
Different interface timing
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 | AD7845JR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Higher resolution provides finer output steps and better accuracy; a 16-bit DAC offers 16x more codes than a 12-bit device, so they are not functionally interchangeable in precision applications. |
| Number of DAC Channels | 1 | 1 | Both are single-channel DACs, so channel count alone does not differentiate them for substitutability. |
| Interface Type | Serial (SPI-compatible) | Parallel | Serial vs parallel interface fundamentally changes the host connection and pinout, requiring different board routing and firmware, so they are not drop-in replacements. |
| Output Type | Voltage | Current | Voltage-output and current-output DACs serve different load and signal-chain requirements; a current-output device typically needs an external op-amp to produce a voltage, affecting circuit design. |
| Supply Voltage | ±12 V to ±15 V (dual supply) | ±12 V to ±15 V (dual supply) | Matching supply requirements simplifies power-rail reuse, though other differences still prevent direct substitution. |
| Package / Mounting | 20-Lead SOIC (surface mount) | 28-Lead PLCC (surface mount) | Different package footprints and pin counts mean the PCB layout must be redesigned; they cannot share the same land pattern. |
| Operating Temperature Range | -40 °C to +85 °C | 0 °C to +70 °C | The wider industrial temperature range of the AD7849BRZ allows use in harsher environments where the commercial-grade AD7845JR may not be specified. |
| Integral Nonlinearity (INL) | ±1 LSB (typical) | ±1/2 LSB (typical) | INL defines deviation from an ideal transfer function; differing linearity specs affect accuracy budgets and may require recalibration when swapping parts. |
| Settling Time | 10 µs (to ±1 LSB) | 5 µs (to ±1/2 LSB) | Settling time determines maximum update rate; a faster-settling part may be needed for high-speed control loops, so timing performance must be matched to the application. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7849BRZ | AD7845JR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| 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) | ±1 (Max), ±1 (Max) |
| Architecture | String DAC | R-2R |
| Operating Temperature | -40°C ~ 85°C | 0°C ~ 70°C |
| Voltage - Supply, Digital | 5V | - |
Frequently asked questions
What are the primary differences between the AD7849BRZ and the AD7845JR?
The AD7849BRZ is a 16-bit voltage-output DAC with a serial interface, while the AD7845JR is a 12-bit multiplying DAC with a parallel interface. The AD7849BRZ offers higher resolution and a serial control bus, whereas the AD7845JR provides a faster parallel interface and a multiplying (current-output) architecture suited for different signal-processing tasks.
Are the AD7849BRZ and AD7845JR pin-compatible?
No. The AD7849BRZ is supplied in a 20-lead SOIC (R-20) package, and the AD7845JR is supplied in a 28-lead SOIC (R-28) package. The different package sizes and pin counts mean they are not drop-in replacements for each other.
What are the resolution and interface differences between these two DACs?
The AD7849BRZ provides 16-bit resolution with a serial (SPI-compatible) interface, while the AD7845JR provides 12-bit resolution with a parallel microprocessor interface. The AD7849BRZ is therefore better suited to high-resolution, low-pin-count designs, and the AD7845JR to systems requiring fast parallel updates.
Do the AD7849BRZ and AD7845JR have the same output configuration?
No. The AD7849BRZ is a voltage-output DAC, whereas the AD7845JR is a multiplying DAC with a current output that typically requires an external op-amp for voltage conversion. This difference affects the external circuitry required in each design.
Can the AD7849BRZ and AD7845JR operate from the same supply voltages?
No. The AD7849BRZ operates from dual supplies of ±12 V to ±15 V (with a +5 V logic supply), while the AD7845JR operates from a +5 V to +15 V single supply or ±5 V to ±15 V dual supplies. The supply requirements differ, so the power design must be verified for each part.
Which part is better suited for high-resolution industrial control applications?
The AD7849BRZ, with its 16-bit resolution and voltage output, is generally better suited to high-resolution industrial control and instrumentation applications. The AD7845JR, with 12-bit resolution and a multiplying architecture, is more appropriate for applications such as programmable gain and signal attenuation where a multiplying DAC is required.
Are the AD7849BRZ and AD7845JR interchangeable in an existing design?
No. Differences in resolution, interface type (serial vs. parallel), output configuration (voltage vs. current), package size, and supply requirements mean the two parts are not interchangeable without a full redesign and validation against the manufacturer datasheets.