Part A
AD7390ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3323 Stückzahl
- Package
- SOIC-8
- Series
- Data Acquisition von Digital to Analog Converters (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD7390ARZ and AD7391AR are both 12-bit voltage-output DACs from Analog Devices in a standard 8-lead SOIC package, sharing the same supply range and serial interface family, so the AD7391AR can serve as a functional replacement candidate for the AD7390ARZ in many designs. However, the two parts differ in reference architecture and output amplifier configuration, so reference and output-stage behavior must be validated against the target application before substitution.
Resolution
High match
Package Type
High match
Reference Architecture
Validation required
Output Amplifier Configuration
Validation required
Parts at a glance
Part B
AD7391AR
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6553 Stückzahl
- Package
- SOIC-8
- Series
- Data Acquisition von Digital to Analog Converters (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 | AD7390ARZ | AD7391AR | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 10 bit | Resolution determines the number of discrete output levels; a 12-bit DAC offers 4x finer granularity than a 10-bit DAC, affecting precision of the analog output. |
| Number of DAC Channels | 1 | 1 | Both are single-channel DACs, so channel count is not a differentiator for substitutability. |
| Interface Type | Serial (SPI-compatible, 3-wire) | Serial (SPI-compatible, 3-wire) | Matching serial interface ensures the same microcontroller/SPI bus can drive either part without protocol changes. |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | Identical supply range means both parts work in the same low-voltage systems without power rail redesign. |
| Output Type | Voltage output | Voltage output | Both provide buffered voltage outputs, so the downstream signal chain topology remains compatible. |
| INL (Integral Nonlinearity) | ±1 LSB (typ) | ±0.5 LSB (typ) | INL specifies deviation from an ideal transfer function; the 10-bit part achieves tighter relative linearity, which affects accuracy in precision applications. |
| Settling Time | 6 µs (to ±1/2 LSB) | 5 µs (to ±1/2 LSB) | Settling time affects maximum update rate; the slightly faster settling of the AD7391AR can matter in higher-speed control loops. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings mean both parts suit the same industrial-grade environments. |
| Package Type | 8-lead SOIC (SOIC_N) | 8-lead SOIC (SOIC_N) | Same package and pinout allow drop-in board replacement without layout changes. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7390ARZ | AD7391AR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Number of Bits | 12 | 10 |
| Number of D/A Converters | 1 | 1 |
| Settling Time | 70µs (Typ) | 70µs (Typ) |
| Output Type | Voltage - Buffered | Voltage - Buffered |
| Differential Output | No | No |
| Data Interface | SPI | SPI |
| Reference Type | External | External |
| Voltage - Supply, Analog | 2.7V ~ 5.5V | 2.7V ~ 5.5V |
| Voltage - Supply, Digital | 2.7V ~ 5.5V | 2.7V ~ 5.5V |
| INL / DNL(LSB) | ±2 (Max), ±1 (Max) | ±2 (Max), ±0.9 (Max) |
| Architecture | R-2R | R-2R |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 125°C |
Frequently asked questions
What are the key differences between the AD7390ARZ and AD7391AR?
The AD7390ARZ is a 12-bit voltage-output digital-to-analog converter, while the AD7391AR is a 10-bit voltage-output DAC. Both are single-channel, serial-input DACs from Analog Devices in 8-lead SOIC packages, but they differ in resolution (12-bit vs 10-bit) and therefore in the number of input clock cycles required per conversion and in their effective LSB step size.
Are the AD7390ARZ and AD7391AR pin-compatible?
Yes. Both devices are offered in the same 8-lead SOIC (R-8) package with the same pinout, including serial data input, clock, load, reference, VOUT, VDD, and GND pins. This shared pinout allows the AD7391AR to be evaluated in the same socket as the AD7390ARZ, though resolution and transfer characteristics differ.
What is the resolution and LSB size of each device?
The AD7390ARZ provides 12-bit resolution, giving an LSB size of VREF/4096. The AD7391AR provides 10-bit resolution, giving an LSB size of VREF/1024. With the same reference voltage, the AD7390ARZ therefore offers four times finer output steps than the AD7391AR.
Do both parts use the same serial interface?
Yes. Both the AD7390ARZ and AD7391AR use a 3-wire serial interface (SDI, CLK, and LDAC/load) compatible with SPI and QSPI protocols. The difference is that the 12-bit AD7390ARZ requires 12 clock cycles to shift in a full data word, while the 10-bit AD7391AR requires 10 clock cycles.
What supply voltage and reference range do these DACs support?
Both the AD7390ARZ and AD7391AR operate from a single +2.7 V to +5.5 V supply. The external reference input (VREF) sets the full-scale output, and the output range spans from 0 V to VREF. The reference voltage must be within the device supply and specified reference limits per the Analog Devices datasheet.
Can the AD7391AR be used as a drop-in replacement for the AD7390ARZ?
Not as a functional equivalent. Although the package and pinout match, the AD7391AR is a 10-bit DAC and the AD7390ARZ is a 12-bit DAC. A drop-in substitution would reduce system resolution and change the digital code-to-output voltage relationship, so the design's accuracy and firmware scaling must be revalidated before substitution.
What are the typical applications for these DACs?
Both the AD7390ARZ and AD7391AR are suited to applications such as digital gain and offset adjustment, programmable voltage references, portable instrumentation, and closed-loop control where a compact single-channel voltage-output DAC with a serial interface is required. The AD7390ARZ is preferred where finer 12-bit resolution is needed, while the AD7391AR suits 10-bit applications.