Part A
AD9779ABSVZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2155 Stückzahl
- Package
- TQFP-100
- Series
- Data Acquisition von Digital to Analog Converters (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD9779ABSVZ and AD9775BSVZ are both dual-channel, 16-bit high-speed DACs from Analog Devices in a 100-lead TQFP_EP package, sharing the same supply architecture and digital interface family. While the AD9779A offers a higher maximum update rate and wider input data width than the AD9775, the two devices are functionally aligned for many dual-DAC signal-chain applications. Designers should validate the maximum sample rate, input data bus width, and on-chip interpolation/filter configuration against the target system requirements before committing to a drop-in substitution.
Package Type
High match
Channel Count
High match
Maximum Update Rate
Validation required
Input Data Interface
Validation required
Parts at a glance
Part B
AD9775BSVZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 838 Stückzahl
- Package
- TQFP-80
- 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 | AD9779ABSVZ | AD9775BSVZ | Why it matters |
|---|---|---|---|
| Resolution (DAC bits) | 16 | 14 | Higher resolution provides finer output quantization and lower quantization noise, affecting achievable SNR and signal fidelity. |
| Maximum Update Rate | 1000 MSPS | 400 MSPS | Determines the maximum synthesizable output frequency and bandwidth; a faster DAC supports wider-band or higher-IF signal generation. |
| Number of DAC Channels | 2 | 2 | Dual channels enable I/Q complex signal generation; matching channel count is essential for quadrature transmit architectures. |
| Input Data Interface | Dual LVDS (DDR) | Dual LVDS (DDR) | The digital input format must match the upstream FPGA/ASIC output to ensure correct data transfer and timing. |
| On-chip Interpolation | 2x, 4x, 8x | 2x, 4x, 8x | Interpolation filters relax the input data rate requirements and shape the output spectrum; matching options preserve system architecture. |
| Supply Voltage | 3.3 V (analog), 1.8 V (digital) | 3.3 V (analog), 1.8 V (digital) | Supply rails must be compatible with the board power design; mismatches require regulator or level-shifting changes. |
| Package | 100-lead TQFP-EP | 80-lead TQFP-EP | Package footprint and pinout affect PCB layout; different packages are not drop-in compatible and require board redesign. |
| SFDR | ~78 dBc (at 100 MSPS, 10 MHz output) | ~75 dBc (at 100 MSPS, 10 MHz output) | Spurious-free dynamic range indicates spectral purity; higher SFDR is critical for communication and instrumentation signal chains. |
| Power Consumption | ~1.0 W (typical, full operation) | ~0.6 W (typical, full operation) | Power dissipation impacts thermal design and supply sizing; a higher-power part may require additional cooling or current headroom. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD9779ABSVZ | AD9775BSVZ |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,Analog Devices Inc. |
| Series | - | TxDAC+® |
| Part Status | Active | Active |
| Number of Bits | 16 | 14 |
| Number of D/A Converters | 2 | 2 |
| Settling Time | - | 11ns (Typ) |
| Output Type | Current - Unbuffered | Current - Unbuffered |
| Differential Output | Yes | Yes |
| Data Interface | Parallel | Parallel |
| Reference Type | Internal | External, Internal |
| Voltage - Supply, Analog | 3.13V ~ 3.47V | 3.1V ~ 3.5V |
| Voltage - Supply, Digital | 1.7V ~ 2.05V, 3.13V ~ 3.47V | 3.1V ~ 3.5V |
| INL / DNL(LSB) | ±6, ±2.1 | ±1.5, ±1 |
| Architecture | Oversampling Interpolating DAC | Oversampling Interpolating DAC |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key architectural differences between the AD9779ABSVZ and AD9775BSVZ?
The AD9779ABSVZ is a dual-channel, 16-bit, 1 GSPS digital-to-analog converter (DAC) with an integrated 2x/4x/8x interpolating filter and a serial LVDS interface. The AD9775BSVZ is a dual-channel, 14-bit, 400 MSPS DAC with selectable 2x/4x/8x interpolation and a parallel CMOS input interface. The AD9779A offers higher resolution (16-bit vs 14-bit), a faster maximum update rate (1 GSPS vs 400 MSPS), and a serial LVDS data port, while the AD9775B uses a parallel CMOS data port.
Are the AD9779ABSVZ and AD9775BSVZ pin-compatible or package-compatible?
Both devices are offered in a 100-lead TQFP_EP (thermally enhanced) package, but they are not pin-compatible drop-in replacements. The AD9779A uses a serial LVDS input interface and the AD9775B uses a parallel CMOS input interface, so the digital input pin functions and PCB routing differ. A direct substitution requires a full schematic and layout review against the respective datasheets.
What are the maximum DAC update rates of the AD9779ABSVZ and AD9775BSVZ?
The AD9779ABSVZ supports a maximum DAC update rate of 1 GSPS. The AD9775BSVZ supports a maximum DAC update rate of 400 MSPS. Designs requiring output frequencies or interpolation ratios beyond the AD9775B's 400 MSPS limit must use the AD9779A or another higher-speed device.
How do the digital input interfaces of the AD9779ABSVZ and AD9775BSVZ differ?
The AD9779ABSVZ uses a serial LVDS input interface, which reduces pin count and simplifies high-speed board routing. The AD9775BSVZ uses a parallel CMOS input interface, which requires more data lines and careful attention to simultaneous switching noise and trace matching at the interface. The choice affects FPGA/ASIC I/O planning and PCB layer count.
What resolution does each converter provide?
The AD9779ABSVZ is a 16-bit dual DAC. The AD9775BSVZ is a 14-bit dual DAC. The 16-bit resolution of the AD9779A provides finer amplitude quantization and lower quantization noise, which can be advantageous in high-SFDR signal synthesis applications.
Do both parts include on-chip interpolation filters?
Yes. Both the AD9779ABSVZ and AD9775BSVZ integrate selectable 2x/4x/8x interpolating filters, allowing input data rates below the DAC update rate. The interpolation ratio and filter configuration are programmed through the device's serial control interface on both parts.
Can the AD9775BSVZ be used as a direct replacement for the AD9779ABSVZ in an existing design?
No. Although both are dual-channel interpolating DACs in 100-lead TQFP_EP packages, the AD9775BSVZ has a 14-bit resolution, a 400 MSPS maximum update rate, and a parallel CMOS input interface, whereas the AD9779ABSVZ has 16-bit resolution, 1 GSPS maximum update rate, and a serial LVDS input interface. A direct replacement is not possible without redesigning the digital interface, verifying the clocking scheme, and revalidating performance against the target specifications.
Which part is better suited for high-speed wideband signal synthesis?
The AD9779ABSVZ is better suited for high-speed wideband synthesis because its 1 GSPS maximum update rate and 16-bit resolution support higher output frequencies and wider instantaneous bandwidths than the AD9775BSVZ, which is limited to 400 MSPS and 14-bit resolution. Final selection should be confirmed against the specific spectral mask, SFDR, and interface requirements of the application using the manufacturer datasheets.