Part A
AD9779ABSVZ
Компания Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2155 ПКС
- Package
- TQFP-100
- Series
- Сбор данных - цифровые в аналоговые преобразователи (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD9779ABSVZ and AD9777BSV are both dual-channel 16-bit high-speed DACs from Analog Devices in the same 100-lead TQFP-EP package, sharing a compatible supply and temperature range, so the AD9779ABSVZ can serve as a functional replacement candidate for the AD9777BSV. However, the two parts differ in maximum update rate and on-chip digital signal processing features, so the design must be validated against the target sample rate and interpolation requirements before substitution.
Resolution and Channel Count
High match
Maximum Update Rate
Validation required
Digital Signal Processing Features
Validation required
Package and Supply Compatibility
High match
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 | AD9777BSV | Why it matters |
|---|---|---|---|
| Resolution (DAC bits) | 16 bit | 16 bit | Bit depth determines the quantization noise floor and achievable dynamic range of the synthesized output. |
| Maximum Update Rate | 1000 MSPS | 400 MSPS | Higher update rate enables wider signal bandwidths and higher intermediate frequencies at the DAC output. |
| Number of DAC Channels | 2 | 2 | Dual channels support I/Q transmit architectures and complex signal generation. |
| On-chip Interpolation | 2x, 4x, 8x | 2x, 4x, 8x | Interpolation relaxes the input data rate and simplifies analog reconstruction filtering. |
| Digital Interface | LVDS | LVDS | The interface type determines compatibility with the driving FPGA or DSP and the achievable input bandwidth. |
| Supply Voltage | 3.3 V (analog/digital), 1.8 V (digital core) | 3.3 V | Supply requirements affect board power design and level-shifting needs in a direct replacement. |
| Package | 100-lead TQFP (SV-100) | 80-lead TQFP (SV-80) | Package footprint and pin count must match for a drop-in board replacement. |
| Power Consumption | Approx. 1.0 W at 1000 MSPS | Approx. 0.5 W at 400 MSPS | Power dissipation impacts thermal design and supply sizing in the target system. |
| SFDR | ~78 dBc at 100 MSPS output | ~75 dBc at 100 MSPS output | Spurious-free dynamic range indicates spectral purity and suitability for demanding communications signals. |
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 | AD9779ABSVZ | AD9777BSV |
|---|---|---|
| Series | - | TxDAC+® |
| Part Status | Active | Obsolete |
| Mounting Type | - | Surface Mount |
| Base Product Number | - | AD9777 |
| Number of Bits | 16 | - |
| Number of D/A Converters | 2 | - |
| Output Type | Current - Unbuffered | - |
| Differential Output | Yes | - |
| Data Interface | Parallel | - |
| Reference Type | Internal | - |
| Voltage - Supply, Analog | 3.13V ~ 3.47V | - |
| Voltage - Supply, Digital | 1.7V ~ 2.05V, 3.13V ~ 3.47V | - |
| INL / DNL(LSB) | ±6, ±2.1 | - |
| Architecture | Oversampling Interpolating DAC | - |
| Operating Temperature | -40°C ~ 85°C | - |
Frequently asked questions
What are the key differences between the AD9779ABSVZ and the AD9777BSV?
The AD9779ABSVZ is a dual-channel, 16-bit, 1 GSPS digital-to-analog converter (DAC) with an integrated 2x/4x/8x interpolating filter and on-chip PLL, while the AD9777BSV is a dual-channel, 16-bit, 400 MSPS DAC with 2x/4x/8x interpolation. The AD9779A offers a significantly higher maximum update rate (1 GSPS vs. 400 MSPS) and includes a higher-order interpolation option and on-chip PLL, whereas the AD9777 provides similar 16-bit resolution and dual-channel architecture at a lower speed grade.
Are the AD9779ABSVZ and AD9777BSV pin-compatible?
No. The AD9779ABSVZ is supplied in a 100-lead TQFP_EP package, while the AD9777BSV is supplied in an 80-lead LQFP package. The different package footprints, pin counts, and pin assignments mean they are not drop-in replacements and require separate PCB layouts.
What is the maximum DAC update rate for each device?
The AD9779ABSVZ supports a maximum DAC update rate of 1 GSPS. The AD9777BSV supports a maximum DAC update rate of 400 MSPS. Designs requiring sample rates above 400 MSPS must use the AD9779A or another higher-speed converter.
Do both parts include an on-chip PLL for clock multiplication?
The AD9779ABSVZ includes an on-chip PLL clock multiplier that can generate the DAC sampling clock from a lower-frequency reference. The AD9777BSV does not include an on-chip PLL; its clock input must be supplied externally at the required DAC update rate. This is a significant difference for system clocking architecture.
What interpolation ratios are available on each converter?
Both the AD9779ABSVZ and the AD9777BSV provide 2x, 4x, and 8x interpolation filters. The AD9779A additionally offers higher-order interpolation modes to support its 1 GSPS operation, allowing lower input data rates relative to the DAC update rate.
What is the resolution and channel count of these DACs?
Both the AD9779ABSVZ and the AD9777BSV are dual-channel (two DACs per package) 16-bit digital-to-analog converters. They are intended for applications such as wireless infrastructure transmit paths, broadband communications, and instrumentation where dual high-resolution DACs are required.
Can the AD9777BSV be used as a direct replacement for the AD9779ABSVZ in an existing design?
No. Because the two devices differ in package (80-lead LQFP vs. 100-lead TQFP_EP), maximum update rate (400 MSPS vs. 1 GSPS), and on-chip PLL availability, a direct substitution is not possible. Any replacement requires a new PCB layout, revalidation of the clocking scheme, and verification of the digital interface timing against the target datasheet.