Part A
AD9778BSVZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2822 PCS
- Package
- TQFP-100
- Series
- Data Acquisition - Digital to Analog Converters (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD9778BSVZ and AD9775BSV are both dual-channel 14-bit high-speed DACs from Analog Devices in the same 100-lead TQFP_EP package, sharing a common functional architecture and pin family. While the AD9778BSVZ offers a higher maximum update rate and wider supply range, the AD9775BSV remains a viable functional substitute for lower-speed applications, provided the system timing margin and supply rail tolerances are validated against the target design.
Resolution and Channel Count
High match
Package Type
High match
Maximum Update Rate
Validation required
Supply Voltage Range
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD9778BSVZ | AD9775BSV | Why it matters |
|---|---|---|---|
| Resolution | 14 bit | 14 bit | Both are 14-bit DACs, so resolution is identical and not a differentiator for substitutability. |
| Number of DAC Channels | 2 | 2 | Dual-channel architecture is required for I/Q signal generation in both parts. |
| Maximum Update Rate | 1000 MSPS | 400 MSPS | The AD9778 supports a much higher DAC update rate, enabling wider signal bandwidths and higher intermediate frequencies. |
| Input Interface | Dual LVDS (DDR) | Dual LVDS (DDR) | Both use dual LVDS DDR inputs, so the digital interface is compatible for drop-in replacement. |
| On-Chip Interpolation | 2x / 4x / 8x | 2x / 4x / 8x | Interpolation filters ease output reconstruction filtering and reduce input data rate requirements. |
| On-Chip NCO / Digital Modulation | Yes (32-bit NCO) | Yes (32-bit NCO) | Integrated NCO enables digital upconversion, important for direct IF/RF synthesis architectures. |
| Supply Voltage | 3.3 V analog / 1.8 V digital | 3.3 V analog / 1.8 V digital | Matching supply rails simplify board-level power design when substituting parts. |
| Package | 100-lead TQFP (SV) | 100-lead TQFP (SV) | Identical package and pinout allow physical drop-in replacement on existing boards. |
| Power Consumption | ~1.0 W typical | ~0.7 W typical | Higher update rate in the AD9778 increases power dissipation, affecting thermal and supply design. |
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 | AD9778BSVZ | AD9775BSV |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | - | TxDAC+® |
| Part Status | Active | Obsolete |
| Number of Bits | 14 | - |
| 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 ~ 1.9V, 3.13V ~ 3.47V | - |
| INL / DNL(LSB) | ±1, ±0.65 | - |
| Architecture | Oversampling Interpolating DAC | - |
| Operating Temperature | -40°C ~ 85°C | - |
Frequently asked questions
What are the key differences between the AD9778BSVZ and the AD9775BSV?
The AD9778BSVZ is a dual 14-bit, 1 GSPS digital-to-analog converter (DAC) with a maximum update rate of 1 GSPS, while the AD9775BSV is a dual 14-bit, 400 MSPS DAC with a maximum update rate of 400 MSPS. Both are members of Analog Devices' TxDAC+ family and are pin-compatible in the same 100-lead TQFP_EP package, but the AD9778BSVZ supports a significantly higher sample rate and includes an on-chip 2x/4x/8x interpolating filter with a numerically controlled oscillator (NCO) for digital up-conversion, whereas the AD9775BSV offers 2x/4x/8x interpolation without the NCO.
Are the AD9778BSVZ and AD9775BSV pin-compatible and package-compatible?
Yes. Both devices are offered in the same 100-lead TQFP_EP (thin quad flat pack with exposed pad) package with identical pinout assignments, which allows board-level interchangeability when the surrounding circuitry and clocking scheme support the respective maximum update rates. Designers should still verify supply decoupling, clock input requirements, and configuration pin strapping against each device's datasheet before substituting one for the other.
What is the maximum DAC update rate for each device?
The AD9778BSVZ supports a maximum DAC update rate of 1 GSPS (1,000 MSPS), while the AD9775BSV supports a maximum DAC update rate of 400 MSPS. The higher update rate of the AD9778BSVZ enables wider signal bandwidths and higher intermediate frequency (IF) output capability in transmit signal chains.
Do both parts include digital interpolation filters?
Yes. Both the AD9778BSVZ and AD9775BSV integrate programmable 2x, 4x, and 8x interpolating filters to simplify reconstruction filtering and reduce the output sample rate requirements of the upstream digital signal processor or FPGA. The AD9778BSVZ additionally integrates a digital quadrature modulator with a numerically controlled oscillator (NCO) for up-conversion to an intermediate frequency, which the AD9775BSV does not include.
What is the resolution and DAC architecture of these converters?
Both the AD9778BSVZ and AD9775BSV are dual-channel, 14-bit current-steering DACs based on Analog Devices' TxDAC+ architecture. Each device provides two independent 14-bit DAC outputs with differential current outputs, supporting high dynamic range and low distortion for communications, instrumentation, and broadband signal synthesis applications.
What supply voltages and power consumption should be expected?
Both devices operate from a 3.3 V analog supply and a 1.8 V to 3.3 V digital supply (with a separate digital I/O supply), consistent with the TxDAC+ family datasheets. Power consumption scales with update rate and interpolation settings; the AD9778BSVZ, operating at up to 1 GSPS, dissipates more power than the AD9775BSV at its 400 MSPS maximum. Exact power figures should be taken from the respective Analog Devices datasheets for the specific operating mode.
Which device should be selected for a high-IF transmit application?
For high intermediate frequency (IF) transmit applications requiring output signals beyond roughly 200 MHz, the AD9778BSVZ is the appropriate choice because its 1 GSPS update rate and integrated NCO-based digital up-conversion support higher output frequencies with adequate oversampling. The AD9775BSV, limited to 400 MSPS, is better suited to lower-IF or baseband transmit designs where its 400 MSPS update rate provides sufficient oversampling.
Are evaluation boards and reference designs available for both parts?
Yes. Analog Devices provides evaluation boards for the TxDAC+ family, including the AD9778 and AD9775, which allow designers to characterize dynamic performance, test interpolation and NCO settings, and validate the digital interface. Reference schematics and layout guidance are included in the respective product datasheets and evaluation board documentation available from Analog Devices and authorized distributors.