Part A
AD9778ABSVZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6245 Stückzahl
- Package
- TQFP-100
- Series
- Data Acquisition von Digital to Analog Converters (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD9778ABSVZ and AD9775BSVZ are both dual-channel 14-bit high-speed DACs from Analog Devices in a 100-lead TQFP-EP package, sharing the same core resolution, channel count, and supply architecture. The AD9778ABSVZ offers a higher maximum update rate and wider input data interface flexibility, making it a viable functional upgrade candidate for the AD9775BSVZ in most designs, provided the system timing budget and digital interface configuration are validated against the target board.
Resolution and Channel Count
High match
Package Type
High match
Maximum Update Rate
Validation required
Digital Input 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 | AD9778ABSVZ | AD9775BSVZ | Why it matters |
|---|---|---|---|
| Resolution (Bits) | 14 | 14 | Both are 14-bit DACs, so quantization noise floor and dynamic range are comparable for signal synthesis. |
| Number of DAC Channels | 2 | 2 | Dual-channel architecture supports I/Q transmit paths; matching channel count ensures pin/function compatibility. |
| Maximum Update Rate | 1000 MSPS | 400 MSPS | Higher update rate enables wider signal bandwidth and higher intermediate frequencies; a lower-rate part may not meet wideband transmit requirements. |
| Maximum Input Data Rate | 500 MSPS | 200 MSPS | Determines the maximum baseband sample rate the digital input interface can accept, affecting achievable signal bandwidth. |
| On-Chip Interpolation | 2x, 4x, 8x | 2x, 4x, 8x | Interpolation filters relax the analog reconstruction filter and reduce input data rate requirements; identical options preserve system design flexibility. |
| Digital Interface | LVDS | LVDS | LVDS inputs provide high-speed, low-noise data transfer; matching interface type ensures FPGA/ASIC compatibility. |
| Supply Voltage | 3.3 V (analog and digital) | 3.3 V (analog and digital) | Same supply rails simplify power design and allow drop-in replacement without regulator changes. |
| Package | 100-lead TQFP (SVZ) | 80-lead TQFP (SVZ) | Different package footprints and pin counts mean the parts are not drop-in compatible and require PCB layout changes. |
| Power Consumption (Typical) | Approx. 1.0 W | Approx. 0.7 W | Power dissipation affects thermal design and supply sizing; the higher-rate device consumes more power. |
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 | AD9778ABSVZ | AD9775BSVZ |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,Analog Devices Inc. |
| Series | - | TxDAC+® |
| Part Status | Active | Active |
| Number of Bits | 14 | 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) | ±1.5, ±0.65 | ±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 differences between the AD9778ABSVZ and AD9775BSVZ?
The AD9778A is a dual 14-bit, 1 GSPS digital-to-analog converter (DAC), while the AD9775 is a dual 14-bit, 400 MSPS DAC. Both are members of Analog Devices' TxDAC+ family and are pin-compatible in a 100-lead TQFP-EP package, but the AD9778A supports a significantly higher maximum update rate and includes an on-chip 2x/4x/8x interpolating filter with a numerically controlled oscillator (NCO) for digital up-conversion, whereas the AD9775 offers 2x/4x/8x interpolation without the NCO.
Are the AD9778ABSVZ and AD9775BSVZ pin-compatible?
Yes. Both devices are offered in the same 100-lead TQFP-EP (SVZ) package with an identical pinout, which allows board-level interchangeability. However, firmware and register configuration must be adjusted because the two parts have different maximum clock rates and feature sets.
What is the maximum DAC update rate for each device?
The AD9778ABSVZ supports a maximum DAC update rate of 1 GSPS (1,000 MSPS), while the AD9775BSVZ supports a maximum update rate of 400 MSPS. Designs requiring input data rates above 400 MSPS must use the AD9778A.
Do both parts include digital interpolation filters?
Yes. Both the AD9778A and AD9775 integrate selectable 2x, 4x, and 8x interpolating filters. The AD9778A additionally provides a digital quadrature modulator with a 32-bit NCO, enabling digital up-conversion to an intermediate frequency, which the AD9775 does not include.
What is the resolution and channel count of these DACs?
Both the AD9778ABSVZ and AD9775BSVZ are dual-channel (two DACs per package) 14-bit resolution converters, making them suitable for I/Q transmit signal paths in communications systems.
What digital input interface do these DACs use?
Both devices accept parallel CMOS-compatible input data at 14 bits per channel. The AD9778A supports input data rates up to 500 MSPS per channel in dual-port mode, while the AD9775 supports proportionally lower input rates consistent with its 400 MSPS maximum DAC update rate.
Can the AD9775BSVZ be used as a drop-in replacement for the AD9778ABSVZ?
Not as a direct drop-in replacement. Although the package and pinout match, the AD9775 has a lower maximum update rate (400 MSPS vs. 1 GSPS) and lacks the NCO/digital up-conversion feature of the AD9778A. A design operating above 400 MSPS or relying on the NCO must retain the AD9778A or be re-validated for the reduced performance envelope.