Part A
AD9751ASTZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 3339 Stückzahl
- Package
- LQFP-48
- Series
- Data Acquisition von Digital to Analog Converters (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD9755ASTZRL is a viable functional replacement candidate for the AD9751ASTZ in many designs, as both are 10-bit high-speed TxDAC converters in a 48-lead LQFP package with a parallel CMOS input interface. However, the AD9755 offers a higher maximum update rate and a wider full-scale output current range, so the system clock, output filtering, and current-setting network should be re-validated against the target application before substitution.
Resolution and DAC Architecture
High match
Package and Pin Configuration
High match
Maximum Update Rate
Validation required
Full-Scale Output Current Range
Validation required
Parts at a glance
Part B
AD9755ASTZRL
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 7867 Stückzahl
- 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 | AD9751ASTZ | AD9755ASTZRL | Why it matters |
|---|---|---|---|
| Resolution | 10 bit | 14 bit | Higher resolution provides finer output quantization and lower quantization noise, directly affecting signal fidelity and SFDR performance. |
| Number of DAC Channels | 1 | 1 | Both are single-channel DACs, so channel count is not a differentiator for substitutability. |
| Maximum Update Rate | 300 MSPS | 300 MSPS | Update rate determines the maximum synthesizable output frequency and must match the application's bandwidth requirements. |
| Output Type | Current - Unbuffered | Current - Unbuffered | Current-output DACs require an external I/V stage; matching output type ensures the analog front-end design remains compatible. |
| Supply Voltage | 3.0 V to 3.6 V | 3.0 V to 3.6 V | Supply voltage compatibility ensures the part can drop into the same power rail without redesign. |
| Package / Case | 48-LQFP | 48-LQFP | Identical package and pinout allow direct board-level substitution without layout changes. |
| Operating Temperature Range | -40°C to 85°C | -40°C to 85°C | Matching temperature ranges confirm both parts suit the same environmental conditions. |
| Interface Type | Parallel | Parallel | A matching parallel interface ensures the digital input timing and bus width remain compatible with the host FPGA/ASIC. |
| Mounting Type | Surface Mount | Surface Mount | Both are surface-mount devices, so assembly processes and footprint style are consistent. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD9751ASTZ | AD9755ASTZRL |
|---|---|---|
| Series | TxDAC+® | TxDAC+® |
| Part Status | Active | Discontinued at Digi-Key |
| Number of Bits | 10 | 14 |
| Number of D / A Converters | - | 1 |
| Settling Time | 11ns (Typ) | 11ns (Typ) |
| Output Type | Current - Unbuffered | Current - Unbuffered |
| Differential Output | Yes | Yes |
| Data Interface | Parallel | Parallel |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 3V ~ 3.6V | 3V ~ 3.6V |
| Voltage - Supply, Digital | 3V ~ 3.6V | 3V ~ 3.6V |
| INL / DNL (LSB) | - | ±2.5, ±1.5 |
| Architecture | Current Source | Current Source |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | - | Surface Mount |
| Base Product Number | - | AD9755 |
| Number of D/A Converters | 1 | - |
| INL / DNL(LSB) | ±0.3, ±0.2 | - |
Frequently asked questions
What are the key differences between the AD9751ASTZ and AD9755ASTZRL?
The AD9751ASTZ is a 10-bit, 300 MSPS dual-channel transmit DAC, while the AD9755ASTZRL is a 14-bit, 300 MSPS dual-channel transmit DAC. Both are members of Analog Devices' TxDAC+ family and share the same 48-lead LQFP package and 300 MSPS update rate, but the AD9755ASTZRL offers higher resolution (14-bit vs. 10-bit), which provides improved dynamic range and lower quantization noise for demanding transmit applications.
Are the AD9751ASTZ and AD9755ASTZRL pin-compatible?
Yes. Both devices are offered in the same 48-lead LQFP (ST-48) package and share the same pinout, allowing the AD9755ASTZRL to be used as a higher-resolution drop-in replacement for the AD9751ASTZ in existing PCB layouts, provided the system timing and interface requirements are met.
What is the maximum update rate and resolution of each device?
The AD9751ASTZ provides 10-bit resolution at a maximum update rate of 300 MSPS. The AD9755ASTZRL provides 14-bit resolution at a maximum update rate of 300 MSPS. Both support the same maximum clock frequency, but the AD9755ASTZRL delivers four additional bits of resolution.
What digital input interface do these DACs use?
Both the AD9751ASTZ and AD9755ASTZRL feature a dual-port, interleaved LVCMOS-compatible input interface that accepts data at rates up to 300 MSPS. The AD9755ASTZRL accepts 14-bit input words, while the AD9751ASTZ accepts 10-bit input words, so the driving FPGA or DSP must be configured for the corresponding bus width.
What are the typical power consumption and supply requirements?
Both devices operate from a single 3.0 V to 3.6 V analog and digital supply and typically consume approximately 155 mW at 3.3 V. The AD9755ASTZRL, with its higher resolution, maintains comparable power consumption to the AD9751ASTZ due to the shared TxDAC+ architecture, making both suitable for power-sensitive transmit signal chains.
What are the SFDR and SNR performance differences between the two parts?
The AD9755ASTZRL, with 14-bit resolution, delivers superior spurious-free dynamic range (SFDR) and signal-to-noise ratio (SNR) compared to the 10-bit AD9751ASTZ. The higher resolution of the AD9755ASTZRL reduces quantization noise, resulting in improved spectral purity at the same 300 MSPS output rate, which is critical for wideband communications and instrumentation applications.
Can the AD9755ASTZRL directly replace the AD9751ASTZ in an existing design?
Because both parts share the same 48-lead LQFP package, pinout, supply voltage range, and 300 MSPS update rate, the AD9755ASTZRL can serve as a drop-in replacement for the AD9751ASTZ. However, the system must be verified to support the wider 14-bit input data bus and the associated timing, and the PCB layout should be reviewed for the higher-resolution signal integrity requirements.
What are the typical applications for the AD9751ASTZ and AD9755ASTZRL?
Both devices are intended for high-speed transmit signal chains, including wireless base station transmitters, broadband communications systems, cable modem termination systems, and instrumentation. The AD9755ASTZRL is preferred where higher resolution and better dynamic range are required, while the AD9751ASTZ is suitable for cost-sensitive applications that can tolerate 10-bit resolution.