Part A
AD9745BCPZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6274 Stückzahl
- Package
- VFQFN-72
- Series
- Data Acquisition von Digital to Analog Converters (DAC)
Replacement verdict
Compatible functional replacement candidate
The AD9747BCPZ and AD9745BCPZ are pin-compatible dual-channel 16-bit and 12-bit TxDAC+ converters from the same Analog Devices family, sharing the 72-lead LFCSP package, 1.8 V to 3.3 V supply range, and 210 MSPS update rate. The AD9747BCPZ offers higher 16-bit resolution and superior SFDR, while the AD9745BCPZ provides 12-bit resolution at a lower cost. Substitution is viable when the reduced dynamic performance of the 12-bit device still satisfies the system's spectral requirements; otherwise, the AD9747BCPZ should be retained.
Resolution
High match
Package Type
High match
Supply Voltage
High match
Dynamic Performance
Validation required
Parts at a glance
Part B
AD9747BCPZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 5419 Stückzahl
- Package
- VFQFN-72
- 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 | AD9747BCPZ | AD9745BCPZ | Why it matters |
|---|---|---|---|
| Number of DAC Channels | 2 | 2 | Both are dual-channel DACs, so channel count is identical and does not affect substitutability. |
| Resolution | 16 bits | 12 bits | Resolution determines the quantization accuracy of the output; a 16-bit DAC provides finer amplitude steps than a 12-bit DAC, which affects signal fidelity and dynamic range. |
| Maximum Update Rate | 250 MSPS | 250 MSPS | Update rate sets the maximum sample clock; identical rates mean both can support the same signal bandwidth. |
| Output Type | Current (unbuffered) | Current (unbuffered) | Both provide current-output DACs requiring an external transformer or resistor to convert to voltage, so the output interface is compatible. |
| Supply Voltage | 1.8 V to 3.3 V | 1.8 V to 3.3 V | Matching supply ranges allow the parts to be used in the same power domain without redesign. |
| Package | 72-lead LFCSP | 72-lead LFCSP | Identical package and pinout enable drop-in replacement on an existing PCB layout. |
| SFDR | 80 dBc (at 10 MHz output) | 78 dBc (at 10 MHz output) | Spurious-free dynamic range indicates spectral purity; the higher-resolution part typically offers slightly better SFDR, which matters for demanding communication and instrumentation applications. |
| INL | ±4 LSB | ±1 LSB | Integral nonlinearity affects DC accuracy; the 12-bit part's tighter LSB spec reflects its lower resolution, so absolute accuracy must be evaluated in context. |
| Power Consumption | 345 mW (typical) | 345 mW (typical) | Identical power draw means thermal and supply design can remain unchanged when substituting. |
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 | AD9745BCPZ | AD9747BCPZ |
|---|---|---|
| Part Status | Active | Active |
| Number of Bits | 12 | 16 |
| Number of D/A Converters | 2 | 2 |
| Output Type | Current - Unbuffered | Current - Unbuffered |
| Differential Output | Yes | Yes |
| Data Interface | Parallel | Parallel |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 3.13V ~ 3.47V | 3.13V ~ 3.47V |
| Voltage - Supply, Digital | 1.7V ~ 1.9V, 3.13V ~ 3.47V | 1.7V ~ 1.9V, 3.13V ~ 3.47V |
| INL / DNL(LSB) | ±0.25, ±0.13 | ±4, ±2 |
| Architecture | Quad-Switch | Quad-Switch |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD9747BCPZ and AD9745BCPZ?
The AD9747BCPZ is a dual 16-bit, 250 MSPS digital-to-analog converter, while the AD9745BCPZ is a dual 12-bit, 250 MSPS DAC. Both are members of the Analog Devices AD974x family, are pin-compatible in the same 72-lead LFCSP package, and share the same 250 MSPS maximum update rate, but they differ in resolution (16-bit vs 12-bit) and therefore in dynamic performance specifications such as SNR and SFDR.
Are the AD9747BCPZ and AD9745BCPZ pin-compatible?
Yes. Both devices are offered in the same 72-lead LFCSP (CP-72) package with an identical pinout, which allows a common PCB footprint. However, pin compatibility does not guarantee functional equivalence, so the resolution-dependent performance differences must be validated for the target design.
Do the AD9747BCPZ and AD9745BCPZ have the same maximum sample rate?
Yes. Both the AD9747BCPZ and AD9745BCPZ are specified for a maximum update rate of 250 MSPS, so the sample-rate capability is identical between the two parts.
How does resolution differ between the AD9747BCPZ and AD9745BCPZ?
The AD9747BCPZ provides 16-bit resolution per DAC channel, whereas the AD9745BCPZ provides 12-bit resolution per DAC channel. The higher resolution of the AD9747BCPZ generally yields better signal-to-noise ratio and lower quantization noise, which matters in applications requiring wide dynamic range.
Can the AD9745BCPZ be used as a drop-in replacement for the AD9747BCPZ?
Because both parts share the same package and pinout, the AD9745BCPZ can physically occupy the same footprint, but it is not a functional drop-in replacement. The 12-bit AD9745BCPZ has lower resolution and different AC performance than the 16-bit AD9747BCPZ, so system-level performance must be re-verified against the design requirements before substitution.
Do both devices use the same digital interface and supply requirements?
Both the AD9747BCPZ and AD9745BCPZ are members of the same AD974x family and share a common architecture, including a parallel LVCMOS input interface and similar supply rails (1.8 V digital and 3.3 V analog). Designers should still confirm the exact supply and timing specifications in the respective datasheets, since resolution-dependent parameters differ.
Which part should be selected for higher dynamic performance?
The AD9747BCPZ should be selected when higher dynamic performance is required, because its 16-bit resolution provides better SNR and SFDR than the 12-bit AD9745BCPZ. The AD9745BCPZ is appropriate where 12-bit resolution is sufficient and lower cost or reduced data interface width is preferred.