Part A
AD7674ASTZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4562 PCS
- Package
- LQFP-48
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7674ASTZ and AD7676ASTZRL are both 16-bit successive-approximation ADCs from Analog Devices in the same LQFP-48 package, sharing a compatible digital interface and reference architecture. The AD7674ASTZ offers a faster 800 kSPS throughput versus 500 kSPS for the AD7676ASTZRL, so it can serve as a higher-speed functional substitute where timing margin and power budget permit, while the reverse substitution requires validation against the system's sampling-rate requirements.
Resolution
High match
Package Type
High match
Sampling Rate
Validation required
Digital Interface
High match
Parts at a glance
Part B
AD7676ASTZRL
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 5733 PCS
- Package
- LQFP-48
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7674ASTZ | AD7676ASTZRL | Why it matters |
|---|---|---|---|
| Resolution | 18 bits | 16 bits | Resolution determines the smallest signal change the ADC can resolve; an 18-bit part offers finer quantization than a 16-bit part, affecting achievable dynamic range and precision. |
| Sampling Rate | 800 kSPS | 500 kSPS | Maximum throughput limits the bandwidth of signals that can be digitized; a faster ADC supports higher-frequency inputs or faster multiplexing. |
| Input Type | Differential | Differential | Differential inputs reject common-mode noise and improve distortion performance; matching input topology is essential for drop-in compatibility. |
| INL (Integral Nonlinearity) | ±2.5 LSB max | ±1.5 LSB max | INL specifies deviation from an ideal transfer function; tighter INL yields better absolute accuracy and linearity in measurement systems. |
| SNR (Signal-to-Noise Ratio) | 101 dB typ | 94 dB typ | SNR indicates the noise floor relative to full-scale signal; higher SNR enables detection of smaller signals and better effective resolution. |
| THD (Total Harmonic Distortion) | -110 dB typ | -100 dB typ | THD measures harmonic distortion; lower distortion is critical for spectral purity in AC measurement and communications applications. |
| Supply Voltage | 5 V (analog), 2.7 V to 5 V (digital) | 5 V (analog), 2.7 V to 5 V (digital) | Supply requirements determine power-rail compatibility; matching rails simplifies board-level substitution. |
| Package | 48-lead LQFP | 48-lead LQFP | Package and pinout must match for physical drop-in replacement on an existing PCB footprint. |
| Interface | SPI / Parallel | SPI / Parallel | Digital interface compatibility ensures the host processor can communicate without hardware redesign. |
| Power Consumption | ~90 mW typ | ~70 mW typ | Power dissipation affects thermal budget and supply sizing; lower consumption may be required in power-sensitive designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7674ASTZ | AD7676ASTZRL |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Obsolete |
| Number of Bits | 18 | 16 |
| Sampling Rate(Per Second) | 800k | 500k |
| Number of Inputs | 1 | 1 |
| Input Type | Differential | Differential |
| Data Interface | SPI, Parallel, DSP | SPI, Parallel, DSP |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | External |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the AD7674ASTZ and AD7676ASTZRL?
The AD7674ASTZ is an 18-bit, 800 kSPS charge redistribution SAR ADC, while the AD7676ASTZRL is a 16-bit, 500 kSPS charge redistribution SAR ADC. Both are offered in a 48-lead LQFP package and operate from a 5 V analog supply with a separate digital supply, but they differ in resolution, throughput, and dynamic performance specifications.
Are the AD7674ASTZ and AD7676ASTZRL pin-compatible?
Both devices are specified in the same 48-lead LQFP (ST-48) package, and Analog Devices documents them within the same pinout family for the PulSAR series. However, designers should verify the pin function assignments in each respective datasheet before considering a board-level swap, since configuration and interface pins may differ.
What is the maximum throughput of each device?
The AD7674ASTZ supports a maximum throughput of 800 kSPS, while the AD7676ASTZRL supports a maximum throughput of 500 kSPS. Both use a successive approximation register architecture with a charge redistribution DAC.
What resolution does each ADC provide?
The AD7674ASTZ provides 18-bit resolution with no missing codes, and the AD7676ASTZRL provides 16-bit resolution with no missing codes. The higher resolution of the AD7674ASTZ generally yields better SNR and lower quantization noise, at the cost of reduced throughput.
Do both parts support the same digital interface?
Both devices provide a parallel digital interface and support both serial and parallel host communication modes, with a separate digital supply (VIO) that allows interfacing to 3 V or 5 V logic. Designers should confirm the specific interface timing and mode configuration in each datasheet, as the maximum throughput differs.
What are the analog supply requirements for these ADCs?
Both the AD7674ASTZ and AD7676ASTZRL operate from a 5 V analog supply (AVDD) and a separate digital supply (DVDD/VIO) that can range from 3 V to 5 V, allowing direct connection to lower-voltage logic. Refer to the respective datasheets for exact supply tolerance and decoupling requirements.
Can the AD7676ASTZRL be used as a drop-in replacement for the AD7674ASTZ?
Not as a direct drop-in replacement. Although both are 48-lead LQFP devices in the same PulSAR family, the AD7676ASTZRL offers 16-bit resolution at 500 kSPS versus 18-bit resolution at 800 kSPS for the AD7674ASTZ. A substitution requires validating resolution, throughput, timing, and dynamic performance against the target design requirements and the manufacturer datasheet.
What is the significance of the "RL" suffix on the AD7676ASTZRL part number?
The "RL" suffix denotes tape-and-reel packaging for the AD7676ASTZRL, which is intended for automated surface-mount assembly. The AD7674ASTZ is specified as a tray-packaged device. The electrical performance of the device is not changed by the packaging suffix.