Part A
AD7677ASTZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 1648 PCS
- Package
- LQFP-48
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7677ASTZ is a viable functional replacement candidate for the AD7674ASTZ, sharing the same 18-bit SAR architecture, 48-lead LQFP package, and identical pinout. Designers must validate the higher throughput requirement and confirm the reference and supply configuration in the target application before substitution.
Resolution and Architecture
High match
Package and Pinout
High match
Sampling Rate
Validation required
Supply and Reference Configuration
Validation required
Parts at a glance
Part B
AD7674ASTZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4562 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 | AD7677ASTZ | Why it matters |
|---|---|---|---|
| Resolution | 18 bits | 16 bits | Resolution determines the smallest signal change the ADC can distinguish; an 18-bit part offers 4x finer quantization than a 16-bit part, affecting achievable dynamic range and precision in the application. |
| Maximum Sampling Rate | 800 kSPS | 1 MSPS | The throughput rate sets the highest signal bandwidth that can be digitized; the AD7677 supports a faster conversion rate, which matters for higher-frequency or multiplexed acquisition systems. |
| INL (Integral Nonlinearity) | ±2.5 LSB max | ±1.0 LSB max | INL describes deviation from an ideal transfer function; tighter INL improves absolute accuracy and linearity, which is critical for precision measurement and instrumentation applications. |
| 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 in noise-sensitive designs. |
| Input Type | Differential | Differential | Differential inputs reject common-mode noise and improve distortion performance; both parts share this architecture, so the input front-end design can be reused. |
| Supply Voltage (Analog) | 5 V | 5 V | The analog supply defines the input range and interface levels; matching 5 V supplies means the same reference and driver circuitry can be used for either part. |
| Power Consumption | ~110 mW typ | ~90 mW typ | Power dissipation affects thermal budget and supply sizing; lower consumption in the AD7677 benefits portable or densely packed systems. |
| Package | 48-lead LQFP | 48-lead LQFP | Package and pinout compatibility determines whether a part can be dropped into an existing PCB footprint; identical LQFP packages simplify substitution. |
| Interface | Parallel / Serial (SPI-compatible) | Parallel / Serial (SPI-compatible) | The digital interface must match the host controller; shared parallel and serial options allow flexible system integration for both parts. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7677ASTZ | AD7674ASTZ |
|---|---|---|
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Number of Bits | 16 | 18 |
| Sampling Rate(Per Second) | 1M | 800k |
| 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 | External, Internal |
| 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 AD7677ASTZ?
The AD7674ASTZ is an 18-bit, 800 kSPS charge redistribution SAR ADC, while the AD7677ASTZ is a 16-bit, 1 MSPS charge redistribution SAR ADC. The AD7674ASTZ offers higher resolution (18-bit) at a lower throughput, whereas the AD7677ASTZ provides faster sampling (1 MSPS) at 16-bit resolution. Both are housed in a 48-lead LQFP package and operate from a 5 V analog supply with a separate digital supply.
Are the AD7674ASTZ and AD7677ASTZ pin-compatible?
Yes. Both devices are specified in the same 48-lead LQFP (ST-48) package and share a common pinout, which allows them to be used interchangeably on the same PCB footprint. However, firmware and timing must be validated because resolution and throughput differ.
What are the throughput and resolution specifications of each device?
The AD7674ASTZ provides 18-bit resolution with a maximum throughput of 800 kSPS. The AD7677ASTZ provides 16-bit resolution with a maximum throughput of 1 MSPS. Both use a successive approximation register (SAR) architecture with an internal sample-and-hold circuit.
Do both ADCs support the same analog input range and interface?
Both devices offer a differential analog input with a full-scale range of ±VREF (typically 5 V with a 5 V reference) and support a parallel and serial digital interface. The AD7674ASTZ and AD7677ASTZ both feature a SPI/QSPI/MICROWIRE/DSP-compatible serial port and a parallel interface, allowing direct connection to microcontrollers and DSPs.
What are the power supply requirements for the AD7674ASTZ and AD7677ASTZ?
Both devices operate from a 5 V analog supply (AVDD) and a separate digital supply (DVDD) that can range from 2.7 V to 5.25 V, enabling direct interfacing to 3 V logic. Typical power consumption is approximately 100 mW for the AD7674ASTZ and 90 mW for the AD7677ASTZ at their respective maximum throughputs.
Can the AD7677ASTZ be used as a drop-in replacement for the AD7674ASTZ in an existing design?
Because both parts are pin-compatible in the 48-lead LQFP package, the AD7677ASTZ can be placed on the same footprint. However, it is not a direct functional replacement: the AD7677ASTZ provides 16-bit resolution instead of 18-bit and a higher throughput of 1 MSPS versus 800 kSPS. System firmware, timing, and accuracy budgets must be revalidated before substitution.
What are the typical applications for the AD7674ASTZ and AD7677ASTZ?
Both ADCs are suited for high-speed data acquisition, medical imaging, instrumentation, spectrum analyzers, and industrial process control. The AD7674ASTZ is preferred where 18-bit accuracy is required at up to 800 kSPS, while the AD7677ASTZ is chosen for 16-bit applications requiring up to 1 MSPS throughput.