Part A
AD7678ASTZRL
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 3901 個数
- Series
- データ取得 - アナログ/デジタルコンバータ (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7671ASTZ and AD7678ASTZRL are both 16-bit successive-approximation ADCs from Analog Devices in the same 48-lead LQFP package, sharing a compatible digital interface and reference architecture. The AD7678ASTZRL offers a higher maximum throughput rate, making it a viable functional upgrade candidate for the AD7671ASTZ in most designs, provided the system timing and power budget are validated against the faster sampling rate.
Resolution
High match
Package Type
High match
Sampling Rate
Validation required
Digital Interface
High match
Parts at a glance
Part B
AD7671ASTZ
テキサス・インスツルメンツ
- Lifecycle
- Active
- Stock
- 3582 個数
- Package
- LQFP-48
- Series
- データ取得 - アナログ/デジタルコンバータ (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 | AD7671ASTZ | AD7678ASTZRL | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 18 bit | Higher resolution provides finer quantization steps, directly affecting achievable accuracy and dynamic range in the conversion result. |
| Sampling Rate | 1 MSPS | 100 kSPS | Maximum throughput determines the highest signal bandwidth the ADC can digitize, so a slower part may not support the same application bandwidth. |
| Input Type | Differential, single-ended | Differential | Input configuration affects how the sensor or signal source must be interfaced; a differential-only part cannot directly accept single-ended signals without additional circuitry. |
| Number of Input Channels | 1 | 1 | Channel count determines how many independent signals can be digitized; both are single-channel devices, so multiplexing is required for multi-signal systems. |
| Supply Voltage (Analog) | 5 V | 5 V | Analog supply voltage must match the system rail; identical values mean the same analog power domain can be reused. |
| Interface | Parallel, Serial (SPI/QSPI/MICROWIRE/DSP) | Serial (SPI/QSPI/MICROWIRE/DSP) | Available digital interfaces determine compatibility with the host processor; the parallel option on one part may be required for high-speed or legacy bus designs. |
| INL (Integral Nonlinearity) | ±2.5 LSB max | ±2.5 LSB max | INL quantifies deviation from an ideal transfer function and bounds absolute accuracy; matching values indicate comparable linearity performance. |
| Package / Mounting | 48-LQFP, Surface Mount | 48-LQFP, Surface Mount | Package and mounting style must match the PCB footprint and assembly process for a drop-in replacement. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Temperature range defines the environments in which the part is guaranteed to meet specifications; matching ranges indicate equivalent environmental robustness. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7678ASTZRL | AD7671ASTZ |
|---|---|---|
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Base Product Number | AD7678 | - |
| Number of Bits | 18 | 16 |
| Sampling Rate (Per Second) | 100k | - |
| 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 | - |
| 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 |
| Mounting Type | Surface Mount | - |
| Packaging | Tape & Reel (TR) | - |
| Sampling Rate(Per Second) | - | 1M |
| Number of A/D Converters | - | 1 |
| Features | - | True Bipolar |
Frequently asked questions
What are the key differences between the AD7671ASTZ and AD7678ASTZRL?
The AD7671ASTZ is a 16-bit, 1 MSPS successive-approximation ADC with a parallel interface, while the AD7678ASTZRL is an 18-bit, 100 kSPS charge-redistribution SAR ADC with a serial SPI-compatible interface. They differ in resolution, throughput, output interface, and package pinout, so they are not drop-in replacements for each other.
Do the AD7671ASTZ and AD7678ASTZRL use the same package and pinout?
No. The AD7671ASTZ is supplied in a 48-lead LQFP, and the AD7678ASTZRL is supplied in a 48-lead LQFP as well, but the pin functions and interface signals differ between the two devices. PCB layout and pin assignments must be verified against each respective datasheet before any substitution is considered.
Can the AD7671ASTZ and AD7678ASTZRL be used interchangeably in an existing design?
No. The AD7671ASTZ provides a parallel output interface at up to 1 MSPS with 16-bit resolution, whereas the AD7678ASTZRL provides a serial interface at up to 100 kSPS with 18-bit resolution. Differences in interface, throughput, timing, and control signals prevent direct interchangeability without redesign and validation.
What are the resolution and throughput specifications of each device?
The AD7671ASTZ offers 16-bit resolution with a maximum throughput of 1 MSPS. The AD7678ASTZRL offers 18-bit resolution with a maximum throughput of 100 kSPS. These differences make the AD7671ASTZ suited to higher-speed acquisition and the AD7678ASTZRL suited to higher-resolution, lower-speed applications.
How do the digital interfaces of the AD7671ASTZ and AD7678ASTZRL differ?
The AD7671ASTZ uses a parallel digital output interface for transferring conversion results, while the AD7678ASTZRL uses a serial SPI-compatible interface. System designers must account for these interface differences in FPGA, DSP, or microcontroller connections and in firmware development.
Are the analog input configurations of the AD7671ASTZ and AD7678ASTZRL the same?
No. The AD7671ASTZ supports differential analog input ranges, and the AD7678ASTZRL also provides differential input capability, but the input voltage ranges, reference requirements, and driving requirements differ between the two devices. The analog front-end must be designed according to the specific datasheet of each part.
Which device is better suited for high-resolution, low-speed precision measurement?
The AD7678ASTZRL is better suited for high-resolution, low-speed precision measurement because it provides 18-bit resolution at up to 100 kSPS. The AD7671ASTZ provides 16-bit resolution at up to 1 MSPS and is better suited to higher-speed applications where 16-bit resolution is sufficient.
What should be verified before considering a design change from one part to the other?
Before any change, verify resolution, throughput, interface type, timing specifications, analog input range, reference requirements, power supply requirements, package pinout, and PCB land pattern against the official manufacturer datasheets. Any substitution must be validated in the target design, as the two devices are not functionally equivalent.