Part A
AD7678ASTZ
ADI公司
- Lifecycle
- Active
- Stock
- 4894 件
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Compatible functional replacement candidate
The AD7678ASTZ and AD7674ASTZRL are both 18-bit, 1 MSPS PulSAR analog-to-digital converters from Analog Devices in the same 48-lead LQFP package, sharing a compatible digital interface and reference architecture. The AD7674ASTZRL offers a faster 800 kSPS maximum sample rate versus the AD7678ASTZ's 100 kSPS, making it a viable functional upgrade candidate where higher throughput is acceptable, though the designer must validate timing, power, and AC performance against the specific application requirements before substitution.
Resolution and Architecture
High match
Package and Pinout
High match
Sample Rate
Validation required
Power Consumption
Validation required
Parts at a glance
Part B
AD7674ASTZRL
ADI公司
- Lifecycle
- Active
- Stock
- 7785 件
- Package
- LQFP-48
- Series
- 資料獲取-模數轉換器（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 | AD7678ASTZ | AD7674ASTZRL | Why it matters |
|---|---|---|---|
| Resolution | 18 bits | 18 bits | Bit depth determines the finest analog signal change the ADC can resolve; both are 18-bit so resolution is equivalent. |
| Sampling Rate | 100 kSPS | 800 kSPS | Maximum throughput dictates the highest signal bandwidth that can be digitized; the AD7674 supports 8x faster sampling. |
| Input Type | Differential | Differential | Differential inputs reject common-mode noise and improve dynamic range; both devices use differential inputs. |
| Architecture | SAR | SAR | Successive-approximation architecture offers no latency and good power efficiency; both share the same SAR core. |
| Supply Voltage (Analog) | 5 V | 5 V | Analog supply defines input range and interface levels; both operate from a 5 V analog supply. |
| Interface | SPI / DSP serial | SPI / DSP serial | Serial interface compatibility determines whether the part can drop into an existing digital bus; both support SPI and DSP serial modes. |
| Power Consumption | ~15 mW typical | ~100 mW typical | Power dissipation affects thermal design and battery life; the higher-speed AD7674 consumes substantially more power. |
| Package | 48-lead LQFP | 48-lead LQFP | Package footprint and pinout determine board-level drop-in compatibility; both use the same 48-lead LQFP. |
| INL (Integral Nonlinearity) | ±2.5 LSB max | ±2.5 LSB max | INL specifies worst-case deviation from an ideal transfer function; matching INL means comparable DC accuracy. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7678ASTZ | AD7674ASTZRL |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Number of Bits | 18 | 18 |
| Sampling Rate(Per Second) | - | 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 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Base Product Number | AD7678 | - |
| Sampling Rate (Per Second) | 100k | - |
| Number of A / D Converters | 1 | - |
| Mounting Type | Surface Mount | - |
| Packaging | Tray | - |
Frequently asked questions
What are the key differences between the AD7678ASTZ and AD7674ASTZRL?
The AD7678ASTZ is an 18-bit, 100 kSPS PulSAR analog-to-digital converter, while the AD7674ASTZRL is an 18-bit, 800 kSPS PulSAR ADC. Both are pin-compatible in a 48-lead LQFP package, but the AD7674ASTZRL offers a significantly higher maximum throughput rate. The AD7678ASTZ is supplied in a tray, whereas the AD7674ASTZRL is supplied in tape-and-reel packaging.
Are the AD7678ASTZ and AD7674ASTZRL pin-compatible?
Yes. Both devices are offered in the same 48-lead LQFP (ST-48) package and share a common pinout, which allows the AD7674ASTZRL to be used as a higher-speed drop-in upgrade for the AD7678ASTZ in existing designs, provided the rest of the system supports the higher throughput.
What is the maximum sampling rate of each device?
The AD7678ASTZ supports a maximum throughput of 100 kSPS, while the AD7674ASTZRL supports a maximum throughput of 800 kSPS. Both are 18-bit, charge redistribution successive approximation (SAR) ADCs.
Do both parts support the same analog input configurations?
Yes. Both the AD7678ASTZ and AD7674ASTZRL feature a differential analog input with a full-scale range of ±VREF and support both differential and single-ended input configurations. They also include an on-chip track-and-hold circuit and a flexible serial and parallel digital interface.
What is the difference in power consumption between the two devices?
The AD7678ASTZ typically dissipates approximately 15 mW at 100 kSPS, while the AD7674ASTZRL typically dissipates approximately 100 mW at 800 kSPS. Both devices offer power-down modes to reduce consumption between conversions, and power scales with throughput.
What are the package and ordering differences between AD7678ASTZ and AD7674ASTZRL?
Both parts use the 48-lead LQFP package. The AD7678ASTZ is supplied in a tray (Z grade, RoHS-compliant), while the AD7674ASTZRL is supplied in tape-and-reel (RL suffix, RoHS-compliant). The "Z" suffix on both indicates RoHS-compliant packaging.
Can the AD7674ASTZRL directly replace the AD7678ASTZ in an existing design?
Because both devices are pin-compatible 48-lead LQFP parts with the same interface and reference requirements, the AD7674ASTZRL can generally serve as a drop-in replacement for the AD7678ASTZ. However, the higher 800 kSPS throughput requires that the host processor, clocking, and power supply be validated to support the increased data rate before substitution.