Part A
AD7678ASTZRL
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 3901 PCS
- Series
- Acquisition de données - Convertisseur analogique - numérique (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7678ASTZ and AD7678ASTZRL are functionally identical 18-bit SAR analog-to-digital converters from Analog Devices; the RL suffix denotes tape-and-reel packaging only, so the two part numbers are interchangeable for design and qualification purposes, with the sole distinction being the shipping format.
Resolution and Architecture
High match
Package Type
High match
Electrical Specifications
High match
Packaging and Ordering Format
High match
Parts at a glance
Part B
AD7678ASTZ
Analog Equipment GmbH.
- Lifecycle
- Active
- Stock
- 4894 PCS
- 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 | AD7678ASTZ | AD7678ASTZRL | Why it matters |
|---|---|---|---|
| Resolution | 18 bit | 18 bit | Determines the number of discrete levels the ADC can represent; identical resolution means equivalent measurement granularity. |
| Sampling Rate | 100 kSPS | 100 kSPS | Sets the maximum throughput of the converter; matching rates ensure the same signal bandwidth can be captured. |
| Number of Inputs / Channels | 1 (single-ended) | 1 (single-ended) | Defines how many analog signals can be digitized; identical channel configuration supports direct functional substitution. |
| Architecture | SAR | SAR | The converter architecture affects latency, linearity, and power behavior; matching SAR topology preserves system-level performance. |
| Interface Type | SPI / DSP / Microwire (serial) | SPI / DSP / Microwire (serial) | Determines compatibility with the host controller; identical serial interface allows drop-in replacement without firmware changes. |
| Supply Voltage | 5 V (analog and digital) | 5 V (analog and digital) | Must match the board power rails; identical supply requirements ensure the part can be used in the same circuit. |
| Package / Case | 48-LQFP | 48-LQFP | Footprint and pinout must match for physical interchangeability on the PCB. |
| Mounting Type | Surface Mount | Surface Mount | Assembly method must be compatible with the manufacturing process; identical mounting supports direct substitution. |
| Packaging / Reel | Tray / Tube | Tape & Reel | Packaging format affects automated assembly handling; the RL suffix denotes reel packaging, which matters for pick-and-place production lines. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7678ASTZRL | AD7678ASTZ |
|---|---|---|
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Active |
| Base Product Number | AD7678 | AD7678 |
| Number of Bits | 18 | 18 |
| Sampling Rate (Per Second) | 100k | 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 | 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 |
| Mounting Type | Surface Mount | Surface Mount |
| Packaging | Tape & Reel (TR) | Tray |
Frequently asked questions
What is the difference between AD7678ASTZ and AD7678ASTZRL?
The AD7678ASTZ and AD7678ASTZRL are the same Analog Devices 18-bit, 100 kSPS PulSAR analog-to-digital converter in a 48-lead LQFP package. The suffix "RL" denotes tape-and-reel packaging for automated assembly, while the base AD7678ASTZ is supplied in tray or tube packaging. Electrical performance and die are identical.
Are the AD7678ASTZ and AD7678ASTZRL electrically and functionally interchangeable?
Yes. Both order codes refer to the same AD7678 device (18-bit, 100 kSPS, charge redistribution SAR ADC with internal reference and serial interface). The only difference is the shipping packaging format, so they are interchangeable in circuit design and PCB layout.
What package do the AD7678ASTZ and AD7678ASTZRL use?
Both parts are offered in a 48-lead LQFP (low-profile quad flat package), designated by the "STZ" suffix in the Analog Devices ordering code. The package is RoHS-compliant.
What are the key performance specifications of the AD7678?
The AD7678 is an 18-bit successive-approximation ADC with a throughput of 100 kSPS, an on-chip 2.5 V reference, a serial (SPI/QSPI/MICROWIRE/DSP-compatible) interface, and a pseudo-differential input range of 0 V to 5 V. It operates from a 5 V analog supply and a 2.7 V to 5.25 V digital supply.
Which packaging option should be selected for high-volume production?
For automated pick-and-place SMT lines, the AD7678ASTZRL tape-and-reel format is typically preferred because it supports high-speed reel-fed assembly. The AD7678ASTZ tray/tube format is more common for prototyping, low-volume runs, or manual handling.
Do the AD7678ASTZ and AD7678ASTZRL differ in price or availability?
Pricing and stock levels are set by distributors and can vary between the tray and reel order codes. Buyers should confirm current lead time, minimum order quantity, and unit price with an authorized distributor such as DigiKey, Mouser, or Analog Devices directly, as these commercial parameters change over time.
Are the AD7678ASTZ and AD7678ASTZRL RoHS compliant?
Yes. The "Z" in both order codes indicates a RoHS-compliant, lead-free package finish per Analog Devices ordering conventions. Designers should still verify the current compliance statement on the official Analog Devices product page for the specific lot.