Part A
AD7667ASTZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6318 PCS
- Package
- LQFP-48
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The AD7667ASTZ is a Pb-free, RoHS-compliant version of the AD7667AST and is form, fit, and function compatible, making it a suitable drop-in replacement where environmental compliance is required. Both parts share identical core analog-to-digital converter specifications, differing only in package plating and environmental qualification.
Resolution and Sample Rate
High match
Package Type and Pinout
High match
RoHS Compliance
Not compatible
Operating Temperature Range
High match
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AD7667ASTZ | AD7667AST | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both parts provide identical conversion resolution, so accuracy and LSB size are unchanged. |
| Sampling Rate | 1 MSPS | 1 MSPS | Identical throughput means timing budgets and maximum input frequency handling are the same. |
| Number of Inputs / Configuration | 1 single-ended input | 1 single-ended input | Same input topology allows direct substitution in the signal chain without rewiring. |
| Architecture | SAR | SAR | Same SAR architecture preserves latency, no pipeline delay, and similar noise behavior. |
| Interface Type | Parallel / Serial (SPI, QSPI, MICROWIRE, DSP) | Parallel / Serial (SPI, QSPI, MICROWIRE, DSP) | Identical digital interface options ensure the same host controller connections work for both. |
| Supply Voltage | 5 V analog supply, 2.7 V to 5.25 V digital supply | 5 V analog supply, 2.7 V to 5.25 V digital supply | Same supply requirements mean the existing power design supports either part. |
| Package / Mounting | 48-LQFP, surface mount | 48-LQFP, surface mount | Identical package and footprint allow drop-in board replacement without layout changes. |
| RoHS / Lead-Free Status | RoHS compliant, lead-free (Z suffix) | Non-RoHS, contains lead | The Z suffix denotes lead-free/RoHS compliance, which affects regulatory compliance and solder process compatibility. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Same industrial temperature range means both suit the same environmental conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AD7667ASTZ | AD7667AST |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | PulSAR® | PulSAR® |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 1M | 1M |
| Number of A/D Converters | 1 | 1 |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Number of Inputs | 1 | - |
| Input Type | Pseudo-Differential | - |
| Data Interface | SPI, Parallel, DSP | - |
| Configuration | S/H-ADC | - |
| Ratio - S / H: ADC | 1:1 | - |
| Architecture | SAR | - |
| Reference Type | External, Internal | - |
| Voltage - Supply, Analog | 5V | - |
| Voltage - Supply, Digital | 5V | - |
Frequently asked questions
What is the difference between the AD7667ASTZ and the AD7667AST?
The AD7667ASTZ and AD7667AST are functionally identical 16-bit, 1 MSPS PulSAR analog-to-digital converters. The suffix "Z" denotes RoHS-compliant packaging per Analog Devices' part numbering convention, while the AD7667AST is the non-RoHS version. Both are supplied in a 48-lead LQFP package and share the same electrical specifications.
Are the AD7667ASTZ and AD7667AST electrically and functionally interchangeable?
Yes. Both parts share the same datasheet specifications: 16-bit resolution, 1 MSPS throughput, SAR architecture, and identical pinout in the 48-lead LQFP package. The only documented distinction is RoHS compliance indicated by the "Z" suffix, so they are interchangeable in designs where RoHS status is not a constraint.
What are the key performance specifications of the AD7667?
The AD7667 is a 16-bit, 1 MSPS successive-approximation ADC with an internal 2.5 V reference, a pseudo-differential input range of 0 V to 2.5 V (with REF), and typical SNR of approximately 90 dB. It operates from a 5 V analog supply with a separate 2.7 V to 5.25 V digital supply and includes a serial and parallel interface.
Does the "Z" suffix affect the package or pinout?
No. The "Z" suffix in Analog Devices' part numbering indicates RoHS-compliant construction and does not change the package outline, pin assignments, or PCB land pattern. Both the AD7667ASTZ and AD7667AST use the same 48-lead LQFP footprint.
Which part should be selected for a new RoHS-compliant design?
The AD7667ASTZ should be selected for new designs requiring RoHS compliance, as the "Z" suffix confirms lead-free, RoHS-compliant packaging. The AD7667AST is the non-RoHS variant and is generally not recommended for new designs subject to RoHS directives.
Can the AD7667AST be used as a drop-in replacement for the AD7667ASTZ?
Electrically and mechanically, yes, since both share the same die, package, and pinout. However, substituting the non-RoHS AD7667AST for the RoHS-compliant AD7667ASTZ may violate RoHS compliance requirements of the end product, so the substitution should be evaluated against the applicable regulatory and customer requirements.
What interface options does the AD7667 provide?
The AD7667 provides both a serial interface and a parallel interface for connecting to host processors or DSPs. It also supports daisy-chaining of multiple converters in serial mode, which allows several AD7667 devices to share a single serial port on the host.