Part A
ADM691ARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 4235 PCS
- Package
- SOIC-16
- Series
- PMIC - Supervisores
Replacement verdict
Compatible functional replacement candidate
The ADM691ARZ and ADM691AARN are functionally equivalent microprocessor supervisory circuits from the same ADM691A family, sharing identical core functionality, threshold options, and electrical characteristics. The primary distinction is the package type: the ARZ suffix denotes a 16-lead SOIC (narrow body) package, while the ARN suffix denotes a 16-lead TSSOP package. Both devices are suitable for direct functional substitution in supervisory circuit applications, provided the PCB footprint is adjusted to accommodate the respective package. Designers should verify thermal and layout considerations for the target package before finalizing the replacement.
Function Type
High match
Electrical Specifications
High match
Package Type
Validation required
Pin Configuration
High match
Parts at a glance
Part B
ADM691AARN
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 8217 PCS
- Package
- SOIC-16
- Series
- PMIC - Supervisores
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADM691ARZ | ADM691AARN | Why it matters |
|---|---|---|---|
| Package / Mounting Type | 16-SOIC (0.295", 7.50mm Width), Surface Mount | 16-SOIC (0.154", 3.90mm Width), Surface Mount | The two parts use different SOIC body widths, so PCB land patterns and board space requirements differ; they are not drop-in footprint replacements. |
| Manufacturer Part Number Suffix / Package Code | ARZ (wide-body SOIC, RoHS) | ARN (narrow-body SOIC) | The suffix encodes package variant and lead finish, which determines mechanical fit and compliance status on the assembly. |
| Function | Microprocessor supervisory circuit (power supply monitor with watchdog, reset, and battery switchover) | Microprocessor supervisory circuit (power supply monitor with watchdog, reset, and battery switchover) | Identical core function means both can serve the same supervisory role in a design; substitutability hinges on package and electrical limits. |
| Reset Threshold Voltage | 4.65 V (typical) | 4.65 V (typical) | The reset threshold sets the supply voltage at which the system is held in reset; matching values preserve the same brownout behavior. |
| Supply Voltage Range | 4.75 V to 5.5 V | 4.75 V to 5.5 V | Both operate from a standard 5 V rail within the same window, so power supply design is unchanged between the two. |
| Watchdog Timeout | 1.6 s (typical) | 1.6 s (typical) | The watchdog timeout determines how long the processor may stall before a reset is issued; identical timing keeps firmware timing margins valid. |
| Number of Pins | 16 | 16 | Equal pin count means the same schematic symbol and net assignments apply, simplifying substitution at the design level. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching industrial temperature ratings ensure both parts meet the same environmental requirements in the application. |
| RoHS Compliance | RoHS compliant | RoHS compliant | Both meet RoHS, so environmental compliance documentation and lead-free assembly processes remain consistent. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM691ARZ | ADM691AARN |
|---|---|---|
| Part Status | Active | Obsolete |
| Type | Battery Backup Circuit | Battery Backup Circuit |
| Number of Voltages Monitored | 1 | 1 |
| Voltage - Threshold | 4.65V | 4.65V |
| Output | Open Drain, Push-Pull | Open Drain, Push-Pull |
| Reset | Active High/Active Low | Active High/Active Low |
| Reset Timeout | 35ms Minimum | 140ms Minimum |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the ADM691ARZ and ADM691AARN?
Both are microprocessor supervisory circuits from Analog Devices (originally Analog Devices, now part of Analog Devices, Inc.) that monitor power supplies and provide reset output, watchdog timing, and manual reset functions for microprocessor-based systems. They are functionally identical devices; the difference is the package option.
What is the difference between the ADM691ARZ and ADM691AARN?
The ADM691ARZ is supplied in a 16-lead SOIC (narrow body) package, while the ADM691AARN is supplied in a 16-lead PDIP (plastic dual in-line) package. Both are specified over the industrial temperature range and share the same electrical functionality and pinout.
Are the ADM691ARZ and ADM691AARN electrically interchangeable?
Yes. The two parts share the same die and electrical specifications; the only difference is the package type (SOIC vs PDIP). They are interchangeable electrically, but the PCB footprint and assembly process must match the respective package.
What supply voltage range do the ADM691ARZ and ADM691AARN support?
Both devices operate from a +5 V supply and are designed for 5 V microprocessor systems. They monitor the supply and assert a reset when the voltage falls below the specified reset threshold.
What output configuration do the ADM691ARZ and ADM691AARN provide?
Both devices provide an active-low reset output (RESET) and an active-high reset output (RESET-bar complement), along with a watchdog input and a manual reset input. The reset outputs are push-pull CMOS-compatible drivers.
Can the ADM691ARZ be used as a drop-in replacement for the ADM691AARN on an existing PCB?
No. Although electrically equivalent, the ADM691ARZ is an SOIC package and the ADM691AARN is a PDIP package. A drop-in replacement requires matching the PCB land pattern and assembly footprint; the packages are not footprint-compatible.
What is the watchdog timeout function on the ADM691ARZ and ADM691AARN?
Both devices include a watchdog timer that monitors microprocessor activity via the WDI pin. If the microprocessor fails to toggle WDI within the watchdog timeout period, the watchdog output (WDO) is asserted to signal a fault condition.
Which package should be selected for a new design, ADM691ARZ or ADM691AARN?
For new surface-mount designs, the ADM691ARZ (16-lead SOIC) is typically preferred for automated assembly and board space efficiency. The ADM691AARN (16-lead PDIP) is suited for through-hole prototyping, socketed applications, or legacy boards requiring a DIP footprint.