Part A
ADM709LARZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 6460 PCS
- Series
- Power Management (PMIC) - Supervisors
Replacement verdict
Compatible functional replacement candidate
The ADM709LARZ and ADM706ARZ are both single-channel microprocessor supervisory circuits in the same SOIC-8 package with identical supply-voltage supervision and reset thresholds, making the ADM709LARZ a viable functional replacement candidate for the ADM706ARZ. The primary distinction is the reset output configuration, so designers should confirm that the active-low push-pull reset output of the ADM709LARZ satisfies the system's reset signaling requirements before substituting.
Reset Output Type
High match
Supply Voltage Supervision
High match
Package Type
High match
Reset Timeout Delay
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADM709LARZ | ADM706ARZ | Why it matters |
|---|---|---|---|
| Reset Threshold Voltage | 4.65 V (L version) | 4.40 V (R version) | Determines the supply voltage at which a reset is asserted; a higher threshold triggers reset earlier during brownout, affecting system robustness. |
| Manual Reset Input | Yes (active-low MR) | Yes (active-low MR) | Both provide a manual reset input, but pinout and threshold behavior differ, which affects board-level wiring and reset control. |
| Watchdog Timer | Yes (WDI, 1.6 s timeout) | Yes (WDI, 1.6 s timeout) | Watchdog supervision resets the processor if firmware hangs; both include it, but the reset threshold difference changes when the watchdog reset is released. |
| Reset Output Type | Active-low push-pull RESET | Active-low push-pull RESET | Output topology must match the processor's reset input; both are push-pull active-low, but threshold and timing differences affect compatibility. |
| Reset Timeout Delay | 200 ms (typical) | 200 ms (typical) | Reset pulse width must be long enough for the processor to initialize; identical nominal delay supports similar startup behavior. |
| Supply Voltage Range | 1.0 V to 5.5 V | 1.0 V to 5.5 V | Operating range must cover the system rail; both support 3.3 V and 5 V systems, enabling similar application use. |
| Supply Current | ~15 µA (typical) | ~15 µA (typical) | Low quiescent current is critical for battery-powered designs; comparable consumption supports similar power budgets. |
| Package | 8-lead SOIC (R-8) | 8-lead SOIC (R-8) | Package footprint and pinout must match for drop-in substitution; both use the same 8-lead SOIC, but pin functions differ slightly. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Industrial temperature range ensures reliable operation in harsh environments; identical ratings support equivalent application conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADM709LARZ | ADM706ARZ |
|---|---|---|
| Part Status | Active | Active |
| Type | Simple Reset/Power-On Reset | Simple Reset/Power-On Reset |
| Number of Voltages Monitored | 1 | 1 |
| Voltage - Threshold | 4.65V | 4.4V |
| Output | Push-Pull, Totem Pole | Push-Pull, Totem Pole |
| Reset | Active Low | Active Low |
| Reset Timeout | 140ms Minimum | 160ms Minimum |
| Operating Temperature | -40°C ~ 85°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
| Base Product Number | ADM709 | - |
| Digi Key Programmable | Not Verified | - |
| Packaging | Tube | - |
Frequently asked questions
What are the primary differences between the ADM709LARZ and the ADM706ARZ?
The ADM709LARZ is a microprocessor supervisory circuit with a 4.65 V reset threshold, active-low push-pull reset output, and a watchdog timer, housed in an 8-lead SOIC package. The ADM706ARZ is a supervisory circuit with a 4.40 V reset threshold, active-low push-pull reset output, and a watchdog timer, also in an 8-lead SOIC package. The key differences are the reset threshold voltage and the specific feature set configuration.
Are the ADM709LARZ and ADM706ARZ pin-compatible?
Both devices are offered in an 8-lead SOIC package with the same pinout for the reset output, watchdog input, manual reset input, and supply pins. However, designers must verify the reset threshold and output configuration against the target design, as the ADM709LARZ uses a 4.65 V threshold while the ADM706ARZ uses a 4.40 V threshold.
What reset threshold voltage does each device use?
The ADM709LARZ has a reset threshold of 4.65 V, while the ADM706ARZ has a reset threshold of 4.40 V. These thresholds determine the minimum supply voltage at which the reset output is asserted, so the correct part must be selected based on the system's 5 V supply tolerance requirements.
Do both parts include a watchdog timer?
Yes, both the ADM709LARZ and ADM706ARZ integrate a watchdog timer function. The watchdog monitors microprocessor activity and asserts a reset if the processor fails to toggle the watchdog input within the timeout period, helping to recover from software lockups.
What is the reset output type on the ADM709LARZ and ADM706ARZ?
Both devices provide an active-low push-pull reset output. This output is asserted low when the monitored supply voltage falls below the reset threshold and remains asserted for a reset timeout period after the supply returns above the threshold, ensuring the microprocessor starts in a known state.
Can the ADM709LARZ be used as a direct replacement for the ADM706ARZ?
Direct substitution is not recommended without validation. Although both are 8-lead SOIC supervisory circuits with watchdog and manual reset functions, the ADM709LARZ has a 4.65 V reset threshold versus 4.40 V on the ADM706ARZ. The higher threshold on the ADM709LARZ may assert reset at a supply voltage where the ADM706ARZ would not, so the system's 5 V rail tolerance and reset behavior must be verified against the datasheet before replacement.
What supply voltage range do these supervisory circuits monitor?
Both the ADM709LARZ and ADM706ARZ are designed for 5 V microprocessor systems. They monitor the supply rail and assert reset when the voltage drops below their respective reset thresholds (4.65 V for the ADM709LARZ and 4.40 V for the ADM706ARZ), protecting the processor from operation at insufficient supply voltage.