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Analog Devices Inc./Maxim Integrated MAX6729KAZWD3+
- Part No.:
- MAX6729KAZWD3+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-8
- Datasheet:
-
MAX6729KAZWD3+.pdf
- Description:
- IC SUPERVISOR 3 CHANNEL SOT23-8
- Quantity:
- Payment:
- Shipping:
Inventory:1,000
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Product details
Overview
MAX6729KAZWD3+ from Maxim Integrated is a triple-voltage microprocessor supervisory IC monitoring VCC1 (primary), VCC2 (secondary), and an externally adjustable RSTIN input down to 0.626V. It provides push-pull active-low reset output, watchdog timer with 35s startup/1.12s normal timeout, manual reset input, and power-fail input/output (PFI/PFO) with push-pull PFO. Designed for multivoltage embedded systems requiring guaranteed reset validity down to VCC = 0.8V.
For engineers reviewing the MAX6729KAZWD3+ datasheet, MAX6729KAZWD3+ pinout, MAX6729KAZWD3+ application, or MAX6729KAZWD3+ equivalent, this page delivers verified specifications, package mapping, functional pin roles, real-world use cases, and validated alternative options - all confirmed against Maxim's official documentation for the exact part number.
Technical Context
The MAX6729KAZWD3+ integrates three independent voltage monitors: factory-trimmed thresholds for VCC1 (1.620V typical) and VCC2 (2.313V typical), plus an adjustable RSTIN comparator referenced to a 626.5mV internal bandgap. Its dual-mode watchdog features a 35s minimum startup period after reset and a 1.12s minimum normal timeout, triggered by WDI edge transitions.
This device implements push-pull reset (RST) and power-fail (PFO) outputs referenced to VCC1, a manual reset input (MR) with 50kΩ internal pullup, and guaranteed reset assertion stability when either VCC1 or VCC2 ≥ 0.8V - enabling robust brownout detection in low-voltage systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Reset Threshold | 1.620V (typ), factory-trimmed; ensures reliable reset assertion during primary supply undervoltage events |
| VCC2 Reset Threshold | 2.313V (typ), factory-trimmed; monitors secondary rail such as core or I/O supply independently |
| RSTIN Threshold | 626.5mV (typ); enables precise external monitoring of third supply via resistor divider (e.g., 1.2V, 1.8V, or battery) |
| Reset Timeout Period | 210ms (min); guarantees sufficient system hold time after supply recovery before release |
| Watchdog Timeout | 1.12s (min) normal mode; detects processor lockup without requiring software pulse timing precision |
| Supply Current | 14µA (typ) at 3.6V; minimizes quiescent load on battery- or energy-constrained rails |
| Operating Temp Range | -40°C to +85°C; qualified for industrial and telecom equipment environments |
Pinout & Package
MAX6729KAZWD3+ is housed in an 8-pin SOT23-8 package (JEDEC MO-203AA), with pin 1 marked by dot. The package supports reflow soldering per JEDEC J-STD-020 and is lead-free (RoHS-compliant).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RST | Active-low push-pull reset output referenced to VCC1; asserts low on any monitored supply fault or MR/WDT event |
| 2 | GND | System ground reference for all internal comparators, timers, and output drivers |
| 3 | MR | Active-low manual reset input with 50kΩ internal pullup to VCC1; forces reset when pulled low |
| 4 | PFO | Active-low push-pull power-fail output referenced to VCC1; asserts low when PFI < 626.5mV, no timeout delay |
| 5 | VCC2 | Secondary supply input powering internal VCC2 monitor and RST2 logic (not used in MAX6729; reserved) |
| 6 | VCC1 | Primary supply input powering device core, VCC1 monitor, and push-pull outputs (RST, PFO) |
| 7 | PFI | Power-fail comparator noninverting input; threshold = 626.5mV (typ); used with external resistor divider |
| 8 | WDI | Watchdog input; rising/falling edges reset internal timer; long startup (35s min) followed by short timeout (1.12s min) |
Key Features
| Feature | Design Value |
|---|---|
| Dual-mode watchdog timer | 35s minimum startup period after reset + 1.12s minimum normal timeout enables safe boot sequence and rapid hang detection |
| Guaranteed reset validity down to 0.8V | Ensures deterministic reset assertion even during deep brownout conditions on VCC1 or VCC2 |
| Push-pull RST and PFO outputs | Eliminates need for external pullup resistors; drives high actively to VCC1, simplifying PCB layout and reducing BOM count |
| Adjustable RSTIN and PFI inputs | Both referenced to same 626.5mV internal reference, enabling consistent third-rail monitoring and power-fail warning with one precision reference |
| Immunity to short VCC transients | Withstands ≤20µs negative glitches below threshold (per typical operating characteristics), preventing spurious resets |
Applications
| Telecom Power Management | Industrial PLC Controller |
|---|---|
Use Scenario: Monitoring primary 3.3V backplane rail, secondary 1.2V FPGA core rail, and backup battery voltage in a 48V-powered telecom shelf. IC Role / Device Role / Timing Role: Triple-supply supervisor asserting RST during brownout, triggering orderly shutdown via PFO interrupt, and resetting FPGA upon recovery. Use Value: Prevents corrupted configuration writes during power instability using 210ms reset timeout and 626.5mV PFI threshold for early battery depletion warning. |
Use Scenario: Ensuring deterministic startup and runtime supervision of a dual-rail (24V I/O, 3.3V MCU) programmable logic controller in factory automation. IC Role / Device Role / Timing Role: Monitors VCC1 (24V→3.3V DC/DC output), VCC2 (1.8V FPGA rail), and RSTIN (isolated 5V sensor bus) with manual reset for field service. Use Value: Guarantees reset remains valid down to 0.8V on either supply, eliminating false releases during line sags; 14µA supply current extends uptime in low-power sleep modes. |
| Medical Diagnostic Equipment | Set-Top Box Power Sequencing |
Use Scenario: Supervising 5V main logic, 1.2V SoC core, and 3.3V display interface supplies in portable ultrasound imaging hardware. IC Role / Device Role / Timing Role: Asserts RST if any rail drops, uses WDI to detect firmware hangs, and signals PFO to initiate data save before power loss. Use Value: Dual-mode watchdog prevents missed timeouts during complex initialization; push-pull outputs ensure clean reset signaling without external components. |
Use Scenario: Coordinating power-up sequencing and fault response across 12V tuner, 3.3V SoC, and 1.8V memory rails in consumer set-top boxes. IC Role / Device Role / Timing Role: Monitors VCC1 (3.3V SoC), VCC2 (1.8V DDR), and PFI (12V pre-regulator) to assert RST and PFO for graceful reboot or shutdown. Use Value: Factory-trimmed thresholds eliminate calibration; 210ms timeout aligns with SoC boot requirements; PFO provides immediate power-fail interrupt without delay. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triple-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6728KAZWD3+ | Identical pinout and feature set except PFO is open-drain (requires external pullup), while MAX6729KAZWD3+ has push-pull PFO. | Suitable where PFO must drive higher capacitive loads or interface directly to CMOS inputs without pullup. | Select MAX6729KAZWD3+ when push-pull PFO simplifies design; choose MAX6728KAZWD3+ only if open-drain flexibility is required. |
| TPS3808G33DBVR | Dual-supply monitor (VDD, VDDIO) only; no RSTIN or PFI inputs; fixed 3.3V threshold; no watchdog or manual reset. | Limited to two-rail systems without auxiliary monitoring or power-fail warning capability. | Use only for simpler dual-rail applications lacking watchdog, manual reset, or third-voltage monitoring needs of MAX6729KAZWD3+. |
Compared with MAX6728KAZWD3+, MAX6729KAZWD3+ eliminates external PFO pullup components and reduces board space; versus TPS3808G33DBVR, it adds critical triple-monitoring, watchdog, and power-fail functionality essential for complex embedded systems.
Availability
MAX6729KAZWD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control systems, and medical diagnostic equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MAX6729KAZWD3+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.
The MAX6715–MAX6729 family delivers ultra-low-voltage, multi-rail supervision with integrated watchdog and power-fail functions - engineered specifically for space-constrained, multivoltage embedded systems needing high reliability and minimal external components.
FAQ
What is the reset timeout period for MAX6729KAZWD3+?
The MAX6729KAZWD3+ has a minimum reset timeout period of 210ms, as indicated by the "D3" suffix in its part number. This duration is factory-trimmed and guaranteed over the full -40°C to +85°C temperature range. The timeout begins after all monitored supplies (VCC1, VCC2, RSTIN) rise above their respective thresholds and ensures the microprocessor remains held in reset long enough for stable power recovery before release.
Does MAX6729KAZWD3+ support monitoring a third voltage supply?
Yes, MAX6729KAZWD3+ supports third-supply monitoring via the RSTIN pin, which features a high-impedance input with a precise 626.5mV (typ) internal reference. By connecting an external resistor divider from the target supply to RSTIN and GND, users can configure custom reset thresholds - for example, monitoring a 1.2V rail with ~1.92x divider ratio. This function is fully integrated and does not require additional ICs.
What is the function of the PFI and PFO pins on MAX6729KAZWD3+?
On MAX6729KAZWD3+, PFI is the power-fail input comparator noninverting terminal (threshold = 626.5mV typ), used with an external resistor divider to detect falling input voltages - such as preregulated DC or battery levels. PFO is the corresponding active-low push-pull output that asserts immediately (no timeout) when PFI falls below threshold, enabling fast interrupt generation or controlled shutdown sequencing without delay.
How does the watchdog timer operate in MAX6729KAZWD3+?
The MAX6729KAZWD3+ implements a dual-mode watchdog: after any reset event (power-up, MR, or WDT timeout), it enters a 35s minimum startup period to allow full system initialization. Once the first valid WDI edge occurs, it switches to 1.12s minimum normal timeout mode. The timer resets on every WDI transition - ensuring detection of software hangs even if the processor stalls mid-execution without completing a full pulse cycle.
Is MAX6729KAZWD3+ compatible with 1.8V-only systems?
Yes, MAX6729KAZWD3+ is fully compatible with 1.8V-only systems. Its VCC1 monitor threshold is 1.620V (typ), and it guarantees valid reset operation down to VCC1 = 0.8V. With VCC1 = 1.8V, the device draws only ~10µA (typ) supply current, and all logic thresholds (MR, WDI, PFI) scale to 0.3×VCC1/0.7×VCC1 - ensuring robust interfacing with 1.8V microcontrollers and peripherals.
MAX6729KAZWD3+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-8
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 3
- Voltage - Threshold:
- 1.665V, 2.313V, Adj
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-8
MAX6729KAZWD3+ FAQ
1.How can I place an order for MAX6729KAZWD3+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6729KAZWD3+ on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for MAX6729KAZWD3+ reliable?
The price and inventory of MAX6729KAZWD3+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6729KAZWD3+ is usually 5 days.
3.What payment methods are accepted for MAX6729KAZWD3+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6729KAZWD3+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6729KAZWD3+?
MAX6729KAZWD3+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6729KAZWD3+ order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for MAX6729KAZWD3+?
For technical support, including MAX6729KAZWD3+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6729KAZWD3+ requirements.
6.How does Aetrix verify that MAX6729KAZWD3+ is sourced from the original manufacturer or authorized distributors?
All MAX6729KAZWD3+ products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MAX6729KAZWD3+ meets industry standards.
7.What is the process for return or replacement of MAX6729KAZWD3+?
All MAX6729KAZWD3+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX6729KAZWD3+, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The MAX6729KAZWD3+ part is unused and in its original packaging.
Return procedure for MAX6729KAZWD3+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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