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Analog Devices Inc./Maxim Integrated MAX6729AKASYD3+T
- Part No.:
- MAX6729AKASYD3+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-8
- Datasheet:
-
MAX6729AKASYD3+T.pdf
- Description:
- IC SUPERVISOR MPU SOT23-8
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
The MAX6729AKASYD3+T from Maxim Integrated is a dual-supply ultra-low-voltage microprocessor supervisory circuit with triple-voltage monitoring capability (VCC1, VCC2, and RSTIN), factory-trimmed reset thresholds, 140ms minimum reset timeout, push-pull active-low RST output, and integrated power-fail comparator (PFI/PFO). It guarantees valid reset assertion down to VCC1 or VCC2 = 0.8V and operates across –40°C to +125°C - used in telecom power systems for reliable brownout detection and orderly shutdown.
For engineers reviewing the MAX6729AKASYD3+T datasheet, MAX6729AKASYD3+T pinout, MAX6729AKASYD3+T application, or MAX6729AKASYD3+T equivalent, key selection criteria include its dual-supply monitoring architecture, 140ms reset timeout (suffix D3), 0.626V internal reference for RSTIN, PFI/PFO power-fail interface, and SOT23-8 package compatibility with multivoltage embedded control systems.
Technical Context
This device implements independent voltage comparators for VCC1 (1.58V–4.63V thresholds) and VCC2 (0.79V–3.08V), plus a high-impedance RSTIN input referenced to a 626mV internal bandgap. Its reset logic asserts RST low when any monitored supply falls below threshold and holds for a fixed 140ms timeout after recovery.
The MAX6729AKASYD3+T integrates a power-fail comparator (PFI → PFO) with 2µs propagation delay and 3mV hysteresis, a manual-reset input (MR) with 50kΩ internal pullup to VCC1, and supports watchdog disable via open WDI. All functions operate with guaranteed reset validity at VCC ≥ 0.8V and 14µA typical supply current at 3.6V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Range | 0.8V to 5.5V - powers device and enables primary supply monitoring down to ultralow voltages |
| VCC2 Range | 0.8V to 5.5V - powers secondary monitoring path and supports core/logic rail supervision |
| RSTIN Threshold | 626mV (typ) - enables precise external voltage monitoring via resistor divider (e.g., 0.62V–5V range) |
| Reset Timeout | 140ms (min) - ensures sufficient processor reset hold time for stable boot in telecom/server applications |
| Supply Current | 14µA (typ) at 3.6V - minimizes quiescent load in battery-backed or energy-sensitive systems |
| Operating Temp | –40°C to +125°C - qualified for under-hood automotive, industrial PLC, and base station environments |
| PFI Threshold | 626.5mV (typ) - provides early warning of input rail collapse before main supplies fail |
Pinout & Package
MAX6729AKASYD3+T is housed in an 8-pin SOT23 package (package code K8SN+1, outline 21-0078), with thermal resistance θJA = 180°C/W on multilayer board. Pin functions are validated per Maxim's official pin description table for MAX6728A/MAX6729A/MAX6797A variants.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RST / RST1 | Active-low push-pull reset output referenced to VCC1; asserts when VCC1/VCC2/RSTIN drop or MR is pulled low |
| 2 | GND | System ground reference for all comparators, timers, and I/O |
| 3 | MR | Active-low manual-reset input with 50kΩ internal pullup to VCC1; debounced by 1µs pulse width requirement |
| 4 | VCC2 | Secondary supply input powering VCC2 comparator and RST2 output stage (if present); also used as reference for PFO push-pull high level |
| 5 | VCC1 | Primary supply input powering core logic, VCC1 comparator, RST/RST1/PFO drivers, and MR pullup |
| 6 | PFI | Power-fail monitor input with 626.5mV threshold; high-impedance node for external resistor-divider network |
| 7 | PFO | Active-low push-pull power-fail output referenced to VCC1; deasserts immediately (no timeout) when PFI rises above threshold |
| 8 | RSTIN | Adjustable reset input with 626mV internal reference; enables third-voltage monitoring (e.g., analog rail, battery sense) |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent supply monitors | VCC1 (1.58–4.63V) and VCC2 (0.79–3.08V) thresholds factory-trimmed for ±1.5% accuracy over temperature |
| Triple-voltage supervision | RSTIN input extends monitoring to third rail (e.g., 0.62V–5V) using external resistor divider without added ICs |
| Power-fail interrupt generation | PFI/PFO pair delivers sub-2µs response to input rail collapse - enables firmware-triggered graceful shutdown |
| Guaranteed reset at low VCC | Valid RST assertion maintained even when VCC1 or VCC2 drops to 0.8V - critical for brownout resilience |
| Low-power operation | 14µA typical ICC at 3.6V enables use in always-on subsystems without compromising battery life |
Applications
| Telecom Power Management | Industrial PLC Control |
|---|---|
|
Use Scenario: Monitoring primary 3.3V system rail and auxiliary 1.2V FPGA core supply in 48V-powered telecom shelf controllers. IC Role / Device Role / Timing Role: Dual-supply supervisor asserting RST during simultaneous brownout on both rails; PFO triggers NMI interrupt for backup power switchover. Use Value: Prevents corrupted FPGA configuration and ensures deterministic restart within 140ms after AC loss. |
Use Scenario: Supervising 24V fieldbus input and isolated 5V logic supply in DIN-rail mounted programmable logic controller. IC Role / Device Role / Timing Role: VCC1 monitors 24V-to-5V DC-DC output; VCC2 tracks isolated 3.3V MCU rail; MR enables front-panel reset button. Use Value: Eliminates need for discrete voltage detectors and RC timing networks - reduces BOM count by 3 components. |
| Automotive ADAS Domain Controller | Server Baseboard Management |
|
Use Scenario: Validating 1.8V SoC I/O supply and 1.0V CPU core rail in AEC-Q100-compliant camera ECU with extended temperature range. IC Role / Device Role / Timing Role: VCC1/VCC2 comparators detect undervoltage on dual power domains; RSTIN monitors battery backup voltage (VBAT). Use Value: Enables fail-safe shutdown before memory corruption occurs during cold-cranking events. |
Use Scenario: Coordinating reset sequencing between main 12V PSU, 3.3V management controller, and 1.8V BMC flash supply in rack server motherboard. IC Role / Device Role / Timing Role: RST output holds BMC in reset until all three rails stabilize; PFO signals PSU fault to BMC via dedicated interrupt line. Use Value: Ensures BMC boots only after full power integrity is confirmed - prevents firmware lockup during hot-swap events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-supply supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6728AKASYD3+T | No PFI/PFO function; lacks power-fail monitoring capability | Suitable only where third-rail monitoring is unnecessary and no early power-loss warning required | Select MAX6728AKASYD3+T if PFI/PFO is unused - identical pinout, same 140ms timeout and dual-supply thresholds |
| TPS3808G33DBVR | Single-supply monitor (VDD only); no VCC2 or RSTIN inputs; 3.3V fixed threshold; 200ms timeout | Cannot supervise dual rails or auxiliary voltages - requires additional ICs for multivoltage systems | Choose TPS3808G33DBVR only for simple single-rail 3.3V applications where cost is prioritized over feature integration |
Compared with MAX6728AKASYD3+T, the MAX6729AKASYD3+T adds PFI/PFO for power-fail signaling without layout change; versus TPS3808G33DBVR, it delivers true dual-rail supervision and adjustable third-rail monitoring in one SOT23-8 package - reducing system-level complexity and PCB area.
Availability
MAX6729AKASYD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and automotive ADAS applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned reliability.
Supply support for MAX6729AKASYD3+T 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 and mixed-signal ICs for demanding industrial, automotive, and communications applications - emphasizing reliability, low power, and high integration.
The MAX6715A–MAX6729A family targets multivoltage embedded systems needing compact, robust power supervision - specifically engineered to replace discrete reset circuits while supporting triple-rail monitoring and power-fail alerts in space-constrained designs.
FAQ
What is the reset timeout period for MAX6729AKASYD3+T?
The MAX6729AKASYD3+T has a factory-set minimum reset timeout period of 140ms, indicated by the 'D3' suffix in its part number. This duration is guaranteed over the full –40°C to +125°C operating temperature range and ensures sufficient hold time for microprocessor initialization before release. The timeout begins when all monitored supplies (VCC1, VCC2, RSTIN) rise above their respective thresholds and ends with RST deassertion.
Does MAX6729AKASYD3+T support monitoring a third voltage rail?
Yes, the MAX6729AKASYD3+T supports third-rail monitoring via its RSTIN pin, which features a precise 626mV internal reference voltage. By connecting an external resistor divider between the target rail and ground, designers can set custom reset thresholds from 0.62V upward. This eliminates the need for a separate supervisor IC and maintains full integration in the SOT23-8 footprint.
What is the function of the PFI and PFO pins on MAX6729AKASYD3+T?
The PFI (Power-Fail Input) and PFO (Power-Fail Output) pins on MAX6729AKASYD3+T form a dedicated early-warning path: PFI compares an external voltage (e.g., preregulated input) against a 626.5mV threshold, and PFO asserts active-low within 2µs when that threshold is crossed. Unlike RST, PFO deasserts immediately - enabling firmware-triggered shutdown without reset delay.
Can MAX6729AKASYD3+T operate with VCC1 or VCC2 below 1.0V?
Yes, the MAX6729AKASYD3+T guarantees correct reset output logic state with either VCC1 or VCC2 as low as 0.8V - verified across temperature. This enables reliable brownout detection in ultralow-voltage systems such as battery-powered IoT nodes or deep-sleep MCU domains where supply rails dip near cutoff.
Is the MAX6729AKASYD3+T watchdog timer enabled by default?
No, the watchdog timer in MAX6729AKASYD3+T is disabled by default. It activates only when the WDI pin is driven with valid transitions; leaving WDI unconnected disables the watchdog entirely. The device includes a 200nA internal current source to detect the unconnected state - ensuring no unintended resets occur in watchdog-free configurations.
MAX6729AKASYD3+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-8
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 3
- Voltage - Threshold:
- 2.188V, 2.925V, Adj
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-8
MAX6729AKASYD3+T FAQ
1.How can I place an order for MAX6729AKASYD3+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6729AKASYD3+T 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 MAX6729AKASYD3+T reliable?
The price and inventory of MAX6729AKASYD3+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6729AKASYD3+T is usually 5 days.
3.What payment methods are accepted for MAX6729AKASYD3+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6729AKASYD3+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6729AKASYD3+T?
MAX6729AKASYD3+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6729AKASYD3+T 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 MAX6729AKASYD3+T?
For technical support, including MAX6729AKASYD3+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6729AKASYD3+T requirements.
6.How does Aetrix verify that MAX6729AKASYD3+T is sourced from the original manufacturer or authorized distributors?
All MAX6729AKASYD3+T 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 MAX6729AKASYD3+T meets industry standards.
7.What is the process for return or replacement of MAX6729AKASYD3+T?
All MAX6729AKASYD3+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6729AKASYD3+T, 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 MAX6729AKASYD3+T part is unused and in its original packaging.
Return procedure for MAX6729AKASYD3+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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