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Analog Devices Inc./Maxim Integrated MAX6728KATWD3
- Part No.:
- MAX6728KATWD3
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- -
- Datasheet:
-
MAX6728KATWD3.pdf
- Description:
- IC SUPERVISOR MPU
- Quantity:
- Payment:
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Inventory:1,260
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Product details
Overview
MAX6728KATWD3 from Maxim Integrated is a dual-voltage microprocessor supervisory IC monitoring VCC1 (primary) and VCC2 (secondary) supply rails, with power-fail input (PFI), power-fail output (PFO), and watchdog timer functionality. It asserts active-low reset when either supply drops below factory-trimmed thresholds (VTH1 = 2.925 V, VTH2 = 1.110 V), maintains reset for 140 ms minimum timeout, and operates from -40°C to +125°C in an 8-pin SOT23 package. Used in telecom power systems requiring reliable brownout detection and orderly shutdown.
For engineers reviewing the MAX6728KATWD3 datasheet, MAX6728KATWD3 pinout, MAX6728KATWD3 application, or MAX6728KATWD3 equivalent, this page delivers verified electrical specs, validated pin functions, confirmed triple-monitoring capability (VCC1/VCC2/PFI), and real-world substitution guidance - all aligned with Maxim's official MAX6728A datasheet Rev 5 (10/17).
Technical Context
The MAX6728KATWD3 integrates two independent voltage comparators for VCC1 (1.8V–5.0V range) and VCC2 (0.9V–3.3V range), plus a dedicated PFI comparator referenced to 626.5 mV. Its watchdog timer features dual-mode operation: 35 s minimum startup period after reset, then 1.12 s minimum normal timeout - triggered by WDI edge transitions.
Reset assertion is guaranteed down to VCC1 or VCC2 = 0.8 V, with immunity to sub-20 µs negative VCC transients exceeding 100 mV overdrive. The device supports push-pull or open-drain RST and PFO outputs, both referenced to VCC1, and includes internal 50 kΩ MR pullup and 200 nA WDI unconnected-state detection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Reset Threshold | 2.925 V (typical falling threshold; factory-trimmed suffix 'T' per Reset Voltage Threshold Suffix Guide) |
| VCC2 Reset Threshold | 1.110 V (typical falling threshold; factory-trimmed suffix 'G' per guide) |
| Reset Timeout Period | 140 ms (minimum; suffix 'D3' per Reset Timeout Period Suffix Guide) |
| Supply Current | 10 µA (typ at VCC1 = 3.6 V, outputs not asserted; enables ultra-low-power battery backup) |
| Operating Temperature | -40°C to +125°C (fully specified; AEC-Q100 qualified variants exist but MAX6728KATWD3 is industrial-grade) |
| PFI Threshold Voltage | 626.5 mV (typical; enables precise external power-fail monitoring via resistor divider) |
| Watchdog Timeout | 35 s min startup / 1.12 s min normal mode; prevents false resets during boot while ensuring rapid fault response in runtime |
Pinout & Package
Package: 8-pin SOT23 (JEDEC MO-178AA), 2.9 mm × 1.6 mm × 1.1 mm body, lead(Pb)-free/RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RST | Active-low reset output | Push-pull driver referenced to VCC1; asserts low on VCC1/VCC2 undervoltage, MR low, or PFI low; remains low for 140 ms min after recovery |
| 2 - GND | Ground reference | Common return for all internal comparators, timers, and output drivers; must be low-impedance connection |
| 3 - MR | Active-low manual-reset input | Internally pulled up to VCC1 (50 kΩ); pulling low forces reset; glitch rejection ≥100 ns |
| 4 - VCC2 | Secondary supply input | Powers internal circuitry when > VCC1; input for VCC2 reset comparator (threshold = 1.110 V) |
| 5 - PFI | Power-fail monitor input | High-impedance comparator input (626.5 mV ref); asserts PFO low when voltage falls below threshold |
| 6 - PFO | Active-low power-fail output | Push-pull output referenced to VCC1; deasserts immediately (no timeout) when PFI recovers |
| 7 - VCC1 | Primary supply input | Main power source; powers device when > VCC2; input for VCC1 reset comparator (threshold = 2.925 V) |
| 8 - WDI | Watchdog input | Edge-sensitive; long startup (35 s) after reset, then 1.12 s timeout; unconnected = disabled (200 nA detection) |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | Simultaneous VCC1 (2.925 V) and VCC2 (1.110 V) supervision with separate comparators and hysteresis |
| Integrated power-fail detection | PFI/PFO pair enables early warning of supply collapse without resetting CPU - critical for safe data save before shutdown |
| Dual-mode watchdog timer | 35 s startup window accommodates complex boot sequences; 1.12 s runtime timeout ensures prompt recovery from software hangs |
| Guaranteed reset validity to 0.8 V | Ensures clean reset assertion even during deep brownout conditions where VCC1 or VCC2 dips near 0.8 V |
| Ultra-low quiescent current | 10 µA typical at 3.6 V enables multi-year operation on coin-cell backup supplies |
Applications
| Telecom Power Management | Industrial PLC I/O Modules |
|---|---|
Use Scenario: Monitoring primary 3.3 V and secondary 1.2 V rails in a remote radio unit with battery backup. IC Role / Device Role / Timing Role: Dual-supply supervisor asserting reset if either rail collapses; PFO triggers firmware-initiated graceful shutdown before main power loss. Use Value: Prevents corrupted firmware writes during brownout by guaranteeing reset assertion before VCC1 drops below 2.925 V or VCC2 below 1.110 V. | Use Scenario: Supervising 24 V DC input (via resistor divider) and 5 V logic rail in a DIN-rail mounted controller. IC Role / Device Role / Timing Role: PFI monitors scaled-down 24 V supply; VCC2 monitors 5 V logic; RST holds CPU in reset until both are stable. Use Value: Enables deterministic startup sequence and eliminates spurious resets caused by 24 V ripple or 5 V sequencing delays. |
| Server Baseboard Management | Medical Diagnostic Equipment |
Use Scenario: Coordinating reset timing across multiple voltage domains (12 V, 5 V, 3.3 V, 1.8 V) in a BMC subsystem. IC Role / Device Role / Timing Role: VCC1 monitors 3.3 V auxiliary rail; VCC2 monitors 1.8 V core rail; WDI verifies BMC firmware liveness every 1.12 s. Use Value: Detects BMC lockup without requiring host CPU intervention, enabling autonomous recovery via PCH reset signal. | Use Scenario: Ensuring safe power sequencing and fault response in MRI gradient amplifier control boards. IC Role / Device Role / Timing Role: VCC1 supervises 5 V analog supply; VCC2 monitors 3.3 V digital supply; PFO signals imminent AC line dropout to initiate emergency ramp-down. Use Value: Meets IEC 60601-1 requirements for fail-safe behavior by guaranteeing reset assertion within 140 ms of undervoltage detection. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6723KATWD3 | Same 8-pin SOT23 package, identical VTH1/VTH2 thresholds (2.925 V / 1.110 V) and D3 timeout, but adds RSTIN input for third-voltage monitoring | Supports triple-supply monitoring (VCC1/VCC2/RSTIN); MAX6728KATWD3 lacks RSTIN pin and function | Select MAX6723KATWD3 only if third-rail monitoring is required; otherwise MAX6728KATWD3 offers lower cost and simpler layout |
| TPS3808G33DBVR | Single-supply supervisor (monitors only VCC); 3.3 V fixed threshold; 200 ms timeout; SOT23-6 package; no PFI/PFO or watchdog | Lacks dual-rail, power-fail, and watchdog features; suitable only for basic single-rail reset generation | Choose only for cost-sensitive, single-rail applications where PFI, WDI, and VCC2 monitoring are unnecessary |
Compared with MAX6723KATWD3, MAX6728KATWD3 omits RSTIN to reduce pin count and cost while retaining full PFI/PFO and watchdog functionality; versus TPS3808G33DBVR, it provides comprehensive multirail supervision essential for complex power architectures.
Availability
MAX6728KATWD3 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and medical electronics requiring stable component supply, extended temperature operation, and integrated power-fail signaling.
Supply support for MAX6728KATWD3 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 MAX6715A–MAX6729A family delivers ultra-low-voltage, multirail supervisory circuits optimized for reliability-critical systems where simultaneous monitoring of primary, secondary, and auxiliary supplies is mandatory.
FAQ
What is the exact reset threshold voltage for VCC1 on the MAX6728KATWD3?
The MAX6728KATWD3 has a factory-trimmed VCC1 reset threshold of 2.925 V (typical, falling), corresponding to suffix 'T' in the Reset Voltage Threshold Suffix Guide. This value is guaranteed over -40°C to +125°C with ±0.5% hysteresis and 20 ppm/°C tempco. The actual trip point falls between 2.850 V and 3.000 V per datasheet Electrical Characteristics table.
Does the MAX6728KATWD3 support monitoring a third voltage rail?
No, the MAX6728KATWD3 does not support third-rail monitoring. Unlike MAX6723KATWD3 or MAX6727KATWD3, it lacks the RSTIN pin and associated adjustable comparator. Its supervision is strictly dual-rail (VCC1 and VCC2), augmented by PFI for external power-fail detection - but PFI is not configurable as a general-purpose third-voltage monitor like RSTIN.
What is the function of Pin 5 (PFI) and how is it used in the MAX6728KATWD3?
Pin 5 (PFI) is the power-fail input comparator terminal on the MAX6728KATWD3, referenced to an internal 626.5 mV threshold. When the voltage at PFI drops below this level - typically set via an external resistor divider from a higher supply - the PFO output (Pin 6) asserts low immediately. This enables early warning of supply degradation without triggering system reset, allowing firmware to execute safe shutdown procedures.
Can the watchdog timer on the MAX6728KATWD3 be disabled, and how?
Yes, the watchdog timer on the MAX6728KATWD3 is disabled by leaving Pin 8 (WDI) unconnected. The device incorporates a 200 nA current source to detect the unconnected state. To avoid unintended activation, ensure no external circuit sources more than 50 nA into WDI. Driving WDI high or low continuously - or failing to provide edges within 1.12 s - will assert reset, so disconnection is the only reliable disable method.
What is the guaranteed minimum reset timeout period for the MAX6728KATWD3?
The MAX6728KATWD3 guarantees a minimum reset timeout period of 140 ms, as indicated by the 'D3' suffix in its part number per the Reset Timeout Period Suffix Guide. This duration is fully specified over -40°C to +125°C and applies after any reset trigger event - including VCC1/VCC2 undervoltage, MR assertion, or PFI dropout - and is independent of supply voltage within operating range.
MAX6728KATWD3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- -
- Number of Voltages Monitored:
- -
- Voltage - Threshold:
- -
- Output:
- -
- Reset:
- -
- Reset Timeout:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
MAX6728KATWD3 FAQ
1.How can I place an order for MAX6728KATWD3 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6728KATWD3 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 MAX6728KATWD3 reliable?
The price and inventory of MAX6728KATWD3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6728KATWD3 is usually 5 days.
3.What payment methods are accepted for MAX6728KATWD3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6728KATWD3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6728KATWD3?
MAX6728KATWD3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6728KATWD3 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 MAX6728KATWD3?
For technical support, including MAX6728KATWD3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6728KATWD3 requirements.
6.How does Aetrix verify that MAX6728KATWD3 is sourced from the original manufacturer or authorized distributors?
All MAX6728KATWD3 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 MAX6728KATWD3 meets industry standards.
7.What is the process for return or replacement of MAX6728KATWD3?
All MAX6728KATWD3 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6728KATWD3, 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 MAX6728KATWD3 part is unused and in its original packaging.
Return procedure for MAX6728KATWD3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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