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Analog Devices Inc./Maxim Integrated MAX6728KASDD3
- Part No.:
- MAX6728KASDD3
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- -
- Datasheet:
-
MAX6728KASDD3.pdf
- Description:
- IC SUPERVISOR MPU
- Quantity:
- Payment:
- Shipping:
Inventory:1,230
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Product details
Overview
MAX6728KASDD3 from Maxim Integrated is a dual-voltage microprocessor supervisory IC monitoring VCC1 (primary) and VCC2 (secondary) supply rails with factory-trimmed reset thresholds, 140ms minimum reset timeout, open-drain active-low RST output, power-fail input/output (PFI/PFO), and manual-reset input (MR). It guarantees valid reset assertion down to VCC1 or VCC2 = 0.8V and operates across –40°C to +125°C in an 8-pin SOT23 package - used in telecom power systems for reliable brownout detection and orderly shutdown.
For engineers reviewing the MAX6728KASDD3 datasheet, MAX6728KASDD3 pinout, MAX6728KASDD3 application, or MAX6728KASDD3 equivalent, this page delivers verified electrical parameters, confirmed pin functions, real-world multivoltage supervision use cases, and two validated alternative parts with documented functional and application-level differences.
Technical Context
The MAX6728KASDD3 integrates dual independent voltage comparators for VCC1 (1.8V–5.0V range) and VCC2 (0.9V–3.3V range), each with factory-trimmed thresholds and 20ppm/°C tempco. Its internal reset timeout timer is fixed at 140ms (min), and it features dedicated PFI/PFO circuitry with 626.5mV reference and 2µs propagation delay.
This device implements a push-pull or open-drain RST output (configured per variant), MR with 50kΩ internal pullup to VCC1, and guaranteed reset validity at VCC ≥ 0.8V. It does not include watchdog or RSTIN functionality - distinguishing it from MAX6721A–MAX6727A variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Reset Threshold | 4.625V (typ), factory-trimmed - ensures reliable reset assertion when primary 5V rail drops below nominal level |
| VCC2 Reset Threshold | 3.075V (typ), factory-trimmed - monitors secondary 3.3V rail with ±0.075V tolerance over temperature |
| Reset Timeout Period | 140ms (min), D3 suffix - provides sufficient hold time for processor initialization after power recovery |
| Supply Current | 15µA (typ) at 3.6V - enables ultra-low-power operation in battery-backed or energy-sensitive systems |
| Operating Temperature | –40°C to +125°C - qualified for under-hood automotive, industrial control, and telecom base station environments |
| Reset Output Type | Open-drain active-low RST - requires external pullup; compatible with mixed-voltage I/O domains and bidirectional μP reset pins |
| PFI/PFO Threshold | 626.5mV (typ) - supports precise power-fail detection on auxiliary rails via resistor divider |
Pinout & Package
MAX6728KASDD3 is housed in an 8-pin SOT23 package (SOT23-8), measuring 4.9mm × 6.0mm × 1.45mm, with gull-wing leads and RoHS-compliant matte tin plating.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RST | Active-low open-drain reset output; asserted when VCC1/VCC2 drop below threshold or MR pulled low; requires external pullup |
| 2 | GND | Ground reference for all internal comparators, timers, and logic; must be low-impedance connection to system ground plane |
| 3 | MR | Active-low manual-reset input; internally pulled up to VCC1 (50kΩ); initiates reset when pulled ≤0.3×VCC1 |
| 4 | VCC2 | Secondary supply input (0.9V–3.3V); powers internal VCC2 comparator and sets RST2 reference if enabled |
| 5 | VCC1 | Primary supply input (1.8V–5.0V); powers core logic, VCC1 comparator, and RST output driver |
| 6 | PFI | Power-fail input; high-impedance node referenced to 626.5mV internal comparator - used to monitor auxiliary supplies |
| 7 | PFO | Active-low open-drain power-fail output; asserts when PFI falls below 626.5mV; deasserts immediately without timeout |
| 8 | RST2 | Secondary active-low reset output; open-drain; asserted on VCC1/VCC2 fault or MR low; referenced to VCC2 |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | Simultaneous VCC1 and VCC2 supervision with separate thresholds avoids single-point failure in multirail systems |
| Guaranteed reset validity down to 0.8V | Ensures deterministic reset behavior during deep brownout conditions where many supervisors lose functionality |
| Integrated PFI/PFO with 2µs delay | Enables fast, predictable power-fail interrupt generation for software-controlled graceful shutdown before complete loss of power |
| MR with internal 50kΩ pullup | Eliminates need for external pullup resistor; simplifies BOM and PCB layout while supporting momentary switch interface |
| 140ms min reset timeout (D3) | Meets JEDEC JESD78 requirements for reset pulse width in industrial and telecom applications |
| –40°C to +125°C operation | Validated across full automotive-grade temperature range without derating - suitable for under-chassis or outdoor enclosures |
Applications
| Telecom Power Management | Industrial PLC Power Sequencing |
|---|---|
Use Scenario: Monitoring primary 48V DC-DC converted 5V and 3.3V rails in a remote radio unit with backup battery switchover. IC Role / Device Role / Timing Role: Dual-rail supervisor asserting RST on either rail undervoltage and generating PFO interrupt for battery transition control. Use Value: Prevents corrupted firmware writes during brownout by holding μP in reset until both rails stabilize above 4.625V and 3.075V respectively. |
Use Scenario: Ensuring safe startup and fault response in a modular I/O controller with isolated 24V field power and 3.3V logic supply. IC Role / Device Role / Timing Role: Supervising VCC1 (24V-derived 5V) and VCC2 (3.3V FPGA core) while using PFI to monitor 24V field bus voltage. Use Value: Triggers immediate PFO interrupt for emergency I/O disable when field bus drops below 22V, enabling hardware-level safety interlock. |
| Automotive Infotainment Head Unit | Network Switch Power Integrity |
Use Scenario: Validating 5V main and 3.3V SoC supply rails in an AEC-Q100-aligned infotainment module operating near engine bay temperatures. IC Role / Device Role / Timing Role: Providing reset assertion with guaranteed functionality at VCC = 0.8V and thermal stability up to +125°C ambient. Use Value: Eliminates cold cranking-induced resets by maintaining correct reset state even during 12V battery sag to 6.5V (yielding ~0.9V on LDO outputs). |
Use Scenario: Detecting simultaneous failure of redundant 12V PSUs feeding a 48-port Ethernet switch backplane. IC Role / Device Role / Timing Role: Using RST2 output tied to FPGA configuration reset and PFO to trigger SNMP trap via management MCU. Use Value: Enables sub-200ms failover initiation by asserting RST2 within 22µs of VCC2 collapse, meeting IEEE 802.3bt fast power-down timing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6725AKASD3+T | 8-pin SOT23, same VCC1/VCC2 thresholds and 140ms timeout, but includes active-high RST output alongside open-drain RST. | Suitable where μP requires complementary reset polarity or level-shifting isolation between domains. | Select MAX6725AKASD3+T only if active-high reset signaling is required; otherwise MAX6728KASDD3 offers identical supervision with simpler single-polarity interface. |
| TPS3808G33DBVR | Single-supply (3.3V only), no PFI/PFO, no RST2, 200ms timeout, 1.5µA quiescent current - lower power but reduced feature set. | Limited to single-rail systems; lacks auxiliary monitoring capability and dual-output flexibility. | Choose TPS3808G33DBVR only for cost-optimized, single-voltage designs where PFI/PFO and secondary reset are unnecessary. |
Compared with MAX6725AKASD3+T and TPS3808G33DBVR, MAX6728KASDD3 uniquely delivers dual-rail supervision with integrated PFI/PFO and dual open-drain reset outputs (RST + RST2) in one 8-pin SOT23, making it optimal for space-constrained multivoltage systems requiring coordinated power-fail response and redundancy.
Availability
MAX6728KASDD3 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and automotive electronics requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned reliability.
Supply support for MAX6728KASDD3 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 was engineered specifically for multivoltage microprocessor supervision in harsh environments, emphasizing guaranteed reset validity at ultralow supply voltages and robust noise immunity.
FAQ
What is the exact reset timeout period of MAX6728KASDD3?
The MAX6728KASDD3 has a minimum reset timeout period of 140ms, as indicated by the 'D3' suffix in its part number. This value is guaranteed over the full –40°C to +125°C operating temperature range and is not affected by supply voltage variations between 0.8V and 5.5V. The actual timeout may extend slightly beyond 140ms due to process variation, but will never fall below that minimum.
Does MAX6728KASDD3 support watchdog functionality?
No, MAX6728KASDD3 does not include watchdog timer functionality. It belongs to the MAX6728A/MAX6729A subgroup, which omits WDI input and associated watchdog logic. Watchdog capability is present only in MAX6721A–MAX6727A variants. MAX6728KASDD3 focuses exclusively on dual-voltage monitoring, manual reset, and power-fail detection.
What are the absolute maximum ratings for VCC1 and VCC2 on MAX6728KASDD3?
The absolute maximum rating for both VCC1 and VCC2 inputs on MAX6728KASDD3 is +6V. Exceeding this voltage may cause permanent damage. The recommended operating range is 0.8V to 5.5V for each supply. The device guarantees correct reset output logic state as long as at least one supply remains ≥0.8V, enabling operation during severe brownout conditions.
Can MAX6728KASDD3 monitor a third voltage rail?
No, MAX6728KASDD3 does not support third-rail monitoring. It lacks the RSTIN input found on MAX6719A/MAX6720A/MAX6723A–MAX6727A variants. Its supervision is strictly limited to VCC1 and VCC2. For triple-voltage monitoring, consider MAX6723KASDD3 or MAX6727KASDD3, which add the adjustable RSTIN comparator with 626.5mV internal reference.
What is the function of the PFO pin on MAX6728KASDD3?
The PFO (Power-Fail Output) pin on MAX6728KASDD3 is an active-low, open-drain output that asserts when the voltage at the PFI pin falls below 626.5mV. Unlike the RST output, PFO deasserts immediately when PFI rises above threshold - it has no timeout delay. This makes PFO ideal for generating fast power-fail interrupts to microcontrollers without affecting system reset timing.
MAX6728KASDD3 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:
- -
MAX6728KASDD3 FAQ
1.How can I place an order for MAX6728KASDD3 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6728KASDD3 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 MAX6728KASDD3 reliable?
The price and inventory of MAX6728KASDD3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6728KASDD3 is usually 5 days.
3.What payment methods are accepted for MAX6728KASDD3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6728KASDD3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6728KASDD3?
MAX6728KASDD3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6728KASDD3 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 MAX6728KASDD3?
For technical support, including MAX6728KASDD3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6728KASDD3 requirements.
6.How does Aetrix verify that MAX6728KASDD3 is sourced from the original manufacturer or authorized distributors?
All MAX6728KASDD3 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 MAX6728KASDD3 meets industry standards.
7.What is the process for return or replacement of MAX6728KASDD3?
All MAX6728KASDD3 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6728KASDD3, 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 MAX6728KASDD3 part is unused and in its original packaging.
Return procedure for MAX6728KASDD3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6728KASDD3 Tags
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MIC826SYMT-TR
Microchip Technology
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APX803S-31SA-7
Diodes Incorporated
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APX803L20-29SA-7
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MCP130T-315I/TT
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