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Analog Devices Inc./Maxim Integrated MAX6728KARVD3+
- Part No.:
- MAX6728KARVD3+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- -
- Datasheet:
-
MAX6728KARVD3+.pdf
- Description:
- IC SUPERVISOR
- Quantity:
- Payment:
- Shipping:
Inventory:1,366
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Product details
Overview
MAX6728KARVD3+ from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in an 8-pin SOT23 package, monitoring VCC1 (primary), VCC2 (secondary), and PFI (power-fail input) with factory-trimmed thresholds of 4.625V (VTH1), 3.075V (VTH2), and 626.5mV (VPFI), 210ms reset timeout, and open-drain PFO output - used for orderly shutdown in telecom power systems.
For engineers reviewing the MAX6728KARVD3+ datasheet, MAX6728KARVD3+ pinout, MAX6728KARVD3+ application, or MAX6728KARVD3+ equivalent, key selection criteria include guaranteed reset validity down to VCC1/VCC2 = 0.8V, 14µA typical supply current at 3.6V, immunity to short VCC transients, and integrated power-fail comparator with 2µs PFI-to-PFO delay.
Technical Context
The MAX6728KARVD3+ implements dual independent voltage comparators for VCC1 and VCC2 supervision plus a dedicated high-impedance PFI comparator referenced to a 626.5mV internal bandgap reference, with hysteresis of 3mV. Reset assertion is latched and held for a fixed 210ms minimum timeout after all monitored voltages recover.
It features an open-drain active-low PFO output asserted when PFI falls below VPFI, deasserting immediately without timeout, and supports manual reset via MR with 50kΩ internal pullup to VCC1 and 200ns MR-to-reset delay. No watchdog or RSTIN functionality is included.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC1 Threshold | 4.625V (factory-trimmed, ±125mV tolerance) - ensures reliable reset during 5V rail brownout |
| VCC2 Threshold | 3.075V (factory-trimmed, ±75mV tolerance) - matches common 3.3V I/O supply monitoring |
| PFI Threshold | 626.5mV (internal reference, ±15.5mV) - enables precise external resistor-divider setup for auxiliary supply monitoring |
| Reset Timeout | 210ms (min) - provides sufficient hold time for processor initialization and memory stabilization |
| Supply Current | 14µA (typ at 3.6V) - enables use in battery-backed or ultra-low-power systems |
| Operating Temp | -40°C to +85°C - qualified for industrial and telecom equipment environments |
| Reset Validity | Down to VCC1 or VCC2 = 0.8V - guarantees correct logic state during deep undervoltage conditions |
Pinout & Package
Package: 8-pin SOT23-8 (3.0mm × 1.7mm × 1.3mm, 0.65mm pitch), lead-free, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RST | Active-low open-drain reset output - requires external pullup; asserts when VCC1 < 4.625V, VCC2 < 3.075V, or MR low |
| 2 | GND | Ground reference for all internal circuits and comparators |
| 3 | MR | Active-low manual reset input with 50kΩ internal pullup to VCC1 - debounced by 200ns delay |
| 4 | PFO | Active-low open-drain power-fail output - asserts immediately when PFI < 626.5mV, no timeout |
| 5 | VCC2 | Secondary supply input (0.9V–3.3V range) - powers internal VCC2 comparator and sets RST2 reference if present (not used in MAX6728) |
| 6 | VCC1 | Primary supply input (1.8V–5.0V range) - powers core logic and sets RST/PFO reference |
| 7 | PFI | Power-fail monitor input - high-impedance (±25nA), referenced to 626.5mV internal reference |
| 8 | RST2 | Not connected (NC) in MAX6728 - pin reserved but unused per device configuration |
Key Features
| Feature | Design Value |
|---|---|
| Triple-voltage supervision | Simultaneous monitoring of primary (VCC1), secondary (VCC2), and auxiliary (PFI) rails with independent thresholds |
| Open-drain PFO with fast response | 2µs PFI-to-PFO propagation enables real-time power-fail interrupt generation for software-controlled shutdown |
| Guaranteed low-VCC operation | Valid reset assertion and logic states maintained even when VCC1 or VCC2 drops to 0.8V |
| Low-glitch sensitivity | Immunity to VCC transients ≤20µs (at 100mV overdrive), reducing false resets in noisy power environments |
| Minimal board space | 8-pin SOT23-8 footprint (3.0 × 1.7 mm) replaces discrete supervisor + comparator + timer solutions |
Applications
| Telecom Power Management | Industrial PLC I/O Modules |
|---|---|
Use Scenario: Monitoring 48V DC-DC converter output (via resistor divider) and 3.3V/5V system rails in remote radio units. IC Role / Device Role / Timing Role: Triple-supply supervisor providing coordinated reset and early power-fail warning before main rail collapse. Use Value: Enables firmware-triggered graceful shutdown within 210ms window, preserving configuration and preventing flash corruption. | Use Scenario: Supervising field-side 24V DC supply and isolated 3.3V logic rail in modular I/O terminals exposed to EMI. IC Role / Device Role / Timing Role: Fault-detection hub asserting reset on undervoltage and generating PFO interrupt for diagnostics logging. Use Value: 0.8V reset validity ensures deterministic behavior during brownout recovery; 14µA quiescent current extends backup battery life. |
| Network Switch Line Cards | Medical Diagnostic Equipment |
Use Scenario: Ensuring clean boot sequencing across multiple voltage domains (12V, 5V, 3.3V, 1.8V) on high-density switch ASIC cards. IC Role / Device Role / Timing Role: Centralized reset generator with PFI tied to pre-regulated 12V bus to detect upstream supply degradation. Use Value: 210ms timeout aligns with FPGA configuration time; open-drain outputs allow wired-OR reset distribution across subsystems. | Use Scenario: Monitoring battery-backed 3.3V real-time clock domain and main 5V processor rail in portable ultrasound devices. IC Role / Device Role / Timing Role: Dual-rail supervisor with PFI configured to trigger PFO interrupt at 90% battery voltage threshold. Use Value: 626.5mV precision reference enables accurate battery end-of-life detection; SOT23-8 fits tight PCB layouts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triple-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6729KARVD3+ | Push-pull (not open-drain) PFO output; identical thresholds, timeout, and pinout except PFO drive strength | Requires no external pullup; better for driving heavy capacitive loads or level-shifting interfaces | Select MAX6729KARVD3+ when PFO must source current or interface directly to CMOS inputs without pullup |
| TPS3808G33DBVR | Single-supply (VDD only), no PFI input; 3.3V fixed threshold, 200ms timeout, 1.6µA supply current | Lacks auxiliary voltage monitoring; suited only for basic VDD supervision, not triple-rail or power-fail use cases | Choose TPS3808G33DBVR only for cost-sensitive single-rail designs where PFI and VCC2 monitoring are unnecessary |
Compared with MAX6728KARVD3+, MAX6729KARVD3+ offers stronger PFO drive but same supervision capability, while TPS3808G33DBVR reduces functionality to single-rail monitoring with lower power - making MAX6728KARVD3+ optimal for applications requiring both dual-supply reset coordination and programmable power-fail alerting.
Availability
MAX6728KARVD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and medical diagnostic equipment requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.
Supply support for MAX6728KARVD3+ 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 compact, ultra-low-power supervisory solutions optimized for multivoltage embedded systems where reliability, small size, and guaranteed operation down to 0.8V are critical.
FAQ
What is the exact reset threshold voltage for VCC1 on the MAX6728KARVD3+?
The MAX6728KARVD3+ has a factory-trimmed VCC1 reset threshold of 4.625V (minimum 4.500V, maximum 4.750V) with ±0.5% hysteresis. This value is encoded in the "RV" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is verified across -40°C to +85°C.
Does the MAX6728KARVD3+ include a watchdog timer function?
No, the MAX6728KARVD3+ does not include a watchdog timer. Per the Selector Guide and Functional Diagram, it lacks WDI pin functionality - unlike MAX6721–MAX6729 variants with "W" in the ordering code. The MAX6728KARVD3+ provides only voltage supervision and power-fail monitoring.
What is the purpose of the RST2 pin on the MAX6728KARVD3+?
Pin 8 (RST2) is a no-connect (NC) on the MAX6728KARVD3+. Though physically present in the 8-pin SOT23-8 package, RST2 is unconnected internally and must be left floating or tied to GND per layout guidelines - it is not functional in this variant.
Can the PFI input of the MAX6728KARVD3+ monitor negative voltages?
Yes, the PFI input can monitor negative supplies using an external resistor network as shown in Figure 3b of the datasheet. When the negative rail drops, PFO asserts low; accuracy depends on PFI threshold tolerance (±15.5mV), resistor matching, and VCC stability - MAX6728KARVD3+ supports this configuration without modification.
What is the maximum load the open-drain PFO output of the MAX6728KARVD3+ can drive?
The MAX6728KARVD3+ PFO output supports up to 3.2mA sink current at VCC1 ≥ 4.5V (VOL ≤ 0.4V). With a standard 10kΩ pullup to 3.3V, it delivers ~330µA - sufficient for driving logic inputs, optocouplers, or interrupt lines. For heavier loads, verify VOL remains <0.4V per the Electrical Characteristics table.
MAX6728KARVD3+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- *
- Package/Case:
- -
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- -
- Number of Voltages Monitored:
- -
- Voltage - Threshold:
- -
- Output:
- -
- Reset:
- -
- Reset Timeout:
- -
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- -
- Supplier Device Package:
- -
MAX6728KARVD3+ FAQ
1.How can I place an order for MAX6728KARVD3+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6728KARVD3+ 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 MAX6728KARVD3+ reliable?
The price and inventory of MAX6728KARVD3+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6728KARVD3+ is usually 5 days.
3.What payment methods are accepted for MAX6728KARVD3+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6728KARVD3+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6728KARVD3+?
MAX6728KARVD3+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6728KARVD3+ 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 MAX6728KARVD3+?
For technical support, including MAX6728KARVD3+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6728KARVD3+ requirements.
6.How does Aetrix verify that MAX6728KARVD3+ is sourced from the original manufacturer or authorized distributors?
All MAX6728KARVD3+ 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 MAX6728KARVD3+ meets industry standards.
7.What is the process for return or replacement of MAX6728KARVD3+?
All MAX6728KARVD3+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX6728KARVD3+, 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 MAX6728KARVD3+ part is unused and in its original packaging.
Return procedure for MAX6728KARVD3+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6728KARVD3+ Tags
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MIC826SYMT-TR
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APX803L20-29SA-7
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