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Analog Devices Inc./Maxim Integrated MAX6421XS26+T
- Part No.:
- MAX6421XS26+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-82A, SOT-343
- Datasheet:
-
MAX6421XS26+T.pdf
- Description:
- IC MPU/RESET CIRC 2.63V SC70-4
- Quantity:
- Payment:
- Shipping:
Inventory:3,366
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Product details
Overview
The MAX6421XS26+T from Analog Devices is a low-power microprocessor supervisor IC that monitors VCC supply voltage and asserts an active-low push-pull reset signal when voltage falls below 2.625V (±2.5% over temperature). It features capacitor-adjustable reset timeout (3.0–5.75ms with 1500pF), guaranteed operation down to VCC = 1V, and 1.6µA typical quiescent current. It is used in battery-powered embedded controllers to prevent code execution errors during brownout.
For engineers reviewing the MAX6421XS26+T datasheet, MAX6421XS26+T pinout, MAX6421XS26+T application, or MAX6421XS26+T equivalent, key selection criteria include reset threshold accuracy (±2.5% over –40°C to +125°C), push-pull output drive capability (3.2mA sink at 4.5V), capacitor-set timeout flexibility, and SC70-4 package compatibility with space-constrained portable designs.
Technical Context
This device implements a precision voltage detector with laser-trimmed internal resistors to set the 2.625V reset threshold, combined with a 240nA SRT pin ramp current source that charges an external capacitor to generate the reset timeout delay. The reset assertion logic is fully analog and immune to short VCC transients ≤50µs at 100mV overdrive.
The push-pull RESET output guarantees valid logic levels across the full 1.0–5.5V supply range, with VOL ≤0.4V at 3.2mA sink and VOH ≥0.8×VCC at 800µA source - enabling direct interface to CMOS microcontrollers without pull-up resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.625V ±2.5% over –40°C to +125°C - ensures reliable brownout detection across automotive/industrial temperature ranges |
| Quiescent Current | 1.6µA typical at VCC ≤2.0V - enables multi-year battery life in always-on portable equipment |
| Reset Timeout | 3.00–5.75ms with 1500pF on SRT - configurable delay meets µP reset timing requirements without fixed internal timers |
| VCC Operating Range | 1.0V to 5.5V - supports operation during deep brownout and compatibility with 1.2V–5V logic domains |
| RESET Output Type | Active-low push-pull - eliminates need for external pull-up, simplifies PCB layout and reduces BOM count |
| VCC to RESET Delay | 80µs - fast response to supply collapse prevents spurious MCU execution |
| Package | 4-pin SC70 - 1.25mm × 0.85mm footprint ideal for wearables and compact IoT nodes |
Pinout & Package
The MAX6421XS26+T is housed in a 4-pin SC70 package (package code X4+1, outline 21-0098) with 0.65mm pitch and exposed pad not connected internally.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VCC | Supply input and reset threshold monitoring node - must be decoupled locally; valid operation starts at 1.0V |
| 2 | GND | Ground reference for all internal circuitry and RESET output - requires low-impedance connection |
| 3 | RESET | Active-low push-pull reset output - drives low to reset µP; high impedance when deasserted is not applicable (push-pull) |
| 4 | SRT | Set Reset Timeout input - connects to external capacitor (CSRT) to program delay; sensitive to leakage and stray capacitance |
Key Features
| Feature | Design Value |
|---|---|
| Laser-trimmed reset threshold | 2.625V with ±2.5% tolerance over full temperature range - eliminates manual calibration in production |
| Capacitor-adjustable timeout | 275µs base delay + 2.73×10⁶ × CSRT - supports precise µP reset hold times from sub-millisecond to >10ms |
| Guaranteed RESET validity to VCC = 1V | VOH ≥0.8×VCC and VOL ≤0.4V down to 1.0V supply - ensures deterministic reset signaling during deep undervoltage |
| Immunity to short VCC transients | No false reset for ≤50µs glitches at 100mV below threshold - improves system robustness in noisy power environments |
| Low-leakage SRT ramp current | 240nA ±20% - enables accurate timeout setting with standard 1500pF ceramic capacitors |
Applications
| Portable Medical Sensors | Battery-Powered Industrial Controllers |
|---|---|
Use Scenario: Wearable ECG monitor operating from coin-cell battery with dynamic load switching causing supply droop. IC Role / Device Role / Timing Role: Voltage supervisor asserting RESET during <2.625V brownout to halt firmware execution until stable power resumes. Use Value: Prevents memory corruption and sensor data loss by enforcing clean restart after supply recovery, leveraging 1.6µA quiescent current to extend battery life. | Use Scenario: Remote PLC I/O module powered by LiSOCl₂ battery in harsh industrial environment (-40°C to +85°C). IC Role / Device Role / Timing Role: Brownout detector triggering controlled µP reset when input rail sags due to motor startup transients. Use Value: Ensures deterministic system state recovery using ±2.5% threshold accuracy over temperature and push-pull output eliminating pull-up resistor failure modes. |
| Automotive Body Control Modules | Smart Home Edge Nodes |
Use Scenario: Low-voltage CAN node in vehicle door module subjected to load dump and cold-crank conditions. IC Role / Device Role / Timing Role: Supervisory circuit holding µP in reset during VCC dip below 2.625V, with timeout delay ensuring sufficient hold time for power stabilization. Use Value: Meets AEC-Q100 stress requirements via design heritage (MAX6340UK31/V+T qualified), while 80µs VCC-to-RESET delay prevents glitch-induced resets. | Use Scenario: Zigbee-enabled thermostat with intermittent RF transmission causing brief supply sag on 3.3V rail. IC Role / Device Role / Timing Role: Reset generator interfacing directly to ARM Cortex-M0+ reset pin via push-pull output, no external components required. Use Value: Reduces BOM cost and board area by eliminating pull-up resistor, while capacitor-adjustable timeout accommodates varying µP reset timing specs across firmware versions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor reset applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6421US26+T | SOT143-4 package (larger footprint, 1.4mm × 1.1mm vs SC70's 1.25mm × 0.85mm); identical electrical specs | Preferred where thermal mass or hand-soldering reliability is prioritized over minimal size | Select MAX6421US26+T for manual assembly or higher power dissipation margin; MAX6421XS26+T for ultra-compact automated PCBs |
| TLV803EB26DBZR | Fixed 2.63V threshold (±1.5%), 200ms min timeout (non-adjustable), 0.5µA IQ, SOT23-3 package | Lacks capacitor-adjustable delay and operates only down to VCC = 1.6V - unsuitable for deep brownout detection | Choose TLV803EB26DBZR only if fixed long timeout and ultra-low IQ dominate design priorities and VCC never drops below 1.6V |
Compared with MAX6421US26+T, the MAX6421XS26+T offers identical supervision functionality in a 25% smaller SC70 footprint, while TLV803EB26DBZR trades adjustability and low-VCC operation for lower quiescent current and simpler 3-pin implementation - making it suitable only for less demanding voltage-margin applications.
Availability
The MAX6421XS26+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered industrial controllers, and automotive body control modules requiring stable component supply with guaranteed long-term availability.
Supply support for MAX6421XS26+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
Analog Devices is a global semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control systems.
The MAX6421XS26+T belongs to the MAX6340/MAX6421–MAX6426 family of low-power microprocessor supervisors designed specifically for reliable power-monitoring in space- and energy-constrained embedded systems.
FAQ
What is the exact reset threshold voltage of the MAX6421XS26+T?
The MAX6421XS26+T has a nominal reset threshold of 2.625V, with ±1.5% accuracy at +25°C and ±2.5% over the full –40°C to +125°C operating temperature range. This value is laser-trimmed at wafer test and confirmed in the Electrical Characteristics table under VTH parameter.
Does the MAX6421XS26+T require an external pull-up resistor on the RESET pin?
No, the MAX6421XS26+T features an active-low push-pull RESET output, which actively drives both high and low states. Unlike open-drain variants (e.g., MAX6423XS26+T), it does not require an external pull-up resistor - simplifying design and reducing component count.
How is the reset timeout period set for the MAX6421XS26+T?
The reset timeout period for the MAX6421XS26+T is set by connecting an external capacitor (CSRT) between the SRT pin and GND. The relationship is tRP = 2.73×10⁶ × CSRT + 275µs, yielding 3.00–5.75ms with a 1500pF capacitor. Ceramic capacitors with <10nA leakage are recommended.
Can the MAX6421XS26+T operate reliably when VCC drops below 1.6V?
Yes, the MAX6421XS26+T is guaranteed to assert and maintain a valid RESET signal down to VCC = 1.0V, with VOL ≤0.4V at 3.2mA sink and VOH ≥0.8×VCC at 800µA source. This enables robust brownout protection in ultra-low-voltage battery applications where supply may sag to 1.0–1.2V.
What package type and dimensions does the MAX6421XS26+T use?
The MAX6421XS26+T uses a 4-pin SC70 package (Analog Devices package code X4+1, outline 21-0098), measuring 1.25mm × 0.85mm with 0.65mm pin pitch. It is RoHS-compliant, lead(Pb)-free, and supplied in tape-and-reel format.
MAX6421XS26+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SC-82A, SOT-343
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 2.625V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- Adjustable/Selectable
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-4
MAX6421XS26+T FAQ
1.How can I place an order for MAX6421XS26+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6421XS26+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 MAX6421XS26+T reliable?
The price and inventory of MAX6421XS26+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6421XS26+T is usually 5 days.
3.What payment methods are accepted for MAX6421XS26+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6421XS26+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6421XS26+T?
MAX6421XS26+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6421XS26+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 MAX6421XS26+T?
For technical support, including MAX6421XS26+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6421XS26+T requirements.
6.How does Aetrix verify that MAX6421XS26+T is sourced from the original manufacturer or authorized distributors?
All MAX6421XS26+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 MAX6421XS26+T meets industry standards.
7.What is the process for return or replacement of MAX6421XS26+T?
All MAX6421XS26+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6421XS26+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 MAX6421XS26+T part is unused and in its original packaging.
Return procedure for MAX6421XS26+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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