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Analog Devices Inc./Maxim Integrated MAX6421XS16+T
- Part No.:
- MAX6421XS16+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-82A, SOT-343
- Datasheet:
-
MAX6421XS16+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SC70-4
- Quantity:
- Payment:
- Shipping:
Inventory:145
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Product details
Overview
MAX6421XS16+T from Analog Devices is a low-power microprocessor supervisor IC with active-low push-pull reset output, 1.575V nominal reset threshold (±2.5% over temperature), capacitor-adjustable reset timeout (275µs to 5.75ms), and guaranteed operation down to VCC = 1V. It monitors supply voltage in portable and battery-powered systems to prevent erroneous µP execution during power-up, brownout, or power-down.
For engineers reviewing the MAX6421XS16+T datasheet, MAX6421XS16+T pinout, MAX6421XS16+T application, or MAX6421XS16+T equivalent, key selection criteria include reset threshold accuracy, ultra-low quiescent current (1.6µA typ), SC70-4 package footprint, push-pull output drive capability, and immunity to short VCC transients.
Technical Context
The MAX6421XS16+T implements a precision voltage detector with laser-trimmed internal resistors to set its 1.575V reset threshold. Its reset assertion is triggered when VCC falls below this threshold, and deassertion is delayed by an externally adjustable timeout determined by a ramp current (240nA) charging a capacitor on the SRT pin to a 0.65V internal reference.
It operates across –40°C to +125°C, maintains valid reset logic down to VCC = 1V, and features hysteresis (4×VTH) to prevent chatter near threshold. The push-pull output drives high/low without external pull-up, supporting direct interface to CMOS µP reset inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 1.575V ±2.5% over –40°C to +125°C - ensures reliable detection of 1.6V system rails under full temperature range |
| Quiescent Current | 1.6µA typical at VCC ≤ 2.0V - enables multi-year battery life in always-on monitoring applications |
| Reset Timeout Range | 275µs (CSRT = 0) to 5.75ms (CSRT = 1500pF) - configurable via single external capacitor for µP reset timing compliance |
| Output Type | Active-low push-pull - eliminates need for external pull-up resistor; sinks 1.2mA at VCC ≥ 2.7V |
| Supply Range | 1.0V to 5.5V - supports operation during deep brownout and compatibility with 1.2V–5V logic domains |
| VCC to Reset Delay | 80µs at 1mV/µs VCC fall rate - fast response to supply collapse prevents code corruption |
| Operating Temp | –40°C to +125°C - qualified for automotive under-hood and industrial embedded environments |
Pinout & Package
MAX6421XS16+T is housed in a 4-pin SC70-4 package (package code X4+1, outline 21-0098), measuring 1.25mm × 0.85mm × 0.55mm, with wettable flanks and RoHS-compliant lead-free finish ("+T" suffix).
| Pin | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VCC | Supply input and reset threshold monitor - must be decoupled locally; valid operation starts at 1.0V |
| 2 | GND | Analog ground reference - requires low-impedance connection to system ground plane |
| 3 | RESET | Active-low push-pull reset output - directly drives µP reset pin; no external pull-up needed |
| 4 | SRT | Set-reset-time input - connects to external capacitor to program timeout; sensitive to leakage and stray capacitance |
Key Features
| Feature | Design Value |
|---|---|
| Capacitor-adjustable reset timeout | Enables precise µP reset hold time tuning (275µs–5.75ms) using one low-cost ceramic capacitor |
| Guaranteed reset validity to VCC = 1V | Ensures deterministic reset behavior during deep brownout, critical for fail-safe embedded control |
| Immunity to short VCC transients | Rejects glitches ≤50µs duration when VCC dips 100mV below threshold - reduces false resets in noisy environments |
| Low 1.6µA quiescent current | Minimizes battery drain in always-on supervision, enabling >10-year operation on coin cells |
| Laser-trimmed reset threshold | Delivers ±1.5% accuracy at +25°C and ±2.5% over full temperature range - eliminates calibration overhead |
Applications
| Portable Medical Sensors | Battery-Powered IoT Nodes |
|---|---|
Use Scenario: Continuous glucose monitor powered by CR2032 coin cell, requiring reliable reset during battery voltage sag. IC Role / Device Role / Timing Role: Voltage supervisor asserting active-low RESET to ARM Cortex-M0+ MCU until VCC recovers above 1.575V and holds for ≥3ms. Use Value: Prevents firmware lockup during intermittent battery contact; 1.6µA ICC extends sensor lifetime beyond 5 years. | Use Scenario: LPWAN node using LoRa transceiver and ultra-low-power sensor hub, operating from 2×AA alkaline cells. IC Role / Device Role / Timing Role: Monitors declining stack voltage and triggers controlled MCU shutdown before brownout-induced memory corruption. Use Value: Capacitor-adjustable timeout (CSRT = 1nF → ~3ms) matches Nordic nRF52840's minimum reset pulse requirement. |
| Automotive Body Control Modules | Industrial Handheld Testers |
Use Scenario: 12V-to-3.3V powered BCM subjected to load-dump and cold-crank transients. IC Role / Device Role / Timing Role: Supervises 3.3V rail and asserts RESET during cold-crank events where VCC dips to 2.5V for <100ms. Use Value: Immunity to 50µs transients avoids spurious resets; –40°C to +125°C rating ensures under-dash reliability. | Use Scenario: Ruggedized multimeter with real-time clock and flash memory, powered by rechargeable Li-ion. IC Role / Device Role / Timing Role: Guarantees clean µP reset on power-on and during battery swap, with timeout configured for FPGA configuration time. Use Value: Push-pull output drives reset net without pull-up, reducing BOM count and PCB area in space-constrained enclosure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor reset supervision applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6421US16+T | SOT143-4 package (vs. SC70-4); identical electrical specs and pinout | Larger footprint (2.1mm × 1.3mm vs. 1.25mm × 0.85mm); higher thermal resistance | Select for manual assembly or legacy board compatibility where SC70 handling is impractical |
| TLV803EB16DBVR | Fixed 1.6V threshold; 350nA IQ; open-drain output; SOT-23-3 package | Requires external pull-up; lower drive strength; no timeout adjustability | Choose for cost-sensitive, space-constrained designs where fixed 350ms timeout suffices and µP accepts open-drain reset |
Compared with MAX6421XS16+T, MAX6421US16+T offers identical functionality in a larger, more hand-solderable package, while TLV803EB16DBVR trades adjustability and push-pull drive for lower cost and ultra-low IQ - making it suitable only where timeout flexibility and direct µP interface are not required.
Availability
MAX6421XS16+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered IoT nodes, and automotive body control modules requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.
Supply support for MAX6421XS16+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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The MAX6421XS16+T belongs to the MAX6340/MAX6421–MAX6426 family of low-power µP supervisors, designed specifically for reliable power-on reset, brownout protection, and capacitor-programmable timeout in space- and energy-constrained embedded systems.
FAQ
What is the exact reset threshold voltage of MAX6421XS16+T and how does it vary with temperature?
The MAX6421XS16+T has a nominal reset threshold of 1.575V, with ±1.5% accuracy at +25°C and ±2.5% over the full –40°C to +125°C operating range. This is confirmed by Table 1 in the datasheet, where suffix "16" corresponds to min/typ/max values of 1.536V/1.575V/1.614V. The device uses laser-trimmed resistors to achieve this stability, and normalized threshold drift versus temperature is characterized in Figure MAX6421/26 toc08.
Does MAX6421XS16+T require an external pull-up resistor on the RESET pin?
No, MAX6421XS16+T does not require an external pull-up resistor because it features an active-low push-pull RESET output. The output actively drives low (≤0.3V at 1.2mA sink) and high (≥0.8×VCC) without external components. This is explicitly stated in the General Description and Pin Description sections, distinguishing it from open-drain variants like MAX6423XS16+T.
How is the reset timeout period set for MAX6421XS16+T, and what capacitor value yields a 4ms timeout?
The reset timeout for MAX6421XS16+T is set by connecting a capacitor (CSRT) between the SRT pin and GND. The relationship is tRP = 2.73×10⁶ × CSRT + 275µs (tRP in seconds, CSRT in farads). To achieve 4ms (0.004s), solve: CSRT = (0.004 − 0.000275) / 2.73×10⁶ ≈ 1365pF. A standard 1500pF ceramic capacitor yields 4.375ms, per the Electrical Characteristics table.
Can MAX6421XS16+T operate reliably when VCC drops below 1.6V, and down to what voltage?
Yes, MAX6421XS16+T guarantees valid RESET output down to VCC = 1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. While its reset threshold is 1.575V, the output remains functional and well-defined (VOL ≤ 0.3V, VOH ≥ 0.8×VCC) even as VCC declines to 1.0V - a key feature for brownout recovery in low-voltage systems.
What package type and dimensions does MAX6421XS16+T use, and is it RoHS-compliant?
MAX6421XS16+T uses the SC70-4 package (code X4+1), measuring 1.25mm × 0.85mm × 0.55mm with wettable flanks. The "+T" suffix confirms it is supplied in tape-and-reel format with lead-free (RoHS-compliant) finish, as documented in the Package Information and Ordering Information sections of the datasheet.
MAX6421XS16+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:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 1.575V
- 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
MAX6421XS16+T FAQ
1.How can I place an order for MAX6421XS16+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6421XS16+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 MAX6421XS16+T reliable?
The price and inventory of MAX6421XS16+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6421XS16+T is usually 5 days.
3.What payment methods are accepted for MAX6421XS16+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6421XS16+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6421XS16+T?
MAX6421XS16+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6421XS16+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 MAX6421XS16+T?
For technical support, including MAX6421XS16+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6421XS16+T requirements.
6.How does Aetrix verify that MAX6421XS16+T is sourced from the original manufacturer or authorized distributors?
All MAX6421XS16+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 MAX6421XS16+T meets industry standards.
7.What is the process for return or replacement of MAX6421XS16+T?
All MAX6421XS16+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6421XS16+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 MAX6421XS16+T part is unused and in its original packaging.
Return procedure for MAX6421XS16+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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