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Analog Devices Inc./Maxim Integrated MAX6421US23-T
- Part No.:
- MAX6421US23-T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- TO-253-4, TO-253AA
- Datasheet:
-
MAX6421US23-T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SOT143-4
- Quantity:
- Payment:
- Shipping:
Inventory:5,000
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Product details
Overview
MAX6421US23-T from Maxim Integrated is a low-power microprocessor reset supervisor IC in SOT143-4 package, featuring an active-low push-pull RESET output, 2.313V factory-trimmed reset threshold (±1.5% at +25°C), capacitor-adjustable reset timeout (275µs minimum), and guaranteed operation down to VCC = 1V. It monitors system supply voltage during power-up, power-down, and brownout conditions in portable battery-powered controllers.
For engineers reviewing the MAX6421US23-T datasheet, MAX6421US23-T pinout, MAX6421US23-T application, or MAX6421US23-T equivalent, key selection criteria include reset threshold accuracy, quiescent current (1.6µA typ), SRT capacitor-based timeout adjustability, push-pull output drive capability, and SOT143-4 footprint compatibility with space-constrained embedded designs.
Technical Context
The MAX6421US23-T implements a precision bandgap-based voltage detector with 2.313V nominal reset threshold and 4mV hysteresis, referenced to an internal 0.65V ramp comparator. Its SRT pin sources a stable 240nA current to charge an external capacitor, generating a programmable reset timeout period per tRP = 2.73×10⁶ × CSRT + 275µs.
It asserts RESET low when VCC falls below threshold and holds it low for the full timeout after VCC rises above threshold. The push-pull output guarantees VOL ≤ 0.4V at ISINK = 3.2mA (VCC ≥ 4.5V) and VOH ≥ 0.8×VCC at ISOURCE = 800µA, ensuring robust interface with CMOS µP reset inputs across 1.6V–5V supply range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.313V ±1.5% (typ at +25°C); ensures reliable detection of 2.3V rail brownout without false triggering |
| Quiescent Current | 1.6µA (typ at +25°C); enables multi-year battery life in always-on monitoring applications |
| Reset Timeout Min | 275µs (CSRT = 0); provides minimum assertion time sufficient for most µP power-up sequences |
| VCC Operating Range | 1.0V to 5.5V; supports valid RESET assertion even as supply collapses to 1V |
| Output Type | Active-low push-pull; eliminates need for external pullup and drives µP reset input directly |
| VCC to Reset Delay | 80µs (VCC falling at 1mV/µs); ensures fast response to supply collapse |
| Hysteresis | 4 × VTH = 9.252mV; prevents oscillation near threshold during slow VCC transitions |
Pinout & Package
MAX6421US23-T is housed in a 4-pin SOT143-4 surface-mount package (outline 21-0052), measuring 2.1mm × 2.3mm × 0.95mm, with gull-wing leads and RoHS-compliant lead-free finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VCC | Supply and threshold monitor input | Primary power connection; voltage applied here sets reset trigger point and powers internal circuitry |
| 2 - GND | Ground reference | Analog and digital ground return; must be low-impedance path for accurate threshold sensing |
| 3 - RESET | Active-low push-pull reset output | Drives µP reset pin low during fault; actively pulls high when deasserted-no external pullup required |
| 4 - SRT | Set reset timeout input | Connects to external capacitor; 240nA current source charges CSRT to determine timeout duration |
Key Features
| Feature | Design Value |
|---|---|
| Capacitor-adjustable timeout | Enables precise reset hold time tuning (e.g., 100ms for ARM Cortex-M boot) via single external capacitor |
| Guaranteed reset validity to VCC = 1V | Ensures deterministic reset behavior even during deep brownout, critical for fail-safe shutdown |
| Immunity to short VCC transients | Rejects <50µs glitches 100mV below threshold-prevents spurious resets in noisy automotive environments |
| Low-leakage SRT interface | 240nA ramp current source minimizes sensitivity to PCB leakage, enabling accurate timeout on prototype boards |
| Factory-trimmed threshold | 2.313V ±1.5% tolerance eliminates need for external resistor divider calibration in production |
Applications
| Battery-Powered Controllers | Portable Medical Devices |
|---|---|
Use Scenario: A handheld glucose meter uses coin-cell battery and requires guaranteed reset during battery depletion. IC Role / Device Role / Timing Role: MAX6421US23-T monitors 3.3V rail and asserts RESET when voltage drops below 2.313V during discharge. Use Value: 1.6µA quiescent current extends battery life; 275µs minimum timeout ensures µP completes safe data save before shutdown. | Use Scenario: An ambulatory ECG patch operates continuously for 7 days on a Li-ion cell with variable load. IC Role / Device Role / Timing Role: MAX6421US23-T provides brownout protection during RF transmission surges that dip VCC transiently. Use Value: Immunity to 50µs/100mV transients prevents false resets; push-pull output drives low-capacitance ASIC reset pin directly. |
| Automotive Body Control Modules | Industrial Sensor Nodes |
Use Scenario: A door module experiences cold-crank VCC sag to 2.1V during engine start. IC Role / Device Role / Timing Role: MAX6421US23-T holds MCU in reset until VCC recovers above 2.313V and sustains for programmed timeout. Use Value: Valid operation down to VCC = 1V ensures reset remains asserted throughout worst-case crank profile. | Use Scenario: A wireless temperature sensor node sleeps at 1µA and wakes every 10 seconds to transmit. IC Role / Device Role / Timing Role: MAX6421US23-T supervises the 1.8V LDO powering the MCU and radio during wake cycles. Use Value: SOT143-4 footprint fits tight PCB area; capacitor-adjustable timeout aligns precisely with firmware boot sequence. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor reset supervision applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6421XS23-T | Same electrical specs and reset threshold, but in SC70-4 package (2.0mm × 2.1mm) | SC70 offers slightly smaller footprint but lower thermal mass and different solder reflow profile | Select MAX6421XS23-T only if board layout requires SC70-4 land pattern and thermal constraints permit |
| TPS3808G125DBVR | Fixed 1.25V threshold, 350ms min timeout, 2.5µA ICC, SOT23-5 package | Lacks adjustable timeout and higher threshold; requires external resistor divider for 2.3V detection | Choose TPS3808G125DBVR only if fixed timeout suffices and design can accommodate 5-pin layout and threshold scaling |
Compared with MAX6421XS23-T, the MAX6421US23-T offers identical supervision functionality in a mechanically distinct SOT143-4 package optimized for thermal stability in automotive ambient; versus TPS3808G125DBVR, it delivers precise 2.313V detection without external components and field-programmable timeout-critical for compact, low-power, and high-reliability embedded systems.
Availability
MAX6421US23-T is available at Aetrix Electronics and suitable for battery-powered controllers, portable medical devices, and automotive body electronics requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for MAX6421US23-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
Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in analog and mixed-signal ICs for power, sensing, and interface applications.
The MAX6421 series belongs to Maxim's microprocessor supervisor product line, designed specifically for ultra-low-power, precision voltage monitoring in space- and energy-constrained embedded systems.
FAQ
What is the exact reset threshold voltage of the MAX6421US23-T?
The MAX6421US23-T has a factory-trimmed nominal reset threshold of 2.313V, with ±1.5% accuracy at +25°C and ±2.5% over the full -40°C to +125°C operating range. This value is laser-trimmed during production and corresponds to the "23" suffix in the part number, per Table 1 of the datasheet.
How do I calculate the reset timeout period for the MAX6421US23-T?
The reset timeout period tRP for MAX6421US23-T is calculated using tRP = (2.73 × 10⁶) × CSRT + 275µs, where CSRT is the capacitance (in farads) connected between the SRT pin and ground. For example, a 1500pF capacitor yields tRP ≈ 4.375ms. The device guarantees minimum timeout of 275µs even with CSRT = 0.
Does the MAX6421US23-T require an external pullup resistor on the RESET pin?
No, the MAX6421US23-T does not require an external pullup resistor because it features an active-low push-pull RESET output. The internal driver actively pulls the pin low during reset assertion and high during deassertion, eliminating reliance on external components for logic-level definition.
Can the MAX6421US23-T operate reliably during cold-crank automotive conditions?
Yes, the MAX6421US23-T is rated for -40°C to +125°C operation and guarantees valid RESET output down to VCC = 1V. Its immunity to transients ≤50µs at 100mV below threshold makes it suitable for cold-crank scenarios where VCC may sag to ~2.1V briefly-ensuring the microcontroller remains held in reset until stable supply is restored.
What package type and dimensions does the MAX6421US23-T use?
The MAX6421US23-T uses a 4-pin SOT143-4 package (outline 21-0052), with dimensions of 2.1mm × 2.3mm × 0.95mm and gull-wing leads. It is RoHS-compliant and available in lead-free form (denoted by "-T" suffix); the top mark is "KADE".
MAX6421US23-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- TO-253-4, TO-253AA
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 2.313V
- 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:
- SOT-23-4
MAX6421US23-T FAQ
1.How can I place an order for MAX6421US23-T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6421US23-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 MAX6421US23-T reliable?
The price and inventory of MAX6421US23-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6421US23-T is usually 5 days.
3.What payment methods are accepted for MAX6421US23-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6421US23-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6421US23-T?
MAX6421US23-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6421US23-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 MAX6421US23-T?
For technical support, including MAX6421US23-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6421US23-T requirements.
6.How does Aetrix verify that MAX6421US23-T is sourced from the original manufacturer or authorized distributors?
All MAX6421US23-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 MAX6421US23-T meets industry standards.
7.What is the process for return or replacement of MAX6421US23-T?
All MAX6421US23-T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6421US23-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 MAX6421US23-T part is unused and in its original packaging.
Return procedure for MAX6421US23-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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