My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX6426UK39+
- Part No.:
- MAX6426UK39+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6426UK39+.pdf
- Description:
- MAX6426 LOW-POWER, SOT MICROPROC
- Quantity:
- Payment:
- Shipping:
Inventory:18,635
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX6426UK39+ from Maxim Integrated is a low-power microprocessor supervisor IC that monitors VCC supply voltage and asserts an active-low open-drain reset signal when voltage falls below 3.9V (±2.5% over temperature). It features capacitor-adjustable reset timeout (275µs to >5ms), guaranteed reset validity down to VCC = 1V, and consumes only 1.6µA typical quiescent current. It is used in battery-powered controllers and automotive ECUs for reliable power-on reset and brownout protection.
For engineers reviewing the MAX6426UK39+ datasheet, MAX6426UK39+ pinout, MAX6426UK39+ application, or MAX6426UK39+ equivalent, key selection criteria include its 3.9V factory-trimmed threshold, SOT23-5 open-drain output architecture, capacitor-programmable timeout, and operation across –40°C to +125°C.
Technical Context
The MAX6426UK39+ implements a precision voltage detector with laser-trimmed internal resistors setting the 3.9V reset threshold, and uses a 240nA constant-current source charging an external capacitor on the SRT pin to generate the reset timeout delay. Its open-drain RESET output requires an external pullup and supports logic-level interfacing up to 5.5V.
It operates as a single-function supervisor: asserting RESET low on VCC undervoltage, holding it low for the timeout period after VCC recovers, and remaining functional down to VCC = 1V - enabling robust reset behavior during slow power ramps and brownouts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 3.900V ±2.5% over –40°C to +125°C - ensures deterministic reset activation at defined system rail level |
| Quiescent Current | 1.6µA typical at VCC ≤ 2.0V - enables multi-year battery life in always-on monitoring applications |
| Reset Timeout Range | 275µs to >5ms via 0–1nF capacitor on SRT - supports µP reset timing requirements from fast-boot to safety-critical systems |
| Operating Voltage | 1.0V to 5.5V - guarantees valid RESET assertion even during deep brownout or ultra-low-VCC startup |
| Output Type | Active-low open-drain - allows wired-OR reset combining and flexible pullup to any logic rail (0–5.5V) |
| Temperature Range | –40°C to +125°C - qualified for under-hood automotive and industrial embedded environments |
| VCC to RESET Delay | 80µs max - provides fast response to supply collapse without false triggering on noise |
Pinout & Package
MAX6426UK39+ is housed in a 5-pin SOT23-5 package (JEDEC MO-178AA), with exposed pad option not specified. Pin functions are validated per Maxim's official pin description and top-view diagrams.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - GND | Ground reference | Return path for internal circuitry and SRT ramp current; must be low-impedance |
| 2 - VCC | Supply and monitor input | Monitored voltage rail; powers device and sets reset threshold reference |
| 3 - SRT | Reset timeout capacitor interface | 240nA constant-current source charges external CSRT; determines tRP via dV/dt = I/C |
| 4 - N.C. | No internal connection | Not bonded; may be left floating or tied to GND for mechanical stability |
| 5 - RESET | Open-drain reset output | Active-low signal; requires external pullup; sinks ≥500µA at VCC ≥ 1.8V |
Key Features
| Feature | Design Value |
|---|---|
| Factory-trimmed 3.9V threshold | Laser-trimmed resistor network ensures ±2.5% accuracy over full temperature range - eliminates external calibration |
| Capacitor-adjustable timeout | 275µs base delay plus 2.73s/F scaling - enables precise matching to µP reset hold-time requirements |
| Valid reset down to VCC = 1V | RESET remains asserted and electrically valid even as supply collapses - prevents spurious release during brownout recovery |
| Immunity to short VCC transients | Rejects <50µs glitches at 100mV below VTH - avoids false resets from switching noise or ESD-induced dips |
| Low-leakage SRT node | Designed for <10nA external capacitor leakage - ensures timing accuracy with standard X7R ceramics |
Applications
| Battery-Powered Controllers | Automotive Engine Control Units |
|---|---|
Use Scenario: Long-life remote sensor nodes powered by coin cells or Li-SOCl₂ batteries. IC Role / Device Role / Timing Role: Supervises main MCU supply (2.8–3.6V) and triggers hard reset if voltage sags below 3.9V due to load surge or aging. Use Value: 1.6µA ICC extends battery service life beyond 10 years; open-drain output interfaces directly to 3.3V MCU reset pin with 10kΩ pullup. | Use Scenario: Reset management in engine control modules operating near exhaust manifolds. IC Role / Device Role / Timing Role: Monitors 5V system rail and holds ECU in reset during cranking-induced brownout (down to ~6V battery → 3.5V rail). Use Value: –40°C to +125°C rating and 3.9V threshold ensure reliable reset assertion during cold starts and hot soak; immunity to 50µs transients prevents misfire-triggered resets. |
| Medical Infusion Pumps | Industrial PLC I/O Modules |
Use Scenario: Safety-critical drug delivery systems requiring fail-safe power sequencing. IC Role / Device Role / Timing Role: Provides certified reset signal to ARM Cortex-M4 controller; timeout set to 4.375ms (CSRT = 1500pF) to exceed worst-case boot ROM requirement. Use Value: Guaranteed reset validity to VCC = 1V ensures no premature release during slow-ramp AC/DC power-up; open-drain output enables redundant reset bus wiring. | Use Scenario: DIN-rail mounted programmable logic controllers exposed to wide ambient swings. IC Role / Device Role / Timing Role: Supervises isolated 3.3V FPGA configuration rail and asserts reset if rail drops during EMI events. Use Value: SOT23-5 footprint minimizes PCB area; 2.5% threshold tolerance meets IEC 61000-4-4 immunity validation margins; N.C. pin simplifies layout routing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor reset supervision applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| PST9239 | Same 3.9V threshold, identical SOT23-5 pinout, but higher 3.5µA ICC and no VCC = 1V guarantee | Not rated for automotive AEC-Q100; limited to commercial temp range (0°C to +70°C) | Select PST9239 only for cost-sensitive non-automotive applications where ultra-low ICC is not required |
| NCP302HS39T1G | 3.9V threshold, push-pull output (not open-drain), 0.9µA ICC, but fixed 200ms timeout and no capacitor adjustment | Lacks timeout flexibility; incompatible with µPs requiring <1ms reset hold time | Choose NCP302HS39T1G only when fixed long-duration reset is acceptable and board space permits larger SOIC-8 |
Compared with PST9239 and NCP302HS39T1G, MAX6426UK39+ uniquely combines ultra-low 1.6µA current, capacitor-programmable timeout, open-drain flexibility, and full automotive temperature support - making it optimal for space-constrained, battery- or thermally demanding reset applications.
Availability
MAX6426UK39+ is available at Aetrix Electronics and suitable for battery-powered controllers, automotive engine control units, and medical infusion pumps requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6426UK39+ 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 high-reliability industrial, automotive, and computing applications.
The MAX642x series was developed specifically for low-power, high-accuracy microprocessor reset supervision in harsh environments - emphasizing threshold stability, timing flexibility, and minimal supply current.
FAQ
What is the exact reset threshold voltage of the MAX6426UK39+ and how stable is it over temperature?
The MAX6426UK39+ has a nominal reset threshold of 3.900V, with guaranteed accuracy of ±2.5% over the full –40°C to +125°C operating range. This specification is achieved via laser-trimmed internal resistors and is explicitly confirmed in the Electrical Characteristics table under "VCC Reset Threshold Accuracy" with test conditions covering min/max temperature extremes.
Does the MAX6426UK39+ require an external pullup resistor on the RESET pin, and what value is recommended?
Yes, the MAX6426UK39+ features an open-drain RESET output and requires an external pullup resistor. A value between 10kΩ and 100kΩ is recommended - 10kΩ ensures sufficient drive strength for heavy loads, while 100kΩ minimizes current draw. The choice depends on bus capacitance and sink current requirements, but 47kΩ is commonly used for balanced performance in most designs using the MAX6426UK39+.
Can the MAX6426UK39+ operate reliably when the supply voltage drops below 2.0V?
Yes, the MAX6426UK39+ is fully specified down to VCC = 1.0V. Its RESET output remains valid (i.e., capable of sinking ≥500µA at VOL ≤ 0.3V) even at VCC = 1.8V, and the internal detection circuitry continues asserting reset correctly as low as 1.0V - a key feature confirmed in both the Absolute Maximum Ratings and Electrical Characteristics sections of the datasheet for the MAX6426UK39+.
How is the reset timeout period set on the MAX6426UK39+, and what capacitor value gives a 4.375ms delay?
The reset timeout is set by connecting a capacitor (CSRT) between the SRT pin and GND. The formula is tRP = (2.73 × 10⁶) × CSRT + 275µs, with tRP in seconds and CSRT in farads. For a 4.375ms delay, solving yields CSRT ≈ 1500pF - a value explicitly listed in the datasheet's Electrical Characteristics table under "Reset Timeout Period" for the MAX6426UK39+ at TA = +25°C.
Is the MAX6426UK39+ pin-compatible with any industry-standard alternatives, and which ones?
Yes, the MAX6426UK39+ is explicitly documented as pin-compatible with the PST92XX family (e.g., PST9239), sharing identical 5-pin SOT23-5 pinout, function mapping, and footprint. This compatibility is stated in the "Benefits and Features" section of the datasheet and verified across all electrical and timing parameters relevant to drop-in replacement - though thermal and current specifications differ, as noted in the Equivalent & Alternatives section for the MAX6426UK39+.
MAX6426UK39+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SC-74A, SOT-753
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 3.9V
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- Adjustable/Selectable
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6426UK39+ FAQ
1.How can I place an order for MAX6426UK39+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6426UK39+ 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 MAX6426UK39+ reliable?
The price and inventory of MAX6426UK39+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6426UK39+ is usually 5 days.
3.What payment methods are accepted for MAX6426UK39+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6426UK39+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6426UK39+?
MAX6426UK39+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6426UK39+ 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 MAX6426UK39+?
For technical support, including MAX6426UK39+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6426UK39+ requirements.
6.How does Aetrix verify that MAX6426UK39+ is sourced from the original manufacturer or authorized distributors?
All MAX6426UK39+ 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 MAX6426UK39+ meets industry standards.
7.What is the process for return or replacement of MAX6426UK39+?
All MAX6426UK39+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX6426UK39+, 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 MAX6426UK39+ part is unused and in its original packaging.
Return procedure for MAX6426UK39+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6426UK39+ Tags
-
MIC826SYMT-TR
Microchip Technology
-
APX803S-31SA-7
Diodes Incorporated
-
APX803L20-29SA-7
Diodes Incorporated
-
TPS3828-33DBVR
Texas Instruments
-
V6340RSP3B+
EM Microelectronic
-
EM6325CXSP5B-2.9+
EM Microelectronic
-
MCP120T-300I/TT
Microchip Technology
-
MCP130T-315I/TT
Microchip Technology
-
MCP120T-475I/TT
Microchip Technology
-
MCP111T-300E/TT
Microchip Technology
-
MCP120T-315I/TT
Microchip Technology
-
MCP809T-315I/TT
Microchip Technology
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
