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Analog Devices Inc./Maxim Integrated MAX6845UKD3+
- Part No.:
- MAX6845UKD3+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-74A, SOT-753
- Datasheet:
-
MAX6845UKD3+.pdf
- Description:
- MAX6845 ULTRA-LOW-VOLTAGE UP RES
- Quantity:
- Payment:
- Shipping:
Inventory:2,080
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Product details
Overview
MAX6845UKD3+ from Maxim Integrated is an ultra-low-voltage microprocessor supervisory circuit with adjustable reset threshold, active-low open-drain RESET output, 210ms typical reset timeout, ±2.5% threshold accuracy over temperature, and operation down to VCC = 0.55V - designed for reliable power monitoring in portable, battery-powered, and telecom systems.
For engineers reviewing the MAX6845UKD3+ datasheet, MAX6845UKD3+ pinout, MAX6845UKD3+ application, or MAX6845UKD3+ equivalent, this page delivers verified specifications, SOT23-5 pin mapping, real-world use cases in low-voltage µP systems, and two validated alternative parts with documented functional and interface differences.
Technical Context
The MAX6845UKD3+ implements a precision voltage comparator referenced to an internal 187.4mV bandgap-derived threshold at the RESET IN pin, enabling externally adjustable reset points via resistive divider networks tied to VCC. It features debounced manual reset (MR) with 20kΩ internal pullup and 150ns glitch rejection.
Its reset assertion logic responds to either falling RESET IN voltage below 187.4mV (referenced to VCC) or MR low assertion, holding RESET low for a fixed 210ms (typ) timeout after recovery. The open-drain output supports level-shifting and bidirectional µP reset interfaces with external pullup to 0–6V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold Type | Adjustable via RESET IN pin (187.4mV reference to VCC) |
| Reset Timeout Period | 210ms typical - ensures stable µP initialization after brownout recovery |
| Supply Voltage Range | 0.55V to 1.8V - supports core supplies of modern ultra-low-voltage SoCs and MCUs |
| Supply Current | 5.7µA typical at 0.9V - enables multi-year battery life in always-on monitoring |
| Reset Output Type | Active-low open-drain - allows wired-OR configuration and level translation across supply domains |
| Threshold Accuracy | ±2.5% over -40°C to +85°C - eliminates need for external calibration in industrial environments |
| MR Input Behavior | Internal 20kΩ pullup; 1µs minimum pulse width - simplifies pushbutton interface without external components |
Pinout & Package
MAX6845UKD3+ is housed in a space-saving 5-pin SOT23-5 package (JEDEC MO-178AA), optimized for high-density portable PCB layouts and reflow-compatible assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | GND | Ground reference for all internal comparators and bias circuits |
| 2 | RESET | Active-low open-drain reset output - requires external pullup; sinks up to 80µA at VCC ≥ 0.83V |
| 3 | RESET IN | High-impedance input for adjustable reset threshold - referenced to VCC; 25nA max leakage enables high-R divider networks |
| 4 | MR | Active-low manual reset input - internally pulled up to VCC; asserts reset when pulled ≤ 0.3×VCC |
| 5 | VCC | Supply input and voltage reference source - powers device and serves as reference for RESET IN divider |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Reset Threshold | Set via external resistor divider on RESET IN - supports custom VCC thresholds from 0.8V to 1.5V without trimming |
| Guaranteed Reset Validity | RESET remains functional down to VCC = 0.55V - ensures deterministic behavior during deep brownout |
| Transient Immunity | Rejects VCC glitches < 150ns wide - prevents spurious resets in noisy power environments |
| Low-Power Operation | 5.7µA supply current at 0.9V - reduces quiescent load on battery-backed rails |
| Bidirectional Reset Interface | Open-drain RESET enables direct connection to µP bidirectional reset pins with single pullup - no level translators required |
Applications
| Portable Medical Sensors | Industrial IoT Edge Nodes |
|---|---|
Use Scenario: Wearable ECG monitor powered by coin-cell battery with 0.9V LDO output. IC Role / Device Role / Timing Role: Supervises 0.9V core rail and triggers controlled µC reset during battery sag. Use Value: 210ms timeout prevents premature wake-up; 5.7µA ICC extends battery life beyond 3 years in sleep mode. |
Use Scenario: Wireless sensor node in factory automation with dual-supply architecture (0.85V MCU core, 3.3V radio). IC Role / Device Role / Timing Role: Monitors 0.85V core supply using RESET IN divider; drives shared reset bus via open-drain output. Use Value: Open-drain output pulls up to 3.3V rail - enables single reset signal to coordinate both MCU and transceiver startup. |
| 5G Small Cell Baseband Units | Automotive Infotainment Power Sequencing |
Use Scenario: FPGA-based baseband processor requiring precise power-rail sequencing and brownout detection. IC Role / Device Role / Timing Role: Provides reset assertion synchronized to 1.0V core supply collapse; interfaces to FPGA's bidirectional INIT_B pin. Use Value: 187.4mV internal reference enables accurate 1.0V threshold setting with <1% resistor tolerance - meets 3GPP timing compliance. |
Use Scenario: Head unit with ASIL-B compliant power management, where 1.2V SoC supply must be validated before boot. IC Role / Device Role / Timing Role: Configured with D3 timeout and E-threshold suffix (0.833V) to supervise 1.2V rail via resistive divider. Use Value: ±2.5% threshold accuracy over -40°C to +105°C (derated) ensures robust operation across automotive temperature extremes. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6844UKD3+ | Active-high push-pull RESET output; identical RESET IN, MR, timeout, and threshold specs | Requires inverted reset logic path; incompatible with µPs expecting active-low reset assertion | Select when system design mandates active-high reset signaling and no level translation is feasible |
| TPS3808G33DBVR | Fixed 3.3V reset threshold; 200ms timeout; 2.5µA ICC; SOT23-6 package | Lacks adjustable threshold and manual reset; not suitable for sub-1V monitoring or user-triggered reset | Choose only for higher-voltage (≥3.3V) applications where simplicity and ultra-low ICC outweigh configurability needs |
Compared with MAX6844UKD3+, the MAX6845UKD3+ provides active-low open-drain output for flexible bus interfacing, while TPS3808G33DBVR offers lower ICC but sacrifices adjustability and manual reset - making MAX6845UKD3+ uniquely suited for ultra-low-voltage, field-configurable reset supervision.
Availability
MAX6845UKD3+ is available at Aetrix Electronics and suitable for portable medical sensors, industrial IoT edge nodes, 5G small cell baseband units, and automotive infotainment systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6845UKD3+ 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, communications, and computing applications.
The MAX6841–MAX6845 family was engineered specifically for ultra-low-voltage microprocessor supervision in battery-constrained and thermally harsh environments - delivering guaranteed reset validity down to 0.55V with minimal external components.
FAQ
What is the exact reset timeout period for MAX6845UKD3+?
The MAX6845UKD3+ has a typical reset active timeout period of 210ms, with minimum and maximum values of 140ms and 280ms respectively, as defined by the D3 suffix in its part number. This fixed delay ensures sufficient hold time for microprocessor initialization after power recovery, and is guaranteed over the full -40°C to +85°C operating temperature range.
How does the RESET IN pin function on MAX6845UKD3+?
The RESET IN pin on MAX6845UKD3+ is a high-impedance input referenced to VCC, with a precise internal threshold of 187.4mV. When the voltage at this pin falls below that threshold (e.g., due to a falling VCC monitored via external resistor divider), MAX6845UKD3+ asserts its open-drain RESET output. Leakage current is limited to ±25nA, enabling use of high-value resistors to minimize power consumption.
What is the lowest valid VCC voltage for MAX6845UKD3+ operation?
MAX6845UKD3+ guarantees functional reset assertion down to VCC = 0.55V for the active-low open-drain output. Below this, the output stage ceases sinking current and becomes high-impedance. The device continues monitoring VCC and RESET IN down to 0.55V, and its internal circuitry remains operational within the full 0.55V–1.8V supply range specified in the datasheet.
Can MAX6845UKD3+ drive a reset line shared with other ICs?
Yes - the open-drain RESET output of MAX6845UKD3+ is explicitly designed for wired-OR configurations. When used with a common pullup resistor, multiple MAX6845UKD3+ devices (or other open-drain supervisors) can share a single reset bus. Each device independently pulls the line low to assert reset, and the bus returns high only when all devices release it.
Does MAX6845UKD3+ include manual reset functionality?
Yes, MAX6845UKD3+ includes a dedicated MR (manual reset) pin with internal 20kΩ pullup to VCC. Pulling MR low forces an immediate reset assertion, which remains active for the full 210ms timeout after MR is released. No external components are needed for basic pushbutton implementation, and the input rejects glitches shorter than 150ns.
MAX6845UKD3+ 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:
- Power Supply Monitor
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- Adjustable/Selectable
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 1.12s Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
MAX6845UKD3+ FAQ
1.How can I place an order for MAX6845UKD3+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6845UKD3+ 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 MAX6845UKD3+ reliable?
The price and inventory of MAX6845UKD3+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6845UKD3+ is usually 5 days.
3.What payment methods are accepted for MAX6845UKD3+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6845UKD3+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6845UKD3+?
MAX6845UKD3+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6845UKD3+ 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 MAX6845UKD3+?
For technical support, including MAX6845UKD3+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6845UKD3+ requirements.
6.How does Aetrix verify that MAX6845UKD3+ is sourced from the original manufacturer or authorized distributors?
All MAX6845UKD3+ 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 MAX6845UKD3+ meets industry standards.
7.What is the process for return or replacement of MAX6845UKD3+?
All MAX6845UKD3+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX6845UKD3+, 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 MAX6845UKD3+ part is unused and in its original packaging.
Return procedure for MAX6845UKD3+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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