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Analog Devices Inc./Maxim Integrated MAX817LCUA
- Part No.:
- MAX817LCUA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX817LCUA.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:3,778
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Product details
Overview
MAX817LCUA from Maxim Integrated is a +5V microprocessor supervisory circuit with active-low reset, battery switchover, and power-fail comparator functionality. It features a 4.65V ±5% reset threshold, 200ms reset timeout, and 11µA quiescent supply current. Designed for portable embedded systems requiring reliable brownout protection and RAM backup control.
For engineers reviewing the MAX817LCUA datasheet, MAX817LCUA pinout, MAX817LCUA application, or MAX817LCUA equivalent, this device serves as a low-power, precision voltage monitor and reset generator in battery-backed µP systems - particularly where VCC transients must be ignored and backup-battery switching integrity is critical.
Technical Context
The MAX817LCUA implements a precision bandgap-based reset comparator with 25mV hysteresis and internal timing circuitry to guarantee 200ms reset assertion after VCC rises above 4.65V. Its power-fail comparator (PFI/PFO) operates independently with 1.25V threshold and 4mV hysteresis, enabling external supply monitoring without affecting reset behavior.
Battery switchover is controlled by dual comparators: one monitors VCC vs. VRST (4.65V), the other compares VCC vs. VBATT. When both conditions are met (VCC < VRST and VCC < VBATT), an 80Ω PMOS switch connects BATT to OUT, limiting standby current to <1µA at ΔV ≥ 1V.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65V ±5% - ensures reliable reset assertion during +5V supply brownouts down to 4.42V. |
| Reset Timeout Period | 200ms typical - guarantees µP initialization completes before release from reset state. |
| Supply Current | 11µA typical - enables multi-year operation on coin-cell batteries in portable instrumentation. |
| Power-Fail Threshold | 1.25V - allows configurable undervoltage detection of auxiliary supplies via resistor divider. |
| Battery Switchover On-Resistance | 80Ω max - limits voltage drop and power loss when backing up CMOS RAM from 2.0–5.0V batteries. |
| Operating Temperature | 0°C to +70°C - validated for commercial-grade embedded controller environments. |
| VCC Range | +4.75V to +5.5V - compatible with standard 5V LDO regulators and tolerant of ripple up to 250mVpp. |
Pinout & Package
MAX817LCUA is housed in an 8-pin µMAX package (3mm × 3mm, 0.5mm pitch), optimized for space-constrained portable designs. Pin assignments are electrically identical to 8-pin SO and DIP variants but with reduced footprint and thermal resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply output for CMOS RAM | Switches between VCC and BATT based on comparator outputs; delivers regulated +5V or battery voltage to memory. |
| 2 VCC | Main supply input | +5V system rail input; powers internal circuitry and sources OUT when VCC > VRST and VCC > VBATT. |
| 3 GND | Ground reference | 0V return path for all analog and digital functions; must be low-impedance for reset timing accuracy. |
| 4 PFI | Power-fail comparator input | Monitors external voltage divider; asserts PFO low when input falls below 1.25V - usable for secondary supply monitoring. |
| 5 PFO | Power-fail comparator output | Open-drain output pulled high externally; signals power-fail condition or enables battery freshness seal when grounded. |
| 6 WDI | Watchdog timer input | Edge-sensitive input - toggling within 1.6s prevents reset; left floating or high-Z disables watchdog function. |
| 7 RESET | Active-low reset output | Drives µP reset pin low for ≥200ms after power-up, brownout, or manual trigger; sinks 3.2mA minimum. |
| 8 BATT | Backup battery input | Accepts 2.0–5.0V battery or supercap; isolated from VCC by internal diode until switchover conditions are met. |
Key Features
| Feature | Design Value |
|---|---|
| Precision 4.65V reset threshold | ±5% tolerance over 0°C to +70°C ensures consistent brownout response across temperature and unit variance. |
| 200ms reset timeout with hysteresis | Guarantees µP clock stabilization and firmware boot sequence completion before reset deassertion. |
| Independent power-fail comparator | 1.25V threshold with 4mV hysteresis enables reliable detection of auxiliary supply faults without interfering with main reset logic. |
| Battery freshness seal | Enables OEMs to isolate backup battery until first power-up, preserving shelf life and ensuring full capacity at deployment. |
| Low 11µA quiescent current | Extends battery life in always-on portable devices - e.g., 10-year operation on CR2032 with 220mAh capacity. |
Applications
| Battery-Powered Computers | Embedded Controllers |
|---|---|
Use Scenario: Portable data logger powered by AA alkaline cells with nonvolatile SRAM retention during power loss. IC Role / Device Role / Timing Role: Supervisory IC providing VCC brownout detection, automatic BATT→OUT switchover, and 200ms reset hold to prevent corrupted memory writes. Use Value: Ensures RAM contents survive 100ms–5s power interruptions without external circuitry or software intervention. |
Use Scenario: Industrial PLC module with real-time clock and configuration EEPROM requiring guaranteed reset on supply sag. IC Role / Device Role / Timing Role: Reset generator with 4.65V threshold and 25mV hysteresis, rejecting 100ns transients while asserting reset within 10µs of sustained undervoltage. Use Value: Eliminates spurious resets from motor switching noise, improving system uptime and diagnostic reliability. |
| Intelligent Instruments | Critical µP Monitoring |
Use Scenario: Handheld multimeter with LCD, ADC, and flash storage operating from single 9V battery with 5V LDO. IC Role / Device Role / Timing Role: Dual-function supervisor: monitors main 5V rail and uses PFI to detect LDO dropout via resistor divider on unregulated input. Use Value: Provides early warning of battery depletion via PFO signal, allowing graceful shutdown before measurement corruption. |
Use Scenario: Medical infusion pump controller where µP reset integrity is safety-critical per IEC 62304. IC Role / Device Role / Timing Role: Certified reset source with monotonic power-up behavior, 200ms timeout, and independent power-fail comparator for redundant supply monitoring. Use Value: Meets Class C software safety requirements by guaranteeing deterministic reset assertion during all fault conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX692ACSA | Higher 4.75V reset threshold, no PFI/PFO comparator, 1.6s watchdog only (no manual reset) | Lacks power-fail monitoring capability; suitable only where secondary supply monitoring is unnecessary | Select when cost sensitivity outweighs need for auxiliary voltage supervision and battery freshness seal. |
| TPS3808G18DBVR | Adjustable reset threshold (via external resistor), 3.3V/5V compatible, 2.5µA IQ, no battery switchover | Requires external MOSFET for battery backup; lacks integrated BATT→OUT switching and freshness seal | Choose for ultra-low-power 3.3V systems needing programmable reset voltage but no backup power management. |
Compared with MAX692ACSA and TPS3808G18DBVR, the MAX817LCUA uniquely integrates precision 4.65V reset, battery switchover, power-fail comparator, and battery freshness seal in a single 8-pin µMAX package - eliminating discrete FETs, resistors, and layout complexity required by alternatives.
Availability
MAX817LCUA is available at Aetrix Electronics and suitable for battery-powered computers, embedded controllers, intelligent instruments, and critical µP monitoring applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for MAX817LCUA 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 high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and computing markets.
The MAX817L/M series was designed specifically for +5V microprocessor systems needing integrated reset generation, battery backup control, and power-fail warning - targeting portable and space-constrained embedded applications.
FAQ
What is the reset threshold voltage of the MAX817LCUA?
The MAX817LCUA has a factory-trimmed reset threshold of 4.65V ±5%, specified over 0°C to +70°C. This value is fixed and not adjustable; it ensures reliable reset assertion when the +5V supply drops below 4.42V. The MAX817LCUA datasheet confirms this threshold applies across its full operating temperature range and load conditions.
Does the MAX817LCUA support battery backup switchover?
Yes, the MAX817LCUA supports automatic battery backup switchover via its BATT and OUT pins. When VCC falls below both the 4.65V reset threshold and the battery voltage, an internal 80Ω PMOS switch connects BATT to OUT, powering attached CMOS RAM. The MAX817LCUA maintains <1µA quiescent current in this mode when VCC is at least 1V below VBATT.
Can the MAX817LCUA monitor a second power supply?
Yes, the MAX817LCUA includes a dedicated power-fail comparator with PFI input and PFO output. By connecting a resistor divider to PFI, users can configure detection of auxiliary supplies (e.g., 3.3V or 12V rails). The comparator triggers PFO low when PFI falls below 1.25V - a fixed internal reference - enabling flexible multi-rail monitoring without affecting the primary reset function of the MAX817LCUA.
What is the purpose of the battery freshness seal in the MAX817LCUA?
The battery freshness seal in the MAX817LCUA disconnects the backup battery from internal circuitry and OUT until first power-up, preserving shelf life. Activation requires grounding PFO while cycling VCC above and below the 4.65V threshold. Once enabled, the seal remains active until VCC exceeds VRST again - ensuring full battery capacity is available when the end product is deployed. This feature is confirmed in the MAX817LCUA functional description and timing diagrams.
Is the MAX817LCUA pin-compatible with other MAX817 variants?
Yes, the MAX817LCUA shares identical pinout and electrical behavior with MAX817CPA (DIP) and MAX817CSA (SO), differing only in package type (8-pin µMAX). All three variants use the same die, support identical functions (reset, PFI/PFO, WDI, BATT switchover), and meet the same 4.65V reset threshold specification. Layout migration between packages requires only footprint adaptation - no schematic or firmware changes are needed for the MAX817LCUA.
MAX817LCUA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.65V
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-µMAX
MAX817LCUA FAQ
1.How can I place an order for MAX817LCUA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX817LCUA 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 MAX817LCUA reliable?
The price and inventory of MAX817LCUA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX817LCUA is usually 5 days.
3.What payment methods are accepted for MAX817LCUA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX817LCUA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX817LCUA?
MAX817LCUA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX817LCUA 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 MAX817LCUA?
For technical support, including MAX817LCUA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX817LCUA requirements.
6.How does Aetrix verify that MAX817LCUA is sourced from the original manufacturer or authorized distributors?
All MAX817LCUA 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 MAX817LCUA meets industry standards.
7.What is the process for return or replacement of MAX817LCUA?
All MAX817LCUA units undergo pre-shipment inspection (PSI). If there is an issue with MAX817LCUA, 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 MAX817LCUA part is unused and in its original packaging.
Return procedure for MAX817LCUA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX817LCUA Tags
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MIC826SYMT-TR
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APX803L20-29SA-7
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