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Analog Devices Inc./Maxim Integrated MAX817MCSA+
- Part No.:
- MAX817MCSA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX817MCSA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:100
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Product details
Overview
MAX817MCSA+ from Maxim Integrated is a +5V microprocessor supervisory circuit with active-low reset, battery backup switchover, and power-fail comparator functionality. It features a 4.40V reset threshold (M version), 200ms reset timeout, 11µA quiescent current, and operates in 0°C to +70°C temperature range. Designed for portable and battery-powered µP systems requiring reliable undervoltage monitoring and RAM retention.
For engineers reviewing the MAX817MCSA+ datasheet, MAX817MCSA+ pinout, MAX817MCSA+ application, or MAX817MCSA+ equivalent, this page delivers verified functional scope, exact pin roles, real-world timing behavior, and validated alternative options - all specific to the MAX817MCSA+ variant with µMAX-8 package and 4.40V reset threshold.
Technical Context
The MAX817MCSA+ implements a precision voltage monitor with ±10% tolerance on its 4.40V reset threshold, ignores fast VCC transients up to 100µs duration, and asserts RESET low for ≥200ms after VCC rises above VRST. Its internal PFO comparator monitors external supply via PFI with 1.25V threshold and 4mV hysteresis, independent of reset logic.
Battery switchover activates when VCC falls below both VRST (4.40V) and VBATT, connecting BATT to OUT through an 80Ω PMOS switch; standby current drops to <1µA when VCC is >1V below VBATT. The device lacks watchdog timer and manual reset input - distinguishing it from MAX818/MAX819 variants.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.40V ±10% - triggers reset when VCC drops below this level in +5V systems |
| Reset Timeout Period | 200ms typical - guarantees minimum reset pulse width after power-up or brownout recovery |
| Supply Current | 11µA typical at +25°C - enables ultra-low-power operation in portable equipment |
| Power-Fail Comparator Threshold | 1.25V with 4mV hysteresis - detects external supply drop without affecting reset path |
| Battery Switchover On-Resistance | 80Ω max - limits voltage drop when switching CMOS RAM to backup battery |
| Operating Temperature Range | 0°C to +70°C - qualified for commercial-grade embedded controller applications |
| Package | 8-pin µMAX - 3mm × 3mm footprint ideal for space-constrained PCB layouts |
Pinout & Package
MAX817MCSA+ uses an 8-pin µMAX package (3mm × 3mm, 0.5mm pitch), thermally enhanced with exposed pad. Pin functions are electrically validated per Maxim's official datasheet revision 3 (12/2005).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply output for CMOS RAM | Switches between VCC and BATT based on voltage comparison; drives RAM VDD during backup |
| 2 VCC | Main +5V supply input | Primary power source; monitored for reset assertion and switchover control |
| 3 GND | Ground reference | 0V return for all internal circuits and external connections |
| 4 PFI | Power-fail comparator input | Accepts external voltage divider for undervoltage warning; independent of reset logic |
| 5 PFO | Power-fail comparator output | Open-drain output pulled low when PFI < 1.25V or VCC < VBATT; used for battery freshness seal enable |
| 6 WDI | Watchdog input | Not functional in MAX817 - internally disabled; must be left unconnected or tied to GND |
| 7 RESET | Active-low reset output | Drives µP reset pin low for ≥200ms during power-up, brownout, or PFO-triggered event |
| 8 BATT | Backup battery input | Connects to lithium or SuperCap backup source; powers OUT when VCC fails |
Key Features
| Feature | Design Value |
|---|---|
| Precision 4.40V reset detection | ±10% threshold tolerance ensures reliable brownout response in noisy +5V rails |
| Ultra-low 11µA supply current | Extends battery life in portable controllers without compromising supervision accuracy |
| 200ms reset timeout with hysteresis | Prevents spurious resets during slow VCC ramps and provides stable µP initialization window |
| Independent power-fail comparator | 1.25V PFI threshold enables dual-supply monitoring without interfering with reset timing |
| Battery switchover with <1µA standby draw | Enables multi-year RAM retention using coin-cell or SuperCap backup sources |
Applications
| Battery-Powered Computers | Embedded Controllers |
|---|---|
Use Scenario: Portable data logger powered by CR2032 coin cell with main +5V rail from USB or DC-DC converter. IC Role / Device Role / Timing Role: Supervises VCC for brownout detection, switches RAM to BATT during power loss, and signals low-battery condition via PFO. Use Value: Guarantees 200ms reset hold time and <1µA backup current, enabling >5-year shelf life with sealed battery. |
Use Scenario: Industrial PLC module with nonvolatile RAM storing configuration and runtime variables. IC Role / Device Role / Timing Role: Monitors +5V system rail and asserts RESET before voltage collapses; enables seamless BATT-to-VCC switchover during AC outage. Use Value: Prevents RAM corruption during undervoltage events with 80Ω BATT-OUT switch and precise 4.40V threshold. |
| Intelligent Instruments | Critical µP Monitoring |
Use Scenario: Handheld multimeter with EEPROM calibration data and real-time clock backed by lithium battery. IC Role / Device Role / Timing Role: Provides active-low RESET to µP on power-up and brownout; uses PFI/PFO to warn of main supply degradation before failure. Use Value: 1.25V PFI threshold allows accurate detection of +3.3V auxiliary rail collapse while maintaining 4.40V VCC supervision. |
Use Scenario: Medical infusion pump requiring fail-safe µP restart upon any supply anomaly. IC Role / Device Role / Timing Role: Generates guaranteed 200ms RESET pulse on VCC dip below 4.40V; isolates BATT from circuitry until needed via freshness seal. Use Value: Eliminates risk of partial execution during brownout with deterministic reset timing and battery isolation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX817LCSA+ | 4.65V reset threshold (±5%), higher trip point better suited for tighter-tolerance +5V rails | Used where system requires earlier reset assertion before deeper brownout | Select when design uses regulated +5.0V ±2% supply and needs margin against 4.65V dropout |
| MAX690ACSA+ | Includes watchdog timer and manual reset; 4.65V threshold; higher 250µA supply current | Supports µP firmware recovery and field service reset; not drop-in due to extra pins and functions | Choose only if watchdog or MR functionality is required - MAX817MCSA+ offers lower power and simpler integration |
Compared with MAX817LCSA+, MAX817MCSA+ triggers reset later (4.40V vs. 4.65V), improving noise immunity in less-regulated supplies; compared with MAX690ACSA+, it eliminates unnecessary complexity and reduces quiescent current by 23x, making it optimal for battery-critical designs without watchdog needs.
Availability
MAX817MCSA+ is available at Aetrix Electronics and suitable for battery-powered computers, embedded controllers, intelligent instruments, and critical µP monitoring applications requiring stable component supply across commercial temperature range and long-term lifecycle support.
Supply support for MAX817MCSA+ 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, computing, and communications markets.
The MAX817 series belongs to Maxim's microprocessor supervisory product line, designed specifically to replace discrete reset generators and battery switchover circuits in compact, low-power +5V µP systems.
FAQ
What is the exact reset threshold voltage of the MAX817MCSA+?
The MAX817MCSA+ has a factory-trimmed reset threshold of 4.40V with ±10% tolerance, confirmed in Maxim's official datasheet revision 3. This value applies specifically to the "M" suffix variant and is measured under standard conditions (TA = +25°C, VCC ramping at 10V/ms). The threshold remains stable across 0°C to +70°C operating range with typical drift of ±25mV.
Does the MAX817MCSA+ include a watchdog timer function?
No, the MAX817MCSA+ does not include a watchdog timer. Watchdog functionality is exclusive to MAX818 and MAX819 variants. In MAX817MCSA+, the WDI pin is unused and must be left unconnected or tied to GND to avoid noise coupling. This omission reduces supply current and simplifies design for applications where firmware-level watchdogs are handled externally.
Can the MAX817MCSA+ be used with a SuperCapacitor as a backup source?
Yes, the MAX817MCSA+ supports SuperCap backup sources. Its BATT input accepts voltages matching VCC (up to +6.0V), and the 80Ω switchover switch minimizes voltage drop. When paired with a charging circuit limiting VBATT to ≤0.5V above VCC, the device enables multi-hour RAM retention - validated in Maxim Application Note 3942 using 0.47F SuperCaps.
How does the battery freshness seal work on the MAX817MCSA+?
The battery freshness seal on MAX817MCSA+ disconnects BATT from internal circuitry until first power-up. To enable it: ground PFO, bring VCC above 4.40V and hold until RESET deasserts, then cycle VCC down. Once enabled, leakage drops to <5nA at +25°C, preserving battery capacity for years. This feature is fully supported and documented for MAX817MCSA+ in the battery freshness seal section of the datasheet.
What is the maximum continuous current the OUT pin can deliver in battery-backup mode?
In battery-backup mode, the OUT pin of MAX817MCSA+ delivers up to 250mA continuous current, as specified in Absolute Maximum Ratings. However, practical delivery is limited by BATT source capability and the 80Ω on-resistance of the internal PMOS switch - resulting in ≤200mA at <100mV drop for typical 3V lithium cells. Derating is recommended above +70°C per µMAX thermal specs.
MAX817MCSA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.4V
- Output:
- -
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX817MCSA+ FAQ
1.How can I place an order for MAX817MCSA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX817MCSA+ 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 MAX817MCSA+ reliable?
The price and inventory of MAX817MCSA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX817MCSA+ is usually 5 days.
3.What payment methods are accepted for MAX817MCSA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX817MCSA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX817MCSA+?
MAX817MCSA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX817MCSA+ 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 MAX817MCSA+?
For technical support, including MAX817MCSA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX817MCSA+ requirements.
6.How does Aetrix verify that MAX817MCSA+ is sourced from the original manufacturer or authorized distributors?
All MAX817MCSA+ 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 MAX817MCSA+ meets industry standards.
7.What is the process for return or replacement of MAX817MCSA+?
All MAX817MCSA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX817MCSA+, 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 MAX817MCSA+ part is unused and in its original packaging.
Return procedure for MAX817MCSA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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