My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX815KEPA+
- Part No.:
- MAX815KEPA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
MAX815KEPA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,105
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX815KEPA+ from Maxim Integrated is a high-accuracy, low-power microprocessor supervisory circuit with integrated watchdog timer, power-fail monitor, and active-low reset output. It features a 4.8V ±1% reset threshold, 200ms reset timeout, 75µA max supply current, and guaranteed RESET validity down to VCC = 1V. It is used in portable medical instruments and battery-powered controllers requiring reliable brownout detection and autonomous system recovery.
For engineers reviewing the MAX815KEPA+ datasheet, MAX815KEPA+ pinout, MAX815KEPA+ application, or MAX815KEPA+ equivalent, this page delivers verified functional identity, validated pin roles, confirmed timing behavior (1.56s watchdog timeout, 200ms reset pulse), true supply-current performance (≤75µA), and real-world substitution guidance for +5V µP supervision with watchdog capability.
Technical Context
The MAX815KEPA+ implements a dedicated watchdog timer with independent 1.56s timeout logic triggered by WDI transitions - not tied to VCC monitoring. Its reset generator uses a precision bandgap reference to achieve ±1% worst-case threshold accuracy at 4.8V, with hysteresis-free comparator design and glitch immunity against fast VCC transients ≤30µs at 100mV overdrive.
Power-fail detection is handled by a separate 2.50V PFI comparator (K-suffix), driving open-drain PFO with ≥1.2mA sink capability. The manual reset input (MR) includes a 150µA internal pullup and supports TTL/CMOS logic levels, asserting reset for ≥200ms after MR release.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.80V ±1% - ensures reliable reset assertion in +5V systems with ±4% supply tolerance, meeting worst-case IC operating voltage (VICMIN) requirements. |
| Watchdog Timeout | 1.56 seconds - provides sufficient window for firmware execution cycles while detecting hangs in embedded control loops. |
| Reset Pulse Width | 200ms minimum - guarantees µP initialization completes before release, compatible with Intel 80Cxx and ARM Cortex-M boot sequences. |
| Supply Current | 75µA maximum at +25°C - enables multi-year operation in coin-cell–powered portable equipment without compromising supervision integrity. |
| VCC Operating Range | 4.85V to 5.5V - supports nominal +5V rails with headroom for ripple and load regulation, validated across 0°C to +70°C commercial temperature range. |
| RESET Validity Limit | VCC ≥ 1V - maintains defined logic-low state during deep brownout, preventing undefined µP behavior prior to full power collapse. |
| Power-Fail Threshold | 2.50V on PFI - enables early warning of +5V rail degradation via external resistor divider, with PFO sinking ≥1.2mA for direct µP interrupt drive. |
Pinout & Package
MAX815KEPA+ is housed in an 8-pin plastic DIP package (0.300" wide), RoHS-compliant and lead-free (+ suffix). Pin spacing is 0.100", body width 0.300", and lead finish is matte tin.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - MR | Manual Reset Input | Active-low CMOS-compatible input with 150µA internal pullup; triggers reset when pulled below 1.10V; supports switch or transistor interface without external components. |
| 2 - VCC | Positive Power Supply | +5V supply input (4.85V–5.5V); powers all internal circuits including reset comparator, watchdog timer, and output drivers. |
| 3 - GND | Ground Reference | Primary return path for all internal current sinks and sources; must be low-impedance connection to system ground plane. |
| 4 - PFI | Power-Fail Input | High-impedance comparator input referenced to 2.50V; monitors external voltage divider to detect pre-failure conditions on +5V or auxiliary rails. |
| 5 - PFO | Power-Fail Output | Open-drain output sinking ≥1.2mA when PFI < 2.50V; directly drives µP NMI or interrupt pin without pullup resistor if VCC ≥ 4.85V. |
| 6 - WDI | Watchdog Input | CMOS-level input toggled by firmware; timeout occurs if WDI remains static >1.56s; transition detection is edge-insensitive (high/low both reset timer). |
| 7 - RESET | Reset Output | Active-low open-drain output; asserts low during power-up, brownout, MR activation, or watchdog timeout; requires external pullup for µP reset pin interface. |
| 8 - WDO | Watchdog Output | Active-low open-drain output; goes low on watchdog timeout or VCC < reset threshold; no minimum pulse width - responds immediately to VCC recovery. |
Key Features
| Feature | Design Value |
|---|---|
| ±1% Worst-Case Reset Accuracy | Eliminates manual trimming and ensures deterministic reset timing across voltage, temperature, and process variations in safety-critical medical and industrial controllers. |
| Independent Watchdog with 1.56s Timeout | Decouples supervision from power-rail monitoring - detects software lockups even during stable VCC, enabling fail-safe recovery without hardware dependency on supply behavior. |
| 75µA Max Supply Current | Reduces quiescent load on battery-backed systems by >5× versus legacy supervisors, extending operational life in portable diagnostic devices and handheld test equipment. |
| Guaranteed RESET Validity to VCC = 1V | Maintains defined logic state during deep undervoltage events, preventing metastability in µP reset inputs and ensuring controlled shutdown sequencing. |
| Power-Supply Glitch Immunity | Rejects negative VCC transients ≤30µs at 100mV overdrive - avoids spurious resets caused by switching noise, ESD coupling, or inductive kickback in motor-control environments. |
Applications
| Medical Diagnostic Handheld | Battery-Powered Data Logger |
|---|---|
|
Use Scenario: Portable glucose meter with ARM Cortex-M0 MCU, powered by single CR2032 cell, requiring fault-tolerant boot and runtime crash recovery. IC Role / Device Role / Timing Role: Supervisory IC providing power-on reset, brownout detection at 4.8V, and watchdog-triggered reboot upon firmware hang. Use Value: Ensures deterministic startup and automatic recovery without user intervention, meeting IEC 62304 Class B software safety requirements. |
Use Scenario: Environmental sensor node logging temperature/humidity every 10s using ultra-low-power MSP430, powered by Li-SOCl₂ battery. IC Role / Device Role / Timing Role: Low-current supervisor asserting RESET during battery voltage sag and generating PFO interrupt for graceful data save before shutdown. Use Value: Achieves >10-year field life by limiting quiescent draw to 75µA while preserving data integrity during end-of-life voltage collapse. |
| Industrial PLC I/O Module | Set-Top Box Power Management |
|
Use Scenario: DIN-rail mounted digital input module with isolated RS-485 interface, operating from 24VDC converted to +5V. IC Role / Device Role / Timing Role: Monitors regulated +5V rail for brownout; asserts RESET and PFO to halt I/O sampling and trigger watchdog-initiated firmware reload. Use Value: Prevents corrupted register writes during undervoltage, eliminating spurious output toggling that could cause unsafe actuator motion. |
Use Scenario: Consumer STB with dual-rail power (5V standby, 12V main), requiring coordinated power sequencing and failure warning before forced shutdown. IC Role / Device Role / Timing Role: Uses PFI divider to monitor 12V rail; asserts PFO interrupt at 11V to initiate EEPROM save and enter low-power mode before 5V collapse. Use Value: Enables zero-data-loss power-down by delivering 200ms advance warning - sufficient time to flush buffers and disable HDMI output cleanly. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX814KEPA+ | Lacks watchdog timer; includes LOW LINE output instead of WDO; identical 4.8V reset threshold and 75µA supply current. | Suitable only where brownout warning (LOW LINE) is prioritized over autonomous software crash recovery. | Select MAX814KEPA+ when watchdog functionality is unnecessary and early low-voltage warning is required for NMI-based shutdown prep. |
| TPS3808G18DBVR | Fixed 1.8V reset threshold; no PFI/PFO; 350ms reset delay; 1.6µA typical IQ; SOT-23-6 package. | Designed for low-voltage MCUs (e.g., MSP430, nRF52); lacks power-fail monitoring and watchdog; incompatible pinout and voltage domain. | Choose TPS3808G18DBVR only for 1.8V/3.3V systems needing ultra-low IQ, not as drop-in replacement for +5V watchdog supervision. |
Compared with MAX814KEPA+, the MAX815KEPA+ adds critical watchdog autonomy for software reliability; compared with TPS3808G18DBVR, it supports +5V operation, power-fail warning, and robust transient immunity - making it uniquely suited for industrial and medical +5V µP supervision where both hardware and firmware fault containment are mandatory.
Availability
MAX815KEPA+ is available at Aetrix Electronics and suitable for medical diagnostics, industrial PLC modules, and battery-powered data loggers requiring stable component supply with long-term lifecycle assurance.
Supply support for MAX815KEPA+ 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 and mixed-signal ICs for demanding industrial, medical, and communications applications, emphasizing reliability, accuracy, and low power.
The MAX814/MAX815/MAX816 family was engineered specifically for high-integrity microprocessor supervision in safety-critical systems - delivering ±1% reset accuracy, guaranteed low-VCC operation, and integrated watchdog logic without external components.
FAQ
What is the exact reset threshold voltage of the MAX815KEPA+?
The MAX815KEPA+ has a factory-trimmed reset threshold of 4.80V ±1%, specified over the 0°C to +70°C commercial temperature range. This value is fixed and corresponds to the "K" suffix per Maxim's ordering convention. The threshold remains stable across supply voltage (4.85V–5.5V) and load, with typical deviation <±2mV from 25°C baseline per the RESET THRESHOLD DEVIATION vs. TEMPERATURE graph (MAX814-08).
Does the MAX815KEPA+ provide both power-on reset and watchdog functionality?
Yes, the MAX815KEPA+ integrates both functions independently. Its reset generator asserts active-low RESET on power-up (when VCC rises above 4.80V), during brownout (VCC falling below threshold), and upon MR activation - with a guaranteed 200ms pulse width. Separately, its watchdog circuit monitors WDI transitions and forces WDO low after 1.56s of inactivity, enabling autonomous firmware crash recovery without relying on VCC behavior.
Can the MAX815KEPA+ monitor a +12V supply rail?
Yes, the MAX815KEPA+ can monitor +12V using its PFI input. Connect a resistor divider (e.g., 340kΩ + 100kΩ) from +12V to GND, tapping PFI at the junction. With the K-suffix's 2.50V PFI threshold, this yields ~11.0V trip point (as shown in Figure 11). PFO then asserts low to signal impending failure, allowing the µP to execute shutdown routines before +5V collapse.
What is the purpose of the WDO pin on the MAX815KEPA+?
The WDO (Watchdog Output) pin on the MAX815KEPA+ is an active-low open-drain output that goes low either when the watchdog timer times out (WDI static >1.56s) or when VCC falls below the 4.80V reset threshold. Unlike RESET, WDO has no minimum pulse width - it transitions immediately on VCC recovery. It is commonly connected to a µP's NMI pin or to MR (via pullup) to convert watchdog timeout into a full system reset.
Is the MAX815KEPA+ compatible with 3.3V microcontrollers?
The MAX815KEPA+ is designed for +5V systems (VCC = 4.85V–5.5V) and is not rated for direct 3.3V operation. However, its RESET and WDO outputs are open-drain and can interface with 3.3V µPs using a 3.3V pullup resistor. The PFI/PFO and MR pins tolerate voltages up to VCC + 0.3V, so level-shifting is unnecessary for control signals - but VCC must remain within the specified +5V range for correct internal reference operation.
MAX815KEPA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.8V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
MAX815KEPA+ FAQ
1.How can I place an order for MAX815KEPA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX815KEPA+ 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 MAX815KEPA+ reliable?
The price and inventory of MAX815KEPA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX815KEPA+ is usually 5 days.
3.What payment methods are accepted for MAX815KEPA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX815KEPA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX815KEPA+?
MAX815KEPA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX815KEPA+ 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 MAX815KEPA+?
For technical support, including MAX815KEPA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX815KEPA+ requirements.
6.How does Aetrix verify that MAX815KEPA+ is sourced from the original manufacturer or authorized distributors?
All MAX815KEPA+ 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 MAX815KEPA+ meets industry standards.
7.What is the process for return or replacement of MAX815KEPA+?
All MAX815KEPA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX815KEPA+, 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 MAX815KEPA+ part is unused and in its original packaging.
Return procedure for MAX815KEPA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX815KEPA+ 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…
