My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX819MCSA+T
- Part No.:
- MAX819MCSA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX819MCSA+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,265
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX819MCSA+T from Maxim Integrated is a +5V microprocessor supervisory circuit with manual reset input, active-low reset output, battery backup switchover, and power-fail comparator functionality. It features a 4.40V ±10% reset threshold, 200ms reset timeout, 11µA quiescent supply current, and operates in 0°C to +70°C temperature range. It is used in portable embedded controllers requiring reliable brownout detection and battery-backed RAM retention.
For engineers reviewing the MAX819MCSA+T datasheet, MAX819MCSA+T pinout, MAX819MCSA+T application, or MAX819MCSA+T equivalent, key selection considerations include manual reset support, 4.40V reset threshold tolerance, battery switchover hysteresis, PFI/PFO comparator behavior, and µMAX-8 package compatibility with space-constrained PCB layouts.
Technical Context
The MAX819MCSA+T implements a precision voltage monitor with fixed 4.40V reset threshold (±10%), internal 200ms reset timeout timer, and dedicated manual reset input (MR) with 63kΩ internal pull-up. Its power-fail comparator (PFI/PFO) operates independently of the reset generator and supports external low-battery or power-fail warning generation.
It integrates a battery switchover circuit that connects BATT to OUT when VCC falls below both VRST (4.40V) and VBATT, with 80Ω on-resistance in backup mode and <1µA standby current when VCC is >1V below VBATT. The MR input asserts reset for as long as it is held low and for 200ms after release, independent of watchdog or power-fail events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.40V ±10% - ensures reliable reset assertion during +5V supply brownout down to 4.0V |
| Reset Timeout Period | 200ms typical - guarantees µP remains held in reset long enough for stable clock and supply recovery |
| Supply Current | 11µA typical at +25°C - enables multi-year operation in battery-powered portable instruments |
| Manual Reset Pulse Width | ≥100ns minimum - supports clean reset initiation from mechanical switches or logic outputs |
| Battery Switchover On-Resistance | 80Ω max - limits voltage drop across BATT-to-OUT path during RAM backup operation |
| Operating Temperature | 0°C to +70°C - qualified for commercial-grade embedded controller applications |
| PFI Input Threshold | 1.25V ±5mV - provides accurate undervoltage detection for auxiliary supplies or battery monitoring |
Pinout & Package
MAX819MCSA+T is housed in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), compatible with SO-8 and DIP-8 footprints but offering 60% area reduction. Pin 1 is marked with a dot; pin numbering follows standard counter-clockwise orientation from top-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 OUT | Supply output for CMOS RAM | Switches between VCC and BATT based on voltage comparison; powers backup RAM during brownout |
| 2 VCC | +5V main supply input | Primary power source; monitored for reset assertion and used as reference for all internal comparators |
| 3 GND | Ground reference | 0V return for all analog and digital functions; must be low-impedance connection to system ground plane |
| 4 PFI | Power-fail comparator input | Monitors external voltage divider; triggers PFO low when input falls below 1.25V threshold |
| 5 PFO | Power-fail comparator output | Open-drain output; can drive MR input directly to generate power-fail-induced reset |
| 6 WDI | Watchdog input | Not functional in MAX819 - left unconnected or tied to VCC/GND; no watchdog timer present |
| 7 RESET | Active-low reset output | Drives µP reset pin low for ≥200ms; sinks 3.2mA min at 0.4V, sources 800µA min at VCC–1.5V |
| 8 MR | Manual reset input | Active-low input with 63kΩ internal pull-up; asserts reset when pulled ≤0.8V and holds for 200ms after release |
Key Features
| Feature | Design Value |
|---|---|
| Manual reset input with internal pull-up | 63kΩ resistor eliminates need for external pull-up; supports direct switch-to-ground interface without debounce |
| Dedicated power-fail comparator (PFI/PFO) | Independent 1.25V reference enables monitoring of secondary supplies or battery voltage without affecting reset timing |
| Battery backup switchover with hysteresis | Automatic transition to BATT when VCC < VRST and VCC < VBATT; 20mV hysteresis prevents oscillation near threshold |
| Low-quiescent-current design | 11µA supply current extends shelf life and runtime in always-on portable equipment with coin-cell backup |
| Reset output with guaranteed timing | 200ms minimum active duration ensures µP initialization completes before code execution resumes |
Applications
| Battery-Powered Portable Instruments | Embedded Controller Supervision |
|---|---|
Use Scenario: Handheld multimeters and data loggers using coin-cell batteries to retain calibration data and real-time clock during main power loss. IC Role / Device Role / Timing Role: MAX819MCSA+T monitors VCC, asserts RESET during brownout, and switches RAM supply to BATT to preserve volatile settings. Use Value: Enables >10-year data retention on CR2032 cells due to 11µA quiescent current and automatic switchover with <1µA backup-mode draw. | Use Scenario: Industrial PLC modules requiring deterministic reset behavior after AC power interruption or undervoltage events. IC Role / Device Role / Timing Role: MAX819MCSA+T provides precise 4.40V reset threshold and 200ms timeout to prevent partial firmware execution during unstable supply conditions. Use Value: Eliminates need for external RC reset circuits; reduces BOM count while guaranteeing µP enters known state before boot sequence begins. |
| Intelligent Sensor Nodes | Critical µP Monitoring in Medical Devices |
Use Scenario: Wireless environmental sensors powered by primary Li-ion cells, with backup supercapacitor for short-term outage resilience. IC Role / Device Role / Timing Role: MAX819MCSA+T uses PFI to monitor battery health and triggers PFO-driven alert or safe shutdown before critical voltage collapse. Use Value: Leverages uncommitted comparator to add predictive low-battery warning without additional ICs or µP GPIO overhead. | Use Scenario: Portable ECG monitors where RAM corruption during power transition could compromise patient safety data. IC Role / Device Role / Timing Role: MAX819MCSA+T gates RAM supply via OUT pin and asserts RESET synchronously with VCC drop, preventing write errors during brownout. Use Value: Integrates battery switchover, reset generation, and manual reset into single µMAX-8 device-reducing board area by 40% vs discrete solution. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX819LCSA+T | 4.65V ±5% reset threshold instead of 4.40V ±10%; identical pinout, timing, and feature set | Suitable for tighter-tolerance +5V systems where 4.65V threshold better matches supply regulation spec | Select MAX819LCSA+T when system VCC ripple and tolerance require higher reset threshold precision |
| TPS3808G33DBVR | 3.3V reset threshold, 350ms timeout, 2.5µA IQ; SOT-23-6 package; no PFI/PFO or MR input | Designed for 3.3V µP systems; lacks manual reset and auxiliary comparator; smaller footprint but fewer functions | Choose TPS3808G33DBVR only for cost- and size-sensitive 3.3V designs where PFI/MR are unnecessary |
Compared with MAX819LCSA+T, the MAX819MCSA+T offers lower reset threshold for earlier brownout response in less-regulated +5V rails; compared with TPS3808G33DBVR, it supports 5V operation, manual reset, and dual-comparator supervision-but requires larger µMAX-8 footprint.
Availability
MAX819MCSA+T is available at Aetrix Electronics and suitable for battery-powered portable instruments, embedded controller supervision, intelligent sensor nodes, critical µP monitoring in medical devices, and industrial data acquisition systems requiring stable component supply across extended production cycles.
Supply support for MAX819MCSA+T 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 power management, sensing, and interface applications in industrial, computing, and portable markets.
The MAX817/MAX818/MAX819 product line delivers integrated microprocessor supervisory functions-including reset generation, battery switchover, and power-fail detection-for compact, low-power embedded systems operating from +5V supplies.
FAQ
What is the reset threshold voltage of the MAX819MCSA+T?
The MAX819MCSA+T has a factory-trimmed reset threshold of 4.40V with ±10% tolerance, optimized for detecting brownout conditions in nominal +5V systems. This value is specified over the full 0°C to +70°C operating temperature range and exhibits 25mV hysteresis to prevent chatter near the trip point. The threshold is internally generated and does not require external components.
Does the MAX819MCSA+T include a watchdog timer function?
No, the MAX819MCSA+T does not include a watchdog timer. Unlike the MAX817 and MAX818 variants, the MAX819 family omits the WDI input and associated watchdog circuitry. Pin 6 (WDI) is a no-connect terminal in the MAX819MCSA+T and must be left floating or tied to VCC/GND per layout guidelines. All watchdog-related timing parameters and features documented for MAX817/MAX818 do not apply to MAX819MCSA+T.
How does the manual reset (MR) input behave on the MAX819MCSA+T?
The MR input on the MAX819MCSA+T is an active-low signal with a 63kΩ internal pull-up resistor. When pulled to ≤0.8V, it immediately asserts RESET and holds it low for the full 200ms timeout period-even if MR returns high before expiration. During this time, MR state is ignored if the battery freshness seal is enabled. The input accepts TTL/CMOS logic levels and supports direct connection to momentary switches without external debounce components.
Can the MAX819MCSA+T be used with a backup supercapacitor instead of a battery?
Yes, the MAX819MCSA+T supports supercapacitor-based backup power. Its BATT input accepts voltages from 2.0V to 5.5V, and the switchover circuit activates when VCC falls below both VRST (4.40V) and VBATT. With proper charging circuitry (e.g., diode + current-limited resistor), a 0.47F supercap can provide several minutes of RAM retention. The <1µA backup-mode supply current minimizes self-discharge impact on hold-up time.
What is the purpose of the PFI and PFO pins on the MAX819MCSA+T?
The PFI (Power-Fail Input) and PFO (Power-Fail Output) pins implement an independent voltage comparator with a 1.25V threshold. PFI monitors an external voltage divider; when its input drops below 1.25V, PFO pulls low. This allows the MAX819MCSA+T to generate power-fail warnings or trigger resets for auxiliary supplies. PFO can be connected directly to MR to create a secondary reset source-though doing so disables the battery freshness seal function.
MAX819MCSA+T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- 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
MAX819MCSA+T FAQ
1.How can I place an order for MAX819MCSA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX819MCSA+T 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 MAX819MCSA+T reliable?
The price and inventory of MAX819MCSA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX819MCSA+T is usually 5 days.
3.What payment methods are accepted for MAX819MCSA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX819MCSA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX819MCSA+T?
MAX819MCSA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX819MCSA+T 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 MAX819MCSA+T?
For technical support, including MAX819MCSA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX819MCSA+T requirements.
6.How does Aetrix verify that MAX819MCSA+T is sourced from the original manufacturer or authorized distributors?
All MAX819MCSA+T 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 MAX819MCSA+T meets industry standards.
7.What is the process for return or replacement of MAX819MCSA+T?
All MAX819MCSA+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX819MCSA+T, 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 MAX819MCSA+T part is unused and in its original packaging.
Return procedure for MAX819MCSA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX819MCSA+T 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…
