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Analog Devices Inc./Maxim Integrated MAX705CSA+T
- Part No.:
- MAX705CSA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX705CSA+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:7,217
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Product details
Overview
MAX705CSA+T from Maxim Integrated is a low-cost microprocessor supervisory circuit in 8-pin SO package, providing active-low reset output, 1.6s watchdog timer, 1.25V power-fail comparator input, and debounced manual-reset input. It asserts a guaranteed 200ms reset pulse when VCC drops below 4.65V and remains valid down to VCC = 1V - used for reliable power-up sequencing and brownout protection in embedded control systems.
For engineers reviewing the MAX705CSA+T datasheet, MAX705CSA+T pinout, MAX705CSA+T application, or MAX705CSA+T equivalent, this page delivers verified functional identity, confirmed SO-8 pin mapping, exact reset threshold (4.65V), watchdog timeout (1.6s), PFI threshold (1.25V), and two validated alternative parts with documented technical and application differences.
Technical Context
The MAX705CSA+T integrates four core supervisory functions on a single die: precision supply monitoring with 40mV hysteresis, a self-clearing watchdog timer triggered by WDI edge transitions, a high-impedance (±25nA) 1.25V reference-based power-fail comparator, and TTL/CMOS-compatible MR input with 250μA internal pull-up. All logic outputs drive standard CMOS loads with guaranteed VOL ≤ 0.4V at 3.2mA sink.
Its reset generator uses an internal RC timing network to ensure ≥140ms minimum pulse width after VCC rise or MR release, while the watchdog timeout is factory-trimmed to 1.6s (1.0–2.25s range). The device operates across 1.0V to 5.5V supply range and guarantees RESET validity down to VCC = 1V - critical for battery-backed or low-voltage wake-up scenarios.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 4.65V ±150mV - triggers reset during brownout when +5V rail falls below safe µP operating level |
| Reset Pulse Width | 200ms typical - ensures sufficient duration to fully initialize microcontrollers like 80C51 or ARM Cortex-M0 |
| Watchdog Timeout | 1.6s ±650ms - provides deterministic firmware hang detection without external components |
| PFI Threshold | 1.25V ±50mV - enables precise early-warning power-fail detection via external voltage divider |
| Supply Current | 150–350µA - supports always-on monitoring in low-power industrial sensors and metering devices |
| VCC Operating Range | 1.0V to 5.5V - allows operation during battery backup or deep-sleep wake-up before main regulator stabilizes |
| MR Input Pull-Up | 250µA - eliminates need for external pull-up resistor when using pushbutton manual reset |
Pinout & Package
MAX705CSA+T is housed in an 8-pin SO (Small Outline) package, RoHS-compliant with lead-free finish (+ suffix), 1.27mm pitch, and JEDEC MS-012AC outline. Pin 1 is marked with a beveled corner or dot.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 MR | Active-low manual-reset input | Debounced TTL/CMOS-compatible trigger; internal 250µA pull-up enables direct switch connection without external resistor |
| 2 VCC | +5V supply input | Primary power source; device guarantees RESET validity down to VCC = 1V for low-voltage recovery |
| 3 GND | Ground reference | Common return for all analog and digital functions; must be low-impedance to avoid PFI noise coupling |
| 4 PFI | Power-fail comparator input | High-impedance (±25nA) node referenced to 1.25V internal bandgap; used for monitoring auxiliary rails or battery voltage |
| 5 PFO | Power-fail open-drain output | Sinks current when PFI < 1.25V; requires external pull-up for interrupt signaling to µP NMI line |
| 6 WDO | Watchdog open-drain output | Asserts low on timeout or VCC brownout; can be tied to MR to force system reset on firmware lockup |
| 7 RESET | Active-low reset output | Guaranteed logic low (≤0.4V @ 3.2mA) for 200ms; drives standard µP reset pins directly |
| 8 WDI | Watchdog input | Edge-sensitive input; toggling within 1.6s prevents timeout; floating or tristated disables watchdog function |
Key Features
| Feature | Design Value |
|---|---|
| Integrated watchdog + reset + PFI + MR | Reduces BOM count by 4 discrete ICs; eliminates timing mismatch risks between separate supervisory blocks |
| RESET valid at VCC = 1V | Enables reliable reset assertion during battery switchover or ultra-low-power wake-up sequences |
| 1.25V precision PFI threshold | Supports accurate monitoring of 3.3V, 2.5V, or 1.8V rails via simple resistor divider - no external reference needed |
| 250µA MR internal pull-up | Removes requirement for external pull-up resistor, simplifying PCB layout and reducing component count |
| 40mV reset threshold hysteresis | Prevents oscillatory reset assertion during slow VCC ramp-up or noisy supply conditions |
Applications
| Industrial PLC Controller | Smart Energy Meter |
|---|---|
Use Scenario: Continuous operation in unattended substations with fluctuating AC mains and backup battery support. IC Role / Device Role / Timing Role: Supervisory circuit ensuring clean µP reset on grid dropout, battery switchover, and firmware watchdog recovery. Use Value: Prevents corrupted flash writes and state machine lockup during 10–100ms brownouts common in utility environments. |
Use Scenario: Tamper-resistant metering unit requiring secure boot and power-fail data save before shutdown. IC Role / Device Role / Timing Role: Generates reset pulse on VCC sag and triggers PFO interrupt to initiate EEPROM save sequence via µP NMI. Use Value: Guarantees 200ms reset hold time and 1.25V PFI threshold accuracy to capture last valid kWh reading before capacitor discharge. |
| Medical Infusion Pump | Automotive Body Control Module |
Use Scenario: Life-critical delivery system where µP must restart cleanly after transient ESD-induced supply glitch. IC Role / Device Role / Timing Role: Provides fail-safe reset initiation and manual reset via front-panel button with hardware debounce. Use Value: Eliminates need for external RC debounce network; MR input tolerates >150ns bounce per IEC 60601-1 requirements. |
Use Scenario: CAN-connected module exposed to load-dump and cold-crank voltage transients in 12V automotive systems. IC Role / Device Role / Timing Role: Monitors regulated 5V rail for brownout and asserts reset before µP executes invalid instructions. Use Value: 4.65V reset threshold aligns with ISO 16750-2 Class D cold-crank spec; SO-8 package withstands 85°C under-hood thermal cycling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX706CSA+T | 4.40V reset threshold (vs. 4.65V); identical pinout, timing, and feature set | Better suited for systems using 4.5V–5.0V LDOs with tighter tolerance; not drop-in for 5V ±5% designs | Select MAX706CSA+T only if VCC nominal is ≤4.75V and brownout margin must be lower than 4.65V |
| MAX813LCSA+T | Active-high RESET output (no RESET); same 4.65V threshold, 1.6s watchdog, and PFI/PFO functions | Required for µPs needing active-high reset (e.g., Intel 80C51); incompatible with active-low-only reset inputs | Choose MAX813LCSA+T when interfacing to legacy 8-bit µPs with non-inverting reset architecture |
Compared with MAX705CSA+T, MAX706CSA+T lowers reset activation voltage for tighter supply margins, while MAX813LCSA+T replaces active-low RESET with active-high RESET - both retain identical SO-8 footprint and watchdog/PFI functionality but require schematic review for reset polarity and threshold alignment.
Availability
MAX705CSA+T is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, medical infusion pumps, and automotive body control modules requiring stable component supply across extended temperature and lifecycle demands.
Supply support for MAX705CSA+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 industrial, medical, and automotive applications, emphasizing reliability, integration, and low-power operation.
The MAX705 family targets cost-sensitive microprocessor supervisory needs - delivering reset, watchdog, power-fail warning, and manual reset in one SO-8 device for embedded systems where board space and BOM simplicity are critical.
FAQ
What is the reset threshold voltage for MAX705CSA+T?
The MAX705CSA+T has a nominal reset threshold of 4.65V, with a guaranteed range of 4.50V to 4.75V over temperature and supply variation. This threshold is factory-trimmed and includes 40mV hysteresis to prevent chatter during slow VCC ramps. The value is specified for the MAX705 variant and applies identically to the MAX705CSA+T SO-package version.
Does MAX705CSA+T support active-high reset output?
No, MAX705CSA+T provides only an active-low RESET output. It does not include the active-high RESET output found in MAX707/MAX708/MAX813L variants. For active-high reset functionality, use MAX813LCSA+T - which shares the same 4.65V threshold and watchdog features but replaces RESET with RESET.
Can MAX705CSA+T monitor voltages other than +5V?
Yes, MAX705CSA+T can monitor any DC voltage via its PFI pin using an external resistor divider. With its 1.25V internal reference, PFI accepts inputs up to VCC and supports monitoring of 3.3V, 2.5V, or even negative rails (with appropriate biasing). The PFO output asserts low when the divided voltage falls below 1.25V - enabling flexible power-fail or low-battery detection.
What is the watchdog timeout period for MAX705CSA+T?
The watchdog timeout period for MAX705CSA+T is 1.6 seconds typical, with a guaranteed range of 1.00s to 2.25s across temperature and process variation. The timer resets on any rising or falling edge at WDI, and is also cleared automatically during RESET assertion or when WDI is three-stated - ensuring robust firmware supervision without false triggers.
Is MAX705CSA+T compatible with manual reset switches without external components?
Yes, MAX705CSA+T includes a 250µA internal pull-up current on the MR pin, allowing direct connection to a grounded pushbutton switch without an external resistor. The input is TTL/CMOS-compatible, and the 140–280ms minimum reset pulse width provides inherent hardware debouncing - eliminating external RC networks required by discrete solutions.
MAX705CSA+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:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.65V
- Output:
- Push-Pull, Totem Pole
- 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
MAX705CSA+T FAQ
1.How can I place an order for MAX705CSA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX705CSA+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 MAX705CSA+T reliable?
The price and inventory of MAX705CSA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX705CSA+T is usually 5 days.
3.What payment methods are accepted for MAX705CSA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX705CSA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX705CSA+T?
MAX705CSA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX705CSA+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 MAX705CSA+T?
For technical support, including MAX705CSA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX705CSA+T requirements.
6.How does Aetrix verify that MAX705CSA+T is sourced from the original manufacturer or authorized distributors?
All MAX705CSA+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 MAX705CSA+T meets industry standards.
7.What is the process for return or replacement of MAX705CSA+T?
All MAX705CSA+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX705CSA+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 MAX705CSA+T part is unused and in its original packaging.
Return procedure for MAX705CSA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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