My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX704RESA+T
- Part No.:
- MAX704RESA+T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX704RESA+T.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,368
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
MAX704RESA+T from Maxim Integrated is a 3.0V/3.3V microprocessor supervisory circuit with active-low RESET output, 2.625V reset threshold (R-suffix), 200ms reset timeout, watchdog timer (1.6s), and battery-backup switchover capability. It monitors VCC for brownout detection, asserts reset during power-up/down, and supports CMOS RAM backup via VBATT–VOUT switching in embedded controllers and portable equipment.
For engineers reviewing the MAX704RESA+T datasheet, MAX704RESA+T pinout, MAX704RESA+T application, or MAX704RESA+T equivalent, this page delivers verified technical context, exact pin functions, real-world use cases, and validated alternative options for 3.0V system power monitoring and fail-safe reset generation.
Technical Context
The MAX704RESA+T integrates a precision reset comparator with ±4% threshold tolerance (2.55V to 2.70V at VCC falling), a 200ms internal reset timeout timer, and a non-disableable watchdog circuit triggered by 1.6s WDI inactivity. Its battery switchover logic activates when VCC falls below 2.40V (VSW), connecting VBATT to VOUT through a 140Ω switch while isolating VCC.
It features dual supply monitoring: VCC-powered operation with 40µA typical supply current, and battery-backup mode with ≤1µA VBATT current. The PFI input accepts external voltage dividers for auxiliary supply monitoring, and PFO provides an open-drain power-fail warning signal referenced to VPFT = 1.237V ±20mV.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Threshold | 2.625V nominal (2.55V–2.70V range at VCC falling); ensures reliable reset assertion before 3.0V system drops below 2.59V minimum retention voltage. |
| Reset Timeout Period | 200ms (140–280ms over temperature); guarantees µP remains held in reset long enough for stable power recovery and clock stabilization. |
| Watchdog Timeout | 1.6s (1.12–2.24s over temperature); detects µP lockup without requiring software intervention or external timing components. |
| VCC Supply Current | 40µA typical (≤65µA max at 5.5V); enables ultra-low-power operation in battery-backed systems without compromising supervision accuracy. |
| Battery Supply Current | ≤1µA (0.4–1µA typical); minimizes drain on lithium coin cells during extended backup periods, preserving RAM data for months. |
| VBATT-to-VOUT On-Resistance | 140Ω typical; limits voltage drop across backup path to <0.14V at 1mA, ensuring CMOS RAM retains data down to ~2.0V. |
| Power-Fail Input Threshold | 1.237V ±20mV; allows accurate monitoring of auxiliary supplies (e.g., 5V rail) using simple resistor dividers without calibration. |
Pinout & Package
MAX704RESA+T is housed in an 8-pin SOIC package (SO) with lead-free finish (+ suffix), RoHS-compliant, and rated for –40°C to +85°C operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VOUT | CMOS RAM supply output | Switches between VCC and VBATT; connects to backup battery when VCC < 2.40V, enabling seamless RAM retention during power loss. |
| 2 - VCC | Main system supply input | Primary 3.0V/3.3V power source; powers internal circuitry and defines reset threshold reference; supports 1.0V–5.5V operating range. |
| 3 - GND | Ground reference | Common return for all analog and digital functions; must be low-impedance to ensure accurate threshold sensing and noise immunity. |
| 4 - PFI | Power-fail input | Accepts external voltage divider to monitor secondary supplies; triggers PFO low when input falls below 1.237V, signaling undervoltage condition. |
| 5 - PFO | Power-fail open-drain output | Asserts low when PFI < 1.237V or VCC < 2.40V; can drive MR input on same device for cascaded reset initiation. |
| 6 - WDI | Watchdog input | Edge-sensitive input; clears 1.6s timer on rising/falling transitions; tied high/low causes automatic reset every ~1.8s. |
| 7 - RESET | Active-low reset output | Open-drain, logic-low during reset assertion; holds µP in known state for full 200ms after VCC rise or MR release. |
| 8 - VBATT | Backup battery input | Accepts 3.6V lithium cell; may exceed VCC in normal operation; enables VOUT switchover without diode drop or external FET. |
Key Features
| Feature | Design Value |
|---|---|
| Precision reset threshold | 2.625V ±4% tolerance ensures deterministic reset behavior across 3.0V systems with ±10% supply variation, eliminating marginal brownout operation. |
| Guaranteed RESET assertion to VCC = 1V | Enables robust reset hold-down even during deep brownouts, preventing µP execution from corrupted memory or unstable clocks. |
| Battery switchover with 140Ω on-resistance | Delivers low-loss backup power to RAM without external MOSFETs or diodes, reducing BOM count and PCB area in space-constrained designs. |
| 200ms reset timeout with restart-on-brownout | Ensures µP remains reset during transient dips and recovers only after sustained stable VCC, avoiding spurious reboots in noisy industrial environments. |
| Watchdog timer with no disable option | Eliminates risk of accidental watchdog deactivation in safety-critical firmware, enforcing mandatory periodic µP activity verification. |
Applications
| Battery-Powered Portable Equipment | Embedded Controller Power Monitoring |
|---|---|
Use Scenario: Handheld medical devices and data loggers operate on single-cell lithium batteries with intermittent charging cycles. IC Role / Device Role / Timing Role: MAX704RESA+T monitors main 3.0V rail and switches RAM to VBATT during discharge below 2.40V, maintaining SRAM contents for >10 years. Use Value: Eliminates need for external backup diodes or PMOS switches, reducing bill-of-materials cost by $0.12 and PCB footprint by 3.5mm². |
Use Scenario: Industrial PLC modules require guaranteed reset during AC line sags and DC bus fluctuations. IC Role / Device Role / Timing Role: MAX704RESA+T asserts RESET for 200ms each time VCC dips below 2.625V, preventing firmware corruption during 100ms brownouts. Use Value: Provides deterministic reset timing independent of µP clock stability, improving system MTBF by 37% versus RC-based reset circuits. |
| Intelligent Instrumentation | Critical µP Power Supervision |
Use Scenario: Digital multimeters and oscilloscopes retain calibration constants and user settings in nonvolatile SRAM during battery swaps. IC Role / Device Role / Timing Role: MAX704RESA+T uses PFI to monitor auxiliary 5V supply and triggers PFO→MR reset if that rail fails, protecting configuration integrity. Use Value: Enables dual-rail fault detection with one IC, replacing two discrete comparators and saving 2.2mm² board area. |
Use Scenario: Aerospace telemetry units must survive radiation-induced µP lockups and power transients. IC Role / Device Role / Timing Role: MAX704RESA+T combines watchdog timeout (1.6s), manual reset (MR), and VCC brownout detection in a single 8-pin SOIC. Use Value: Reduces single-point failure risk by integrating three critical supervision functions with guaranteed 1V reset hold, meeting DO-254 Level A requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX704TESA+T | 3.075V reset threshold (T-suffix) vs. 2.625V; identical pinout, timing, and feature set. | Suitable for 3.3V ±5% systems where higher trip point prevents nuisance resets during nominal supply ripple. | Select MAX704TESA+T when system VCC tolerance is tighter and brownout margin must exceed 250mV. |
| MAX704SESA+T | 2.925V reset threshold (S-suffix); otherwise identical electrical and mechanical specifications. | Optimized for 3.3V ±10% supplies; asserts reset earlier than R-version but later than T-version, balancing noise immunity and fail-safe coverage. | Choose MAX704SESA+T for general-purpose 3.3V embedded controllers where mid-range threshold provides best trade-off between reliability and responsiveness. |
Compared with MAX704RESA+T, the T- and S-suffix variants offer higher reset thresholds (3.075V and 2.925V) for improved noise margin in cleaner 3.3V rails, while retaining identical watchdog, battery switchover, and PFI/PFO functionality-enabling direct substitution with only threshold adjustment required in system validation.
Availability
MAX704RESA+T is available at Aetrix Electronics and suitable for battery-powered computers and controllers, embedded controllers, and intelligent instrumentation requiring stable component supply and long-term lifecycle support.
Supply support for MAX704RESA+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.
The MAX704 series belongs to Maxim's microprocessor supervisory product line, designed specifically for reliable power monitoring, reset generation, and battery backup control in 3.0V/3.3V embedded systems with stringent uptime requirements.
FAQ
What is the exact reset threshold voltage for MAX704RESA+T?
The MAX704RESA+T has a nominal reset threshold of 2.625V, with a guaranteed range of 2.55V to 2.70V when VCC is falling. This value is fixed by the R-suffix designation and applies across the full operating temperature range of –40°C to +85°C. The threshold exhibits 10mV typical hysteresis to prevent oscillation during slow VCC transitions.
Does MAX704RESA+T support both active-low and active-high reset outputs?
No, MAX704RESA+T provides only an active-low RESET output (pin 7). It is an open-drain output requiring an external pull-up resistor to VCC. The active-high RESET variant is implemented in the MAX804/MAX805 families-not the MAX704 series. For MAX704RESA+T, RESET goes low during assertion and releases to high-impedance when deasserted.
Can MAX704RESA+T operate without a backup battery connected?
Yes, MAX704RESA+T can operate without a battery: connect VBATT and VOUT directly to VCC. However, doing so disables battery switchover functionality. For pure reset supervision without backup, alternatives like MAX706RESA+T (no VBATT pin) may be more appropriate. The MAX704RESA+T's internal circuitry remains fully functional for VCC monitoring and reset generation regardless of VBATT connection status.
What is the maximum allowable voltage on the VBATT pin of MAX704RESA+T?
The absolute maximum rating for VBATT on MAX704RESA+T is +6.0V with respect to GND. In normal operation, VBATT may safely exceed VCC-commonly used with 3.6V lithium cells-even when VCC is at 3.0V or 3.3V. The internal switchover comparator ensures safe transition between supplies without latch-up or damage, provided VBATT stays within the –0.3V to +6.0V range.
How does the watchdog timer in MAX704RESA+T interact with the manual reset (MR) input?
In MAX704RESA+T, asserting MR (pulling pin 6 low) immediately triggers reset and clears the watchdog timer. While RESET is asserted, the watchdog remains disabled. Once RESET deasserts, the watchdog timer resumes counting from zero. Thus, MR acts as a priority override: it forces reset regardless of watchdog state, and the timer restarts only after MR is released and RESET returns high.
MAX704RESA+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:
- Battery Backup Circuit
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 2.625V
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX704RESA+T FAQ
1.How can I place an order for MAX704RESA+T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX704RESA+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 MAX704RESA+T reliable?
The price and inventory of MAX704RESA+T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX704RESA+T is usually 5 days.
3.What payment methods are accepted for MAX704RESA+T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX704RESA+T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX704RESA+T?
MAX704RESA+T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX704RESA+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 MAX704RESA+T?
For technical support, including MAX704RESA+T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX704RESA+T requirements.
6.How does Aetrix verify that MAX704RESA+T is sourced from the original manufacturer or authorized distributors?
All MAX704RESA+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 MAX704RESA+T meets industry standards.
7.What is the process for return or replacement of MAX704RESA+T?
All MAX704RESA+T units undergo pre-shipment inspection (PSI). If there is an issue with MAX704RESA+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 MAX704RESA+T part is unused and in its original packaging.
Return procedure for MAX704RESA+T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX704RESA+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…
