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Analog Devices Inc./Maxim Integrated MAX6303ESA+
- Part No.:
- MAX6303ESA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX6303ESA+.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:619
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Product details
Overview
MAX6303ESA+ from Maxim Integrated is a low-power, adjustable-reset/adjustable-watchdog microprocessor supervisory circuit in an 8-pin SO package. It features active-low push-pull RESET output, 4µA supply current, guaranteed reset assertion down to VCC = 1V, and adjustable reset threshold (≥1.22V) via external resistor divider. It is used in battery-powered embedded controllers requiring reliable brownout detection and software hang protection.
For engineers reviewing the MAX6303ESA+ datasheet, MAX6303ESA+ pinout, MAX6303ESA+ application, or MAX6303ESA+ equivalent, key selection considerations include its push-pull active-low reset output, -40°C to +85°C industrial temperature range, SO-8 RoHS-compliant packaging, and dual-capacitor-adjustable timing for both reset timeout (2.8–5.2ms typical) and watchdog timeout (2.8–5.2ms normal / 1.4–2.6s extended mode).
Technical Context
The MAX6303ESA+ implements a precision bandgap reference (1.22V) feeding a comparator that monitors voltage at RESET IN, with hysteresis (20mV) for noise immunity. Its reset logic asserts RESET low when monitored voltage falls below VRST and holds it low for a user-defined timeout period set by capacitor CSRT.
Its watchdog function uses a precision 500nA current source at SWT to generate timing; WDS selects between normal mode (tWD ≈ 2.67 × CSWT in µs) and extended mode (tWD × 500), with WDI transitions clearing the timer. The device guarantees valid RESET assertion even as VCC drops to 1V, supporting robust power-fail detection in portable systems.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Current | 4.0µA typical - enables multi-year operation on coin-cell batteries in always-on monitoring applications. |
| Reset Threshold Voltage | 1.22V internal reference - sets minimum detectable undervoltage; externally adjustable above 1.22V via R1/R2 divider. |
| Reset Timeout Period | 4.0ms typical (CSRT = 1500pF) - ensures µP completes power-up initialization before release from reset. |
| Watchdog Timeout (Normal) | 4.0ms typical (CSWT = 1500pF, WDS = GND) - matches short firmware loops in real-time control tasks. |
| Watchdog Timeout (Extended) | 2.0s typical (CSWT = 1500pF, WDS = VCC) - supports long sleep intervals in ultra-low-power wake-up timer designs. |
| Operating Voltage Range | +2.0V to +5.5V - compatible with 3.3V and 5V systems, including partially discharged Li-ion or alkaline supplies. |
| Temperature Range | -40°C to +85°C - qualified for industrial and automotive under-hood auxiliary electronics. |
Pinout & Package
Package: 8-pin SO (Small Outline), RoHS-compliant, lead-free, surface-mount. Pin pitch: 1.27mm. Body size: 4.9mm × 6.0mm × 1.75mm (JEDEC MS-012).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET IN | High-impedance reset threshold input | Connects to center tap of external R1/R2 divider; sets VRST = 1.22 × (R1 + R2)/R2; leakage ±1nA avoids threshold drift. |
| 2 - GND | Ground reference | Common return for all internal circuits and external timing capacitors; must be low-impedance for stable timing. |
| 3 - SRT | Reset timeout capacitor input | Sinks 500nA precision current; CSRT value directly sets tRP (tRP = 2.67 × CSRT); requires low-leakage ceramic cap. |
| 4 - SWT | Watchdog timeout capacitor input | Sinks 500nA precision current; CSWT value sets base tWD (tWD = 2.67 × CSWT); same capacitor type requirement as SRT. |
| 5 - WDS | Watchdog mode select | Logic-high (VCC) enables 500× extended timeout; logic-low (GND) selects normal mode; transition resets watchdog timer. |
| 6 - WDI | Watchdog input | Rising/falling edge clears watchdog timer; pulse width ≥30ns sufficient; high-impedance in normal mode, driven in extended mode. |
| 7 - RESET | Active-low push-pull reset output | Drives µP reset pin directly; VOH ≥ VCC − 0.4V @ 0.8mA, VOL ≤ 0.4V @ 3.2mA; no external pullup required. |
| 8 - VCC | Power supply input | Operates from 2.0V–5.5V; requires local 0.1µF ceramic bypass capacitor placed adjacent to pin for noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable reset threshold | Settable >1.22V using two external resistors - enables precise brownout detection across diverse supply rails (e.g., 2.5V, 3.3V, 5V). |
| Capacitor-adjustable reset timeout | tRP = 2.67 × CSRT (CSRT in pF, tRP in µs) - allows fine-tuning to match µP power-up sequence without firmware changes. |
| 500× watchdog timeout multiplier | WDS pin toggles between ms-scale (normal) and second-scale (extended) timeouts - eliminates need for separate wake-up timers. |
| Guaranteed reset at VCC ≥ 1V | RESET asserted and held low until VCC drops below 1V - ensures deterministic behavior during deep brownout or battery depletion. |
| Power-supply transient immunity | Immune to negative transients ≤50µs at 100mV overdrive - prevents false resets from switching noise or ESD-induced glitches. |
Applications
| Battery-Powered Portable Equipment | Industrial Embedded Controllers |
|---|---|
|
Use Scenario: Handheld medical meter operating from single AA cell with declining voltage profile. IC Role / Device Role: Monitors battery voltage via resistor divider on RESET IN; asserts RESET when voltage drops below 2.2V; triggers full shutdown after timeout. Use Value: Prevents erratic operation or data corruption during end-of-life battery discharge while extending usable runtime via precise threshold setting. |
Use Scenario: Programmable logic controller (PLC) I/O module exposed to 24V DC supply fluctuations in factory environments. IC Role / Device Role: Supervises 3.3V logic rail derived from 24V; detects brownouts and software hangs via WDI polling; initiates controlled recovery sequence. Use Value: Eliminates need for external RC reset networks and discrete watchdog ICs-reducing BOM count and board area by 30%. |
| Intelligent Instrumentation | Critical Microprocessor Monitoring |
|
Use Scenario: Digital multimeter with auto-ranging firmware requiring periodic watchdog servicing during measurement cycles. IC Role / Device Role: Provides adjustable watchdog timeout (via CSWT) matched to longest firmware loop; WDS toggled to extend timeout during calibration routines. Use Value: Enables adaptive supervision-prevents spurious resets during known long-duration operations while maintaining fail-safe coverage. |
Use Scenario: Safety-critical HVAC controller where µP lockup must trigger immediate hardware reset without software intervention. IC Role / Device Role: Generates hardware-level RESET signal independent of µP state; immune to supply transients; guarantees reset assertion down to VCC = 1V. Use Value: Meets IEC 61508 SIL-2 functional safety requirements for hardware fault tolerance in reset path. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6304ESA+ | Active-high push-pull RESET output; identical timing, threshold, and package. | Required where host µP accepts only active-high reset assertion (e.g., certain ARM Cortex-M variants). | Select MAX6304ESA+ only when system-level reset polarity mandates active-high signaling; otherwise MAX6303ESA+ provides direct compatibility with most legacy µPs. |
| TPS3808G12DBVR | Fixed 1.2V reset threshold; 2.5µA quiescent current; no adjustable watchdog; SOT-23-6 package. | Suitable for cost-sensitive, space-constrained designs where fixed threshold suffices and watchdog is unnecessary. | Choose TPS3808G12DBVR for simplified layout and lower unit cost in non-watchdog applications; MAX6303ESA+ remains preferred when adjustable timing or watchdog functionality is required. |
Compared with MAX6304ESA+, the MAX6303ESA+ offers identical adjustability and industrial temperature rating but delivers active-low reset-critical for interfacing with older µPs and bidirectional reset pins. Against TPS3808G12DBVR, MAX6303ESA+ trades higher pin count and slightly higher IQ for essential design flexibility in reset threshold, timeout, and watchdog configuration.
Availability
MAX6303ESA+ is available at Aetrix Electronics and suitable for battery-powered portable equipment, industrial embedded controllers, intelligent instrumentation, and critical microprocessor monitoring requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6303ESA+ 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 U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.
The MAX630x family was designed specifically for low-power, configurable microprocessor supervision in resource-constrained systems-emphasizing ultra-low IQ, flexible reset/watchdog timing, and robust operation across wide voltage and temperature ranges.
FAQ
What is the guaranteed minimum supply voltage at which MAX6303ESA+ asserts RESET?
The MAX6303ESA+ guarantees RESET assertion at VCC ≥ 1V. This means that as long as the supply voltage remains at or above 1V, the device will hold RESET low if the monitored voltage (at RESET IN) falls below the programmed threshold. Below 1V, reset output drive capability degrades, though a pulldown resistor can maintain validity down to 0V per application note guidelines. This specification makes MAX6303ESA+ suitable for deeply discharging battery systems.
How do I configure the reset timeout period for MAX6303ESA+?
To configure the reset timeout period for MAX6303ESA+, connect a low-leakage ceramic capacitor (CSRT) between pin 3 (SRT) and ground. The timeout period is calculated as tRP = 2.67 × CSRT, where CSRT is in pF and tRP is in µs. For example, a 1500pF capacitor yields ~4.0ms typical timeout. Ensure CSRT leakage <10nA and minimize PCB trace capacitance near SRT to preserve timing accuracy, as the pin sources a precision 500nA current.
Can MAX6303ESA+ monitor voltages other than VCC?
Yes, MAX6303ESA+ can monitor any DC voltage - not just VCC - by connecting the target voltage (e.g., 3.3V rail, sensor supply, battery node) to pin 1 (RESET IN) through an appropriate resistor divider. The internal 1.22V reference and comparator allow setting VRST = 1.22 × (R1 + R2)/R2. This enables independent supervision of multiple rails or external analog signals, provided the divider presents minimal loading and leakage to avoid threshold error.
What is the difference between MAX6303ESA+ and MAX6301ESA+?
The core difference is output structure: MAX6303ESA+ features an active-low push-pull RESET output (pin 7), while MAX6301ESA+ uses an active-low open-drain output. Push-pull eliminates the need for an external pullup resistor, simplifying layout and improving noise immunity. Both share identical timing adjustability, supply current (4µA), temperature range (-40°C to +85°C), and SO-8 packaging. Choose MAX6303ESA+ when driving standard CMOS reset inputs directly; choose MAX6301ESA+ only when interfacing with bidirectional or wired-OR reset buses.
Does MAX6303ESA+ support watchdog disable functionality?
Yes - the watchdog function in MAX6303ESA+ can be disabled in extended mode (WDS = VCC) by leaving WDI unconnected or three-stating its driver. In this state, the internal watchdog counter drives WDI with a brief pulse (~94% into timeout) to automatically clear itself, preventing reset assertion. In normal mode (WDS = GND), watchdog cannot be disabled; WDI must be actively toggled within the timeout period. This dual-mode flexibility supports both continuous supervision and scheduled wake-up use cases.
MAX6303ESA+ 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:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- Adjustable/Selectable
- Output:
- Push-Pull, Totem Pole
- Reset:
- Active Low
- Reset Timeout:
- 2.8ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX6303ESA+ FAQ
1.How can I place an order for MAX6303ESA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6303ESA+ 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 MAX6303ESA+ reliable?
The price and inventory of MAX6303ESA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6303ESA+ is usually 5 days.
3.What payment methods are accepted for MAX6303ESA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6303ESA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6303ESA+?
MAX6303ESA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6303ESA+ 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 MAX6303ESA+?
For technical support, including MAX6303ESA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6303ESA+ requirements.
6.How does Aetrix verify that MAX6303ESA+ is sourced from the original manufacturer or authorized distributors?
All MAX6303ESA+ 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 MAX6303ESA+ meets industry standards.
7.What is the process for return or replacement of MAX6303ESA+?
All MAX6303ESA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX6303ESA+, 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 MAX6303ESA+ part is unused and in its original packaging.
Return procedure for MAX6303ESA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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