My Inquiry
My Account
Analog Devices Inc./Maxim Integrated MAX6840XSD3
- Part No.:
- MAX6840XSD3
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SC-82A, SOT-343
- Datasheet:
-
MAX6840XSD3.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL SC70-4
- Quantity:
- Payment:
- Shipping:
Inventory:933
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
The MAX6840XSD3 from Maxim Integrated is an ultra-low-voltage microprocessor supervisory circuit with open-drain active-low reset output, adjustable reset threshold via RESET-IN pin (typical 444mV), 210ms reset timeout period (D3 suffix), and guaranteed operation down to VCC = 1.1V. It monitors supply rails as low as 0.44V using external resistor dividers and delivers 7.5µA typical supply current for battery-powered systems such as portable medical sensors and low-power IoT edge nodes.
For engineers reviewing the MAX6840XSD3 datasheet, MAX6840XSD3 pinout, MAX6840XSD3 application, or MAX6840XSD3 equivalent, this device serves as a precision voltage-monitoring reset supervisor for sub-1.2V core supplies where adjustable trip points, noise-immune reset assertion, and SC70-4 footprint compatibility are critical selection criteria.
Technical Context
The MAX6840XSD3 implements a high-impedance RESET-IN comparator referenced to a stable 444mV internal threshold, enabling precise monitoring of supply voltages from 0.44V to 3.3V via external resistive dividers. Its open-drain RESET output supports level-shifting across multiple supply domains and interfaces directly with bidirectional µP reset pins without additional logic.
It features ±3.0% RESET-IN threshold accuracy over –40°C to +85°C, 100ns MR glitch rejection (though MR is not present on MAX6840), and immunity to short negative VCC transients up to 200mV overdrive. The 210ms reset timeout ensures reliable processor initialization after brownout recovery.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Timeout Period | 210ms - Ensures sufficient hold time for full µP core initialization after supply recovery |
| RESET-IN Threshold | 444mV (±3.0%) - Enables accurate monitoring of supplies as low as 0.44V using external divider |
| Supply Current | 7.5µA (typ at 1.2V) - Minimizes quiescent drain in always-on battery-backed systems |
| VCC Operating Range | 1.1V to 3.3V - Supports modern ultra-low-voltage SoCs and ASICs with 1.2V/1.1V core rails |
| Output Type | Open-drain active-low RESET - Allows wired-OR configuration and level-shifting to higher voltage domains |
| Temperature Range | –40°C to +85°C - Validated for industrial and extended-temperature embedded applications |
| Package | 4-pin SC70 - 2.0mm × 2.1mm footprint compatible with space-constrained portable PCB layouts |
Pinout & Package
MAX6840XSD3 is housed in a 4-pin SC70 package (2.0mm × 2.1mm, 0.5mm pitch), optimized for high-density portable designs. Pin 1 is RESET-IN, Pin 2 is VCC, Pin 3 is GND, and Pin 4 is RESET (open-drain active-low).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | RESET-IN | High-impedance input for adjustable reset threshold; connects to external resistor divider to set trip point |
| 2 | VCC | Power supply and reference rail (1.1V–3.3V); powers internal circuitry and defines operating range |
| 3 | GND | Analog and digital ground reference; must be low-impedance connection for comparator stability |
| 4 | RESET | Open-drain active-low reset output; requires external pullup to define logic HIGH level (0–6V) |
Key Features
| Feature | Design Value |
|---|---|
| Adjustable Reset Threshold | Set via external resistor divider on RESET-IN; enables monitoring of supplies from 0.44V to 3.3V with ±3.0% accuracy |
| Open-Drain RESET Output | Supports bidirectional µP reset I/O and level-shifting to higher voltage domains (e.g., 1.2V core → 3.3V I/O domain) |
| 210ms Fixed Timeout | Guarantees minimum reset pulse width for reliable boot sequence completion in low-power µPs |
| Ultra-Low Supply Current | 7.5µA typical at 1.2V enables multi-year battery life in always-on sensor nodes and wearables |
| VCC Immunity to Transients | Rejects negative VCC glitches ≤100ns at 200mV overdrive, reducing false resets in noisy power environments |
Applications
| Portable Medical Sensors | Low-Power IoT Edge Nodes |
|---|---|
|
Use Scenario: Continuous glucose monitor with 1.1V ARM Cortex-M0+ MCU and coin-cell battery. IC Role / Device Role / Timing Role: Supervises 1.1V core rail using RESET-IN divider; asserts open-drain RESET to halt MCU during brownout until stable supply returns. Use Value: 7.5µA quiescent current extends battery life beyond 2 years; 210ms timeout ensures full ADC calibration before firmware execution. |
Use Scenario: Wireless environmental sensor node powered by energy-harvesting circuit (1.2V output). IC Role / Device Role / Timing Role: Monitors harvested 1.2V rail via RESET-IN; generates reset pulse when voltage sags below 1.15V due to transient load. Use Value: Adjustable threshold avoids premature resets during brief load spikes; open-drain output interfaces directly with 3.3V RF transceiver reset line. |
| Industrial PLC I/O Modules | Battery-Backed Real-Time Clock Systems |
|
Use Scenario: DIN-rail mounted I/O module with isolated 1.2V FPGA core and 24V field bus interface. IC Role / Device Role / Timing Role: Resets FPGA on 1.2V rail undervoltage; RESET output pulled to 3.3V domain for system-wide synchronization. Use Value: SC70-4 footprint saves board space in dense modular designs; ±3.0% threshold accuracy ensures consistent trip point across temperature. |
Use Scenario: Smart meter with RTC backed by supercapacitor and 1.2V backup regulator. IC Role / Device Role / Timing Role: Detects backup rail collapse below 1.15V using RESET-IN; holds RTC in reset until capacitor recharges above threshold. Use Value: Guaranteed operation down to VCC = 1.1V prevents spurious resets during slow capacitor discharge; 210ms timeout matches RTC initialization timing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar voltage-monitoring reset applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6381XR29+T | Fixed 2.93V reset threshold; push-pull active-low output; no RESET-IN pin | Suitable only for fixed 3.3V/2.5V supply monitoring; lacks adjustability for sub-1.2V rails | Select when monitoring standard logic rails and board space allows SOT23-3 |
| TPS3808G33DBVR | Fixed 3.3V threshold; 200ms timeout; 1.8V–6.0V VCC range; no RESET-IN | Requires higher VCC (≥1.8V); cannot monitor <1.2V supplies; different timeout tolerance | Choose for higher-VCC systems where TI's qualification and long-term availability are prioritized |
Compared with MAX6840XSD3, MAX6381XR29+T offers simpler fixed-threshold supervision but cannot replace it in ultra-low-voltage adjustable applications; TPS3808G33DBVR provides tighter timeout tolerance and broader VCC range but lacks RESET-IN flexibility and sub-1.2V capability essential for modern low-power SoCs.
Availability
MAX6840XSD3 is available at Aetrix Electronics and suitable for portable medical sensors, low-power IoT edge nodes, and industrial PLC I/O modules requiring stable component supply with guaranteed long-term manufacturability and traceable sourcing.
Supply support for MAX6840XSD3 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, communications, and consumer applications.
The MAX6832–MAX6840 family was designed specifically for ultra-low-voltage microprocessor supervision in battery-powered and energy-constrained systems, emphasizing sub-1.2V operation, adjustable thresholds, and minimal quiescent current.
FAQ
What is the function of the RESET-IN pin on the MAX6840XSD3?
The RESET-IN pin on the MAX6840XSD3 is a high-impedance input that connects to an external resistor divider to set the adjustable reset threshold. The internal comparator triggers reset when RESET-IN falls below its 444mV reference. This enables precise monitoring of supply voltages from 0.44V to 3.3V-critical for applications like 1.1V SoC cores where fixed-threshold supervisors fail. The MAX6840XSD3 requires VCC ≥1.1V to guarantee RESET-IN threshold accuracy.
Does the MAX6840XSD3 have a manual reset (MR) input?
No, the MAX6840XSD3 does not include a manual reset (MR) input. Unlike MAX6835/MAX6836/MAX6837 variants, the MAX6840XSD3 belongs to the MAX6838/MAX6839/MAX6840 group, which replaces MR with the RESET-IN pin for adjustable threshold monitoring. Its functional block diagram confirms absence of MR; instead, reset assertion is solely controlled by the voltage at RESET-IN relative to the 444mV internal reference.
What is the significance of the 'D3' suffix in MAX6840XSD3?
The 'D3' suffix in MAX6840XSD3 specifies a 210ms reset timeout period-the duration RESET remains asserted after RESET-IN rises above the 444mV threshold. This value is confirmed in Table 2 ("Active Timeout Period Guide") of the datasheet. The D3 option ensures sufficient hold time for complex µP initialization sequences while avoiding excessive delays in fast-recovery systems. Other options include D0 (70µs), D1 (1.5ms), D2 (30ms), and D4 (1680ms).
Can the MAX6840XSD3 operate with a VCC lower than 1.1V?
No, the MAX6840XSD3 requires VCC ≥1.1V to guarantee specified performance, particularly RESET-IN threshold accuracy (±3.0%). While absolute maximum ratings allow VCC down to 0.55V for push-pull variants, the MAX6840XSD3's electrical characteristics table explicitly states "VCC = 1.1V to 3.3V" for RESET-IN operation. Below 1.1V, RESET-IN comparator behavior is undefined and threshold accuracy degrades beyond specification limits.
How does the open-drain RESET output of the MAX6840XSD3 interface with a µP having a bidirectional reset pin?
The open-drain RESET output of the MAX6840XSD3 interfaces directly with bidirectional µP reset pins by connecting RESET to the µP's reset I/O through a single external pullup resistor. Either device can assert reset: the MAX6840XSD3 pulls RESET low during undervoltage, and the µP can drive the line low for software-initiated resets. This eliminates need for external logic or diodes. Figure 4 in the datasheet validates this configuration for MAX6840XSD3 and identical variants.
MAX6840XSD3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SC-82A, SOT-343
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- Adjustable/Selectable
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 140ms Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SC-70-4
MAX6840XSD3 FAQ
1.How can I place an order for MAX6840XSD3 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6840XSD3 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 MAX6840XSD3 reliable?
The price and inventory of MAX6840XSD3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6840XSD3 is usually 5 days.
3.What payment methods are accepted for MAX6840XSD3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6840XSD3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6840XSD3?
MAX6840XSD3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6840XSD3 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 MAX6840XSD3?
For technical support, including MAX6840XSD3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6840XSD3 requirements.
6.How does Aetrix verify that MAX6840XSD3 is sourced from the original manufacturer or authorized distributors?
All MAX6840XSD3 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 MAX6840XSD3 meets industry standards.
7.What is the process for return or replacement of MAX6840XSD3?
All MAX6840XSD3 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6840XSD3, 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 MAX6840XSD3 part is unused and in its original packaging.
Return procedure for MAX6840XSD3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX6840XSD3 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…
