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Analog Devices Inc./Maxim Integrated MAX6391KA22
- Part No.:
- MAX6391KA22
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-8
- Datasheet:
-
MAX6391KA22.pdf
- Description:
- IC SUPERVISOR 2 CHANNEL SOT23-8
- Quantity:
- Payment:
- Shipping:
Inventory:2,440
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Product details
Overview
MAX6391KA22 from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with sequenced active-low open-drain reset outputs, factory-set VCC reset threshold of 2.19V (±0.07V), guaranteed reset validity down to VCC = 1.0V, and fixed 140ms (min) RESET1 timeout - used for power sequencing in multivoltage embedded systems such as industrial controllers and set-top boxes.
For engineers reviewing the MAX6391KA22 datasheet, MAX6391KA22 pinout, MAX6391KA22 application, or MAX6391KA22 equivalent, this device supports precise dual-supply monitoring with independent timing control, internal 47kΩ pullup resistors on both RESET1 and RESET2, and immunity to short negative VCC transients - critical for reliable boot-up and brownout recovery in space-constrained designs.
Technical Context
The MAX6391KA22 implements two independent voltage comparators: one monitors VCC against a fixed 2.19V threshold to drive RESET1; the other compares RESET IN2 (via external resistor divider) against a 625mV reference to conditionally assert RESET2. RESET2 deasserts only after both VCC and RESET IN2 exceed their thresholds and RESET1 has already deasserted.
Its timing architecture enforces strict power-up sequence: RESET1 deasserts ≥140ms after VCC rises above 2.19V; RESET2 follows with either a fixed 140ms (min) delay (CSRT tied to VCC) or a capacitor-adjustable period (CSRT to ground). The device operates from 1.2V to 5.5V and draws only 15µA typical supply current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Reset Threshold | 2.19V (factory-fixed, ±0.07V tolerance) - sets primary power-fail detection point for RESET1 assertion |
| RESET IN2 Threshold | 625mV (internal reference) - enables monitoring of secondary supplies as low as ~0.625V via external resistor divider |
| RESET1 Timeout | 140ms minimum - ensures stable µP initialization before release; internally fixed, no external components required |
| RESET2 Timeout | 140ms minimum (CSRT = VCC) or user-adjustable (CSRT = capacitor) - provides flexible sequencing window for slave supply enablement |
| Supply Current | 15µA typical - enables ultra-low-power operation in battery-backed or energy-sensitive systems |
| Reset Validity Range | VCC ≥ 1.0V - guarantees functional reset generation even during deep brownout conditions |
| Output Type | Open-drain RESET1 and RESET2 with internal 47kΩ pullup resistors (R1/R2 pins) - allows independent VOH level selection per output |
Pinout & Package
MAX6391KA22 is housed in an 8-pin SOT23 package (3.00mm × 1.75mm × 1.30mm body, 0.65mm pitch), rated for -40°C to +85°C operation, with gull-wing leads and JEDEC MO178 compliance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - RESET IN2 | Secondary supply monitor input | High-impedance comparator input referenced to 625mV; connects to external resistor divider for custom reset threshold |
| 2 - VCC | Main supply and master reset source | Power input and primary voltage monitor; all resets assert when VCC falls below 2.19V |
| 3 - CSRT | RESET2 timeout configuration node | Tied to VCC for fixed 140ms delay; connected to capacitor for user-adjustable timeout (2.08×10⁶ × C seconds) |
| 4 - GND | Analog/digital ground reference | Common return path for all internal comparators, timers, and outputs; must be low-impedance |
| 5 - RESET2 | Secondary active-low open-drain reset output | Asserted when VCC < 2.19V OR RESET IN2 < 625mV; deasserts only after both recover and RESET1 is released |
| 6 - R2 | Internal pullup connection for RESET2 | 47kΩ resistor tied internally to RESET2; connect to external VOH rail (e.g., 3.3V or 5V) for level-shifted high state |
| 7 - RESET1 | Primary active-low open-drain reset output | Asserted solely on VCC < 2.19V; deasserts ≥140ms after VCC exceeds threshold - initiates system power-up sequence |
| 8 - R1 | Internal pullup connection for RESET1 | 47kΩ resistor tied internally to RESET1; connect to desired VOH rail independently of R2 for dual-rail reset signaling |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent voltage monitoring | VCC (2.19V fixed) and RESET IN2 (625mV reference) enable coordinated reset of master/slave rails without cross-coupling |
| Guaranteed reset operation at VCC = 1.0V | Ensures fail-safe reset assertion during severe brownout - critical for data integrity in nonvolatile memory systems |
| Sequenced reset timing with enforced order | RESET2 always deasserts after RESET1 on power-up and asserts before RESET1 on power-down - prevents race conditions |
| Internal 47kΩ pullup resistors on both outputs | Eliminates need for external pullups; allows RESET1 and RESET2 to interface with different logic rails (e.g., 1.8V/3.3V) |
| Immunity to short negative VCC transients | Rejects glitches ≤100ns at ≥10mV overdrive - avoids spurious resets in electrically noisy environments |
Applications
| Industrial PLC Controllers | Set-Top Box Power Management |
|---|---|
|
Use Scenario: Dual-rail power sequencing for FPGA + ARM SoC subsystems where 1.2V core and 3.3V I/O must power up in strict order. IC Role / Device Role / Timing Role: Primary supervisor enforcing RESET1 → RESET2 sequence; VCC monitors 3.3V rail, RESET IN2 monitors 1.2V via resistor divider. Use Value: Prevents I/O initialization before core stabilization - eliminates bus contention and configuration lockup during cold start. |
Use Scenario: Reliable boot sequencing across 5V analog front-end, 3.3V demodulator, and 1.2V decoder ICs in broadcast receivers. IC Role / Device Role / Timing Role: Dual-threshold supervisor asserting RESET1 on main 5V rail, RESET2 on regulated 3.3V rail with 140ms stagger. Use Value: Ensures demodulator firmware loads only after analog supply stabilizes - reduces channel acquisition failure rate by >99%. |
| Network Attached Storage (NAS) Controllers | Medical Diagnostic Imaging Modules |
|
Use Scenario: Coordinating power-up of SATA controller (3.3V), DDR3 memory (1.5V), and USB hub (5V) in compact NAS enclosures. IC Role / Device Role / Timing Role: Sequencing supervisor using CSRT = VCC for fixed 140ms RESET2 delay; RESET IN2 monitors DDR3 supply. Use Value: Guarantees memory initialization completes before controller access - prevents ECC errors and filesystem corruption. |
Use Scenario: Fail-safe reset coordination between X-ray detector ASIC (2.5V), image processor (1.8V), and safety watchdog MCU (3.3V). IC Role / Device Role / Timing Role: Critical µP supervisor with VCC = 3.3V (watchdog rail), RESET IN2 = 2.5V (detector rail) via 100kΩ/40.2kΩ divider. Use Value: Maintains reset assertion until all safety-critical rails reach valid levels - satisfies IEC 62304 Class C software lifecycle requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-voltage supervisory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6391KA23 | VCC reset threshold = 2.32V (vs. 2.19V); otherwise identical pinout, timing, and features | Suitable where higher VCC trip point is required to accommodate 2.5V ±10% supply tolerance | Select MAX6391KA23 if system VCC nominal is 2.5V and margin requires ≥2.3V threshold; MAX6391KA22 fits 2.2V–2.3V rails. |
| TLV809E22DBVR | Single-supply supervisor (2.2V threshold), no RESET IN2 input or sequenced outputs; SOT23-5 package | Lacks secondary supply monitoring and RESET2 sequencing - only suitable for single-rail systems | Use TLV809E22DBVR only when only one supply needs monitoring and board space is extremely constrained (5-pin vs. 8-pin). |
Compared with MAX6391KA23 and TLV809E22DBVR, the MAX6391KA22 uniquely delivers dual-supply sequencing with factory-trimmed 2.19V accuracy and internal pullups - enabling robust multirail startup without layout compromises or external timing components.
Availability
MAX6391KA22 is available at Aetrix Electronics and suitable for industrial controllers, medical imaging modules, network-attached storage systems, and set-top box designs requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX6391KA22 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, computing, and communications applications.
The MAX6391/MAX6392 product line was designed specifically for multivoltage microprocessor systems requiring deterministic, sequenced reset generation - addressing reliability gaps in dual-rail power domains where standard single-supply supervisors fall short.
FAQ
What is the exact VCC reset threshold voltage for MAX6391KA22?
The MAX6391KA22 has a factory-trimmed VCC reset threshold of 2.19V, with a guaranteed tolerance of ±0.07V (2.12V to 2.25V) across the full -40°C to +85°C temperature range. This value is laser-trimmed during production and documented in the ordering guide table - it is not adjustable and applies exclusively to the MAX6391KA22 variant.
Does MAX6391KA22 support manual reset functionality?
No, MAX6391KA22 does not include manual reset capability. That feature is exclusive to the MAX6392 family (e.g., MAX6392KA22), which adds an active-low MR pin. The MAX6391KA22 relies solely on VCC and RESET IN2 monitoring for automatic reset generation - no external MR signal path exists in its pinout or internal logic.
How is the RESET2 timeout period configured on MAX6391KA22?
On MAX6391KA22, RESET2 timeout is configured via the CSRT pin: connecting CSRT to VCC selects a fixed 140ms (minimum) delay, while connecting CSRT to a capacitor-to-ground enables user-adjustable timing (tRP2 ≈ 2.08×10⁶ × CCSRT seconds). The device automatically detects the connection mode - no register programming or external logic is needed.
Can MAX6391KA22 monitor a 1.8V supply as the secondary voltage?
Yes, MAX6391KA22 can monitor a 1.8V supply on RESET IN2 using an external resistor divider. With the internal 625mV reference, a standard divider (e.g., R3 = 182kΩ, R4 = 100kΩ) scales 1.8V down to 625mV at RESET IN2. The input draws only 50nA, minimizing loading - confirmed in the Electrical Characteristics table under RESET IN2 Input Current.
What package type and dimensions does MAX6391KA22 use?
MAX6391KA22 uses an 8-pin SOT23 package (SOT23-8) measuring 3.00mm × 1.75mm × 1.30mm with 0.65mm lead pitch. Its mechanical drawing complies with JEDEC MO178, features gull-wing leads, and specifies coplanarity ≤4 mils - verified in the Package Information section of the datasheet.
MAX6391KA22 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-8
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 2.19V, Adj
- Output:
- Open Drain or Open Collector
- Reset:
- Active Low
- Reset Timeout:
- 140ms/Adjustable Minimum
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-8
MAX6391KA22 FAQ
1.How can I place an order for MAX6391KA22 through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6391KA22 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 MAX6391KA22 reliable?
The price and inventory of MAX6391KA22 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6391KA22 is usually 5 days.
3.What payment methods are accepted for MAX6391KA22?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6391KA22 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6391KA22?
MAX6391KA22 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6391KA22 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 MAX6391KA22?
For technical support, including MAX6391KA22 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6391KA22 requirements.
6.How does Aetrix verify that MAX6391KA22 is sourced from the original manufacturer or authorized distributors?
All MAX6391KA22 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 MAX6391KA22 meets industry standards.
7.What is the process for return or replacement of MAX6391KA22?
All MAX6391KA22 units undergo pre-shipment inspection (PSI). If there is an issue with MAX6391KA22, 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 MAX6391KA22 part is unused and in its original packaging.
Return procedure for MAX6391KA22:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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