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Analog Devices Inc./Maxim Integrated MAX6451UT29L-T
- Part No.:
- MAX6451UT29L-T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Supervisors
- Package:
- SOT-23-6
- Datasheet:
-
MAX6451UT29L-T.pdf
- Description:
- IC SUPERVISOR UP RESET CIRCUIT
- Quantity:
- Payment:
- Shipping:
Inventory:2,380
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Product details
Overview
The MAX6451UT29L-T from Maxim Integrated is a dual-supply microprocessor supervisory circuit with one fixed-threshold (2.925V) and one adjustable-threshold reset monitor, featuring one delayed manual reset input (MR1, 6.72s setup) and one immediate manual reset input (MR2), in a 6-pin SOT23 package. It asserts an active-low push-pull RESET output for ≥140ms after VCC or RSTIN drops below threshold or upon MR2 rising edge, and guarantees valid reset down to VCC = 1.0V. It is used in smart-card-detect and interrupt-before-reset systems requiring immunity to nuisance switch closures.
For engineers reviewing the MAX6451UT29L-T datasheet, MAX6451UT29L-T pinout, MAX6451UT29L-T application, or MAX6451UT29L-T equivalent, key selection criteria include its dual manual reset behavior (delayed + immediate), 2.925V fixed VCC threshold, 0.63V RSTIN reference, 6.72s MR1 setup timeout, and guaranteed operation over –40°C to +85°C.
Technical Context
The MAX6451UT29L-T integrates two independent reset comparators: one monitors VCC against a factory-trimmed 2.925V threshold with 60ppm/°C tempco and 2×VTH hysteresis; the other monitors the external RSTIN pin against a precise 0.630V internal reference, enabling adjustable monitoring of voltages as low as 0.63V via resistor divider. Its dual manual reset architecture separates long-duration system reset (MR1, 6.72s low) from immediate event-triggered assertion (MR2 rising edge).
RESET is push-pull active-low with VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.55V) and VOH ≥ 0.8×VCC at ISOURCE = 500µA (VCC ≥ 3.15V). The device consumes only 6µA typical supply current at VCC = 3.6V and remains functional down to VCC = 1.0V, ensuring robust brownout detection during power ramp-down.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Reset Threshold | 2.925V (factory-trimmed, ±0.075V max deviation; enables reliable 3.3V rail supervision) |
| RSTIN Reference Voltage | 0.630V (precise internal reference; sets adjustable threshold for external voltage monitoring) |
| MR1 Setup Timeout | 6.72s (extended low-time requirement prevents false resets from brief button presses) |
| MR2 Trigger Mode | Rising-edge sensitive (immediate one-shot RESET pulse on high-to-low transition debounce cleared) |
| Reset Timeout Period | 140ms minimum (guaranteed minimum pulse width ensures µP reset completion) |
| Supply Current | 6µA typical at 3.6V (ultra-low quiescent current extends battery life in portable systems) |
| Operating Temperature | –40°C to +85°C (fully specified for industrial and automotive cabin environments) |
Pinout & Package
MAX6451UT29L-T is housed in a RoHS-compliant 6-pin SOT23 package (U6-1 outline, 90-0175 land pattern), with 1.27mm pitch, 2.9mm × 1.6mm footprint, and thermal pad optional. Pin 1 = GND, Pin 2 = VCC, Pin 3 = MR1, Pin 4 = MR2, Pin 5 = RSTIN, Pin 6 = RESET.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pin 1) | Ground reference | Common return path for all internal circuits; must be low-impedance connection to system ground plane |
| VCC (Pin 2) | Main supply input | Powers the IC and serves as primary monitored voltage source; operates from 1.0V to 5.5V |
| MR1 (Pin 3) | Delayed manual reset input | Active-low input with 50kΩ internal pullup; requires ≥6.72s low assertion to trigger one-shot RESET |
| MR2 (Pin 4) | Immediate manual reset input | Active-high edge-triggered input; rising edge pulses RESET for ≥140ms; debounced for 210ms on falling edge |
| RSTIN (Pin 5) | Adjustable threshold monitor input | High-impedance (±25nA leakage) comparator input referenced to 0.630V; connects to resistor divider for custom voltage monitoring |
| RESET (Pin 6) | Active-low push-pull output | Drives µP reset pin directly; sinks ≥1.2mA at VCC ≥ 2.55V; no external pullup required |
Key Features
| Feature | Design Value |
|---|---|
| Dual manual reset architecture | Combines 6.72s delayed MR1 for intentional system reset and edge-triggered MR2 for immediate event response (e.g., smart card insertion) |
| Adjustable RSTIN monitoring | 0.630V precision reference enables accurate monitoring of sub-1V rails (e.g., core supplies) using high-value external resistors |
| Nuisance-reset immunity | Extended MR1 setup period and 210ms MR2 falling-edge debounce eliminate false triggers from switch bounce or EMI transients |
| Brownout resilience | Valid RESET assertion guaranteed down to VCC = 1.0V ensures reliable reset during deep undervoltage conditions |
| Low-power supervision | 6µA typical ICC at 3.6V supports always-on monitoring in battery-powered consumer and medical devices |
Applications
| Smart Card Detection | Interrupt-Before-Reset Systems |
|---|---|
Use Scenario: Detecting insertion/removal of secure memory cards in point-of-sale terminals or embedded gateways. IC Role / Device Role / Timing Role: MR2 monitors card-detect switch; rising edge triggers immediate 140ms RESET pulse to signal host µP, while MR2 falling edge is debounced 210ms to prevent removal glitches. Use Value: Eliminates need for external debounce circuitry and enables deterministic card presence signaling without CPU polling. | Use Scenario: Front-panel pushbutton serving dual role-short press triggers software interrupt, long press (≥6.72s) forces hard reset. IC Role / Device Role / Timing Role: MR1 connected to same switch; µP reads switch state for interrupt, while MAX6451UT29L-T asserts hardware RESET only after extended low time. Use Value: Reduces BOM count by merging interrupt and reset functions into single mechanical interface, improving user experience and reliability. |
| Industrial Power-Rail Monitoring | Medical Device Brownout Protection |
Use Scenario: Supervising both main 3.3V logic rail and isolated 1.2V FPGA core supply in programmable logic controllers. IC Role / Device Role / Timing Role: VCC pin monitors 3.3V rail at 2.925V threshold; RSTIN pin monitors 1.2V rail via resistor divider referenced to 0.630V. Use Value: Single IC replaces two discrete supervisors, reducing board area and enabling coordinated reset timing across multiple voltage domains. | Use Scenario: Ensuring safe shutdown of patient-monitoring equipment during AC power loss or battery depletion. IC Role / Device Role / Timing Role: Monitors main 3.3V supply and backup 1.8V rail; RESET asserted when either falls below threshold and held ≥140ms to complete data save routines. Use Value: Guarantees µP reset validity down to VCC = 1.0V, preventing undefined states during critical low-voltage transitions in life-support systems. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar microprocessor supervisor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6452UT29L-T | Open-drain RESET output (vs. push-pull); identical VCC/RSTIN thresholds, MR1/MR2 timing, and package | Requires external pullup resistor; suitable where level-shifting or wired-OR reset bus is needed | Select MAX6452UT29L-T only if open-drain logic compatibility or multi-source reset arbitration is required. |
| MAX6449UT29L-T | Lacks MR2 immediate-reset input; provides two delayed manual reset inputs (MR1 + MR2) instead of MR1 + MR2 edge-triggered | Cannot support smart-card-detect or instant-event triggering; suited for dual-button safety reset only | Choose MAX6449UT29L-T only when dual extended-setup reset (e.g., service technician dual-button sequence) is mandatory. |
Compared with MAX6452UT29L-T, the MAX6451UT29L-T offers direct-drive push-pull RESET without external components; compared with MAX6449UT29L-T, it adds MR2 edge-trigger capability essential for responsive event detection-making it uniquely suited for smart-card and interrupt-before-reset designs.
Availability
MAX6451UT29L-T is available at Aetrix Electronics and suitable for smart-card readers, medical monitors, industrial PLCs, and consumer set-top boxes requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for MAX6451UT29L-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, communications, and consumer applications.
The MAX6443–MAX6452 family was engineered to solve nuisance-reset problems in front-panel-controlled electronics, combining extended manual reset timing, dual-supply monitoring, and ultra-low power consumption in miniature packages.
FAQ
What is the exact VCC reset threshold voltage for MAX6451UT29L-T?
The MAX6451UT29L-T has a factory-trimmed VCC reset threshold of 2.925V, with a maximum deviation of ±0.075V over temperature. This value is set by the "29" suffix per Table 1 and is guaranteed across the full –40°C to +85°C operating range with 60ppm/°C tempco and 2×VTH hysteresis. The threshold ensures reliable supervision of standard 3.3V power rails while accommodating typical tolerance bands.
How does the MR2 pin function on MAX6451UT29L-T?
The MR2 pin on MAX6451UT29L-T is an immediate, edge-triggered manual reset input. A rising edge (low-to-high transition) causes the RESET output to pulse low for ≥140ms. Its falling edge is internally debounced for 210ms to suppress false triggers during switch release. Unlike MR1, MR2 does not require sustained low time-making it ideal for smart-card detect or emergency interrupt signals where speed matters.
Can MAX6451UT29L-T monitor a 1.2V supply rail?
Yes, MAX6451UT29L-T can monitor a 1.2V supply using its RSTIN pin. With a precise 0.630V internal reference, an external resistor divider (e.g., R1 = 225kΩ, R2 = 250kΩ) sets the trip point to 1.2V per VMON-TH = 0.63 × (R1 + R2)/R2. RSTIN draws only ±25nA, allowing high-value resistors to minimize current draw-critical for battery-operated medical or portable devices.
What is the minimum VCC voltage at which MAX6451UT29L-T guarantees valid RESET operation?
MAX6451UT29L-T guarantees valid RESET output logic down to VCC = 1.0V. Below this, current-sinking capability degrades and RESET may float. For applications requiring assertion down to 0V, a 100kΩ pulldown resistor must be added to the RESET pin-but only with push-pull versions like MAX6451UT29L-T (not open-drain variants). This ensures fail-safe behavior during deep brownouts.
Is MAX6451UT29L-T pin-compatible with other devices in the MAX6443–MAX6452 family?
MAX6451UT29L-T uses a 6-pin SOT23 package shared with MAX6449, MAX6450, and MAX6452, but pin functions differ: MR2 on MAX6451UT29L-T is edge-triggered, whereas MR2 on MAX6449/MAX6450 is delayed. Direct replacement is not possible without layout and firmware review. Always verify pin mapping and reset timing behavior before substitution-especially MR2 functionality and RESET output type (push-pull vs. open-drain).
MAX6451UT29L-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- SOT-23-6
- Packaging:
- Bulk
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Multi-Voltage Supervisor
- Number of Voltages Monitored:
- 2
- Voltage - Threshold:
- 2.925V, Adj
- 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:
- SOT-6
MAX6451UT29L-T FAQ
1.How can I place an order for MAX6451UT29L-T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX6451UT29L-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 MAX6451UT29L-T reliable?
The price and inventory of MAX6451UT29L-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX6451UT29L-T is usually 5 days.
3.What payment methods are accepted for MAX6451UT29L-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX6451UT29L-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX6451UT29L-T?
MAX6451UT29L-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX6451UT29L-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 MAX6451UT29L-T?
For technical support, including MAX6451UT29L-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX6451UT29L-T requirements.
6.How does Aetrix verify that MAX6451UT29L-T is sourced from the original manufacturer or authorized distributors?
All MAX6451UT29L-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 MAX6451UT29L-T meets industry standards.
7.What is the process for return or replacement of MAX6451UT29L-T?
All MAX6451UT29L-T units undergo pre-shipment inspection (PSI). If there is an issue with MAX6451UT29L-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 MAX6451UT29L-T part is unused and in its original packaging.
Return procedure for MAX6451UT29L-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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