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HomeProductsIntegrated Circuits (ICs)Specialized ICsCAT809REUR
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CAT809REUR - AMI Semiconductor/onsemi

Manufacturer Part Number
CAT809REUR
Manufacturer
onsemi
Allelco Part Number
32D-CAT809REUR
Warranty
1 Year Allelco Warranty - Find out more
Stock Status:
3,870 pcs available, New & Original
Parts Description
DAC91001
Data sheet
-
Category
Integrated Circuits (ICs) > Specialized ICs
RoHs Status
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In stock: 3870

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Specifications

CAT809REUR Tech Specifications
AMI Semiconductor/onsemi - CAT809REUR technical specifications, attributes, parameters and parts with similar specifications to AMI Semiconductor/onsemi - CAT809REUR

Product Attribute Attribute Value
Part Number CAT809REUR
Package DAC91001
Description DAC91001
Stock Condition Get 3870 pcs available quantity at Allelco
Payment PayPal / TT / Credit Card / Western Union
Allelco Certifications ESD / ISO 9001 / ISO 13485 / ISO 28000
Product Attribute Attribute Value
Manufacturer onsemi
RoHs Status -
Warranty 100% Perfect Functions
Transport port Hong Kong
Shipping by DHL / FedEx / UPS / TNT / SF Express
RFQ Email info@allelco.com

Frequently Asked Questions(FAQ)

What is the primary function of the CAT809REUR voltage supervisor IC, and how does it support system reliability in power-sensitive applications?
The CAT809REUR is a precision voltage monitoring device designed to supervise supply voltages in electronic systems. It provides power-on reset functionality by monitoring the input voltage and generating a valid logic-level output only when the monitored voltage exceeds a defined threshold. This ensures that microcontrollers and digital circuits do not execute erroneous instructions during unstable or undervoltage conditions. In battery-powered devices such as IoT sensors or portable medical equipment, maintaining stable operation during voltage transients is critical, and the CAT809REUR contributes to this by introducing a 100 ms typical delay before asserting the reset signal, allowing transient dips to settle without triggering a false reset.
How does the CAT809REUR compare to other reset ICs like the MAX809 or MCP1833 in terms of threshold accuracy and response time for 3.3V systems?
The CAT809REUR offers a fixed 2.93V reset threshold with ±1.5% accuracy over temperature, making it suitable for precise 3.3V rail supervision. Unlike adjustable versions, it eliminates the need for external resistors but sacrifices flexibility. Compared to the MAX809L, which also targets 3.3V systems, the CAT809REUR features a slightly longer reset timeout—typically 100 ms versus 200 μs—which may be preferable in systems where power-up glitches are common. However, the MAX809L offers faster response, beneficial in high-noise environments. The MCP1833, while a low-dropout regulator, does not provide reset supervision, so it cannot replace the supervisory function of the CAT809REUR despite offering voltage regulation.
Can the CAT809REUR be used in automotive-grade temperature applications, and what limitations should designers consider regarding reliability under thermal stress?
No, the CAT809REUR is not rated for automotive-grade operation. It operates over a standard commercial temperature range typically from 0°C to +70°C or up to +85°C, depending on the variant. Automotive applications require AEC-Q100 compliance and extended temperature ranges up to +125°C, which this device does not meet. Using it in harsh environmental conditions without additional thermal management may lead to accelerated aging or parametric drift, particularly in high-power-density designs where local heating could push junction temperatures beyond safe limits. Designers should verify thermal performance in enclosure simulations and consider derating if operating near maximum temperature ratings.
What is the impact of enabling the watchdog feature on power consumption, and how can the CAT809REUR’s low quiescent current benefit battery life in portable designs?
The CAT809REUR includes an optional watchdog timer that requires periodic stimulus from the microcontroller via the WDI pin. When enabled, the watchdog draws additional current due to internal clocking, increasing total quiescent current slightly above its base value of ~6 µA. However, even with the watchdog active, power consumption remains extremely low, typically under 10 µA, which is negligible compared to the sleep current of modern MCUs. In battery-operated devices such as wearables or remote sensors, this minimal draw extends operational life significantly—potentially adding months of runtime on a single coin cell or small Li-ion pack—without compromising system stability.
Is the CAT809REUR compatible with 5V logic systems, and what precautions are necessary when interfacing its open-drain output to higher-voltage domains?
The CAT809REUR monitors a specific input voltage (e.g., 2.93V) and is not designed for direct 5V system integration unless used to supervise a lower-voltage subsystem. Its open-drain RESET output can safely interface with 5V logic as long as an external pull-up resistor is connected to the 5V rail. Without proper pull-up, the output may not reach full logic-high levels, potentially causing recognition issues in 5V CMOS inputs. Additionally, care must be taken to ensure that the maximum absolute rating for the RESET pin (typically Vcc + 0.3V) is not exceeded. Using a pull-up resistor within the recommended range (e.g., 10 kΩ to 100 kΩ) ensures clean transitions and reliable communication across voltage domains.
How does the SOT23-3 package influence PCB layout decisions when integrating the CAT809REUR into compact consumer electronics?
The SOT23-3 package occupies minimal board space, enabling high component density in space-constrained designs such as smartphones or wearable devices. However, its small footprint increases sensitivity to parasitic inductance and capacitance during high-frequency noise events. To maintain reliable operation, the input bypass capacitor (typically 0.1 µF placed close to the Vcc pin) must be located within millimeters of the CAT809REUR to minimize loop area and suppress transient-induced resets. Thermal considerations are also relevant; although the device has low power dissipation, prolonged operation near ambient limits in sealed enclosures may require careful airflow planning or thermal simulation to avoid junction overheating.
Can the CAT809REUR operate reliably in systems with frequent brownout events, and how does its hysteresis behavior affect reset stability?
Yes, the CAT809REUR supports reliable operation during repeated brownout conditions thanks to its inherent noise immunity and lack of built-in hysteresis. Unlike some comparator-based supervisors, it relies on internal filtering rather than external components to reject transient glitches. During a brownout event, the device will assert reset once Vcc drops below 2.93V minus threshold tolerance. Upon recovery, a 100 ms delay ensures the voltage has stabilized before releasing reset, preventing chatter. This makes it well-suited for environments with fluctuating supplies, such as solar-powered nodes or motor-driven systems, where sudden load changes cause voltage sag.
What role does the WDI pin play in system diagnostics, and how should designers implement software-based fault detection using the CAT809REUR?
The Watchdog Input (WDI) pin allows the microcontroller to demonstrate functional integrity by toggling the pin at regular intervals. If the CPU fails to respond or hangs, the WDI signal stops, and after approximately 1.6 seconds (typical), the internal watchdog counter expires, forcing a reset. This enables automatic recovery from software lockups. Designers should integrate periodic toggling of the WDI line into the main application loop or interrupt service routine, with timing slightly less than the expiration period to avoid accidental resets. This adds a layer of diagnostic capability beyond voltage supervision, contributing to overall system robustness in unattended deployments.
How does the CAT809REUR differ from the CAT810REUR in terms of threshold voltage and application suitability?
The CAT809REUR has a fixed reset threshold of 2.93V, making it ideal for supervising 3.3V logic rails. In contrast, the CAT810REUR features a 4.63V threshold, intended for 5V system supervision. While both share the same SOT23-3 package and similar electrical characteristics (quiescent current, timeout delay), their target supply voltages differ significantly. Selecting between them depends entirely on the nominal system voltage. Using a CAT810REUR in a 3.3V design would result in premature resets during normal operation, whereas using a CAT809REUR in a 5V system might fail to detect undervoltage conditions until the supply drops below 4.6V, risking data corruption.
Are there any known compatibility issues when cascading multiple CAT809REUR devices on the same PCB for multi-rail supervision?
Cascading multiple CAT809REUR units for independent rail monitoring is technically possible but requires careful attention to shared ground integrity and propagation delays. Since each device uses an open-drain output, they can be OR’ed together with a common pull-up resistor. However, cumulative propagation delays (each ~100 ms) mean the overall reset assertion time increases proportionally with the number of devices. Additionally, noise coupling between closely spaced SOT23 footprints could increase susceptibility to cross-talk. For most applications, it is more robust to use dedicated supervisors per rail or opt for integrated multi-channel alternatives unless space and cost constraints demand discrete solutions.
What testing methodology ensures correct CAT809REUR functionality during prototype validation?
Functional verification should include dynamic voltage ramp tests using a programmable power supply to confirm that the RESET pin deasserts precisely when Vcc crosses above 2.93V + threshold tolerance. A slow ramp rate (e.g., 10 mV/ms) helps visualize the transition point accurately. Additionally, inject transient dips (±200 mV, <50 ms) around the threshold to validate immunity to glitches. Watchdog testing involves disabling the WDI toggle in firmware and confirming that a reset occurs within 1.6–2.0 seconds. Oscilloscope probing of the RESET line relative to Vcc during these tests confirms correct timing and logic levels, ensuring real-world reliability before mass production.
How does the absence of an enable/disable pin in the CAT809REUR affect power sequencing in complex SoC designs?
Unlike some supervisory ICs, the CAT809REUR lacks a dedicated enable pin, meaning it begins monitoring immediately upon power application. This simplifies control logic but removes the ability to delay supervision startup intentionally. In advanced power architectures with multiple rails powered sequentially, simultaneous assertion of supervision across all rails may cause unintended resets if one rail powers up slower than others. Designers must either ensure uniform power-up timing or use external sequencing circuitry. Alternatively, placing a small series resistor and capacitor at the input can create a soft-start effect, though this introduces minor voltage drop and should be validated against minimum operating conditions.
Can the CAT809REUR be used in conjunction with DC-DC converters to improve overall system stability?
Yes, integrating the CAT809REUR with a switching regulator enhances system reliability by detecting converter failures or output droop. For example, in a buck converter feeding a 3.3V MCU, the CAT809REUR can monitor the regulated output and trigger a reset if the converter fails to maintain voltage. This prevents corrupted state machines or memory writes during unstable conversion. However, the fast transient response of modern DC-DC converters often renders the 100 ms delay excessive; in such cases, a faster-response supervisor (≤50 μs) may be preferable unless extended noise filtering is required. The CAT809REUR remains valuable when combined with linear regulators or in legacy designs with slower regulation dynamics.
What are the implications of using the CAT809REUR in high-altitude or vacuum environments where thermal conductivity differs from standard conditions?
Operating the CAT809REUR in high-altitude or vacuum environments affects heat dissipation due to reduced convective cooling. Although the device dissipates very little power (on the order of microwatts), localized heating from nearby components or radiation absorption in vacuum may elevate junction temperatures beyond datasheet assumptions. Designers should conduct thermal modeling using worst-case power profiles and consider conduction paths through PCB layers or mechanical contacts. Additionally, outgassing materials in sealed enclosures could deposit contaminants on the device, potentially altering thermal impedance over time. These factors necessitate conservative margining in extreme environments, even for low-power discretes like the CAT809REUR.
How does the CAT809REUR support compliance with IEC 61000-4-2 ESD standards in industrial control systems?
While the CAT809REUR itself is not certified for ESD protection, its low input impedance and internal clamping diodes help absorb minor transient spikes common in industrial settings. Proper PCB layout—including short traces, adequate ground planes, and proximity to bulk decoupling capacitors—maximizes resilience. To meet IEC 61000-4-2 Level 3 (4 kV contact discharge), additional external protection such as TVS diodes at the input or along signal lines is typically required. The open-drain output also benefits from series resistance and filtering, reducing susceptibility to fast transients. Integrating these measures alongside the CAT809REUR ensures robust operation in electrically noisy environments without relying solely on the supervisor IC’s inherent robustness.
What is the significance of the “RE” suffix in the CAT809REUR part number, and how does it relate to manufacturing traceability?
The “RE” in CAT809REUR denotes a specific reel packaging format compliant with industry-standard tape-and-reel dimensions used in automated pick-and-place assembly. This suffix indicates that the device is supplied in standard 7-inch reels containing 3,000 units, facilitating high-volume SMT production. It does not affect electrical performance but ensures compatibility with automated lines. Traceability is enhanced through batch codes and date stamps embedded in the marking, allowing manufacturers to track production lots for quality assurance. Understanding this nomenclature helps procurement teams source correct quantities and align with assembly workflows, avoiding costly mismatches during manufacturing.

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Customer Reviews

Evaluation: 10 Articles

  • Arch***ct
    Jul 15, 2026

    Used this device in a communication signal processing board. Stable timing and no unexpected issues during implementation.

  • FPGA***lorer88
    Jul 7, 2026

    The FPGA works properly and all functions operate as expected. Documentation required some additional research, but overall it is a usable device for smaller signal processing projects.

  • Nath***oleman
    Jun 29, 2026

    Used this sensor component in an industrial automation setup. Detection accuracy was consistent and installation was straightforward.

  • Emil***rperTech
    Jun 23, 2026

    Works exactly as described. I used it as a USB-to-SPI bridge in a small MCU development project and communication was stable from the first setup.

  • Liam***terTech
    Jun 15, 2026

    Used this CPLD in a logic control project. Programming was straightforward and signal timing matched the design requirements.

  • Nath***rooks
    Jun 11, 2026

    Installed this power component in a converter board. Output remained stable under different load conditions and thermal performance was better than expected.

  • Dani***alkerTech
    Jun 1, 2026

    Product works, but setup took more effort than expected. Once configured the MCU ran reliably, although documentation support felt older compared with newer platforms. Fine for maintenance projects.

  • Yuki***aka88
    May 26, 2026

    信号通信プロジェクトでこのRS-485トランシーバーを使用しました。設置は簡単で、長距離ケーブルでも通信は安定していました。消費電力も、以前使用していたものより低くなっています。

  • Stev***aker
    May 20, 2026

    Solid diode for power rectification. Works well in switching circuits.

  • Bran***Lewis
    May 11, 2026

    Compact FPGA with good performance. Suitable for basic signal processing tasks.

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Region Country Logistic Time(Day)
America United States 5
Brazil 7
Europe Germany 5
United Kingdom 4
Italy 5
Oceania Australia 6
New Zealand 5
Asia India 4
Japan 4
Middle East Israel 6
DHL & FedEx Shipment Charges Reference
Shipment charges(KG) Reference DHL(USD$)
0.00kg-1.00kg USD$30.00 - USD$60.00
1.00kg-2.00kg USD$40.00 - USD$80.00
2.00kg-3.00kg USD$50.00 - USD$100.00
Note:
The above table is for reference only. There may have some data bias for the uncontrollable factors.
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AMI Semiconductor/onsemi

CAT809REUR

AMI Semiconductor/onsemi
32D-CAT809REUR

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