onsemi CAT810SSDI-T3

Overview

CAT810SSDI-T3 from onsemi is a 3-pin SOT-23 push-pull active HIGH power supply supervisor IC for microprocessor reset monitoring in +2.93 V systems. It asserts RESET HIGH when VCC falls below 2.93 V and maintains the signal for ≥140 ms after VCC recovers, operates down to VCC = 1.0 V, draws ≤6 µA supply current, and features ±0.05 V threshold accuracy over −40°C to +85°C.

For engineers reviewing the CAT810SSDI-T3 datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, package dimensions, reset timing behavior, industrial-grade transient immunity, and direct replacement guidance for embedded control, white goods, and intelligent instrumentation designs.

Technical Context

The CAT810SSDI-T3 implements a precision bandgap voltage reference with 30 ppm/°C tempco, a digital delay circuit ensuring minimum 140 ms reset timeout, and a push-pull output stage capable of sourcing ≥150 µA at VOH ≥0.8×VCC. Its internal comparator ignores transients ≤100 mV amplitude and <4 µs duration.

Unlike open-drain CAT803 variants, CAT810SSDI-T3 provides active HIGH reset logic compatible with microcontrollers requiring high-true reset assertion, eliminates external pull-up resistors, and guarantees valid output state even when VCC drops as low as 1.0 V-requiring only an external pull-up to VCC per datasheet Figure 9.

Key Specifications

Pinout & Package

The CAT810SSDI-T3 is housed in a JEDEC-compliant 3-pin SOT-23 (Case 527AG) surface-mount package measuring 2.92 × 1.30 × 1.02 mm, with gull-wing leads and matte-tin plating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power supply supervisor applications.

Compared with MAX810SUT+T and TPS3801K33DBVR, CAT810SSDI-T3 uniquely combines active HIGH push-pull output, 6 µA supply current, and guaranteed reset validity down to 1.0 V-making it optimal for ultra-low-power, high-reliability embedded systems where reset polarity and deep brownout behavior are design-critical.

Availability

CAT810SSDI-T3 is available at Aetrix Electronics and suitable for computing peripherals, smart home appliances, energy metering, portable test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for CAT810SSDI-T3 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier delivering energy-efficient, high-performance silicon solutions for automotive, industrial, cloud, medical, and IoT applications.

The CAT810 series belongs to onsemi's power supply supervisor product line, engineered specifically for robust, low-cost microprocessor reset generation in industrial and consumer electronics with strict reliability and thermal stability requirements.

FAQ

What is the exact reset threshold voltage of the CAT810SSDI-T3 and how tightly is it specified?

The CAT810SSDI-T3 has a nominal reset threshold voltage of 2.93 V, with a guaranteed tolerance of ±0.05 V over the full industrial temperature range (−40°C to +85°C). This specification is confirmed in Table 4 of the official datasheet (Rev. 33, October 2012), where the S threshold shows min/max values of 2.85 V and 3.00 V at temperature extremes. The 30 ppm/°C tempco further ensures minimal drift across operating conditions, making CAT810SSDI-T3 suitable for precision reset applications in stable +2.93 V domains.

Does the CAT810SSDI-T3 require an external pull-up resistor on its RESET pin?

No, the CAT810SSDI-T3 does not require an external pull-up resistor because it features a push-pull active HIGH output stage. Unlike the open-drain CAT803 family, CAT810SSDI-T3 actively drives RESET HIGH during fault and LOW during normal operation. However, per datasheet Figure 9, a pull-up resistor from RESET to VCC is recommended *only* to ensure a defined logic state when VCC drops below 1.0 V-this is a fail-safe measure, not a functional requirement for normal operation.

What is the minimum VCC voltage at which CAT810SSDI-T3 guarantees valid RESET output behavior?

The CAT810SSDI-T3 guarantees valid RESET output behavior down to VCC = 1.0 V, as explicitly stated in the Features section and validated in Absolute Maximum Ratings (Table 3) and Figure 9 of the datasheet. At VCC ≥1.0 V, the device correctly asserts RESET HIGH when VCC falls below 2.93 V and holds it for ≥140 ms after recovery. Below 1.0 V, the output state is not guaranteed unless an external pull-up to VCC is applied-ensuring deterministic behavior even during deep brownout events.

How does the reset timeout period of CAT810SSDI-T3 vary with temperature and supply voltage?

The reset timeout period (TR) of CAT810SSDI-T3 ranges from 140 ms (minimum) to 460 ms (maximum) over −40°C to +85°C, as specified in Table 4. This variation is inherent to the internal digital delay circuit and is independent of VCC within the 1.2–5.5 V operating range. Figure 2 confirms the monotonic increase in timeout with temperature, peaking near 260 ms at +85°C for the S-threshold variant. Designers must use the 460 ms maximum value for worst-case timing analysis in safety-critical boot sequences.

Is CAT810SSDI-T3 pin-compatible with MAX810 or other industry-standard supervisors?

CAT810SSDI-T3 is a direct functional replacement for MAX810 in industrial-temperature applications, as confirmed in the datasheet description ("direct replacements for the MAX810"), but it is *not* pin-compatible with MAX810SUT+T due to differing output logic: CAT810SSDI-T3 is active HIGH push-pull, while MAX810SUT+T is active LOW open-drain. Both use SOT-23-3 packages with identical pinout (GND–RESET–VCC), but the RESET pin function differs-requiring schematic and firmware review before substitution. No pin-to-pin drop-in replacement exists without verifying reset polarity compatibility.