Overview
The CAT811TTBI-GT3 is a microprocessor supervisory circuit produced by onsemi. This device is designed to monitor power supplies and generate a reset signal when the power supply voltage falls below a preset threshold level. It is a direct replacement for the MAX811 in applications operating over the industrial temperature range and features a manual reset input. The CAT811 uses floating gate technology, allowing for custom reset threshold values, and is available in several industry-standard threshold levels to support various voltage systems (+5.0 V, +3.3 V, +3.0 V, and +2.5 V).
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| VCC Range | TA = 0°C to +70°C | 1.0 | 5.5 | V | |
| VCC Range | TA = −40°C to +85°C | 1.2 | 5.5 | V | |
| Supply Current (ICC) | TA = −40°C to +85°C, VCC < 3.6 V (S/T versions) | 6 | 15 | 20 | μA |
| Reset Threshold Voltage (VTH) | TA = +25°C (T version) | 3.04 | 3.08 | 3.11 | V |
| Reset Threshold Voltage (VTH) | TA = −40°C to +85°C (T version) | 3.00 | 3.15 | V | |
| Reset Active Timeout Period | TA = −40°C to +85°C | 140 | 400 | ms | |
| Operating Ambient Temperature Range | −40 | +85 | °C |
Key Features
- Precision monitoring of +5.0 V (± 5%, ± 10%, ± 20%), +3.3 V (± 5%, ± 10%), +3.0 V, and +2.5 V systems.
- Manual reset input with an internal 20 kΩ pull-up resistor.
- Active LOW reset output (push-pull configuration).
- Direct replacement for the MAX811 in applications operating over the industrial temperature range.
- Reset valid down to VCC = 1.0 V.
- Low power supply current (typically 6 μA to 20 μA).
- Power supply transient immunity.
- Available in SOT-143 packages with Sn or NiPdAu green lead finishes.
- Pb-free, halogen-free/BFR-free, and RoHS compliant.
Applications
- Computers, servers, laptops, and cable modems.
- Wireless communications.
- Embedded control systems.
- White goods and power meters.
- Intelligent instruments.
- PDAs and handheld equipment.
Q & A
- What is the primary function of the CAT811TTBI-GT3?
The CAT811TTBI-GT3 is a microprocessor supervisory circuit designed to monitor power supplies and generate a reset signal when the power supply voltage falls below a preset threshold level.
- What are the available threshold levels for the CAT811TTBI-GT3?
The CAT811TTBI-GT3 is available in several industry-standard threshold levels, including +5.0 V, +3.3 V, +3.0 V, and +2.5 V.
- What is the significance of the manual reset input?
The manual reset input allows for a manual assertion of the reset signal by applying a logic LOW to the MR pin, which keeps the RESET active as long as MR is LOW and for 140 ms after MR returns HIGH.
- How does the CAT811TTBI-GT3 handle power supply transients?
The device ignores fast transients on the power supply, ensuring that short duration transients (typically 4 μs or less and 100 mV amplitude) do not cause a false reset.
- What is the operating temperature range of the CAT811TTBI-GT3?
The device is fully specified over the industrial temperature range of −40°C to +85°C.
- Is the CAT811TTBI-GT3 RoHS compliant?
- What package type is the CAT811TTBI-GT3 available in?
The device is available in a compact 4-pin SOT-143 package.
- How does the reset timing work for the CAT811TTBI-GT3?
The reset signal is asserted LOW when the power supply voltage falls below the threshold and remains asserted for at least 140 ms after the power supply voltage has risen above the threshold.
- Can the CAT811TTBI-GT3 interface with bi-directional reset pins?
- What is the recommended pull-down resistor value for ensuring the RESET pin is in a known state when VCC is under 1.0 V?
A 100 kΩ pull-down resistor between the RESET pin and GND is recommended to ensure the RESET pin is in a known state when VCC is under 1.0 V.
