Overview
The NCP308SN280T1G is a part of the NCP308 series of supervisory circuits produced by onsemi. This IC is designed to monitor system voltages and assert a RESET signal when the monitored voltage drops below a specified threshold or when the Manual Reset (MR) input is driven low. The device is optimized for a wide range of applications, including DSP, microcontroller, and FPGA/ASIC systems.
The NCP308SN280T1G is specifically configured with a fixed threshold voltage of 2.61 V, making it suitable for monitoring 2.8 V voltage rails. It features a very low quiescent current, high threshold voltage accuracy, and flexible delay time programmability.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| VDD Supply Voltage Range | −40°C < TJ < +125°C | 1.6 | 5.5 | V | |
| IDD Supply Current | VDD = 3.3V, RESET not asserted, MR, RESET, CT open | 1.6 | 5.0 | μA | |
| VOL Low-level output voltage of RESET | 1.6V ≤ VDD ≤ 5.5V, IOL = 1.0 mA | 0.4 | V | ||
| VIT Negative going SENSE threshold voltage | 2.61 | V | |||
| VIT% Threshold Voltage Accuracy | TJ = +25°C | −0.31 | −0.31 | +0.31 | % |
| tD Reset Delay Time | CT = 100 pF | 1.25 | 10 | s | |
| TJ Operating Temperature Range | −40 | +125 | °C |
Key Features
- Wide Supply Voltage Range: 1.6 V to 5.5 V
- Low Quiescent Current: 1.6 μA (typical)
- High Threshold Voltage Accuracy: ±0.31% (typical)
- Manual Reset Input (MR): Supports manual reset with internal pull-up resistor
- Open-Drain RESET Output: Active low open-drain output with optional push-pull configuration
- Flexible Delay Time Programmability: Delay times from 1.25 ms to 10 s using the CT pin
- Small Package Options: TSOP-6 and WDFN6 2 x 2 mm, Pb-Free packages
- AEC-Q100 Qualified and PPAP Capable: Suitable for automotive and other critical applications
Applications
- DSP or Microcontroller Applications
- Notebook/Desktop Computers
- PDAs/Hand-Held Products
- Portable/Battery-Powered Products
- FPGA/ASIC Applications
Q & A
- What is the primary function of the NCP308SN280T1G?
The primary function is to monitor system voltages and assert a RESET signal when the voltage drops below the specified threshold or when the Manual Reset input is driven low.
- What is the threshold voltage for the NCP308SN280T1G?
The threshold voltage is 2.61 V, suitable for monitoring 2.8 V voltage rails.
- How is the reset delay time programmed in the NCP308SN280T1G?
The reset delay time can be programmed using the CT pin with various configurations, including connecting it to VDD, leaving it open, or using a capacitor to set a user-defined delay time.
- What is the operating temperature range of the NCP308SN280T1G?
The operating temperature range is −40°C to +125°C.
- What are the package options for the NCP308SN280T1G?
The device is available in TSOP-6 and WDFN6 2 x 2 mm, Pb-Free packages.
- Is the NCP308SN280T1G suitable for automotive applications?
Yes, it is AEC-Q100 qualified and PPAP capable, making it suitable for automotive and other critical applications.
- How does the Manual Reset input work?
The Manual Reset input (MR) is internally tied to VDD by a 90 kΩ pull-up resistor and asserts the RESET signal when driven low.
- What is the quiescent current of the NCP308SN280T1G?
The quiescent current is 1.6 μA (typical).
- How accurate is the threshold voltage of the NCP308SN280T1G?
The threshold voltage accuracy is ±0.31% (typical).
- What is the purpose of the SENSE input pin?
The SENSE input pin is used to monitor the system voltage directly, and if the voltage drops below the threshold voltage, it asserts the RESET signal.
