S-1009N44I-N4T1U

Introduction

The S-1009N44I-N4T1U is a three-terminal negative voltage supervisor IC designed to monitor a negative voltage supply rail in mobile phone and other consumer electronics application. It has an active-high reset signal output, RESET and an open-drain signal output, UVLO with an adjustable under-voltage lockout level. In order to guarantee the absolute backward compatibility of the S-1009N44I-N4T1U within existing designs, it includes two protection functions, a temperature-compensated under-voltage lockout function and a factory set current-regulator function.

Application Field and Working Principle

1.Application Field

The S-1009N44I-N4T1U is especially suitable for use in the following applications:

• Mobile phones
• Consumer electronics

2.Working Principle

The S-1009N44I-N4T1U is based on a negative rail voltage supervisor IC, which monitors a negative voltage supply rail. The chip utilizes a factory-set temperature-compensated under-voltage lockout (UVLO) function to provide accurate monitoring of the negative voltage supply rail. When the UVLO voltage is greater than the preset UVLO threshold the reset output (RESET) is pulled low indicating that the system is active. If the UVLO voltage drops below the preset threshold the RESET is pulled high indicating that the system is in under-voltage lockout condition. Additionally, the S-1009N44I-N4T1U includes a current-regulator function that allows the IC to regulate the current, thus preventing circuit damage due to over-current conditions.

Technology Advantages

1.Small Size

The S-1009N44I-N4T1U is packaged in a small SOT-23-5 package, which has a size of 2.6mm x 1.6mm x 0.85mm. This allows the IC to be used in very compact designs, thus reducing the size and cost of the system.

2.High Reliability

The S-1009N44I-N4T1U includes several protection features such as reverse polarity protection and over-voltage protection, which provide high level of system reliability. Additionally, the IC uses a factory-set temperature-compensated UVLO function which ensures that the IC is able to accurately monitor the negative voltage supply rail.

3.Ease of Use

The S-1009N44I-N4T1U provides a very easy to use interface. The IC has four terminals (VCC, GND, UVLO and RESET) which can be connected directly to the negative voltage supply rail without the need of additional components. The IC can be easily configured using the available pins and it is compatible with most standard voltage regulator circuits.

Conclusion

The S-1009N44I-N4T1U is a three-terminal negative voltage supervisor IC designed for use in mobile and consumer electronics applications. It provides a compact and easy to use interface and offers high level of system reliability by including several protection features. The factory-set temperature-compensated UVLO function ensures that the IC is able to accurately monitor the negative voltage supply rail.