LP3855ET-1.8

LP3855ET-1.8 is a linear voltage regulator IC produced by Texas Instruments (TI). It is an integrated three-terminal regulator primarily designed for use as a Secondary-Side Power Converter in off-line topologies. As such, it fits into a broad range of industry segments such as automotive, industrial and mobile applications. This device provides multiple low-noise, low-dropout, high-efficiency and low-power dissipation features.

Features

• Wide Operating Voltage Range: 1.8 V to 36 V
• High ±1.1% output voltage accuracy
• Output current up to 1.5A
• Low Dropout Voltage: 700 mV [typ] at 1.5A
• Low Shutdown Input Current: 0.15 µA [typ]
• Stable with Low-ESR Ceramic Capacitors

Application Field

LP3855ET-1.8 is widely used in automotive, industrial, and mobile applications. The device is suitable for applications such as boost voltage regulators, LED lighting, backlight LED drivers, DC-DC converters, battery chargers, power ports, and USB power ports.

Working Principle

LP3855ET-1.8 is an integrated three-terminal regulator that features a low-dropout voltage of 700mV, excellent regulation performance and low power dissipation. The device is designed to operate with an input voltage range of 1.8 V to 36 V. The output voltage range is adjustable from 1.24 V up to VIN-3.3 V. The device features a built-in current source output which holds the logic state and current requirements.

The LP3855ET-1.8 uses a dynamic voltage adjustment technique and requires only two external resistors to set the output voltage. The internal N-channel MOSFET is configured as a low-side switch for use in controlling the output voltage. The output voltage is further regulated by a precision adjustable error amplifier, whose reference voltage is divided from an internal 1.25V reference by an external resistor divider network. The output leakage current decreases with increased output voltage due to the increased gate-source voltage of the internal MOSFET.

Conclusion

The LP3855ET-1.8 is an efficient and cost-effective linear voltage regulator IC designed to provide multiple low-noise, low-dropout, high-efficiency and low-power dissipation features. This device is suitable for applications such as boost voltage regulators, LED lighting, backlight LED drivers, DC-DC converters, battery chargers, power ports, and USB power ports. Working with an input voltage range of 1.8 V to 36 V, the LP3855ET-1.8 features a wide output voltage range and uses a dynamic voltage adjustment technique.