LT1615IS5-1#TRMPBF

LT1615IS5-1#TRMPBF Application Field and Working Principle

The LT1615IS5-1#TRMPBF, also known as the LT1615, is a series of high-efficiency, low power, single-output synchronous, and step-down DC/DC regulators from Linear Technology Corporation, designed for applications such as industrial, automotive and telecom. The LT1615 family is highly integrated and can deliver output currents up to 8A at a maximum VIN of 40V and efficiency up to 96%. It integrates two power MOSFETs, a VIN current sense, and an over-temperature protection, as well as an integrated loop compensation. The output voltage of the LT1615 can be adjusted from 0.95V to 24V.

The LT1615 regulators are available in 8-pin and 10-pin thermally enhanced MLP packages and a 10-pin Green or RoHS compliant package options. It supports pulse-by-pulse limiting, soft start, and over-current protection. It has a junction temperature range of -40°C to +125°C and is RoHS-compliant.

Application Field:

The LT1615 features a low quiescent current of 15 mA which makes it suitable for industrial and automotive applications requiring a wide range operating temperature and extended lifespan. The LT1615 is specifically designed for applications requiring a high accuracy and low output voltage ripple, such as embedded controllers, industrial switches, and digital audio components. It is well suited for applications such as battery-powered device, portable computing and measurement devices, automotive systems, board mounted power supplies, and system power management.

Working Principle:

The LT1615 operates as a buck regulator where power is transferred from the input VIN to the output VOUT via two power MOSFETs. The VIN switch is driven by an internal oscillator and the frequency of operation can be adjusted by the external RSEL resistor to reduce switching noise and EMI. The output voltage is set by the voltage feedback loop and is maintained by the error amplifier. The IC is monitored by an over-temperature protection circuit which shuts down the regulator in case of overheating.

The LT1615 also features a synchronous rectification function which increases efficiency by allowing the device to be operated in continuous conduction mode. The synchronous rectification also reduces input capacitor requirements and allows frequencies to be adjusted to reduce EMI radiation. The LT1615 is additionally protected against over-current and over-temperature conditions.