105V with 96% efficiency and ultra-low EMI/EMC emission characteristics
3A Synchronous Step-Down Regulator

Analog Devices announced the release of the new LTC7103, a synchronous step-down switching regulator with a 2.3A, 105V input. Designed to support a high input voltage range of 4.4V to 105V, enabling operation with continuous high-voltage input sources or inputs with high-voltage surges, the new product eliminates the need for system designers to use external surge suppression devices. For this reason, it is ideal for a wide range of automotive, industrial, and telecommunications applications, including 48V automotive, 36V to 72V telecom, aerospace, and dual-battery commercial vehicles.

The LTC7103 can provide a continuous output current of up to 2.3A through its built-in high-efficiency power switch. It incorporates unique technology that reduces EMI/EMC emissions to ultra-low levels, enabling it to easily pass automotive CISPR #25 Class 5 standards while maintaining excellent efficiency. The LTC7103 achieves power conversion efficiencies of over 96% for 12V output and over 90% for 3.3V output.

To avoid noise-sensitive frequency bands, the user can use the LTC7103's built-in PLL to set the switching frequency between 200 kHz and 2 MHz or synchronize it with any frequency within the range.

The LTC7103 uses a unique fixed-frequency average current mode control architecture. It enables fast and accurate output current programming and monitoring without the use of external sensing resistors. Due to this adjustable current limiting, the LTC7103 is suitable for current source applications such as battery or capacitor charging and LED lighting.



It consumes only 2µA of input standby current while controlling the no-load output voltage, thereby extending battery operating time in always-on applications. Low-ripple Burst Mode operation maintains low output ripple while providing high efficiency at light loads. If even lower ripple is required, pulse-skipping mode can be selected. The LTC7103 features a low minimum on-time of 40ns and a maximum duty cycle of 100%, allowing the output voltage to be set to any value within the range of 1V to the maximum input voltage.

It provides eight pin-selectable fixed output voltage setting points, including widely used rails between 1.2V and 15V. Since the output voltage is provided pre-programmed in this way, there is no need for a separate external resistor divider, which reduces board footprint and lowers no-load standby current consumption. The internal voltage loop compensation function automatically adjusts according to the switching frequency to ensure speed and stability. Otherwise, the voltage loop can be optimized using an external OPTI-LOOP compensation technique.

LTC7103 is provided in a thermally enhanced 5mm x 6mm QFN-36 (26) package that meets the pin spacing requirements for high voltage. The industrial temperature-supported version LTC7103IUHE has been tested to operate in an operating junction temperature range of –40°C to 125°C, and the high-temperature version LTC7103HUHE has been tested to operate in a temperature range of –40°C to 150°C. The high-reliability version LTC7103MPUHE operates in a temperature range of –55°C to 150°C.