DC2833A - Schematic1/17/2022
Demonstration circuit 2833A is a 100V monolithic DC/DC step-down regulator featuring the LTC7103-1. The demo board is designed for a 5V/2.3A output from a 5V to 100V input operation at a 400kHz switching frequency. The wide input range makes it suitable for automotive, industrial, medical instrument, and telecom applications. This buck regulator has a peak efficiency of 93.5% at 12VIN, 88.3% at 48VIN and 81.5% at 100VIN (see Figure 3 in the demo manual).
The LTC7103-1 is a compact, high efficiency synchronous monolithic step-down switching regulator with fast current programming. The power switches, compensation network and other necessary circuits are inside of the LTC7103-1 to minimize external components and simplify design. The LTC7103-1 has wide operating range from 4.4V to 105V. A 40ns minimum on-time, together with 100% maximum duty cycle allow practical use at any output voltage between 1V and VIN. The switching frequency can be programmed either via an oscillator resistor or an external clock over a 200kHz to 2MHz range. Additional features include a fast and accurate output current programming and monitoring, and ultralow EMI/EMC emissions.
The demo board has an EMI filter installed. The EMI performance of the board (with EMI filter) is shown in Figure 2 in the demo manual. The figure shows that the circuit passes the CISPR 25 radiated emission test with a wide margin. To achieve EMI/EMC performance as shown in Figure 2, the input EMI filter is required and the input voltage should be applied at +VIN_EMI turret pin.
The demo board provides current monitor and output clock signal to interface with an external application circuit. User selectable mode selection (JP1) is provided and Burst Mode® operation position is selected by default. Burst Mode operation increases light load efficiency while pulse-skipping mode allows constant-frequency operation to a lighter load. Forced continuous mode improves output voltage ripple at light load by allowing constant-frequency operation for entire range of output load. This demo board allows phase-locked loop (PLL) synchronization to an external clock by selecting SYNC mode on JP1 and by providing a clock signal on CLKIN turret.
The LTC7103-1 data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with the demo manual for DC2833A. The LTC7103-1 is assembled in the 36 (26) lead QFN package. Proper board layout is essential for maximum thermal and electrical performance. See the data sheet sections for details.
Documentation & Resources
DC2833A - Demo Manual (Rev. 0)1/17/2022
DC2833A - Design Files1/17/2022
Pricing displayed is based on 1-piece.
Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.