DEMO MANUAL DC1963A LT8310 48V to 12V/6A IN Isolated Forward Converter Description Demonstration circuit 1963A is a resonant reset forward The DC1963A takes advantage of the LT8310s input converter featuring the LT 8310 controller. undervoltage and overvoltage protection to shutdown the system when the input voltage is outside of the set limits. This circuit was designed to demonstrate the high level The DC1963A also has precise overcurrent protection of performance, and small solution size attainable using that allows for continuous operation under short circuit the LT8310. It operates at a 250kHz switching frequency, conditions. The low power dissipation under a short circuit and regulates a 12V, 6A output from a 36V to 72V input condition ensures high reliability even during a prolonged source, making it well suited for telecom, industrial, and output voltage short circuit. other applications. Table 1 summarizes the performance of the DC1963A. The LT8310 data sheet gives a complete description of the part, operation and application information. The data The LT8310 is a constant-frequency forward converter sheet must be read in conjunction with this quick start controller with a low side N-channel MOSFET gate driver. guide for demo circuit 1963A. Output regulation is handled on the secondary side by the LT1431, which is an adjustable shunt voltage regulator Design files for this circuit board are available at providing feedback to the primary side via an opto-coupler. DEMO MANUAL DC1963A Quick s p D Demonstration circuit 1963A is easy to set up to evalu- NOTE: If there is no output, temporarily disconnect the ate the performance of the LT8310. Refer to Figure 1 for load to make sure that the load is not set too high. proper measurement equipment setup and follow the 4. Once the proper output voltage is established, adjust procedure below: the input voltage and load current within the operating 1. With power off, connect the input power supply to the range and observe the output voltage regulation, ripple board through +V and V terminals. Connect the voltage, efficiency and other parameters. IN IN load to the terminals +V and V on the board. OUT OUT NOTE: When measuring the input or output voltage ripples, 2. Turn on the power at the input. care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the input or output voltage NOTE: Make sure that the input voltage does not exceed ripple by touching the probe tip directly across the +V IN 72V. Input voltages lower than 36V can keep the converter and V , or +V and V terminals. See Figure 2 for IN OUT OUT from turning on due to the undervoltage lockout feature proper scope probe technique. of the LT8310. 3. Check for the proper output voltages. The output should be regulated at 12V (2%). dc1963af 2 ure roce tart