DEMO MANUAL DC2154A LTM8056 58V , 48V Buck-Boost IN OUT Module Regulator DESCRIPTION Demonstration circuit 2154A features the LTM 8056, a Input current monitoring and regulation requires the in- buck-boost Module regulator that accepts input volt- stallation of a current sense resistor. The SVIN input for ages lower, higher or the same as the output, but is also controller power can be made a diode-OR of power V IN highly efficient due to its four-switch architecture. The and the output voltage to extend the operating range of output for DC2154A is 24V and the input voltage range power V to lower voltages. There are places to mount IN is 7V to 58V. The maximum output current is 3A and the optional components that add an LC input filter and also a switching frequency is 525kHz. unity gain buffer to operate multiple DC2154As in parallel. DC2154A supports the adjustable and controllable features The LTM8056 data sheet must be read in conjunction with of the LTM8056 including output voltage and current this demo manual to properly use or modify DC2154A. regulation, switching frequency, RUN threshold, soft-start Design files for this circuit board are available at period, synchronization and reverse inductor current in- DEMO MANUAL DC2154A BOARD PHOTO QUICK START PROCEDURE the V or V capacitors. See Figure 3 for proper scope To use DC2154A to evaluate the performance of the IN OUT probe technique. Solder terminals near the input or output LTM8056, refer to Figure 1 for the proper measurement capacitors, if necessary. equipment setup, Figure 2 for the maximum output current versus input voltage and then follow the procedure below: 1. Connect the RUN terminal to ground with a clip-on lead. Connect the power supply (with power off), load, and NOTE: Do not hot-plug the V terminal at high input IN meters as shown in Figure 1. voltages. The absolute maximum voltage on V is 60V IN and hot-plugging a power supply through wire leads to 2. After all connections are made, turn on the input power the demonstration circuit can cause the voltage on the and verify that the input voltage is between 7V and 58V. extremely low ESR ceramic input capacitor to ring to 3. Remove the clip-on lead from RUN. Verify that V OUT twice its DC value. In order to protect the LTM8056, an is24V. aluminum electrolytic capacitor with higher ESR is placed at the input terminals. This may protect against some, but NOTE: If V is too low, temporarily disconnect the load OUT not all, input transients due to a hot-plugged power supply. to make sure that the load is not set too high. See Application Note 88 for more details. Once the proper output voltage is established, adjust the NOTE: When measuring the input or output voltage ripple, input voltage and load within the operating range and care must be taken to avoid a long ground lead on the observe the output voltage regulation, ripple voltage, ef- oscilloscope probe. Measure the input or output voltage ficiency and other parameters. ripple by touching the probe tip directly to terminals across dc2154af 2