DEMO MANUAL DC1533A LTM8045 Inverting/SEPIC Module Converter with Up to 700mA Output DESCRIPTION Demo circuit DC1533A features the LTM 8045, an inverting/ modifying or installing the appropriate resistors or capaci- SEPIC Module converter delivering up to 700mA of output tor. The LTM8045 data sheet must be read in conjunction current. DC1533A is configured as an inverting converter, with this demo manual to properly use or modify demo but can be easily changed to a SEPIC configuration for circuit DC1533A. non-inverting step-up or step-down functionality. The Design files for this circuit board are available at user adjustable features of the LTM8045 such as output DEMO MANUAL DC1533A QUICK START PROCEDURE Demo circuit DC1533A is an easy way to evaluate the V and GND terminals. See Figure 3 for proper scope OUT performance of the LTM8045. Refer to Figure 1 for the probe technique. proper measurement equipment setup and Figure 2 for 1. Place JP1 in the ON position. the maximum output current versus input voltage, then 2. Connect the power supply (with power off), load, and follow the procedure below: meters as shown in Figure 1. NOTE: Do not hot-plug the V terminal at high input volt- IN 3. After all connections are made, turn on the input power ages. Hot-plugging a power supply through wire leads and verify that the output voltage is 5V. to the demonstration circuit can cause the voltage on the extremely low ESR ceramic input capacitor to ring to NOTE: If the output voltage is too low, temporarily discon- twice its DC value. In order to protect the LTM8045, an nect the load to make sure that the load is not set too high. aluminum electrolytic capacitor with higher ESR is placed 4. Once the proper output voltage is established, adjust at the input terminals. This may protect against some, but the load within the operating range and observe the not all, input transients due to a hot-plugged power supply. output voltage regulation, ripple voltage, efficiency and See Application Note 88 for more details. other parameters. NOTE: When measuring the input or output voltage ripple, NOTE: See the section that follows for instructions to care must be taken to avoid a long ground lead on the convert DC1533A to a 5V SEPIC with a positive V . OUT OUT oscilloscope probe. Measure the input or output voltage ripple by touching the probe tip directly across the V or IN Figure 1. Proper Measurement Equipment Setup dc1533af 2