SLVSBD1B December 2012 – August 2025 TPS65175
PRODUCTION DATA
Flying capacitors
A flying capacitor in the range 100 nF to 1 μF is suitable for most applications. Larger values experience a smaller voltage drop by the end of each switching cycle, and allow higher output voltages and/or currents to be achieved. Smaller values tend to be physically smaller and a bit cheaper. For best performance, it is recommended to include a resistor of a few ohms (1 Ω is a good value to start with) in series with the flying capacitor to limited peak currents occurring at the instant of switching.
Storage capacitors
For lowest output voltage ripple, low-ESR ceramic capacitors are recommended. The actual value is not critical and 1 μF to 10 μF is suitable for most applications. Larger capacitors provide better performance in applications where large load transient currents are present.
Transistor placed on the input (Figure 8-1)
A collector capacitor is required. A range of 100 nF to 1μF is suitable for most applications. Larger values are more suitable for high current applications but can affect stability if they are too big.
Transistor placed on the output (Figure 8-1)
An emitter capacitor is required. A range of 1μF to 10 μF is suitable for most applications. A smaller ratio between the emitter capacitor and the output capacitor is better for startup reason. A combination of COUT = 4.7 μF, CFLY = 220 nF, (and CEMITTER = 4.7 μF) is a good starting point for most applications (the final values can be optimized on a case-by-case basis if necessary).