Hi,
I'm working on a battery powered application, using the LM17130 battery from Saft. It has a nominal voltage of 3 V, but will drop a few hundred mV in use (depending on temperature, load etc). This means I will need a DC/DC converter from about 2.2V with an output of +5V. Due to extremely limited space on my circuit board, I like using inductorless charge pumps, and was considering the TPS60140, but I can't seem to find a Spice model for this IC. Is there one? I'm basically making two voltage rails, a +5V with a current draw between 18 and 30mA, and a -5V rail with a current draw between 1 and 11 mA (depending on what sensor I will be using). For the -5V rail I was thinking about using the LTC1751-5 from Linear. I would like to simulate this setup in Spice for two reasons: 1) See if there will be a problem cascading the TPS60140 with the LTC1751-5, and 2) Look at the inrush current and fluctuations in current draw, to make sure it complies with the spec sheet of the LM17130 battery.
I've included a lot more information here than what the subject might indicate, just in case someone has a smarter solution ; ) Btw, small size is paramount, with a required efficiency of 80% or higher. Due to the small size of the PCB, heat might also be an issue.
Thanks!
