Microchip Technology Inc.’s TC1219 (switching frequency at 12 kHz) and TC1220 (switching frequency at 35 kHz) are inverting charge pump voltage convert- ers that are specified using rather large capacitors (10 µF for the TC1219 and 3.3 µF for the TC1220). These capacitor sizes allow the designer the luxury of a reasonably low output resistance (25Ω typical) capable of driving load currents up to 25 mA. However, these larger-value external capacitors are more expensive and require additional printed circuit board (PCB) space than their smaller-valued counterparts. Additionally, the time required to shutdown these charge pump convert- ers becomes longer with larger-value external capaci- tors and in certain higher-speed applications, this unfortunate feature can be devastating. AN813 Applying the TC1219/TC1220 Inverting Charge Pumps with Small External Capacitor Values Author: Patrick Maresca Connect to VIN for Microchip Technology Inc. +5V DC Measurements 2 Connect to External 6 VIN Func. Gen. For Tuning ……