TPS60211

The TPS6021x step-up, regulated charge pumps generate a 3.3-V ±4% output voltage from a 1.8-V to 3.6-V input voltage. These devices are typically powered by two alkaline, NiCd, or NiMH battery cells or by one primary lithium MnO2 (or similar) coin cell and operate down to a minimum supply voltage of 1.6 V. Continuous output current is a minimum of 100 mA for the TPS60210 and TPS60211, and 50 mA for the TPS60212 and TPS60213, all from a 2-V input.

Three operating modes can be programmed using the SNOOZE\ pin. When SNOOZE\ is low, the device is put into snooze mode. In snooze mode, the device operates with a typical quiescent current of 2 uA while the output voltage is maintained at 3.3 V ±6%. This is lower than the self-discharge current of most batteries. Load current in snooze mode is limited to 2 mA. When SNOOZE\ is high, the device is put into normal operating mode. During normal operating mode, the device operates in the newly developed linskip mode where it switches seamlessly from the power saving pulse-skip mode at light loads to the low-noise constant-frequency linear-regulation mode once the output current exceeds the linskip current threshold of about 7 mA. In this mode, the device operates from the internal oscillator. The device is synchronized to an external clock signal if SNOOZE\ is clocked; thus switching harmonics can be controlled and minimized.

Only four external capacitors are needed to build a complete low-ripple dc/dc converter. The push-pull operating mode of two single-ended charge pumps assures the low output voltage ripple as charge is continuously transferred to the output. All the devices can start with full load current. The devices include a low-battery detector that issues a warning if the battery voltage drops below a user-defined threshold voltage or a power-good detector that goes active when the output voltage reaches about 90% of its nominal value. This dc/dc converter requires no inductors; therefore, EMI of the system is reduced to a minimum, making it easier to use in designs. It is available in the small 10-pin MSOP package (DGS).