Regulated 3.3-V Low Ripple Charge Pump With Power Good Indicator

The TPS6020x Step-up regulated Charge Pumps generate a 3.3-V 4% output voltage from a 1.8-V to 3.6-V input voltage. The devices are typically powered by two Alkaline, NiCd or NiMH battery cells and operate down to a minimum supply voltage of 1.6 V. Continuous output current is a minimum of 100 mA for the TPS60200 and TPS60201 and 50 mA for the TPS60202 and TPS60203 all from a 2-V input. 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 current is continuously transferred to the output.
The devices operate in the newly developed LinSkip mode. In this operating mode, the device 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 threshold of about 7-mA. Even in pulse-skip mode the output ripple is maintained at a very low level because the output resistance of the Charge Pump is still regulated.
Three operating modes CAN be programmed using the EN pin. EN = low disables the device, shuts down all internal circuits and disconnects the output from the input. EN = high enables the device and programs it to run from the internal Oscillator The devices operate synchronized to an external Clock signal if EN is clocked; thus switching harmonics CAN be controlled and minimized. 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.
Device options with either a low-battery or power good detector are available. This DC/DC converter requires no inductors therefore EMI of the system is reduced to a minimum. It is available in the small 10-pin MSOP package (DGS).
By Texas Instruments