Dual-Voltage Level 200-mA LDO for Handheld Devices from Texas Instruments
Texas Instruments has introduced what it says is the first dual-level 200-mA low-dropout linear regulator with simple dynamic voltage scaling in a tiny, five-ball chip-scale package. The flexibility of this device benefits applications that require two levels of output voltage regulation for programming of eFUSE or SIM cards with additional memory, such as wireless handsets, PDAs, smart phones, MP3 players and other handheld devices.
TI’s new TPS728185315 LDO features a very low dropout of 230 mV with an input voltage range of 2.7 V to 6.5 V and fixed output voltages between 0.9 V and 3.6 V. The LDO also comes with EEPROM preset voltage options of 1.85 V and 3.15 V. The LDO enables the designer to set switchable voltages for eFUSE and SIM cards, such as a higher voltage for fuse programming or with detection of the SIM card, and a lower voltage at the end of programming. The designer can switch between two voltages in a finite amount of time without over and undershoots. Dynamic voltage scaling also helps reduce leakage currents in sub-micron multimillion transistor processors used extensively in portable applications, such as TI’s ultra-low power MSP430 microcontrollers.
An integrated precision bandgap and error amplifier provides an overall 2.5 percent accuracy over load, line and temperature extremes. The TPS728185315 provides a high power-supply rejection ratio (PSRR) over a wide frequency range of up to 1 MHz, fast 160 µs start-up time and excellent line and load transient response. The device is fully specified over a temperature range of -40º C to 125º C.