LDOs Offer Noise-Sensitive Apps With Ultra-Low Noise, High PSRR

Three new families of low-dropout linear regulators (LDOs) provide low noise, high power-supply ripple rejection (PSRR), and fast transient response. These features suit the LDOs for powering noise-sensitive analog circuitry such as RF receivers and transmitters, voltage-controlled oscillators (VCOs), and audio amplifiers. The units support applications with output currents of 500 mA, 1 A, and 1.5 A, like battery-powered Bluetooth-enabled digital still cameras and PDAs. They also support applications that operate from a 5/3.3-V distributed bus, including line cards and high-end audio products. Ultra-low output noise measures 33 mV at 100 Hz to 100 kHz. PSRR levels up to 53 dB at 10 kHz benefit noise-sensitive applications. The TPS795xx (500 mA), TPS796xx (1 A), and TPS786xx (1.5 A) families are available in fixed-output voltages that are adjustable over a range of 1.2 to 5.5 V. The devices are available in a five-pin SOT223-5 or a five-pin DDPAK package. In the SOT223-5 package, the TPS795xx, TPS796xx, and TPS786xx cost $0.96, $1.04, and $1.28 each in 1000-unit quantities.