RP100x

The RP100x has the following features including Supply Current is Typ. 18A;Standby Current is Typ. 0.1A;Dropout Voltage is Typ. 0.13V (IOUT=150mA, VOUT=2.8V);Ripple Rejection is Typ. 75dB (f=1kHz);Temperature-Drift Coefficient of Output Voltage  is Typ. ±30ppm/°C;Line Regulation is Typ. 0.02%/V.

The RP100x Series are CMOS-based voltage regulator ICs with high output voltage accuracy, extremely low supply current, low ON-resistance, and high ripple rejection. Each of these ICs consists of a voltage reference unit, an error amplifier, resistor-net for voltage setting, a current limit circuit, and a chip enable circuit.These ICs perform with low dropout voltage and a chip enable function. The line transient response and load transient response of the RP100xSeries are excellent, thus these ICs are very suitable for the power supply for hand-held communication equipment.The output voltage of these ICs is fixed with high accuracy. Since the packages for these ICs are SOT-23-5 and PLP1612-4, therefore high density mounting of the ICs on boards is possible.In these ICs, phase compensation is made for securing stable operation even if the load current is varied. For this purpose, use a capacitor C2 with good frequency characteristics and ESR (Equivalent Series Resistance).Ceramic capacitors have different temperature characteristics and bias characteristics depending on their dimensions and manufacturers. If the setting voltage is 2.5V or more and the capacitor's dimensions for VOUT equal to 1.0mm by 0.5mm or smaller than that, the capacitance value might be extremely low. As a result, the capacitance might be much less than expected value. In such cases, the operation might be unstable at low temperature. (-20°C or less) In that case, use a larger capacity, or a large dimensions' capacitor. (For example 1.6mm by 0.8mm)

Make VDD and GND lines sufficient. If their impedance is high, noise pickup or unstable operation may result.Connect a capacitor C1 with a capacitance value as much as 1.0F or more between VDD and GND pin, and as close as possible to the pins.Set external components, especially the output capacitor C2, as close as possible to the ICs, and make wiring as short as possible.