Ricoh Semiconductor Support Centre launches the Ricoh R3119 Series - High Input Voltage Tolerant Voltage Detector

One of the key features of this voltage detector is to reduce current consumption of the high voltage sensing circuit. Traditional voltage detectors require some external resistor divider to decrease the high sensing voltage to a level which can be applied to the voltage detector input. In this way the external circuit consumes a considerable permanent current. R3119 does not require such an external circuit, it senses high voltages directly at its inputs and it consumes less current bringing a significant advantage for battery powered applications such as car accessory applications.

The threshold voltage of the voltage detector is set internally; external parts are not required. It is set in Ricoh's factory at high accuracy by a laser trimming process and has a range from 1.5V to 12V with 0.1V increments. The threshold voltage has a hysteresis to prevent oscillating effects on the output when the sensed voltage crosses the threshold voltage slowly.

R3119 is available in 2 optional versions: one version with an additional Cd pin to connect an external capacitor to set some active reset period on the output. The second version includes an independent Sense input pin separated from the supply voltage pin. It addresses a phenomenon which occurs at the output when sensing near ground voltage level. For example, while decreasing the voltage connected to a shared supply / sense voltage pin, the internal voltage comparator cannot drive the output at values below the minimum operating voltage level. As a result, the output cannot keep its initial logical low level and turns to high by the external pull up resistor. The supply voltage pin of the R3119NxxxE is powered from another source; therefore the sense pin can sense down to ground level and does not show this phenomenon at the output.

With R3119, Ricoh continues to expand its product variety with an extended operating temperature range from -40°C to 105°C, aiming for industrial, car accessories or other markets. This product has an N-Channel Open Drain output and available in a regular SOT23-5 package.

R3119 is in mass production now, samples are available.