42V input window voltage detector monitors both overvoltage and undervoltage

April 20, 2017 // By Nick Flaherty
Ricoh R3152
Ricoh Europe has launched a high-accuracy window voltage detector operating at a supply voltage up to 42V for a wide variety of applications from automotive and industrial to consumer equipment.

The R3152 consists of two voltage detectors each with built-in, highly accurate hysteresis that makes it less sensitive to supply voltage noise and ensures stable operation. This allows a single device to perform window, overvoltage and undervoltage detection, providing a reset signal when the supply voltage exceeds an overvoltage or undervoltage threshold.

Conventional voltage detectors are mostly supervising low-voltage power supplies, the power source for the voltage detector and a processor is shared. In case of a failure or slow start-up of this power source, the voltage detector will fail to operate or become unstable.

The R3152 has the significant advantage of use in a higher supply voltage environment powered directly from automotive batteries and industrial equipment, and functioning independently from the power source for the processor. This provides a more secure supervision and guarantees a proper reset signal. The separated power supply pin from the sense pin, make the voltage detector more flexible to monitor a voltage within the circuit.

The supply current is typically 1.5μA with overvoltage (OV) detection from 2.0V to 5.9V (in 0.01V steps) and undervoltage (UV) detection from 1.6V to 4.8V (again in 0.01V steps).

A built-in voltage regulator stabilizes fluctuation of a car battery, even during a cranking condition. The R3152 monitors for any excessive increase or decrease of the processor supply voltage with high accuracy, thus detecting an operation failure of the system at an early stage. This is important for safety critical automotive applications as it improves safety considerably, and useful for ASIL-B/C systems including ECU, ADAS, and control units including EV inverters and charge controllers.

The 2.9 x 2.8 x 1.1mm SOT-23- 6 package and high withstand voltage of pins are especially designed to prevent any damage to the chip in case short circuit occurs between adjacent pins,and an automotive certified version is also planned.