New Voltage Detector Suitable for Use in Automotive & Industrial Equipment Enhances Safety

Ricoh Electronics Devices Co., Ltd. has launched the R3500 series, a 4-channel high-voltage window voltage detector^*1 suitable for use in products required to meet functional safety standards.

Today’s automotive and industrial equipment must meet increasing needs for functional safety and is required to have high-accuracy monitoring functions on supply voltages for MCUs and SoCs. Additionally, voltage monitoring functions must cover more power supplies than ever.

To meet the needs above, the R3500 series has four voltage detectors in a single chip. Each detector can monitor not only under-voltage but also over-voltage of a targeted power supply, which contributes to high detection coverage. The detection voltage values are settable in 0.01 V step and will help construct a high-accuracy voltage monitoring circuit optimized for your system. Also, voltage monitoring systems combining the R3500 series with the R3152 series or the R3154 series, our conventional 1-channel voltage detector ICs, can cover a wider range of applications.

A typical voltage detector has possibility of failing to operate properly when the voltage it monitors fluctuates largely, because it uses the monitored voltage stepped down to 3.3 V or 5 V as its source voltage. To ensure stable voltage monitoring even under large voltage fluctuations, the R3500 series has a high operating voltage range up to 42 V and separates its voltage monitoring pins from the power supply pin.

For higher security, the R3500 series has a fault-diagnostic function which checks if the IC itself can operate properly, as the new product is designed to enhance safety of systems. This function will help reduce latent faults.

*1 Window Voltage Detector: Type of voltage detector which monitors both under- and over-voltage of targeted voltage

R3500 Series (HSOP-18)

Key Features of R3500 series

1. Under- and Over-voltage Monitoring and Brief Fault-diagnostic Function

The new IC can detect both under-voltage and over-voltage of a power supply, and therefore can reduce the number of voltage detectors added to meet functional safety needs.

The R3500 series is equipped with four SENSE pins and four output pins and can have four different detection voltage values simultaneously. Also, the new product can cover a wider variety of systems by combining it with the R3152 series and the R3154 series, our conventional 1-ch voltage detectors.

Also, a brief fault-diagnostic function can be achieved with its manual reset function which enables checking if the voltage detection operates properly.

2. High Detection Voltage Accuracy and High Hysteresis Accuracy

The new IC achieves high detection voltage accuracy of ±0.5% (Ta=25°C) and -1.25%/+0.75% (-40°C to 125°C), and high hysteresis accuracy of typical 0.5% (max. 0.75%). The detection voltage values can be set in 0.01 V step, so it contributes to constructing high-accuracy power supply monitoring systems optimized for wide variety of applications.

3. High-voltage Input Voltage Pin and Separated SENSE Pins

With operating voltage up to 42 V and maximum rated voltage of 50 V, the R3500 can receive the source voltage directly from a high-voltage power supply such as batteries used in automobiles or industrial equipment. Separation of SENSE pins from the source voltage pin enables the new detector IC to detect abnormality stably even when the target voltage becomes over- or under-voltage.

4. Pin Configuration Preventing Short between Adjacent Pins

The R3500 series adopts HSOP-18 package considering pin assignment for preventing a short between adjacent pins, and thus enables further safety design.