Ivan Carlos Ribeiro Nascimento

High and low side high voltage switch with over voltage and over current protection

The introduction of monolithic electronics in automotive as well as industrial applications makes switches an ubiquitous building block. In this environment switches need to handle high voltage, high currents densities as well as low power consumption. Cost reduction brought by technology scaling allowed adding safety functions to switches and consequently to improve switches reliability. Current limitation, thermal shutdown, overvoltage and under voltage protections are some of these functionalities. This article review circuit topologies commonly used as switches. A new topology with current limitation and no consumption in stand by operation mode is proposed. Based on this topology, high side and low side switches were integrated in smartMOS™ Freescale proprietary technology. Evaluation results are presented and discussed.

A high-speed low-power CMOS comparator using auto-zero offset cancellation technique

A high-speed, small-area and accurate CMOS comparator for low-power applications is presented. The comparator consists of an offset cancelled input stage using a new auto-zero technique. In particular, this circuit is suitable for portable applications, where, usually, very low-power, compact and high speed circuits are required

EMC-EMI optimized high speed CAN line driver

This paper presents the design techniques employed to minimize the irradiated noise emissions of a high speed controller area network (HSCAN) line driver targeted for automotive and industrial applications. Tradeoffs between this and other architectural approaches are presented, focusing on improved emissions without reducing robustness to EMI aggressions. This approach resulted in a complete CAN interface that does not require discrete filters or RF-chokes, lowering implementation costs while improving performance. The interface was successfully implemented in a 0.8mum BCD technology and experimental results are discussed. Finally, possible developments over the derived techniques are presented

Power management techniques for very low consumption and EMI reduction in automotive applications

An event driven synchronous clock state machine scheme has been developed in BiCMOS technology. The proposed implementation uses a voltage and clock system management approach where the circuit works trigged by events, saving power and reducing EMI. A comparison between standard methods using continuous clock and the proposed implementation is presented. This implementation was used into a high speed CAN transceiver device contributing to low power consumption (96uW in sleep and 120uW in standby operating mode) and achieves low EMI under CAN bus idle condition and during transmission (under 40dBuV in the 1 MHz to 1 GHz range). A theoretical analysis and silicon measurements are presented and discussed.