Power ICs Debut as High-side and Low-side Smart Switch Solutions
A slew of high-side and low-side smart switch chips have emerged, offering interesting alternatives for a variety of automotive and industrial use cases.
In applications where high power loads need to be controlled, a common debate is whether to use a high-side or a low-side switch. While both come with their merits, the choice between the two will often come down to the specifics of the application and the priorities of the designer.
Regardless of the choice, safety, reliability, and performance are amongst the most important specifications. For this reason, companies have begun creating more “intelligent” switching solutions, ones that integrate safety and control functionality into the circuit.
Intelligent power switch ICs are important for controlling the drive of the inductive loads of motors, and other devices used in applications such as industrial control. Image used courtesy of Toshiba
This week saw many such intelligent switches reach the market, coming from the likes of Rohm, Toshiba, and STMicroelectronics (ST). In this article, we’ll take a look at each company’s new offerings to see the state of the industry and what switching solutions are available on the market.
Rohm’s Low-side Switch
Earlier this week, Rohm Semiconductor released its new generation of intelligent low-side switches for automotive and industrial applications. The new products, the BV1LExxxEFJ-C and BM2LExxxFJ-C series, are intelligent low-side devices that can switch currents for any type of resistive, capacitive, or inductive loads.
The products are considered “intelligent” because they are designed with integrated over-temperature, over-current, and overvoltage protections, built-in diagnostic features, and microcontroller feedback.
Block diagram of the BV1LE040EFJ-C. Image used courtesy of from Rohm
According to Rohm, these devices are also the industry's first to combine heat suppression with low ON resistance by optimally controlling the number of current-carrying channels using proprietary TDACC technology.
Some important specifications for these devices are on-resistances ranging from 40 mΩ to 250 mΩ and output currents up to 17.5 A.
Toshiba’s Switching Solutions
Also earlier this week, Toshiba announced a pair of intelligent power switches for industrial applications. The new products are the 8-channel high-side switch TPD2015FN and the 8-channel low-side switch TPD2017FN.
Both of these products leverage Toshiba’s proprietary analog consolidation process which allows them to achieve an output stage on-resistance of 400 mΩ, a number that marks a 50% improvement over previous offerings. Both devices offer a power dissipation specification of 1.8 W, internal current limiting, and protection in the form of thermal and overcurrent shutdown features.
Block diagram of the TPD2015FN. Image used courtesy of Toshiba
According to Toshiba, these switches were designed for industrial switching use cases including inductive loads such as motors, solenoids, and lamps. To meet the needs of high-stress industrial applications, each device features a maximum operating temperature of 110°C, which is 25°C higher than current offerings. Additionally, the devices come in an SSOP30 package which is significantly smaller than previous generation switches from Toshiba.
STMicro’s Automotive-centric Devices
Finally, ST also joined the party this week with its own release of high-side drivers for automotive applications. The new lineup consists of five single-channel drivers, VN9004AJ, VN9006AJ, VN9008AJ, VN9012AJ, VN9016AJ, four dual-channel drivers, VND9008AJ, VND9012AJ, VND9016AJ, and VND9025AJ, and two quad-channel drivers, VNQ9025AJ and VNQ9080AJ.
Despite a large number of releases, each of these drivers shares features such as a PowerSSO-16 package style and on-chip protection features such as load-current limiting, load-dump protection up to 35 V, and limiting of fast thermal transients.
STMicro’s VIPower M0-9 technology. Image used courtesy of STMicro
ST says it has designed these switches using their proprietary VIPower M0-9 technology. The vertical architecture of VIPower chips combines Vertical Double Diffused MOS Power devices with their own integrated temperature and current sensors, allowing for control and protection of automotive devices. With this, ST believes the new drivers can address the need for performance and reliability in automotive applications.