The TPSI3050-Q1 isolated switch driver with integrated 10 V gate power supply and the TPSI2140-Q1 isolated switch designed for 1,400 V and 50 mA are used for power supply and signal isolation via a single isolation barrier. They rely on a special concept that improves reliability while significantly reducing solution dimensions and costs compared to existing electromechanical relays and solid-state photo relays. The two devices are the first products in a new solid-state relay portfolio from Texas Instruments, which will also include ICs for high-voltage industrial applications.
“At TI, we are particularly focused on paving new ways for system designers to address complex isolation challenges. Among other things, as the industry moves to 800 V batteries, the goal is to create the conditions for reliable and safe operation of vehicles on the one hand, but also to reduce the space requirements and costs of solutions on the other,” explains Troy Coleman, vice president and general manager of Power Switches, Interface and Lighting at Texas Instruments. The manufacturer achieves these goals primarily by integrating more functionality into its isolation technology.
Across a single isolation barrier, the new solid-state relays can connect and disconnect from a load within microseconds, not milliseconds as with electromechanical relays. This enables safer operation of high-voltage systems in the automotive sector. The TPSI3050-Q1, which offers reinforced insulation up to 5 kVRMS, also lasts ten times longer than electromechanical relays, whose characteristics deteriorate over time. The TPSI2140-Q1, on the other hand, offers basic insulation up to 3.75 kVRMS and can thus achieve more than four times the time-dependent dielectric strength of solid-state relay motor relays.
The solid-state relays combine the power supply and signal transmission in one chip and also make it possible to dispense with at least three components, which significantly reduces the solution dimensions and allows material costs to be cut by up to half. The TPSI3050-Q1, for example, reduces the space requirement by up to 90 % compared to solutions with electromechanical relays by combining an isolated power supply, a digital isolator and a gate driver in one component. In the case of the TPSI2140-Q1, the solution dimensions are reduced by up to 50 % compared to traditional photo relay solutions, as resistors are integrated in addition to a signal field effect transistor and a reed relay can also be dispensed with.
Designed for high-voltage measurements and insulation monitoring, the TPSI2140-Q1 is used in conjunction with a Battery Pack Monitor such as the BQ79631-Q1 to detect insulation faults in 800 V battery management systems faster and more accurately than is possible with solid-state relay photorelays. The TPSI2140-Q1 allows the use of resistors with less than 1 MΩ and can handle over 300% higher avalanche currents than traditional motor relays, contributing to safer human-system interaction.
The TPSI3050-Q1 and TPSI2140-Q1 devices are available exclusively on TI.com in pre-production quantities priced at US$1.99 and US$2.75, respectively (starting at 1,000 units). For evaluation of these products, the TPSI3050Q1EVM and TPSI2140Q1EVM evaluation modules are offered for purchase on www.TI.com at $49 each.