On-chip galvanic isolation provides reliable power control

STGAP1S combines proprietary Bipolar-CMOS-DMOS (BCD) process technology with innovations that enable an isolation layer to be grown on-chip to allow even greater system integration. Up to 1500V can be present on the high-voltage rail without interfering with other circuitry, ensuring a level of robustness that makes the device suitable for use in industrial drives, high-power 600 or 1200V inverters, solar inverters, and uninterruptible power supplies.

The STGAP1S is capable of transmitting high-accuracy PWM signals, with signal-propagation delay of 100ns across the isolation layer. The integrated driver stage can sink or source up to 5A, and has a rail-to-rail output that allows negative drive voltages for use with large IGBTs or wide-bandgap power switches, such as silicon-carbide MOSFETs. Common-mode transient immunity in excess of ±50V/ns allows reliable communication across the isolation layer. Separate sink and source outputs enhance design flexibility and help eliminate external components.

The device also has a built-in SPI port, which provides an industry-standard host connection for configuring the control logic and monitoring status on the fly. The STGAP1S allows enhanced system protection and reliability by providing rich digital diagnostics to the host via this interface.

The intelligent driver also integrates an extensive set of protection features that help maximise reliability in harsh industrial environments. These include an active Miller clamp in the power stage to prevent unwanted transistor turn-on, desaturation detection to protect the power switch under short-circuit conditions, collector-emitter overvoltage protection and output two-level turn-off capability to prevent damaging voltage overshoot, and a dedicated sense pin for over-current detection. Over-temperature protection, under-voltage lockout and over-voltage lockout are also provided.

The STGAP1S is packaged as fully integrated and compact SO24W device. Budgetary pricing is from $3 for orders of 1,000 units.