UCC23525 is a single channel isolated gate driver, with an opto-compatible input stage, that can drive IGBTs, MOSFETs and SiC FETs. It has 5A peak output current capability with max output driver supply voltage of 30V. The inputs and the outputs are galvanically isolated. UCC23525 is offered in an industry standard 6 pin (SO6) package with >8.5mm creepage and clearance. It has a working voltage of 1063-V_RMS, reinforced isolation rating of 5-kV_RMS for 60s and a surge rating of 10-kV_PK. It is pin-to-pin compatible with standard opto isolated gate drivers. While standard opto isolated gate drivers use an LED as the input stage, UCC23525 uses an emulated diode (or "e-diode") as the input stage which does not use light emission to transmit signals across the isolation barrier. The input stage is isolated from the driver stage by TI's proprietary silicon dioxide-based (SiO2) isolation barrier, that not only provides reinforced isolation but also offers superior common mode transient immunity of > 100 kV/us. The e-diode input stage along with silicon dioxide isolation barrier technology gives UCC23525 several performance advantages over standard opto isolated gate drivers. They are as follows:

1. Since the e-diode does not use light emission for its operation, the reliability and aging characteristics of UCC23525 are naturally superior to those of standard opto isolated gate drivers.
2. Higher ambient operating temperature range of 125°C, compared to only 105°C for most opto isolated gate drivers
3. The e-diode forward voltage drop has less part-to-part variation and smaller variation across temperature. Hence, the operating point of the input stage is more stable and predictable across different parts and operating temperature.
4. Higher common mode transient immunity than opto isolated gate drivers
5. Smaller propagation delay than opto isolated gate drivers
6. Due to superior process controls achievable in the SiO2 isolation compared to opto isolation, there is less part-to-part skew in the prop delay, making the system design simpler and more robust
7. Smaller pulse width distortion than opto isolated gate drivers

The signal across the isolation has an on-off keying (OOK) modulation scheme to transmit the digital data across a silicon dioxide based isolation barrier (see Figure 7-1). The transmitter sends a high-frequency carrier across the barrier to represent one digital state and sends no signal to represent the other digital state. The receiver demodulates the signal after advanced signal conditioning and produces the output through a buffer stage. The UCC23525 also incorporates advanced circuit techniques to maximize the CMTI performance and minimize the radiated emissions from the high frequency carrier and IO buffer switching. Figure 7-2 shows conceptual detail of how the OOK scheme works.