[FAQ] UCC5881-Q1: What are the new features in UCC5881-Q1?

UCC5881-Q1 is TI’s latest programmable isolated gate driver, offering pin-to-pin compatibility with the exact same package and pinout as UCC5880-Q1. This enables designers to keep their existing software and hardware design unchanged and drop in the new UCC5881-Q1 on the same Printed Circuit Board (PCB). While most functions remain the same as those of UCC5880-Q1, some protection settings have been added to enable higher flexibility for different power modules (IGBT or SiC). These additional settings are:

1. More DESAT thresholds and new programable LEB/deglitch times:

The addition of configurability in UCC5881-Q1 enables the device to enhance its capability of enabling fast detection for any power module, while also preventing nuisance faults  by adjusting parameters, thereby increasing reliability within the system. Below are the additional UCC5881-Q1 DESAT configurations:

2. New internal communication (INT COMM) fault filtering option:

The newly introduced INT COMM fault filtering feature significantly enhances system reliability by eliminating spurious nuisance faults, specifically by filtering out internal lane packet errors. By default, this feature behaves the same as UCC5880-Q1. However, it also offers two configurable settings: COMM_FLT_PKT_COUNT and COMM_FILT_PKT_TH, which allow for customization to meet specific system needs. The COM_FLTPKT_COUNT setting determines the number of packets to check for errors, with available options of 2, 3, 4, 8, 12, 16, 24, or 32 packets. The COMM_FILT_PKT_TH setting determines the

minimum number of corrupted packets that must be detected within a set of checked packets in order to trigger a fault report, the available settings are: 2, 4, 8, 10, 12, 18, or 24 packets.

For example, if the COMM_FILT_PKT_COUNT is set to 8 packets and the COMM_FILT_PKT_TH is set to 2 packets, the UCC5881-Q1 will check for 2 failed packet transfers out of 8. If 2 or more transfers fail, the INT_COMM fault will be asserted, as illustrated in the figure below. By allowing designers to configure these settings, the INT COMM fault filtering feature provides a robust and flexible solution for ensuring reliable communication and minimizing false fault detections.

This enhancement provides improved noise immunity, enabling the system to maintain stable and efficient operation even in extremely noisy environments.

3. Increased availability of secondary ASC (Active Short Circuit) during VCC2 brownout condition:

The updated UCC5881-Q1 features an enhanced fault handling capability. This capability allows it to detect and manage unlatched faults. It enables the use of a secondary ASC after a VCC2 brownout condition. When a brownout condition occurs, the UCC5881-Q1 allows the secondary ASC inputs to control the output even after VCC2 has recovered, even if a UVLO2 fault is still present.  This enhancement provides greater flexibility and reliability, as the system can continue to operate using the secondary ASC inputs, even if a UVLO2 fault has occurred.

4. Setting to disable INN functionality if interlock is not needed:

It is now possible to disable the INN interlock functionality when it is not required. This provides an alternative configuration option, enabling designers to avoid directly tying INN to GND1 during Shoot-Through Protection (STP) events, this feature allows interlock to be enabled in some system modes, and disabled in others, providing more control and flexibility. This can also enable applications utilizing the power stage for active discharge of the DC Link capacitance.