SNLS757B June 2024 – November 2024 TUSB2E221
PRODMIX
The USB2.0 standard defines high-speed microframes that occur every 125μs. Using a patented design, the TUSB2E221 monitors idle conditions within every high-speed microframe. The TUSB2E221 will enter a low power state if the bus is idle for greater than 7.8125μs and will remain in the low power state until the start of the next μSOF. This feature is enabled by default and can be disabled by clearing HOST_FRAME_LP_EN_Px or DEVICE_FRAME_LP_EN_Px bits.
Table 8-4 shows an example of the typical high-speed idle power the TUSB2E221 consumes based on whether or not the frame based low power is enabled. These results assume the TUSB2E221 is in host repeater mode.
HOST_FRAME_LP_EN_Px | 1.8V current (mA) | 3.3V current (mA) |
---|---|---|
0 (Disabled) | 56 | 2.8 |
1 (Enabled) | 12 | 2.0 |