Evgeniy,
The instantaneous current for each channel clamps at 2A. This means that you can run 8 channels at 50V simultaneously. The specs in the data sheet do expect a 2kohm load however. So 50/50 is 1A peak per channel or 35/50 is 0.7Arms per channel instantaneous. With lower duty cycles, there is more instantaneous current allowed but the device will saturate at 2A anyway.
Thanks,
Chuck Smyth