TCR3U LDO Regulators Toshiba TCR3U LDO Regulators reduce the bias current required to operate LDO regulators at no-load compared with existing products. In addition, these devices have a bypass mode which ensures no sudden increase in bias current when input voltage drops below the preset output voltage level. This issue is a common problem in most typical LDOs. When batteries start depleting, an LDO’s input voltage could drop below the preset output voltage, which would then cause consumption to increase. The TCR3U series bypass mode makes sure this doesn’t happen.