These bus buffers feature three-state outputsthat, when enabled, have the low impedancecharacteristics of a TTL output with additionaldrive capability at high logic levels to permitdriving heavily loaded bus lines without externalpullup resistors. When disabled, both outputtransistors are turned off, presenting ahigh-impedance state to the bus so the output willact neither as a significant load nor as a driver. The’125 and ’LS125A devices’ outputs are disabledwhen G is high. The ’126 and ’LS126A devices’outputs are disabled when G is low.