SLVS074I January 1983 – July 2022 TL494
The dead-time control input provides control of the minimum dead time (off time). The output of the comparator inhibits switching transistors Q1 and Q2 when the voltage at the input is greater than the ramp voltage of the oscillator. An internal offset of 110 mV ensures a minimum dead time of ∼3% with the dead-time control input grounded. Applying a voltage to the dead-time control input can impose additional dead time. This provides a linear control of the dead time from its minimum of 3% to 100% as the input voltage is varied from 0 V to 3.3 V, respectively. With full-range control, the output can be controlled from external sources without disrupting the error amplifiers. The dead-time control input is a relatively high-impedance input (II < 10 μA) and should be used where additional control of the output duty cycle is required. However, for proper control, the input must be terminated. An open circuit is an undefined condition.