12

SCD5031 Rev B

Pre

lim

in

ar

y

OUTPUT DRIVE

Dual push-pull outputs OutA and OutB are provided for driving off chip switches. The output stages are identical:

◆

Totem Pole configuration

◆

Break-before-make switching to prevent harmful cross-conduction spikes

◆

Separate positive and negative supply connections to decouple power stage and sensitive logic

◆

Near rail-to-rail voltage swing

◆

±1A maximum peak current capability (capacitive load)

The outputs have two modes of control depending on whether the 50% toggle option is selected. In the case where the

50% pin is logic low, the outputs are in-phase with each other and the duty cycle is free to take on any value up to 100%.

However, when the 50% pin is asserted high (logic ''1''), the outputs switch from the in-phase condition to the logical

complement (out-of-phase) of each other and the duty cycle is limited to a maximum of 50%.

AUXILIARY AMPLIFIER

The chip includes an uncommitted op-amp with independent shutdown feature for use in any user-defined application.

Some possibilities are:

◆

Signal conditioning of an isolated configuration feedback voltage

◆

Implementation of more sophisticated compensation networks for control loop optimization

The Auxiliary amplifier has a unity gain bandwidth greater than 1MHz and an open loop gain greater than 100dB. The

ENAUX pin is active high such that a logic ''1'' enables the amplifier and logic ''0'' disables it. The amplifier has near

rail-to-rail capability on both the input and output.

FIGURE 8 – Output Saturation Characteristics at +25°C

Voltage

110

V

.25

.20

.15

.10

0

.30

100

Current mA

.05

Sink

Source