SG1731/SG2731/SG3731

4/90 Rev 1.3 9/99

Microelectronics

Inc.

Copyright

 1999

11861

Western

Avenue

∞

∞

∞

∞

∞

Garden

Grove,

CA

92841

4

(714) 898-8121

∞

∞

∞

∞

∞

FAX: (714) 893-2570

APPLICATION CIRCUITS

FIGURE 2 - PULSE WIDTH MODULATION WITH NO DEADBAND

FIGURE 4

FIGURE 3

In this simple battery-powered position servo, the control supply

and driver supply are both single-ended positive with respect to

ground.

A high torque position servo is obtained by buffering the output

drivers to obtain higher output current.

the lower threshold causes Output B to switch to the HIGH state.

If

±V

±V

If

±V

Threshold crossings are generated by shifting the triangle

waveform up and down with the error voltage (Pin 5). A positive

error voltage will result in a pulse width modulated output at

Driver A (Pin 13). Similarly, a negative error voltage produces a

pulse train at Driver B (Pin 12). Figure 2 illustrates this process

for the case where V

It is important to note that the triangle shifting circuit also

attenuates the waveform seen at C

in a waveform at the PWM comparators with a positive peak of

V

when selecting the values for +V