ZSD100
Improved Frequency Control
VCC
ZSD100
RT
VCC
_
SAW
CMOD
GND
Q
RT
Q
COUT
CMOD
COUT
GND
Improved frequency control can be achieved with an external resistor between the RT pin and GND
.
An external resistor reduces the value of the timing capacitors required for the selected operating
frequency and also reduces the ZSD100’s power consumption.
Note: The outputs of the ZSD100 have been designed to avoid cross-conduction in full bridge output
circuits. Large value external timing resistors can lead to a small level of cross-conduction. It is
recommended that external timing resistors are not used with bridge output circuits.
Remote Switching
If the RT pin is switched open-circuit, all internal functions of the IC are shut down.
Logic supply
VCC
ZSD100
RT
VCC
LOGIC
Open
collector
output
_
SAW
CMOD
GND
Q
Q
COUT
CMOD
COUT
GND
Note: A small leakage current in the open collector logic controller will enable the IC. If such leakage
cannot be eliminated, its effect can be easily negated by adding a high value resistor (eg. 100k)
between pin RT and VCC. This resistor will have no effect on frequency control.
Issue 8 - June 2007
© Zetex Semiconductors plc 2007
www.zetex.com