Diodes ZXGD3101T8 - Manual (Page 9)

ZXGD3101T8
Issue 4 - January 2009 9 www.zetex.com
© Diodes Incorporated 2009 www.diodes.com
Typical characteristics
Component selection
It is advisable to decouple the ZXGD3101 closely to V
CC
and ground due to the possibility of high
peak gate currents with C1 in Figure 2.
The proper selection of external resistors R
REF
and R
BIAS
is important to the optimum device
operation. Select a value for resistor R
REF
to give a reference current, I
REF
, of ~3mA. The value of
R
BIAS
must then be 0.6 times the value of R
REF
to give a bias current, I
BIAS
, of 1.6 times I
REF
. This
provides a recommended typical offset voltage of -20mV.
External gate resistors are optional. They can be inserted to control the rise times which may help
with EMI issues, power supply consumption issues or dissipation within the part.
R
REF
= (V
CC
-0.7V)/ 0.003
R
BIAS
= (V
CC
-0.7V)/ 0.005
Layout considerations
The Gate pins should be as close to the MOSFET Gate as possible. Also the ground return loop
should be as short as possible. The decoupling capacitor should be close to the V
CC
and Ground
pin, and should be a X7R type.
For more detailed information refer to application note AN54.