T6319A Taiwan Memory Technology, T6319A Datasheet - Page 5

• Manufacturer Part Number: T6319A
• Description: High Efficiency 2X charge Pump
• Manufacturer: Taiwan Memory Technology

tm
TE
CH
T6319A
Capacitor Selection
The input capacitor stabilizes the input voltage and minimizes the peak current ripple from the
source. The value of the capacitor depends on the impedance of the input source used. Small ESR
(Equivalent Series Resistance) ceramic capacitor with value of 1uF to 10uF would be suitable.
The output capacitor is used to sustain the output voltage when the internal MOSFET is switched on
and smoothing the ripple voltage. The larger the output ripple, the larger the line regulation, which
means the LED current changes if the input voltage changes. Low ESR capacitor should be used to
www.DataSheet4U.com
reduce output ripple voltage. Use a 1uF to 10uF ceramic output capacitor with about 50mOhm to
150mOhm ESR to provide stable switching and good line regulation.
Layout Considerations
High switching frequencies make PC board layout a very important part of design. Good design
minimizes excessive EMI and voltage gradients in the ground plane, both of which can result in
instability or regulation errors.
Input filter capacitor, and output filter capacitor as close to the device as possible, and keep their
traces short, direct, and wide to reduce power loss so as to improve efficiency. Connect their ground
pins at a single common node in a star ground configuration, or at a full ground plane.
The output capacitor should be placed close to the output terminals to obtain better smoothing effect
on the output ripple.
TM Technology Inc. reserves the right
P. 5
Publication Date: MAY. 2007
to change products or specifications without notice.
Revision: A