■ TECHNICAL NOTES
When using these ICs, consider the following points:
Phase Compensation
In these ICs, phase compensation is made for securing stable operation even if the load current is varied. For this purpose, use
a capacitor COUT with good frequency characteristics and ESR (Equivalent Series Resistance).
We use Ceramic Capacitors for evaluation of these ICs.
Recommended Capacitors; GRM40X5R225K6.3 (Murata)
GRM40-034X5R335K6.3 (Murata)
GRM40-034X5R475K6.3 (Murata)
(Note: When the additional ceramic capacitors are connected to the output pin with an output capacitor for phase
compensation, the operation might be unstable. Because of this, test these ICs with as same external components as ones to be
used on the PCB.)
PCB Layout
Make VDD and GND lines sufficient. If their impedance is high, noise pickup or unstable operation may result. Connect a
capacitor with a capacitance value as much as 2.2µF or more between VDD and GND pin, and as close as possible to the pins.
Set external components, especially the output capacitor, as close as possible to the ICs, and make wiring as short as possible.
Rev. 1.11
- 7 -
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
