cui.com
date 11/01/2012 │ page 4 of 5CUI Inc │ SERIES: VWRBT1 │ DESCRIPTION: DC-DC CONVERTER
APPLICATION NOTES
-All of the VWRBT1-SMT Series have been tested according to the following recommended testing circuit before leaving the factory.
This series should be tested under load (Figure 1). If you want to further decrease the input/output ripple, you can increase
capacitance properly or choose capacitors with low ESR. However, the capacitance should not be too high (Table 1).
1. Recommended circuit
It is best to test with full load and not to test without load. To further reduce output ripple, you may increase the external capacitor,
choose a capacitor with low ESR, or add external inductor to the circuit as shown above.
CS Pin
By connecting a low ESR capacitor between this terminal and the pin-7 (Figure 1). the output ripple and noise may be further im-
proved. Generally, the capacitance is no greater than 47uF.
General: Cin & Lin: 22uF & 12uH
CS: 47uF(max) Cout:100uF
2. Input current
Nominal input voltage range. The input current of the power supply must be suffi cient to the startup current (Ip) of the DC/DC mod-
ule (Figure 2)
3. Output Load
In order to ensure the product operates effi ciently and reliably, make sure the specifi ed range of input voltage is not exceeded.
4. NC Terminals
Unless otherwise specifi ed, NC terminals of all series are used for converter's interior circuit connection, and are not allowed connec-
tion of any external circuit.
+Vin
-Vin
+Vout
COM
DC
C
L
L
DC
L C
C
-Vout
Figure 1
Vout Cout/μF (max) C
s
μF
3.3 V 1000 47
5 V 470 47
9 V 330 47
12 V 150 47
15 V 100 47
Table 1
Figure 2
No parallel connection or plug and play.
For more information, please visit the product page.
