rev.

page

date

DESCRIPTION: dc/dc converter

3 of 3

02/2008

20050

phone

phone 503.612.2300 fax

fax 503.612.2382

PART NUMBER: VWRAS2 series

Application Notes:

- All of the VWRAS2-SIP Series have been tested

according to the following recommended testing

circuit before leaving the factory. This series should

be tested under load(Figure 3). 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 2).

- NC Terminals

Unless otherwise specified, NC terminals of all series

are used for converter's interior circuit

connection, and are not allowed connection of any

external circuit.

Operating Temp.(

)

C

Temperature Derating Graph

- Input current

Nominal input voltage range. The input

current of the power supply must be sufficient

to the startup current (Ip) of the DC/DC module

(Figure 2)

Input Voltage (V)

Input Voltage

Range

Ip

Figure 3

- Output Load

In order to ensure the product operates

efficiently and reliably, make sure the specified range

of input voltage is not exceeded.

No parallel connection or plug and play.

External Capacitor Table

Single

Vout(VDC)

Cout(uF)

Dual

Vout(VDC)

Cout(uF)

3.3

2200

-

-

5

1000

±560

9820

±9

±470

12

±12

±330

15

±15

±270

24

-

-

±5

820

680

560

470

Table 2

Remote on/off control (see figure 1)

should input current (Ic) exceed 20mA. The Value of R in Figure 1 can be derived as follows:

R= Vc - Vd - 0.65V

Vc= Voltage at control input

Ic

Vd= Diode (D1) voltage drop (.7V voltage drop typical )

Ic= Input Current (5mA recommended disable current)

example 1 : Logic circuit — Apply 5V TTL logic signal on Vc to disable output

R=

5V -0.7V -0.65V

= 730

Ω

Choose 720

Ω resistor

.005A

example 2 : Short Vin to Vc — Apply 12V on Vc to disable output

R=

12V - 0.7V - 0.65V

= 2130

Ω

Choose 2K

Ω resistor

.005A

-