rev.

page

date

DESCRIPTION: dc-dc converter

4 of 4

06/2010

20050

phone

phone 503.612.2300 fax

www.v-infinity.com

fax 503.612.2383

PART NUMBER: VESD2-SIP

APPLICATION NOTES:

- Input filtering

To reduce the reflected ripple current and minimize EMI,

especially when the converter input is more than 2” away from

the DC source, it is recommended to connect a low ESR

electrolytic capacitor between Vin and Gnd. The values

suggested are as shown in Table 1. If additional filtering is

required, the capacitance may be increased, or expanded to

an LC network as shown in Figure 1.

Input Voltage

External Input Capacitance

4.7 μF

5 V

12 V

2.2 μF

24 V

1.0 μF

TABLE 1

Vout

External Ouput Capacitance

4.7 μF

5 V

9 V

2.2 μF

12 V

1.0 μF

15 V

0.47 μF

TABLE 2

<Figure 1>

DC

C

L

L

DC

Ｌ

C

C

+Vin

-Vin

+Vout

-Vout

COM

ＲＥＧ

ＤＣ ＤＣ

ＤＣ ＤＣ

ＲＥＧ

ＲＥＧ

REG

DC DC

DC DC

REG

REG

+Vin

+Vin

-Vin

-Vin

+Vout

-Vout

COM

+Vout

-Vout

COM

- Minimum loading

During operation, the minimum output load should not be less

than 10% of the full load, and this product should never

be operated under no load. If the actual output power is very

small, please connect a resistor with proper resistance at the

output end in parallel to increase the load.

- Input Regulation

This converter accepts a narrow input range.

With a semi-regulated design, the converter ’s output voltage

will also change proportionally with the input voltage. To

accept a wider input range and to improve line regulation, an

input regulator can be added as shown in Fig. 2

- Protection

The converter has minimal protection against input over-

voltage or output over-load, and may be permanently damaged

if exposed to these conditions. An input clamping device can

be used for input voltage limiting. An input fuse or an output

fuse also be used to protect against over-loading.

- Dual outputs used as a single output

The +Vout and -Vout can be used to obtain a single output

that is the sum of the two outputs. In this case, the COM pin

shouldn’t be used.

- Output Regulation

An external 3-terminal regulator can be connected to the

output of the converter to achieve full regulation. Make sure

the converter ’s output voltage provides sufficient head room

for the regulator. An additional benefit is that the built-in

protection features in the regulator, such as OCP, OTP, etc,

will protect the converter also. In a complimentory supply, a

negative output regulator must be used to achieve the

negative regulated output.

- Output filtering

An output capacitor is needed to meet output ripple

requirements as shown in Table 2. Output capacitance may be

increased for additional filtering, but should not exeed 10 μF

or expanded to an LC network as in Figure 1.