Wall Industries, Inc.

Rev D

MPQ SERIES

Up to 125 Watts, Quarter-Brick DC/DC Converters

02/15/2013

Wall Industries, Inc. • 5 Watson Brook Road, Exeter, NH 03833 • Tel: 603-778-2300 • Toll Free: 888-597-9255 • Fax 603-778-9797

website: www.wallindustries.com • e-mail: sales@wallindustries.com

Page 6 of 7

Remote ON/OFF

These converters have the ability to be remotely turned ON or OFF. The series may be ordered Active-High or Active-Low (place the suffix “R” at the

end of the part number). Active-High means that a logic high at the ENABLE pin will turn ON the supply (Figure 1). With Active-High, if the ENABLE

pin is left floating, the supply will be enabled. Active-Low means that a logic low at the ENABLE pin will turn ON the supply (Figure 2). With Active-

Low, if the ENABLE pin is left floating, the supply will be disabled. If remote On/Off is not used on an Active-Low supply, short the Enable pin to –Vin.

Figure 1: Active High

Figure 2: Active Low

Output Voltage Trim

The output is adjustable from ±10% of the output voltage. To adjust the output voltage low, place a resistor between the TRIM and -SENSE pins

(Figure 3). To adjust the output voltage high, place a resistor between the +SENSE and TRIM pins (Figure 4). The value of the TRIM resistor with

respect to the desired output voltage can be found in Table 1 or derived from the following equations:

(

)

100

Trim

Percent

∆%

where

)

k

(in

11

.

5

%

511

%

5

.

2

100

%

11

.

5

)

k

(in

11

.

5

%

511

/

/

⋅

−

=

=

Ω

−

∆

−

∆

⋅

+

∆

⋅

⋅

=

Ω

−

∆

=

−

+

−

+

−

−

o

onom

o

onom

High

Trim

Low

Trim

V

V

V

V

R

R

Figure 3: Trim Low

Figure 4: Trim High

Table 1: Trim Resistor Values (in kΩ)

TRIM Low

TRIM High

Percent Trim

Vout

RLow

Vout

RHigh

1%

4.950

500.78

5.050

511.00

2%

4.900

245.28

5.100

255.50

3%

4.850

160.11

5.150

170.33

4%

4.800

117.53

5.200

127.75

5%

4.750

91.98

5.250

102.20

6%

4.700

74.95

5.300

85.17

7%

4.650

62.78

5.350

73.00

8%

4.600

53.66

5.400

63.88

9%

4.550

46.56

5.450

56.78

10%

4.500

40.88

5.500

51.10

Note: While decreasing the output voltage, the maximum output

current remains the same, and while increasing the output

voltage, the output current is reduced to maintain the total

output power

.