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APPLICATION INFORMATION

ADJUSTING THE OUTPUT VOLTAGE

PTV12010

GND

GN D

GND

VO

VO Adj

VO

CO

100 mF

(Optional)

RSET

1%, 0.05W

PTV12010L

PTV12010W

SLTS234B – DECEMBER 2004 – REVISED FEBRUARY 2007

The VO Adjust control (pin 8) sets the output voltage of the PTV12010 product. The adjustment range is from

1.2 V to 5.5 V for the W-suffix modules and 0.8 V to 1.8 V for L-suffix modules. The adjustment method requires

the addition of a single external resistor, RSET, that must be connected directly between the VO Adjust and GND

(pin 1 or 2). Table 1 gives the standard value of the external resistor for a number of standard voltages, along

with the actual output voltage that this resistance value provides. For other output voltages, the value of the

required resistor can either be calculated using Equation 1 or simply selected from the range of values given in

Table 3.Figure 11 shows the placement of the required resistor.

Table 1. Standard Values of RSET for Common Output Voltages

PTV12010W

PTV12010L

VO (V)

RSET (kΩ)

VO (V)

RSET (kΩ)

VO (V)

(Required)

(Standard Value)

(Actual)

(Standard Value)

(Actual)

5

0.280

5.009

N/A

N/A

3.3

2.0

3.294

N/A

N/A

2.5

4.32

2.503

N/A

N/A

2

8.06

2.010

N/A

N/A

1.8

11.5

1.801

0.130

1.800

1.5

24.3

1.506

3.57

1.499

1.2

Open

1.200

12.1

1.201

1.1

N/A

N/A

18.7

1.101

1.0

N/A

N/A

32.4

0.999

0.9

N/A

N/A

71.5

0.901

0.8

N/A

N/A

Open

0.800

(1)

A 0.05-W rated resistor may be used. The tolerance should be 1%, with temperature stability of 100 ppm/°C (or

better). Place the resistor as close to the regulator as possible. Connect the resistor directly between pin 8 and pins

1 or 2, using dedicated PCB traces.

(2)

Never connect capacitors from VoAdj to either GND or Vo. Any capacitance added to the VoAdj pin affects the

stability of the regulator.

Figure 11. VO Adjust Resistor Placement

8

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