Application Notes

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Adjusting the Output Voltage of the PTH03060W &

PTH05060W Wide-Output Adjust Power Modules

The Vo Adjust control (pin 4) sets the output voltage of the

PTH03060W and PTH05060W products to a value higher

than 0.8 V. The adjustment range of the PT03060W

(3.3-V input) is from 0.8 V to 2.5 V 1, and the PTH05060W

(5-V input) from 0.8 V to 3.6 V. For an output voltage

other than 0.8 V a single external resistor, Rset, must be

connected directly between the Vo Adjust and GND pins 2.

Table 1-1 gives the preferred 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 the following formula, or

simply selected from the range of values given in Table 1-2.

Figure 1-1 shows the placement of the required resistor.

Rset

= 10 k

Ω ·

0.8 V

– 2.49 k

Ω

Vout – 0.8 V

Figure 1-1; Vo Adjust Resistor Placement

Notes:

1. Modules that operate from a 3.3-V input bus should

not be adjusted higher than 2.5 V.

2. Use a 0.1 W resistor. 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 pins 4 and 7 using dedicated

PCB traces.

3. Never connect capacitors from Vo Adjust to either GND or

Vout. Any capacitance added to the Vo Adjust pin will affect

the stability of the regulator.

0.800

Open

0.825318 k

Ω

0.850

158 k

Ω

0.875104 k

Ω

0.900

77.5 k

Ω

0.92561.5

k

Ω

0.950

50.8 k

Ω

0.97543.2 k

Ω

1.000

37.5 k

Ω

1.02533.1 k

Ω

1.050

29.5 k

Ω

1.07526.6 k

Ω

1.100

24.2 k

Ω

1.12522.1 k

Ω

1.150

20.4 k

Ω

1.17518.8 k

Ω

1.200

17.5 k

Ω

1.22516.3 k

Ω

1.250

15.3 k

Ω

1.27514.4 k

Ω

1.300

13.5 k

Ω

1.32512.7 k

Ω

1.350

12.1 k

Ω

1.37511.4 k

Ω

1.400

10.8 k

Ω

1.42510.3 k

Ω

1.450

9.82 k

Ω

1.4759.36 k

Ω

1.50

8.94 k

Ω

1.55

8.18 k

Ω

1.60

7.51 k

Ω

1.656.92 k

Ω

1.70

6.4 k

Ω

1.755

.93 k

Ω

1.80

5.51 k

Ω

1.855

.13 k

Ω

1.90

4.78 k

Ω

1.954.47 k

Ω

Vout (Standard)

Rset (Pref’d Value)

Vout (Actual)

3.3 V 1

698

Ω

3.309V

2.5 V

2.21 k

Ω

2.502 V

2 V

4.12 k

Ω

2.010 V

1.8 V

5.49 k

Ω

1.803 V

1.5 V

8.87 k

Ω

1.504 V

1.2 V

17.4 k

Ω

1.202 V

1 V

36.5 k

Ω

1.005 V

0.8 V

Open

0.8 V

Table 1-1; Preferred Values of Rset for Standard Output Voltages

PTH03060W & PTH05060W

Table 1-2; Output Voltage Set-Point Resistor Values

Va Req’dRset

Va Req’dRset

2.00

4.18 k

Ω

2.053.91 k

Ω

2.10

3.66 k

Ω

2.153.44 k

Ω

2.20

3.22 k

Ω

2.253.03 k

Ω

2.30

2.84 k

Ω

2.352.67 k

Ω

2.40

2.51 k

Ω

2.452.36 k

Ω

2.50

2.22 k

Ω

2.55

2.08 k

Ω

2.60

1.95 k

Ω

2.651.83 k

Ω

2.70

1.72 k

Ω

2.751.61 k

Ω

2.80

1.51 k

Ω

2.851.41 k

Ω

2.90

1.32 k

Ω

2.951.23 k

Ω

3.00

1.15 k

Ω

3.051.07 k

Ω

3.10

988

Ω

3.15914

Ω

3.20

843

Ω

3.25775

Ω

3.30

710

Ω

3.35647

Ω

3.40

587

Ω

3.455

29

Ω

3.50

473

Ω

3.55

419

Ω

3.60

367

Ω

V

IN

C

IN

330 µF

(Required)

C

OUT

330 µF

(Optional)

GND

V

OUT

V

o Sense

R

SET

0.1 W

1 %

PTH05060W

1

10

4

5

6

2

3

98

7