PTH12030W/L
www.ti.com
SLTS211F–MAY 2003–REVISED FEBRUARY 2007
APPLICATION INFORMATION
ADJUSTING THE OUTPUT VOLTAGE
The VO Adjust control (pin 5) sets the output voltage of the PTH12030W/L. The adjustment range is 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 VOAdjust and GND
pins(1). 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 required resistor can
either be calculated using Equation 1, or simply selected from the range of values given in Table 3. Figure 9
shows the placement of the required resistor.
Table 1. Standard Values of RSET for Standard Output Voltages
PTH12030W
PTH12030L
VO (Required)
5 V
RSET
280 Ω
2 kΩ
VO (Actual)
5.009 V
3.294 V
2.503 V
2.01 V
1.081 V
1.506 V
1.2 V
RSET
N/A
VO (Actual)
N/A
3.3 V
2.5 V
2 V
N/A
N/A
4.32 kΩ
8.06 kΩ
11.5 kΩ
24.3 kΩ
Open
N/A
N/A
N/A
N/A
N/A
1.8 V
1.5 V
1.2 V
1.1 V
1 V
130 Ω
3.57 kΩ
12.1 kΩ
18.7 kΩ
32.4 kΩ
71.5 kΩ
Open
1.8 V
1.499 V
1.201 V
1.101 V
0.999 V
0.901 V
0.8 V
N/A
N/A
N/A
0.9 V
0.8 V
N/A
N/A
N/A
N/A
VOSense
13 12 11
6
Sense
VO
8, 9
V
PTH12030x
O
Adjust
5
GND GND
1, 3, 7 10
CO
330 mF
(Optional)
RSET, 1 %
GND
GND
Figure 9. Vo Adjust Resistor Placement
NOTES
1. RSET: Use a 0.05 W resistor with a tolerance of 1% and temperature stability of 100 ppm/°C (or better).
Connect the resistor directly between pins 5 and 7, as close to the regulator as possible, using dedicated
PCB traces.
2. Never connect capacitors from VO Adjust to either GND or VO. Any capacitance added to the VO Adjust
pin affects the stability of the regulator.
8
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