Datasheet

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APPLICATION INFORMATION
ADJUSTING THE OUTPUT VOLTAGE
V
I
+
C
330 F
(Optional)
O
m
C
560 F
(Required)
I
m
+
GND
V
O
V Sense
O
R
SET
1%
0.1W
PTH12010x
1
10
4
5
62
3
9
7
GND
8
NOTES
PTH12010W , PTH12010L
SLTS205G – JUNE 2003 – REVISED FEBRUARY 2007
The V
O
Adjust control (pin 4) sets the output voltage of the PTH12010 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, R
SET
, that must be connected directly between the V
O
Adjust and GND
pins.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 R
SET
for Standard Output Voltages
PTH12010W PTH12010L
V
O
(Required) R
SET
V
O
(Actual) R
SET
V
O
(Actual)
5 V 280 Ω 5.009 V N/A N/A
3.3 V 2.0 k Ω 3.294 V N/A N/A
2.5 V 4.32 k Ω 2.503 V N/A N/A
2 V 8.06 k Ω 2.010 V N/A N/A
1.8 V 11.5 k Ω 1.081 V 130 Ω 1.800 V
1.5 V 24.3 k Ω 1.506 V 3.57 k Ω 1.499 V
1.2 V Open 1.200 V 12.1 k Ω 1.201 V
1.1 V N/A N/A 18.7 k Ω 1.101 V
1.0 V N/A N/A 32.4 k Ω 0.999 V
0.9 V N/A N/A 71.5 k Ω 0.901 V
0.8 V N/A N/A Open 0.800 V
Figure 11. V
o
Adjust Resistor Placement
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 pins 4 and 7 using dedicated PCB traces.
2. Never connect capacitors from V
O
Adjust to either GND or V
O
. Any capacitance added to the V
O
Adjust
pin affects the stability of the regulator.
8
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