Datasheet

4
5
2
1
3
V
O
V
O
Adjust
V
I
Inhibit
GND
PTR08060W
R
SET
1%, 0.05 W
C
O
C
I
GND
V
I
V
O
GND
UDG-07116
PTR08060W
www.ti.com
SLTS289G AUGUST 2007REVISED MARCH 2013
APPLICATION INFORMATION
ADJUSTING THE OUTPUT VOLTAGE
The V
O
Adjust control (pin 5) sets the output voltage of the PTR08060W product. The adjustment range is from
0.6 V to 5.5 V. 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 pin 3. Table 1 gives the standard external resistor for a
number of common bus voltages, along with the actual voltage the resistance produces.
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 2. Figure 11 shows the placement of the required
resistor.
Table 1. Standard Values of R
SET
for Common Output
Voltages
V
O
(V) R
SET
(k) V
O
(V)
(Required) (Standard Value) (Actual)
5
(1)
0.267 5.018
3.3 0.432 3.327
2.5 0.619 2.501
1.8 0.976 1.802
1.5 1.3 1.500
1.2 1.91 1.210
1 2.87 1.003
0.7 10.7 0.701
(1) The minimum input voltage is 4.5 V or (V
O
/0.83) V, whichever is
greater.
(1) A 0.05-W rated resistor may be used. The tolerance should be 1%, with a temperature stability of 100 ppm/°C (or
better). Place the resistor as close to the regulator as possible. Connect the resistor directly between pins 5 and 3
using dedicated PCB traces.
(2) The V
O
Adjust pin must never be connected directly to GND. The minimum resistance between V
O
Adjust and GND is
limited to 240 .
(3) Never connect capacitors from V
O
Adjust to either GND or V
O
. Any capacitance added to the V
O
Adjust pin will affect
the stability of the regulator.
Figure 11. V
O
Adjust Resistor Placement
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