RT9183
Adjustable Operation
The adjustable version of the RT9183 has an output voltage
range of 0.8V to 4.5V. The output voltage is set by the
ratio of two external resistors as shown in Figure 2. The
value of R2 should be less than 80k to maintain regulation.
In critical applications, small voltage drop is caused by
the resistance (RT) of PC traces between the ground pin of
the device and the return pin of R2 (See Figure 5 shown on
next page).Note that the voltage drop across the external
PC trace will add to the output voltage of the device.
Optimum regulation will be obtained at the point where
the return pin of R2 is connected to the ground pin of the
device directly.
(SOP-8 & TO-263-5)
RT9183
V
VIN
EN
VOUT
V
OUT
IN
R
R
1
C
OUT
Enable
0.1uF
ADJ
GND
10uF
C
10uF
C
IN
2
R
T
Figure 5. Return Pin of External Resistor Connection
Referring to Figure 3 the fixed voltage versions for both
SOP-8 and TO-263-5 packages, the ADJ pin is the input
to the error amplifier and MUST be tied the ground pin of
the device directly otherwise it will be in the unstable state
if the pin voltage more than 0.1V with respect to the ground
pin itself.
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DS9183-12 March 2007
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
