3.0A Ultra Low Dropout Linear Regulator
APPLICATION INFORMATION
TJ3966
Output Adjustment (Adjustable Version)
An adjustable output device has output voltage range of 1.145V to 5.0V. To obtain a desired output
voltage, the following equation can be used with (R1+R2) resistor range of 1kΩ to 100kΩ
⎛
V
⎞
R2
=
R1
⎜
OUT
−
1
⎟
⎝
1.145
⎠
To enhance output stability, a capacitor of 68pF to 100pF can be placed in series with V
OUT
and ADJ.
SENSE Pin
In applications where the regulator output is not very close to the load, the TJ3966 can provide better
remote load regulation characteristics using the SENSE pin. TJ3966 regulates the voltage at the output
pin. Hence, the voltage at the remote load will be lower than the voltage at the output pin as a value of
the voltage drop across the trace series resistance. If the sense option pin is not required, the sense pin
must be connected to the V
OUT
pin. Connecting the sense pin to the remote load will provide regulation
at the remote load because the TJ3966 regulates the voltage at the sense pin when the sense option pin
is used.
Output Capacitor
The TJ3966 requires a proper output capacitance to maintain stability and improve transient response
over current. The ESR of the output capacitor within the limits of 0.5Ω to 10Ω is required. A minimum
capacitance value of 22µF of tantalum or aluminum electrolytic capacitor is recommended. In a case of
ceramic capacitor, a minimum capacitance value of 10µF is required and additional resistance of
minimum 1Ω should be added with the output capacitor in series to maintain its minimum ESR. The
resistance and capacitance have to be varied upon the load current.
VOUT
R2
ADJ
GND
R1
+
22µF
-
OUTPUT
VOUT
R2
ADJ
GND
R1
10µF
OUTPUT
Additional Resistance
Aug. 2010 - Rev. 1.7.1
-
8
-
HTC
HTC [ HTC KOREA TAEJIN TECHNOLOGY CO. ]
