1.5A Ultra Low Dropout Linear Regulator
APPLICATION INFORMATION
TJ3965
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 resistor. The sum of R1 and R2 should be in range
of 1kꢀ to 100kꢀ
V
⎛
⎜
⎞
⎟
OUT
R2 = R1
− 1
1.145
⎝
⎠
To enhance output stability, a capacitor of 68pF to 100pF can be placed in series with VOUT and ADJ.
EN Pin
A CMOS logic level signal at the EN pin will turn-on/off the regulator. If this pin is not used for logic
control, it must be tied to Vin for proper operation. When a pull-up resistor is connected between EN pin
and VEN signal(or VIN line), the resistance should be kept under 10kꢀ.
SENSE Pin
In applications where the regulator output is not very close to the load, the TJ3965 can provide better
remote load regulation characteristics using the SENSE pin. TJ3965 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 VOUT pin. Connecting the sense pin to the remote load will provide regulation
at the remote load because the TJ3965 regulates the voltage at the sense pin when the sense option pin
is used.
Output Capacitor
The TJ3965 requires a proper output capacitance to maintain stability and improve transient response
over current. The ESR of the output capacitor within the limits of 0.5ꢀ to 10ꢀ 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 1ꢀ 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.
Jul. 2010 – Rev. 1.12
- 9 -
HTC
HTC [ HTC KOREA TAEJIN TECHNOLOGY CO. ]
