Data Sheet

21

Rev. 1.2 2016-01-11

TLS805B1SJ/LDV

Application Information

6.2.2

Output Pin

An output capacitor is mandatory for the stability of linear voltage regulators.

The requirement to the output capacitor is given in “Functional Range” on Page 9. The graph “Output

Capacitor Series Resistor ESR(CQ) versus Output Current IQ” on Page 15 shows the stable operation range

of the device.

TLS805B1 is designed to be stable with extremely low ESR capacitors. According to the automotive

environment, ceramic capacitors with X5R or X7R dielectrics are recommended.

The output capacitor should be placed as close as possible to the regulator’s output and GND pins and on the

same side of the PCB as the regulator itself.

In case of rapid transients of input voltage or load current, the capacitance should be dimensioned in

accordance and verified in the real application that the output stability requirements are fulfilled.

6.3

Output Voltage Adjust

divider, connected to the adjust pin ADJ, as shown in Figure 7.

The pin ADJ is connected to the error amplifier comparing the voltage at this pin with the internal reference

voltage of typically 1.2 V.

The output voltage can be easily calculated, neglecting the current flowing into the ADJ pin:

(6.1)

with

big resistors makes the current flowing into the ADJ pin non-negligible. In oder to neglect the current flowing

To set the output voltage to 1.2 V, the adjust pin ADJ should be directly connected to the output pin Q.

Take into consideration that an additional error to the output voltage tolerance may be introduced by the

6.4

Thermal Considerations

Knowing the input voltage, the output voltage and the load profile of the application, the total power

dissipation can be calculated:

(6.2)

with

+

------------------- V

ref

×

=

–

() I

Q

×

+

×

=