Datasheet
LDCL015XX, LDCL015XX33 Application information
Doc ID 022166 Rev 2 11/16
7 Application information
7.1 General operation
The main feature of the LDCL015 is its capability to operate with or without input and output
capacitors. To achieve this goal, the LDO architecture is based on a robust operational
amplifier which has sufficient phase margin over all positions of the output capacitor pole.
The LDCL015 can operate with a 100 nF output capacitor, but also without an output
capacitor, showing in both configurations good supply voltage rejection, stability and
dynamic performance.
7.2 Thermal and short-circuit protection
The LDCL015 is self-protected from short-circuit condition and overtemperature. When the
output load is higher than that supported by the device, the output current is increased until
the limit of 220 mA (typ) is reached, at which point the current is kept constant even when
the load impedance is zero.
Thermal protection acts when the junction temperature reaches 170 °C. At this point the IC
is completely shut down. As soon as the junction temperature falls back below 150 °C, the
device begins operating again.
To calculate the maximum power that the device can dissipate while keeping the junction
temperature below the T
J-OP
, the following formula is used:
Equation 1
P
DMAX
= (125-T
AMB
) / R
thJA
7.3 Output voltage setting for ADJ version
In the adjustable version, the output voltage can be set from 0.8 V up to the input voltage,
minus the voltage drop across the pass transistor (dropout voltage), by connecting a resistor
divider between the ADJ pin and the output, thus allowing remote voltage sensing.
The resistor divider should be selected using the following equation:
Equation 2
V
OUT
= V
ADJ
(1 + R1 / R2), with V
ADJ
= 0.8 V (typ.)
It is recommended to use resistors with values in the range of 10 kΩ to 50 kΩ. Lower values
can also be suitable, but will increase current consumption.
7.4 Enable pin
The LDCL015 features an enable function. When the EN voltage is higher than 2 V, the
device is ON; if it is lower than 0.8 V, the device is OFF.
In shutdown mode, the current consumption is lower than 1 µA.
The EN pin does not have an internal pull-up, which means that it cannot be left floating if it
is not used.