4.1

Voltage regulator

The voltage regulator uses a p-channel MOS transistor as a regulating element. With this structure, a very low

dropout voltage at current up to Io = 200 mA is obtained. The high-precision of the output voltage (±2%) is

obtained with a pre-trimmed reference voltage. The voltage regulator automatically adapts its own quiescent

current to the output current level. In light load conditions the quiescent current goes down to Iqn_LL = 75 µA (low

consumption mode). L99VR01 operates with reduced input voltage (post regulation) minimizing the internal power

dissipation and maximizing the output current.

4.2

Output current limitation

Output current limitation is present to protect the regulator and the application from overload condition, such as

short to ground.

Figure 29. Behavior of output current versus regulated voltage Vo

O(A)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

I

Vo_5V

Vo_3V3

Vo_2V8

Vo_2V5

Vo_1V8

Vo_1V5

Vo_1V2

Vo_0V8

Vs = 13.5V

Ta = 25 ⁰C

The Ishort current can be set in the range from 65 mA to 360 mA through an external resistor Rsh connected

between IShort pin and ground (L99VR01J version only).

L99VR01

Application information

DS13649 - Rev 4

page 16/40