L4909
The current protection is a function of the Vce, i.e. the drop between input and output voltages (Vin-Vo). The
shape of that relationship is shown in following figure 1.
Figure 1.
Figure 2. REGULATOR TYPICAL APPLICATION
FROM
RECTIFIER
ULTRAFAST FUSE
+5V
330nF
4.7K
PULL-UP
RESISTOR
SCR
VINA
(*)EN1
3
6
(*)EN2
7
VINB
13
VO1
2
VO2
14
VO3
11
(*)EN3
9
OC
5
TRIG
4
FB1
1
FB2
15
FB3
12
8
GND
RB3 RB2 RB1
100µF
RA3
RA2
RA1
(*) It is possible to enable the regulators connecting the ENx pins to Vin through a 25KΩ
Suggested value for RAx is 1.2KΩ
The value of RBx must be choosen, depending on the desired output voltage Vox? following the formula:
Vox
RBx = RAx 1.27 -1
100µF
100nF
D00AU1154
100µF
100nF
100nF
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