L4909
EXTERNALLY ADJUSTABLE MULTIFUNCTION REGULATOR
■
3 OUTPUTS
- Vo1 : output voltage variable from 5 to 12 V;
limit current : 1.2 A.
- Vo2 : output voltage variable from 5 to 12 V;
limit current : 1.2 A.
- Vo3 : output voltage variable from 5 to 12 V;
limit current : 1.2 A.
■
ENABLE INPUT FOR EACH REGULATOR
■
FEEDBACK INPUT FOR EACH REGULATOR
■
SHORT CIRCUIT PROTECTION TO GROUND
■
OVERCURRENT WARNING
■
DRIVER FOR EXTERNAL SCR (CROWBAR
PROTECTION)
■
THERMAL SHUTDOWN
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EN1
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EN2
EN3
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O
OC
6
7
9
REFERENCE
GENERATOR
THERMAL
SHUTDOWN
e
t
le
When one output voltage is higher than 20% typ of its
nominal value (for instance in case of input-to-output
short circuit), the crowbar output pin is activated, triggering an external SCR (connected between input
and ground) that blows the input line fuse.
REF
+
REF+20%
3,13
+
REG1
ENABLE
CONTROL
REG2
REG3
+
2
-
1
+
VO1
FB1
+
5
+
OVER
CURRENT
CHECK
REG2
14
-
15
+
TRIG
VINA, VINB
+
REG1
+
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It is a monolithic Multifunction Voltage Regulator; it
contains 3 regulators, (REG1, REG2, REG3) each
one with an enable input and a feedback input, to allow the voltage setting via external resistive divider.
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Each regulator is current limited and furthermore an
OR-ed warning signal is output (open collector, active low output) when the current in a regulator goes
above an over-current threshold (1 A typ for any regulator).
DESCRIPTION
BLOCK DIAGRAM
MULTIWATT15
VO2
FB2
+
4
+
REG3
GND
8
+
11
10
VO3
FB3
D00AU1171
May 2000
1/7
L4909
PIN CONNECTION
15
FB2
14
VO2
13
VINB
12
N.C.
11
VO3
10
FB3
9
EN3
8
GND
7
EN2
6
EN1
5
OC
4
TRIG
3
VINA
2
VO1
1
FB1
TAB CONNECTED TO PIN 8
Table 1. Pin Description
No. Pin
Name
1
FB1
REG1 feedback voltage input
2
Vo1
REG1 output voltage
3
VinA
Input DC supply voltage
4
TRIG
Trigger for external SCR (crowbar protection)
5
OC
Over current warning output
6
EN1
REG1 enable input
7
EN2
REG2 enable input
8
GND
Analog ground
9
EN3
10
FB3
12
bs
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O
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Vo3
N.C.
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11
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Function
)
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REG3 enable input
REG3 feedback voltage input
REG3 output voltage
Not Connected
VinB
Input DC supply voltage
14
Vo2
REG2 output voltage
15
FB2
REG2 feedback voltage input
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D00AU1153
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L4909
ABSOLUTE MAXIMUM RATINGS
Symbol
Vin
Parameter
VinA,VinB input DC supply voltage
Io
Vo1, Vo2, Vo3 output currents
Value
Unit
40
V
internally limited
Voc
OC output voltage
min (15, Vin)
V
VENx
ENx input voltage
15
V
Top
Operating temperature range
Tstg
Storage temperature
0 to 70
o
C
- 40 to 150
oC
Value
Unit
THERMAL DATA
Symbol
Parameter
RTH j-case
Thermal Resistance Junction to Case
1.8
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°C/W
ELECTRICAL CHARACTERISTICS (Cout = 100nF; Vin -Vo = 5V; Io = 10mA; Tcase = 25°C unless otherwise
specified
Symbol
Vo1
Parameter
Test Condition
e
t
le
REG1 output voltage range
V(FB1)
so
Min.
Typ.
5
1.32
V
REG1 output current limit
EN1=ON; Vin-Vo1<12V
∆V o 1
------------V o1
line regulation
Io1=10mA; Vin-Vo1=3 to 25 V
Io1=10mA; Vin-Vo1=3 to 12 V
0.6
0.1
2
%
∆V o 1
------------V o1
load regulation
Io1=10 mA to 1.2A
Io1=10 mA to 0.5A
0.5
0.1
2
%
Vd1
REG1 drop out
2.20
V
SVR1
r
P
e
REG1 supply voltage rejec.
t
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o
Vo2
V(FB2)
1.70
V
Ilim1
u
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o
1.20
12
EN1=ON;
)
s
(
ct
1.27
Unit
REG1 feedback voltage
b
O
-
1.22
Max.
Io1=500mA
freq=120 Hz to 1KHz
REG2 output voltage range
A
60
dB
5
12
V
1.32
V
REG2 feedback voltage
EN2 = ON;
1.22
1.27
REG2 output current limit
EN2=ON; Vin-Vo2<12V
1.20
1.70
∆V o 2
------------V o2
line regulation
Io2=10mA;Vin-Vo2=3 to 25 V
Io2=10mA;Vin-Vo2=3 to 12 V
0.6
0.1
2
%
∆V o 2
------------V o2
load regulation
Io2=10 mA to 1.2A
Io2=10 mA to 0.5A
0.5
0.1
2
%
Vd2
REG2 drop out
Io2=500mA
2.2
V
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Ilim2
A
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L4909
ELECTRICAL CHARACTERISTCS (continued)
Symbol
Parameter
SVR2
REG2 supply voltage rejec.
Vo3
REG3 output voltage range
V(FB3)
Test Condition
Min.
freq=120 Hz to 1KHz
Typ.
Max.
60
Unit
dB
5
12
V
1.32
V
REG3 feedback voltage
EN3=ON;
1.22
1.27
REG3 output current limit
EN3=ON; Vin-Vo3<12V
1.20
1.70
∆V o 3
------------V o3
line regulation
Io3=10mA; Vin-Vo3=3 to 25 V
Io3=10mA; Vin-Vo3=3 to 12 V
0.6
0.1
2
%
∆V o 3
------------V o3
load regulation
Io3=10 mA to 1.2A
Io3=10 mA to 0.5A
0.5
0.1
2
%
Vd3
REG3 drop out
Io3=500mA
REG3 supply voltage rejec.
freq=120 Hz to 1KHz
60
enable input voltage
(active high)
STAND_BY
ON
3.5
Istby
current consumption in stand_by
EN1=EN2=EN3≤0.5 V
ITRIG
current at TRIG output
SCR trigger circuit in ON state;
V(TRIG) = 2V
ZTRIG
TRIG to GND impedance
SCR trigger circuit in OFF state
Ilim3
SVR3
ENx
I(FB)
Feedback’s input current
I(EN)
EN’s input current
(current in the external feedback resistors not
included)
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V_OC_L current_warning output
voltage
V
V
20
µA
25
mA
V
2
µA
V(EN) = 5V
160
µA
one regulator ON; Vo = 12V
two regulators ON; Vo = 12V
three regulators ON; Vo = 12V
11
20
29
mA
(s)
warning conditions
Isink < 3 mA
current_warning leakage
no warning conditions
V(OC) = 15V
I_oc/Ilim
warning threshold current / limit
current
any regulator
Vin - Vout <12V
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0.8
1.52
b
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I_OC_H
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dB
KΩ
any regulator
current consumption in ON state
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c
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V
0.2
any regulator
ct
Ion
)
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2.20
e
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V(FB)_TR FBx voltage for trigger SCR on
A
0.6
0.40
V
1
µA
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.
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Figure 2. REGULATOR TYPICAL APPLICATION
FROM
RECTIFIER
)
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ULTRAFAST FUSE
+5V
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du
VINA
(*)EN1
(*)EN2
330nF
t
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O
bs
4.7K
PULL-UP
RESISTOR
(*)EN3
OC
6
VINB
3
13
2
14
7
11
VO2
VO3
RB3
9
1
5
15
SCR
TRIG
VO1
12
4
8
RB2
RB1
FB1
100µF
FB2
100µF
FB3
100µF
RA3
RA2
100nF
100nF
100nF
RA1
GND
D00AU1154
(*) 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
-1
RBx = RAx
1.27
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L4909
mm
DIM.
MIN.
TYP.
inch
MAX.
MIN.
TYP.
MAX.
A
5
0.197
B
2.65
0.104
C
1.6
D
0.063
1
0.039
E
0.49
0.55
0.019
0.022
F
0.66
0.75
0.026
0.030
G
1.02
1.27
1.52
0.040
0.050
0.060
G1
17.53
17.78
18.03
0.690
0.700
0.710
H1
19.6
0.772
H2
20.2
0.795
L
21.9
22.2
22.5
0.862
0.874
0.886
L1
21.7
22.1
22.5
0.854
0.870
0.886
L2
17.65
18.1
0.695
L3
17.25
17.5
17.75
0.679
0.689
0.699
L4
10.3
10.7
10.9
0.406
0.421
0.429
0.713
L7
2.65
2.9
0.104
M
4.25
4.55
4.85
0.167
0.179
0.191
M1
4.63
5.08
5.53
0.182
0.200
0.218
S
1.9
2.6
0.075
0.102
S1
1.9
2.6
0.075
0.102
Dia1
3.65
3.85
0.144
0.152
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0.114
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OUTLINE AND
MECHANICAL DATA
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Multiwatt15 V
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L4909
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