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Электронный компонент: L4920

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L4920
L4921
June 2000
VERY LOW DROP ADJUSTABLE REGULATORS
.
VERY LOW DROP VOLTAGE
.
ADJUSTABLE OUTPUT VOLTAGE FROM
1.25V TO 20V
.
400mA OUTPUT CURRENT
.
LOW QUIESCENT CURRENT
.
REVERSE VOLTAGE PROTECTION
.
+ 60/
-
60V TRANSIENT PEAK VOLTAGE
PROTECTION
.
SHORT CIRCUIT PROTECTION WITH FOLD-
BACK CHARACTERISTICS
.
THERMAL SHUT-DOWN
DESCRIPTION
Pentaw att
ORDERING NUMBERS : L4920 (Pentawatt)
L4921 (Minidip)
BLOCK DIAGRAM
The L4920 and L4921 are adjustable voltage regu-
lators with a verylow voltage drop (0.4V typ. at 0.4A
T
j
= 25
C), low quiescent current and comprehen-
sive on-chip protection.
Thesedevices are protectedagainst load dump and
field decay transients, polarity reversal and over
heating.
A foldbackcurrent limiter protectsagainstload short
circuits.
The outputvoltage is adjustablethrough an external
divider from 1.25V to 20V. The minimum operating
input voltage is 5.2V (T
J
= 25
C).
Minidip (4 + 4)
These regulators are designed for automotive, in-
dustrial and consumer applications where low con-
sumption is particularly important.
In battery backup and standby applications the low
consumption of these devices extends battery life.
1/7
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Unit
V
i
DC Input Operating Voltage
DC Reverse Input Voltage
Transient Input Overvoltages:
Load Dump:
5ms
t
rise
10ms
f
Fall time constant = 100ms
R
SOURCE
0.5
Field Decay:
5ms
t
fa ll
10ms, R
SOURCE
10
f
Rise time constant = 33ms
35
V
T
J
, T
STG
Junction and Storage Temperature Range
55 to 150
C
PIN CONNECTIONS (top view)
TEST AND APPLICATION CIRCUIT
THERMAL DATA
Symbol
Parameter
Minidip
(4 + 4)
Pentawatt
R
th j-amb
R
th j-pins
R
th j-case
Thermal Resistance Junction-ambient
Thermal Resistance Junction-pins
Thermal Resistance Junction-case
Max
Max
Max
80
C/W
15
C/W
60
C/W
3.5
C/W
C = 100
F is required for stability (ESR
3
over T range)
R2 = 6.2K
.
L4920/L4921
2/7
(*) Foldback protection.
N ote :
1. Design limits are guaranteed (but not 100% production tested) over the indicated temperatu re and supply voltage
ranges. These limits are not used to calculate outgoing quality levels.
ELECTRICAL CHARACTERISTICS (forV
I
= 14.4V,T
J
= 25
C, V
O
= 5V,C
O
= 100
F, unlessOtherwiseSpeci-
fied)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
I
Operating Input Voltage
V
O
4.5V, I
O
= 400mA
V
O
+ 0.7
26
V
V
REF
V
O
< 4.5V, I
O
= 400mA
5.2
26
V
V
REF
Reference Voltage
5.2V < V
I
< 26V
5mA
I
O
400mA (*)
1.20
1.25
1.30
V
V
O
Line Regulation
V
O
+ 1V < V
I
< 26V, V
O
4.5V
I
O
= 5mA
1
10
mV/V
V
O
Load Regulation
5mA
I
O
400mA (*) V
O
4.5V
3
15
mV/V
V
D
Dropout Voltage
I
O
= 10mA
I
O
= 150mA
I
O
= 400mA
0.05
0.2
0.4
0.4
0.7
V
V
V
I
Q
Quiescent Current
I
O
= 0mA
V
O
+ 1V < V
I
<26V
0.8
2
mA
I
O
= 400mA (*)
V
O
+ 1V < V
I
<26V
65
90
mA
I
O
Maximal Output Current
800
mA
I
OSC
Short Circuit Output Current (*)
350
500
mA
(* ) F oldback pr otection
ELECTRICAL CHARACTERISTICS (for V
I
= 14.4V,40
T
J
125
C (note1), V
O
= 5V, C
O
= 100
F, unless
Otherwise Specified)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
Unit
V
I
Operating Input Voltage
V
O
4.5V, I
O
= 400mA
V
O
+ 0.9
26
V
V
REF
V
O
< 4.5V, I
O
= 400mA
5.2
26
V
V
REF
Reference Voltage
5.4V < V
I
< 26V
1.17
1.25
1.33
V
V
O
Line Regulation
V
O
+ 1.2V < V
I
< 26V, V
O
4.5V
I
O
= 5mA
2
15
mV/V
V
O
Load Regulation
5mA
I
O
400mA (*) V
O
4.5V
5
25
mV/V
V
D
Dropout Voltage
I
O
= 150mA
I
O
= 400mA
0.2
0.4
0.4
0.7
V
V
I
Q
Quiescent Current
I
O
= 0mA
V
O
+ 1.2V < V
I
<26V
1,2
3
mA
I
O
= 400mA (*)
V
O
+ 1.2V < V
I
<26V
80
140
mA
I
O
Maximal Output Current
870
mA
I
OSC
Short Circuit Output Current (*)
230
500
mA
L4920/L4921
3/7
Figure 3 : Quiescent Current vs. Output Current
(V
o
= 5V).
APPLICATION INFORMATION
1) The L4920 and L4921 have V
REF
1.25V.Then
the output voltage can be set down to V
REF
but
V
i
must be greater than 5.2V (T
j
= 25
C).
2) As the regulator reference voltage source works
in closed loop, the reference voltage may change
in foldbackcondition.
3) For applications with high V
l
, the total power
dissipation of the device with respect to the ther-
mal resistance of the package may be limiting . The
total power dissipation is :
P
tot
= V
i
l
q
+ (V
i
- V
o
) l
o
A typical curve giving the quiescent current l
q
as a
function of the output current l
o
is shown in fig. 3.
Figure 1 : Output Voltage vs. Temperature.
Figure 2 : Foldback Current Limiting.
L4920/L4921
4/7
PowerMinidip
DIM.
mm
inch
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
A
3.3
0.130
a1
0.7
0.028
B
1.39
1.65
0.055
0.065
B1
0.91
1.04
0.036
0.041
b
0.5
0.020
b1
0.38
0.5
0.015
0.020
D
9.8
0.386
E
8.8
0.346
e
2.54
0.100
e3
7.62
0.300
e4
7.62
0.300
F
7.1
0.280
I
4.8
0.189
L
3.3
0.130
Z
0.44
1.6
0.017
0.063
OUTLINE AND
MECHANICAL DATA
L4920/L4921
5/7
Pentawatt V
DIM.
mm
inch
MIN.
TYP.
MAX.
MIN.
TYP.
MAX.
A
4.8
0.189
C
1.37
0.054
D
2.4
2.8
0.094
0.110
D1
1.2
1.35
0.047
0.053
E
0.35
0.55
0.014
0.022
E1
0.76
1.19
0.030
0.047
F
0.8
1.05
0.031
0.041
F1
1
1.4
0.039
0.055
G
3.2
3.4
3.6
0.126
0.134
0.142
G1
6.6
6.8
7
0.260
0.268
0.276
H2
10.4
0.409
H3
10.05
10.4
0.396
0.409
L
17.55
17.85
18.15
0.691
0.703
0.715
L1
15.55
15.75
15.95
0.612
0.620
0.628
L2
21.2
21.4
21.6
0.831
0.843
0.850
L3
22.3
22.5
22.7
0.878
0.886
0.894
L4
1.29
0.051
L5
2.6
3
0.102
0.118
L6
15.1
15.8
0.594
0.622
L7
6
6.6
0.236
0.260
L9
0.2
0.008
M
4.23
4.5
4.75
0.167
0.177
0.187
M1
3.75
4
4.25
0.148
0.157
0.167
V4
40
(typ.)
L
L1
A
C
L5
D1
L2
L3
E
M1
M
D
H3
Dia.
L7
L6
F1
H2
F
G G1
E1
F
E
L9
V4
R
R
R
RESIN BETWEEN
LEADS
H1
V3
H2
L8
V
V
V1
B
V
V
V4
V4
OUTLINE AND
MECHANICAL DATA
L4920/L4921
6/7
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quences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No
license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specification mentioned in this
publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMi-
croelectronics products are not authorized for use as critical components in life support devices or systems without express written
approval of STMicroelectronics.
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L4920/L4921
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