L4920
L4920
L4921
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
The L4920 and L4921 are adjustable voltage regulators with a verylow voltage drop(0.4V typ. at 0.4A Tj = 25°C), low quiescent current and comprehensive on-chip protection.
Thesedevices are protectedagainst load dumpand field decay transients, polarity reversal and over heating.
A foldbackcurrentlimiter protectsagainstload short circuits.
The outputvoltage is adjustablethrough an external divider from 1.25V to 20V. The minimum operating input voltage is 5.2V (TJ = 25°C).
Pentaw att
Minidip (4 + 4)
ORDERING NUMBERS : L4920 (Pentawatt)
L4921 (Minidip)
These regulators are designed for automotive, industrial and consumer applications where low consumption is particularly important.
In battery backup and standby applications the low consumption of these devices extends battery life.
BLOCK DIAGRAM
June 2000 |
1/7 |
L4920/L4921
ABSOLUTE MAXIMUM RATINGS
Symbol |
Parameter |
Value |
Unit |
Vi |
DC Input Operating Voltage |
35 |
V |
|
DC Reverse Input Voltage |
|
|
|
Transient Input Overvoltages: |
|
|
|
Load Dump: |
|
|
|
5ms ≤ trise ≤ 10ms |
|
|
|
τf Fall time constant = 100ms |
|
|
|
RSOURCE ≥ 0.5Ω |
|
|
|
Field Decay: |
|
|
|
5ms ≤ tfall ≤ 10ms, RSOURCE ≥ 10Ω |
|
|
|
τf Rise time constant = 33ms |
|
|
TJ, TSTG |
Junction and Storage Temperature Range |
± 55 to 150 |
°C |
PIN CONNECTIONS (top view)
TEST AND APPLICATION CIRCUIT
C = 100μF is required for stability (ESR ≤ 3Ω over T range)
R2 = 6.2KΩ.
THERMAL DATA
Symbol |
Parameter |
|
Minidip |
Pentawatt |
|
|
|
(4 + 4) |
|
Rth j-amb |
Thermal Resistance Junction-ambient |
Max |
80 °C/W |
60 °C/W |
Rth j-pins |
Thermal Resistance Junction-pins |
Max |
15 °C/W |
± |
Rth j-case |
Thermal Resistance Junction-case |
Max |
± |
3.5 °C/W |
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L4920/L4921
ELECTRICAL CHARACTERISTICS (forVI =14.4V,TJ = 25°C,VO = 5V,CO = 100μF, unlessOtherwiseSpecified)
Symbol |
Parameter |
Test Condition |
|
Min. |
Typ. |
Max. |
Unit |
VI |
Operating Input Voltage |
VO ≥ 4.5V, IO = 400mA |
|
VO + 0.7 |
|
26 |
V |
|
|
VREF ≤ VO < 4.5V, IO = 400mA |
5.2 |
|
26 |
V |
|
VREF |
Reference Voltage |
5.2V < VI < 26V |
|
1.20 |
1.25 |
1.30 |
V |
|
|
5mA ≤ IO ≤ 400mA (*) |
|
|
|
|
|
VO |
Line Regulation |
VO + 1V < VI < 26V, VO ≥ |
4.5V |
|
1 |
10 |
mV/V |
|
|
IO = 5mA |
|
|
|
|
|
VO |
Load Regulation |
5mA ≤ IO ≤ 400mA (*) VO |
≥ 4.5V |
|
3 |
15 |
mV/V |
VD |
Dropout Voltage |
IO = 10mA |
|
|
0.05 |
|
V |
|
|
IO = 150mA |
|
|
0.2 |
0.4 |
V |
|
|
IO = 400mA |
|
|
0.4 |
0.7 |
V |
IQ |
Quiescent Current |
IO = 0mA |
|
|
|
|
|
|
|
VO + 1V < VI <26V |
|
|
0.8 |
2 |
mA |
|
|
IO = 400mA (*) |
|
|
|
|
|
|
|
VO + 1V < VI <26V |
|
|
65 |
90 |
mA |
IO |
Maximal Output Current |
|
|
|
800 |
|
mA |
IOSC |
Short Circuit Output Current (*) |
|
|
|
350 |
500 |
mA |
(*) F oldback protection
ELECTRICAL CHARACTERISTICS (forVI = 14.4V,±40 ≤ TJ ≤ 125°C (note1), VO = 5V,CO = 100μF, unless Otherwise Specified)
Symbol |
Parameter |
Test Condition |
|
|
Min. |
Typ. |
Max. |
Unit |
|
VI |
Operating Input Voltage |
VO ≥ 4.5V, IO = 400mA |
|
|
|
VO + 0.9 |
26 |
V |
|
|
|
VREF ≤ VO < 4.5V, IO = 400mA |
5.2 |
|
26 |
V |
|||
VREF |
Reference Voltage |
5.4V < VI < 26V |
|
|
|
1.17 |
1.25 |
1.33 |
V |
VO |
Line Regulation |
VO + 1.2V < VI < 26V, |
VO |
≥ |
4.5V |
|
2 |
15 |
mV/V |
|
|
IO = 5mA |
|
|
|
|
|
|
|
VO |
Load Regulation |
5mA ≤ IO ≤ 400mA (*) |
VO |
≥ |
4.5V |
|
5 |
25 |
mV/V |
VD |
Dropout Voltage |
IO = 150mA |
|
|
|
|
0.2 |
0.4 |
V |
|
|
IO = 400mA |
|
|
|
|
0.4 |
0.7 |
V |
IQ |
Quiescent Current |
IO = 0mA |
|
|
|
|
|
|
|
|
|
VO + 1.2V < VI <26V |
|
|
|
|
1,2 |
3 |
mA |
|
|
IO = 400mA (*) |
|
|
|
|
|
|
|
|
|
VO + 1.2V < VI <26V |
|
|
|
|
80 |
140 |
mA |
IO |
Maximal Output Current |
|
|
|
|
|
870 |
|
mA |
IOSC |
Short Circuit Output Current (*) |
|
|
|
|
|
230 |
500 |
mA |
(*) Foldback protection. |
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N ote : 1. Design limits are guaranteed (but |
not 100% production tested) over |
the indicated |
temperatu re |
and supply |
voltage |
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ranges. These limits are not used |
to calculate outgoing quality levels. |
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