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L4920 L4921
VERY LOW DROP ADJUSTABLE REGULATORS
.VERYLOWDROPVOLTAGE .ADJUSTABLE .400mAOUTPUTCURRENT .LOWQUI .REVERSEVOLTAGEPROTECTI .+60/-60VTRANSI .SHORTCI .THERMALSHUT1.25V TO 20V ESCENT CURRENT
OUTPUT VOLTAGE FROM
ON ENT PEAK VOLTAGE
PROTECTION RCUIT PROTECTION WITH FOLDBACK CHARACTERISTICS DOWN
Pentaw att
DESCRIPTION The L4920 and L4921 are adjustable voltage regulators with a verylow voltage drop (0.4V typ. at 0.4A Tj = 25C), low quiescent current and comprehensive 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 (TJ = 25C). BLOCK DIAGRAM
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.
February 1989
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L4920/L4921
ABSOLUTE MAXIMUM RATINGS
Symbol Vi Parameter DC Input Operating Voltage DC Reverse Input Voltage Transient Input Overvoltages: Load Dump: 5ms trise 10ms f Fall time constant = 100ms R SOURCE 0.5 Field Decay: 5ms tfall 10ms, RSOURCE 10 f Rise time constant = 33ms Value 35 Unit V
TJ, TSTG Junction and Storage Temperature Range
- 55 to 150
C
PIN CONNECTIONS (top view)
TEST AND APPLICATION CIRCUIT
C = 100F is required for stability (ESR 3 over T range) R2 = 6.2K.
THERMAL DATA
Symbol R th j-amb Rth j-pins Rth j-case Parameter Thermal Resistance Junction-ambient Thermal Resistance Junction-pins Thermal Resistance Junction-case Max Max Max Minidip (4 + 4) 80 C/W 15 C/W - Pentawatt 60 C/W - 3.5 C/W
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L4920/L4921
ELECTRICAL CHARACTERISTICS (forVI =14.4V,TJ = 25C, VO = 5V,CO = 100F, unlessOtherwiseSpecified)
Symbol VI VREF V O V O VD Parameter Operating Input Voltage Reference Voltage Line Regulation Load Regulation Dropout Voltage Test Condition VO 4.5V, IO = 400mA VREF VO < 4.5V, IO = 400mA 5.2V < VI < 26V 5mA IO 400mA (*) VO + 1V < VI < 26V, VO 4.5V IO = 5mA 5mA IO 400mA (*) VO 4.5V IO = 10mA IO = 150mA IO = 400mA IO = 0mA VO + 1V < VI <26V IO = 400mA (*) VO + 1V < VI <26V IO IOSC Maximal Output Current Short Circuit Output Current (*) Min. VO + 0.7 5.2 1.20 1.25 1 3 0.05 0.2 0.4 0.8 65 800 350 500 Typ. Max. 26 26 1.30 10 15 0.4 0.7 2 90 Unit V V V mV/V mV/V V V V mA mA mA mA
IQ
Quiescent Current
(*) F oldback pr otection
ELECTRICAL CHARACTERISTICS (forVI = 14.4V,-40 TJ 125C (note1), VO = 5V, CO = 100F, unless Otherwise Specified)
Symbol VI VREF V O V O VD IQ Parameter Operating Input Voltage Reference Voltage Line Regulation Load Regulation Dropout Voltage Quiescent Current Test Condition VO 4.5V, IO = 400mA VREF VO < 4.5V, IO = 400mA 5.4V < VI < 26V VO + 1.2V < VI < 26V, VO 4.5V IO = 5mA 5mA IO 400mA (*) VO 4.5V IO = 150mA IO = 400mA IO = 0mA VO + 1.2V < VI <26V IO = 400mA (*) VO + 1.2V < VI <26V IO IOSC Maximal Output Current Short Circuit Output Current (*) Min. VO + 0.9 5.2 1.17 1.25 2 5 0.2 0.4 1,2 80 870 230 500 Typ. Max. 26 26 1.33 15 25 0.4 0.7 3 140 Unit V V V mV/V mV/V V V mA mA mA mA
(*) 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.
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L4920/L4921
Figure 1 : Output Voltage vs. Temperature. Figure 2 : Foldback Current Limiting.
Figure 3 : Quiescent Current vs. Output Current (Vo = 5V).
APPLICATION INFORMATION 1) The L4920 and L4921 have VREF 1.25V.Then the output voltage can be set down to VREF but Vi must be greater than 5.2V (Tj = 25C). 2) As the regulator reference voltage source works in closed loop, the reference voltagemay change in foldbackcondition. 3) For applications with high Vl, the total power dissipation of the device with respect to the ther-
mal resistance of the packagemay be limiting . The total power dissipation is : Ptot = Vi lq + (Vi - Vo) lo A typical curve giving the quiescent current lq as a function of the output current lo is shown in fig. 3.
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L4920/L4921
MINIDIP 4+4 PACKAGE MECHANICAL DATA
DIM. MIN. A a1 B B1 b b1 D E e e3 e4 F I L Z 0.44 3.3 1.6 0.017 8.8 2.54 7.62 7.62 7.1 4.8 0.130 0.063 0.38 0.7 1.39 0.91 0.5 0.5 9.8 0.346 0.100 0.300 0.300 0.280 0.189 0.015 1.65 1.04 mm TYP. 3.3 0.028 0.055 0.036 0.020 0.020 0.386 0.065 0.041 MAX. MIN. inch TYP. 0.130 MAX.
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L4920/L4921
PENTAWATT PACKAGE MECHANICAL DATA
DIM. MIN. A C D D1 E F F1 G G1 H2 H3 L L1 L2 L3 L5 L6 L7 M M1 Dia 3.65 2.6 15.1 6 4.5 4 3.85 0.144 10.05 17.85 15.75 21.4 22.5 3 15.8 6.6 0.102 0.594 0.236 0.177 0.157 0.152 2.4 1.2 0.35 0.8 1 3.4 6.8 10.4 10.4 0.396 0.703 0.620 0.843 0.886 0.118 0.622 0.260 mm TYP. MAX. 4.8 1.37 2.8 1.35 0.55 1.05 1.4 0.094 0.047 0.014 0.031 0.039 0.126 0.260 0.134 0.268 MIN. inch TYP. MAX. 0.189 0.054 0.110 0.053 0.022 0.041 0.055 0.142 0.276 0.409 0.409
L E L1
A
C
D1
L2 L5 L3
D
Dia. F
L6
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H2
L7
F1
G
G1
H3
M
M1
L4920/L4921
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences 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 SGS-THOMSON Microelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. (c) 1996 SGS-THOMSON Microelectronics - Printed in Italy - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A.
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