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| (R) 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. June 2000 1/7 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 2/7 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. 3/7 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. 4/7 L4920/L4921 DIM. MIN. A a1 B B1 b b1 D E e e3 e4 F I L Z 0.44 0.38 0.7 1.39 0.91 mm TYP. 3.3 0.028 1.65 1.04 0.5 0.5 9.8 8.8 2.54 7.62 7.62 7.1 4.8 3.3 1.6 0.017 0.015 0.055 0.036 MAX. MIN. inch TYP. 0.130 MAX. OUTLINE AND MECHANICAL DATA 0.065 0.041 0.020 0.020 0.386 0.346 0.100 0.300 0.300 0.280 0.189 0.130 0.063 PowerMinidip 5/7 L4920/L4921 mm TYP. inch TYP. DIM. A C D D1 E E1 F F1 G G1 H2 H3 L L1 L2 L3 L4 L5 L6 L7 L9 M M1 V4 MIN. 2.4 1.2 0.35 0.76 0.8 1 3.2 6.6 10.05 17.55 15.55 21.2 22.3 2.6 15.1 6 4.23 3.75 3.4 6.8 17.85 15.75 21.4 22.5 MAX. 4.8 1.37 2.8 1.35 0.55 1.19 1.05 1.4 3.6 7 10.4 10.4 18.15 15.95 21.6 22.7 1.29 3 15.8 6.6 MIN. 0.094 0.047 0.014 0.030 0.031 0.039 0.126 0.260 0.396 0.691 0.612 0.831 0.878 0.102 0.594 0.236 0.134 0.268 0.703 0.620 0.843 0.886 MAX. 0.189 0.054 0.110 0.053 0.022 0.047 0.041 0.055 0.142 0.276 0.409 0.409 0.715 0.628 0.850 0.894 0.051 0.118 0.622 0.260 0.187 0.167 OUTLINE AND MECHANICAL DATA 0.2 4.5 4 4.75 0.167 4.25 0.148 40 (typ.) 0.008 0.177 0.157 Pentawatt V L L1 L8 V V1 V R A B C D1 L5 L2 L3 D R V4 H2 F E V4 V3 E R M1 V V M E1 H3 H1 Dia. L7 L6 RESIN BETWEEN LEADS F1 F H2 G G1 V4 L9 6/7 L4920/L4921 Information furnished is believed to be accurate and reliable. However, STMicroelectronics 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 STMicroelectronics. Specification mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics. The ST logo is a registered trademark of STMicroelectronics (c) 2000 STMicroelectronics - Printed in Italy - All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - China - Finland - France - Germany - Hong Kong - India - Italy - Japan - Malaysia - Malta - Morocco Singapore - Spain - Sweden - Switzerland - United Kingdom - U.S.A. http://www.st.com 7/7 |
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