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 FOLDBACK 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 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 = 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 Vi Parameter DC Input Operating Voltage DC Reverse Input Voltage Transient Input Overvoltages: Load Dump: 5ms ≤ trise ≤ 10ms τf Fall time constant = 100ms R SOURCE ≥ 0.5Ω Field Decay: 5ms ≤ tfall ≤ 10ms, RSOURCE ≥ 10Ω τf Rise time constant = 33ms TJ, TSTG Junction and Storage Temperature Range Value Unit 35 V – 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 R th j-amb Rth j-pins Rth j-case 2/7 Parameter Thermal Resistance Junction-ambient Thermal Resistance Junction-pins Thermal Resistance Junction-case Max Max Max Minidip (4 + 4) Pentawatt 80 °C/W 15 °C/W – 60 °C/W – 3.5 °C/W L4920/L4921 ELECTRICAL CHARACTERISTICS (forVI =14.4V,TJ = 25°C, VO = 5V,CO = 100µF, unlessOtherwiseSpecified) Symbol Parameter Test Condition Operating Input Voltage VO ≥ 4.5V, IO = 400mA VREF Reference Voltage VREF ≤ VO < 4.5V, IO = 400mA 5.2V < VI < 26V 5mA ≤ IO ≤ 400mA (*) ∆V O Line Regulation VO + 1V < VI < 26V, VO ≥ 4.5V IO = 5mA ∆V O Load Regulation 5mA ≤ IO ≤ 400mA (*) VO ≥ 4.5V VI VD IQ IO IOSC Dropout Voltage Quiescent Current Max. Unit VO + 0.7 Min. 26 V 5.2 26 V 1.25 1.30 V 1 10 mV/V 1.20 Typ. 3 15 mV/V IO = 10mA IO = 150mA IO = 400mA 0.05 0.2 0.4 0.4 0.7 V V V IO = 0mA VO + 1V < VI <26V 0.8 2 mA IO = 400mA (*) VO + 1V < VI <26V 65 90 mA Maximal Output Current 800 Short Circuit Output Current (*) 350 mA 500 mA (*) F oldback pr otection ELECTRICAL CHARACTERISTICS (forVI = 14.4V,–40 ≤ TJ ≤ 125°C (note1), VO = 5V, CO = 100µF, unless Otherwise Specified) Symbol VI Parameter Operating Input Voltage Test Condition VO ≥ 4.5V, IO = 400mA Min. Typ. Max. Unit VO + 0.9 26 V VREF ≤ VO < 4.5V, IO = 400mA 5.2 26 V 1.17 VREF Reference Voltage 5.4V < VI < 26V 1.25 1.33 ∆V O Line Regulation V VO + 1.2V < VI < 26V, VO ≥ 4.5V IO = 5mA 2 15 mV/V ∆V O Load Regulation 5mA ≤ IO ≤ 400mA (*) VO ≥ 4.5V 5 25 mV/V VD Dropout Voltage IO = 150mA IO = 400mA 0.2 0.4 0.4 0.7 V V IQ Quiescent Current IO = 0mA VO + 1.2V < VI <26V 1,2 3 mA 80 140 mA IO = 400mA (*) VO + 1.2V < VI <26V IO IOSC Maximal Output Current 870 Short Circuit Output Current (*) 230 mA 500 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 = 25°C). 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- 4/7 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. L4920/L4921 mm DIM. MIN. A TYP. inch MAX. MIN. 3.3 TYP. MAX. 0.130 a1 0.7 B 1.39 1.65 0.055 0.065 B1 0.91 1.04 0.036 0.041 b b1 0.028 0.5 0.38 0.020 0.5 D 0.015 0.020 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 Z 3.3 0.44 OUTLINE AND MECHANICAL DATA 0.130 1.6 0.017 PowerMinidip 0.063 5/7 L4920/L4921 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. mm TYP. 2.4 1.2 0.35 0.76 0.8 1 3.2 6.6 3.4 6.8 10.05 17.55 15.55 21.2 22.3 17.85 15.75 21.4 22.5 2.6 15.1 6 4.23 3.75 0.2 4.5 4 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. inch TYP. 0.094 0.047 0.014 0.030 0.031 0.039 0.126 0.260 0.134 0.268 0.396 0.691 0.612 0.831 0.878 0.703 0.620 0.843 0.886 0.102 0.594 0.236 4.75 0.167 4.25 0.148 40° (typ.) 0.008 0.177 0.157 OUTLINE AND MECHANICAL DATA 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 Pentawatt V L L1 V3 V V V1 B D C D1 L5 L2 V M1 R R A V E L8 R M V4 H2 L3 F E V4 H3 H1 G G1 Dia. F1 L7 F H2 V4 L6 L9 RESIN BETWEEN LEADS 6/7 E1 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. 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