L4925 VERY LOW DROP VOLTAGE REGULATOR OPERATING DC SUPPLY VOLTAGE RANGE 6V TO 28V TRANSIENT SUPPLY VOLTAGE UP TO 40V EXTREMELY LOW QUIESCENT CURRENT HIGH PRECISION OUTPUT VOLTAGE OUTPUT CURRENT CAPABILITY UP TO 500mA VERY LOW DROPOUT VOLTAGE LESS THAN 0.6V RESET CIRCUIT SENSING THE OUTPUT VOLTAGE PROGRAMMABLE RESET PULSE DELAY WITH EXTERNAL CAPACITOR THERMAL SHUTDOWN AND SHORT CIRCUIT PROTECTIONS Pentawatt PowerSO20 ORDERING NUMBERS: L4925 (Pentawatt) L4925PD (PowerSO20) tional functions such as power-on reset and programmable reset delay time. It is designed for supplying microcomputer controlled systems especially in automotive applications. DESCRIPTION The L4925 is a monolithic integrated 5V voltage regulator with a very low dropout output and addiBLOCK DIAGRAM VO Vz PREREGULATOR 5V VREF 1.23V L4925N CT VS Vz CS RES 2µ + - = 2V GND REG RESET D95AT151 June 2000 1/8 This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice. L4925 ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit V SDC DC Operating Supply Voltage 28 V VSTR Transient Supply Voltage (t < 1s) 40 V IO Output Current internally limited VO Output Voltage 20 VRES Output Voltage 20 V IRES Output Current 5 mA Tstg Storage Temperature -55 to 150 °C Operating Junction Temperature -40 to 150 °C 165 °C Tj Tj-SD Thermal Shutdown-Junction Temperature V NOTE: The circuit is ESD protected according to MIL-STD-883C. According to ISO/DIS 7637 the transients must be clamped with external circuitry (see Application Circuit). CONNECTION DIAGRAM N.C. 1 20 N.C. N.C. 2 19 N.C. VS 3 18 N.C. VS 4 17 VOUT N.C. 5 16 VOUT N.C. 6 15 N.C. RES 7 14 CT N.C. 8 13 N.C. N.C. 9 12 N.C. GND 10 11 N.C. D95AT152 THERMAL DATA Symbol Rth j-amb Rth j-case 2/8 Parameter Thermal resistance junction to ambient Thermal resistance junction to case max. max. Pentawatt SO 20 Unit 60 3.5 77 to 97 °C/W °C/W L4925 ELECTRICAL CHARACTERISTICS (VS =14V Tj =–40 to 125°C unless otherwise specified; Symbol Test Condition Min. Typ. Max. VO Output Voltage Parameter VI = 6 to 28V; IO = 1 to 500mA 4.90 5 5.10 V VO Output Voltage VI = 35V; T <1s; IO = 1 to 500mA 5.50 V VDP Dropout Voltage IO = 100mA IO = 500mA 0.3 0.6 V V VIO Input to Output Voltage Difference in Undervoltage Condition VI = 4V; IO = 100mA 0.5 V V OL Line Regulation VI = 6 to 28V; IO = 1 to 1mA 10 mV VOLO Load Regulation IO = 1 to 500mA 50 mV ILIM Current Limit VO = 4.5V; VO = 0; Foldback characteristic 1000 250 1500 mA mA IQSE Quiescent Current IO = 0.3mA 190 360 µA IQ Quiescent Current IO = 500mA 20 mA Max. Unit 5.2 V 0.2 0.3 550 Unit RESET Symbol Parameter V RT Reset Threshold Voltage VRTH Reset Threshold Test Condition Min. Typ. 4.5 50 100 200 mV 60 100 140 ms 5 30 µs 0.4 V 1 µA tRD Reset Pulse Delay C T = 100nF; tR > 100µs tRR Reset Reaction Time C T = 100nF; V RL Reset Output LOW Voltage R RES = 10KΩ to VO; VS => 3V IRH Reset Output HIGH Leakage Current VRES = 5V VCTth Delay Comparator Threshold 2 V VCTth hy Delay Comparator Threshold Hysteresis 200 mV APPLICATION CIRCUIT DIAGRAM VBAT VS VREF 1.23V Co L4925N CT Vz CS Vout Vo Vz PREREGULATOR 5V RES 2µ + RES = 2V GND REG RESET D95AT153 For stability: CS > 1µF; CO > 10µF;ESR < 2.5Ω at 10 KHz Recommended for application: CS =CO = 10µF to 100µF 3/8 L4925 APPLICATION NOTE SUPPLY VOLTAGE TRANSIENTS High supply voltage transients can cause a reset output signal disturbation. For supply voltage greater than 8V the circuit shows a high immunity of the reset output against supply transients of more than 100V/µs. For supply voltage lower than 8V, supply transients of more than 0.4V/µs. can cause a reset signal disturbation. Foldback Characteristics Of Vo FUNCTIONAL DESCRIPTION The L4925 is a monolithic integrated voltage regulator, based on the STM modular voltage regulator approach. Several outstanding features and auxiliary functions are implemented to meet the requirements of supplying microprocessor systems in automotive applications. Nevetrheless, it is suitable also in other applications where the present functions are required. The modular approach of this device allows to get easily also other features and functions when required. VOLTAGE REGULATOR The voltage regulator uses an Isolated Collector Vertical PNP transistor as a regulating element. With this structure very low dropout voltage at currents up to 500mA is obtained. The dropout operation of the standby regulator is maintained down to 3V input supply voltage. The output voltage is regulated up to the transient input supply voltage of 35V. With this feature no functional interruption due to overvoltage pulses is generated. The typical curve showing the standby output voltage as a function of the input supply voltage is shown in fig. 1. The current consumption of the device (quiescent current) is less than 250µA. To reduce the quiescent current peak in the undervoltage region and to improve the transient response in this region, the dropout voltage is controlled. The quiescent current as a function of the supply input voltage is shown in fig. 2. Figure 1: Output Voltage vs. Input Voltage Figure 2: Quiescent Current vs. Supply Voltage 4/8 L4925 RESET CIRCUIT The block circuit diagram of the reset circuit is shown in Figure 3. The reset circuit supervises the output voltage. The reset threshold of 4.5V is defined with the internal reference voltage and standby output divider. The reset pulse delay time t RD, is defined with the charge time of an external capacitor CT: tRD= CT x 2V 2µA The reaction time of the reset circuit originates from the discharge time limitation of the reset capacitor CT and it is proportional to the value of CT. The reaction time of the reset circuit increases the noise immunity.Standby output voltage drops below the reset threshold only a bit longer than the reaction time results in a shorter reset delay time. The nominal reset delay time will be generated for standby output voltage drops longer than approximately 50µs. The typical reset output waveforms are shown in Figure 4. Figure 3 Figure 4 5/8 L4925 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 0.134 0.260 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 0.008 4.75 0.167 0.177 4.25 0.148 0.157 40°(typ.) 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 6/8 E1 L4925 DIM. A a1 a2 a3 b c D (1) D1 E e e3 E1 (1) E2 E3 G H h L N S T MIN. mm TYP. 0.1 0 0.4 0.23 15.8 9.4 13.9 MAX. 3.6 0.3 3.3 0.1 0.53 0.32 16 9.8 14.5 MIN. 0.004 0.000 0.016 0.009 0.622 0.370 0.547 1.27 11.43 10.9 inch TYP. 0.050 0.450 11.1 0.429 2.9 6.2 0.228 0.1 0.000 15.9 0.610 1.1 1.1 0.031 10° (max.) 8° (max.) 5.8 0 15.5 0.8 OUTLINE AND MECHANICAL DATA MAX. 0.142 0.012 0.130 0.004 0.021 0.013 0.630 0.386 0.570 10 0.437 0.114 0.244 0.004 0.626 0.043 0.043 JEDEC MO-166 0.394 PowerSO20 (1) ”D and F” do not include mold flash or protrusions. - Mold flash or protrusions shall not exceed 0.15 mm (0.006”). - Critical dimensions: ”E”, ”G” and ”a3” N R N a2 b A e DETAIL A c a1 DETAIL B E e3 H DETAIL A lead D slug a3 DETAIL B 20 11 0.35 Gage Plane - C- S SEATING PLANE L G E2 E1 BOTTOM VIEW C (COPLANARITY) T E3 1 h x 45 10 PSO20MEC D1 7/8 L4925 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 publicationsupersedes and replaces all information previously supplied. STMicroelectronics products are notauthorizedfor use as critical components in life support devices or systems without express writtenapproval of STMicroelectronics. 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