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L4937NPD
DUAL 5V MULTIFUNCTION VOLTAGE REGULATOR
.STANDBYOUTPUTVOLTAGEPRECI .OUTPUT2TRACKEDTOTHESTANDBYOUT.OUTPUT .VERY .OUTPUTCURRENTS:I .VERYLOWDROPOUT( .OPERATI .POWER.POWER.THERMALSHUTDOWNANDSHORTCI
2% PUT PIN CONNECTION (top view)
SION 5V
2 DISABLE FUNCTION FOR STANDBY MODE LOW QUIESCENT CURRENT, LESS THAN 260A, IN STANDBY MODE 01 = 50mA, I02 = 500mA max 0.4V/0.6V) NG TRANSIENT SUPPLY VOLTAGE UP TO 40V ON RESET CIRCUIT SENSING THE STANDBY OUTPUT VOLTAGE ON RESET DELAY PULSE DEFINED BY THE EXTERNAL CAPACITOR RCUIT PROTECTIONS
PowerSO20 ORDERING NUMBER: L4937NPD
DESCRIPTION The L4937NPD is a monolithic integrated dual voltage regulators with two very low dropout outputs andadditionalfunctionssuchas power-onresetand input voltage sense. They are designed for supplying microcomputer controlled systems specially in automotive applications.
GND N.C. VS VS GND N.C. CT EN N.C. GND
1 2 3 4 5 6 7 8 9 10
D95AT162A
20 19 18 17 16 15 14 13 12 11
GND N.C. VO2 N.C. VO1 GND RESET N.C. N.C. GND
June 2000
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This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
L4937NPD
BLOCK DIAGRAM
VS1
VO1
REFERENCE
1.23V REG1
VS2 EN REG2
VO2
1.23V 2
CT RES
RESET
2.0V
GND
D95AT163
THERMAL DATA
Symbol Rthj-case Parameter Thermal Resistance Junction-Case Max. Value 1.5 Unit C/W
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L4937NPD
ABSOLUTE MAXIMUM RATINGS
Symbol VS Tj, Tstg IEN VEN VRES IRES PD DC Supply Voltage Transient Supply Voltage (T < 1s) Junction and Storage Temperature Range Enable Input Current (VEN 0.3V) Enable Input Voltage Reset Output Voltage Reset Output Current Power Dissipation Parameter Value 28 40 -55 to 150 1 VS 20 5 875 V mA mW Unit V V C mA
Note : The circuit is ESD protected according to MIL-STD-883C.
APPLICATION CIRCUIT
VS1 CS
VO1 CO1
REFERENCE
1.23V REG1
VS2 EN REG2
VO2
1.23V 2
CT RES
CT
RESET
2.0V
GND
D95AT164
CS 1F ; C01 6F ; C02 10F, ESR < 10 at 10KHz
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L4937NPD
ELECTRICAL CHARACTERISTICS (VS = 14V; -40C TJ 125C unless otherwise specified)
Symbol VS V O1 VO2 - VO1 Parameter Operating Supply Voltage Standby Output Voltage Output Voltage 2 Tracking Error 6V VS 25V 1mA IO1 50mA 6V VS 25V 5mA IO2 500mA Enable = LOW IO1 = 10mA IO1 = 50mA Vs = 4V, IO1 = 35mA 4.90 -25 5.00 Test Conditions Min. Typ. Max. 25 5.10 +25 Unit V V mV
VDP1 V IO1
Dropout Voltage 1 Input to Output Voltage Difference in Undervoltage Condition Dropout Voltage 2 Input to Output Voltage Difference in Undervoltage Condition Line Regulation Load Regulation 1 Load Regulation 2 Current Limit 1 Current Limit 2
0.1 0.2
0.25 0.4 0.4
V V V
VDP2 V IO2
IO1 = 100mA IO1 = 500mA Vs = 4.6V, IO1 = 350mA
0.2 0.3
0.3 0.6 0.6
V V V
VOL 1.2 VOLO1 VOLO2 ILIM1 ILIM2 IQSB
6V VS 25V IO1 = 1mA; IO2 = 5mA 1mA IO1 50mA 5mA IO2 500mA VO1 = 4.5V VO1 = 0V (note 1) VO2 = 0V 55 25 550 100 50 1000
20 25 50 200 100 1700
mV mV mV mA mA mA
Quiescent Current Standby Mode IO1 = 0.3mA; T J < 100C (output 2 disabled) VEN 2.4V VS = 14V VS = 3.5V Quiescent Current IO1 = 50mA IO1 = 500mA
210 340
290 850 30
A A mA
IQ
ENABLE
VENL VENH VENhyst IEN Enable Input LOW Voltage (output 2 active) Enable Input HIGH Voltage Enable Hysteresis Enable Input Current 0V < VEN < 1.2V 2.5V < VEN < 7V -0.3 2.4 30 -10 -1 75 -1.5 0 1.5 7 200 -0.5 +1 V V mV A A
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L4937NPD
ELECTRICAL CHARACTERISTICS (continued) RESET
Symbol VRt VRth tRD tRR VRL ILRES VCTh VCTh, hyst Parameter Reset Low Threshold Voltage Reset Threshold Hysteresis Reset Pulse Delay Reset Reaction Time Reset Output LOW Voltage Reset Output HIGH Leakage Delay Comparator Threshold Delay Comparator Threshold Hysteresis CT = 100nF; tR > 100s CT = 100nF RRES = 10K to V01 VS = 1.5V VRES = 5V 2.0 100 Test Conditions Min. Vo1 -0.4 50 55 1 Typ. 4.7 100 100 10 Max. Vo1 -0.1 200 180 50 0.4 1 Unit V mV ms s V A V mV
Note : 1: Foldback characteristic
FUNCTIONAL DESCRIPTION The L4937NDis based on the SGS-THOMSON Microelectronics modular voltage regulator approach. Several out-standing features and auxiliary functions are provided to meet the requirements of supplying the microprocessor systems used in automotive applications. Furthermore the device is suitable also in other applications requiring two stabilized voltages. The modular approach allows other features and functions to be realized easily when required. STANDBY REGULATOR The standby regulator uses an Isolated Collector Vertical PNP transistor as the regulating element. This structure allows a very low dropout voltage at currents up to 50mA. The dropout operation of the standby regulator is maintained down to 2V input supply voltage. The output voltage is regulated up to the transientinput supplyvoltageof 40V.This feature avoids functional interruptions which could be generated by overvoltage pulses. Figure 1 : Output Voltage vs. Input Voltage.
The typical curve of the standby output voltage as a functionof the input supply voltage is shown in fig. 1. The current consumption of the device (quiescent current) is less than 260A when output 2 is disabled (standby mode). The dropout voltage is controlled to reduce the quiescent current peak in the undervoltage region and to improve the transient response in this region. The quiescentcurrent isshown in fig. 2 as a function of the supply input voltage 2. OUTPUT 2 VOLTAGE The output 2 regulator uses the same output structure as the standbyregulator, but rated for anoutput current of 500mA. The output 2 regulatorworks in tracking mode with the standby output voltage as a reference voltage when the output 2. The output 2 regulator can be switched off via the Enable input.
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L4937NPD
Figure 2 : QuiescentCurrent vs. Supply Voltage.
400
200
Figure 3 : Programmable Output 2 Voltage with External Resistors.
RESET CIRCUIT Theblockcircuit diagramof thereset circuit is shown in fig.4. The resetcircuit supervisesthe standbyoutput voltage. The reset threshold of 4.7V is defined by the internal reference voltage and the standby output divider. The reset pulse delay time tRD, is defined by the charge time of an external capacitor CT : CT x 2V tRD = 2A
The reactiontime of the reset circuit dependson the discharge time limitation of the reset capacitor CT and is proportional to the value of CT. The reaction time of the reset circuit increases the noise immunity. In fact,if the standbyoutputvoltage drops below the reset threshold for a time shorter than the reaction time tRR, no reset output variation occurs. The nominal reset delay is generated for standby output voltage drops longer than the time necessary for the complete discharging of the capacitor CT. This time is typically equal to 50s if CT = 100nF.The typical reset output waveforms are shown in fig. 5.
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L4937NPD
Figure 4 :Block Diagram of the Reset Circuit.
Figure 5 : Typical Reset Output Waveforms.
VOUT1 VINPUT
VRT +0.2V VRT
VOUT1
1.5V
tR RESET
tRD tRR
tRD
D95AT216
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L4937NPD
DIM. A a1 a2 a3 b c D (1) D1 E e e3 E1 (1) E2 E3 G H h L N S T mm TYP. inch TYP.
MIN. 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
MAX. 0.142 0.012 0.130 0.004 0.021 0.013 0.630 0.386 0.570
OUTLINE AND MECHANICAL DATA
1.27 11.43 10.9 5.8 0 15.5 0.8 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.) 10
0.050 0.450 0.437 0.114 0.244 0.004 0.626 0.043 0.043
JEDEC MO-166
0.394
(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"
PowerSO20
N
N a2 b e A
R
c DETAIL B a1 E DETAIL A
DETAIL A e3 H
lead
D a3 DETAIL B
20 11
Gage Plane 0.35
slug
-C-
S E2 T E1 BOTTOM VIEW
L
SEATING PLANE G C
(COPLANARITY)
E3
1 10
h x 45
PSO20MEC
D1
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L4937NPD
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
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