L2949E

L2949E ETL | Alldatasheet

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UTC L2949E LINEAR INTEGRATED CIRCUIT UTC UNISONIC TECHNOLOGIES CO. LTD 1 QW-R102-014,A MULTIFUNCTION VERY LOW DROP VOLTAGE REGULATOR

DESCRIPTION

The UTC L2949E is a monolithic integrated 5V voltage regulator with a very low dropout output and additonal functions as power-on reset and input voltage sense.It is designed for supplying the microcomputer controlled systems especially in automotive applications.

FEATURES

*Operating dc supply voltage range 5V to 28V. *Transient supply voltage up to 40V. *Extremely low quiescent current in standby mode. *High precision standby output voltage 5V±1% *Output current capability up to 100mA. *Very low dropout voltage less than 0.5V. *Reset circuit sensing the output voltage *Programmable reset pulse delay with external capacitor *Voltage sense comparator. *Thermal shutdown and short circuit protections. SOP-20 DIP-8 SOP-8 PIN CONNECTIONS V S SI Vz CT VOUT SO RES GND DIP-8/SOP-8 VS SIVz CT VOUT SORES GND N.C. GND GND GND N.C. N.C. GND GND GND GND N.C. N.C. SOP-20

UTC L2949E LINEAR INTEGRATED CIRCUIT UTC UNISONIC TECHNOLOGIES CO. LTD 2 QW-R102-014,A BLOCK DIAGRAM Vz V OUT CT PREREGULATOR 5VVS REG SI REF 1.23V SENSE 1.23V RESET VS GND SO RES ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL RATING UNIT DC Operating Supply Voltage V CC 28 V Transient Supply Voltage(T<1s) V CC TR 40 V Output Current Io Internally Limited Output Voltage Vo 20 V Output Voltage Reset Output Sense Output V RES Vso V Output Current Reset Output Sense Output I RES Iso mA Preregulator Output Voltage Vz 7 V Preregulator Output Current Iz 5 mA Junction Temperature Tj -40～+150 ℃ Storage Temperature Range Tstg -55～+150 ℃

UTC L2949E LINEAR INTEGRATED CIRCUIT UTC UNISONIC TECHNOLOGIES CO. LTD 3 QW-R102-014,A THERMAL DATA DESCRIPTION SYMBOL RATING UNIT Thermal Resistance Junction-ambient D I P - 8 S O P - 8 S O P - 2 0 Rth j-amb 100 200 ℃/W Thermal Resistance Junction-pin (SOP-20) Rth j-pins 15 ℃/W Thermal Shutdown Junction temperature TJSD 165 ℃ ELECTRICAL CHARACTERISTICS(Vs=14V;-40℃<Tj<125℃ unless otherwise specified) PARAMETER SYMBOL CONDITIONS MIN TYP. MAX UNIT Output Voltage Vo Tj=25℃;Io=1mA 4.95 5 5.05 V Output Voltage Vo 6V<V IN<28V,1mA<Io<50mA 4.90 5 5.10 V Output Voltage Vo V IN=40V; T<1s 5mA<Io<100mA 4.75 5.25 V Dropout voltage V D Io=10mA Io=50mA Io=100mA 0.1 0.2 0.3 0.25 0.4 0.5 V V V Input to Output Voltage Difference in Undervoltage Condition V IO VIN=4V,Io=35mA 0.4 V Max Output Leakage Iouth V IN=25V,Vo=5.5V 20 50 80 μA Line Regulation V OL 6V<V IN<28V, Io=1mA 20 mV Load Regulation V OLO 1mA<Io<100mA 30 mV Current Limit I LIM Vo=4.5V Vo=4.5V,TJ=25℃ Vo=0V(note 1) 105 120 200 100 400 400 mA mA Quiescent Current I QSE Io=0.3mA;TJ<100℃ 200 300 μA Quiescent Current I Q Io=100mA 5 mV With this test we guarantee that with no output current the output voltage will not exceed 5.5V RESET PARAMETER SYMBOL CONDITIONS MIN TYP. MAX UNIT Reset Thereshold Voltage V RT Vo-0.5V V Reset Thereshold Hysteresis V RTH 50 100 200 mV Reset Pulse Delay t RD CT=100nF;TR≧100μs 55 100 180 ms Reset Output Low Voltage V RL RRES=10KΩ to Vs ≧1.5V 0.4 V Reset Output Gigh Leakage Current IRH VRES=5V 1 μA Delay Comparator Thereshold V CTth 2 V Delay Comparator Thereshold Hysteresis VCTth,hy 100 mV

UTC L2949E LINEAR INTEGRATED CIRCUIT UTC UNISONIC TECHNOLOGIES CO. LTD 4 QW-R102-014,A SENSE PARAMETER SYMBOL CONDITIONS MIN TYP. MAX UNIT Sense Low Thereshold Vst 1.16 1.23 1.35 V Sense Thereshold Hysteresis Vsth 20 100 200 mV Sense Output Low Voltage V SL VSI≦1.16V;Vs≧3V Rso=10KΩ to Vo 0.4 V Sense Output Leakage I SH Vso=5V;VSI≧1.5V 1 μA Sense Input Current I SI V SI=0 -20 -8 -3 μA PREREGULATOR PARAMETER SYMBOL CONDITIONS MIN TYP. MAX UNIT Preregulator Output Voltage Vz Iz=10μA 4.5 5 6 V Preregulator Output Current Iz 10 μA Note 1:Foldback characteristic APPLICATION CIRCUIT Vz (optional) VOUT CT PREREGULATOR 5V VS REG SI REF 1.23V SENSE 1.23V RESET VS GND SO RES VOUT VBAT For stability:Cs ≧1μF, Co ≧4.7μF, ESR<10Ωat 10KHz Recommended for application:Cs=Co=10µF to 100µF

APPLICATION INFORMATION

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 the reset output against supply transients of more than100V/ μs. For supply voltages less than 8V supply transients of more than 0.4V/ μs can cause a reset signal disturbation. To improve the transient behaviour for supply voltages less than 8V a capacitor at pin 3 can be used. A capacitor at pin 3(C3≦1μF ) reduces also the output noise.

UTC L2949E LINEAR INTEGRATED CIRCUIT UTC UNISONIC TECHNOLOGIES CO. LTD 5 QW-R102-014,A FUNCTIONAL DESCRIPTION The UTC L2949E is a monolithic integrated voltage regulator,based on the STM modular voltage regulator approch.Several outstanding features and auxiliary functions are implemented to meet the requirements of supplying microprocessor systems in automotive applications.Nevertheless,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 lsolated Collector Vertical PNP transistor as a regulating element. 20 100 200 IOUT(mA) Figure 1: Foldback Characteristic of Vo With this structure very low dropout voltage at currents up to 100mA 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 4V.With this feature no functional interruption due to overvoltage pulses is generated.The typical cuve showing the standby.output voltage as a function of the input supply voltage is shown in Fig.2. The current consumption of the device(quiescent current) is less than 300 μA. To reduce the quiescent current peak in the undervoltage region and to improve the transient response inthis region.the dropout voltage is controlled,the quiescent current as a function of the supply input voltage is shown in Fig.3.

UTC L2949E LINEAR INTEGRATED CIRCUIT UTC UNISONIC TECHNOLOGIES CO. LTD 6 QW-R102-014,A VOUT 5V VOUT 0V 2V 5V Vs 40V Figure 2: Output Voltage vs.Input voltage Figure 3: Quiescent Current vs.Supply Voltage 2.0 1.5 1.0 0.5 IQ mA Vs 5V 28V RL=100Ω RL=4.7KΩ Preregulator To improve the transient immunity a preregulator stabilized the internal supply voltage to 5V.This internal voltage is present at Pin3(Vz).This voltage should not be used as an output because the output capability is very small( ≦10μ A). This output may be used as an option when a better transient behaviour for supply voltages less than 8V is required(see also application note). In this case a capacitor(100nF - 1μF) must be connected between Pin3 and GND.If this feature is not used Pin3 must be left open. Reset Circuit The block circuit diagram of the reset circuit is shown in Fig.4. the reset circuit supervises the output voltage. The reset thereshold of 4.5V is defined with the internal reference voltage and standby output drivider. The reset pulse delay time t RD,is defined with the charge time of an external capacitor C T: CT● 2V T R D = 2 μA The reaction time of the reset circuit originates from the discharge time limitation of the reset capacitor C T and is proportional of the reset capacitor CT and is proportional to the value of CT. The reactioin time of the reset circuit increases the noise immunity.Standby output voltagedrops below the reset threshold only a bit longer than th 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 Fig.5. Sense Comparator The sense comparator compares an input signal with an inte rnal voltage reference of typical 1.23V.The use of an external voltage divider makes this comparator flexible in th application. It can be used to supervise the input voltage either before or after the protection diode and to give additional informations to the microprocessor like low voltage warnings.