UTC-IC L2949E

UTC L2949E
LINEAR INTEGRATED CIRCUIT
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.
DIP-8
SOP-8
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%
SOP-20
*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.
PIN CONNECTIONS
Vz
1
20
SI
CT
2
19
VS
N.C.
3
18
N.C.
VS
1
8
VOUT
GND
4
17
GND
SI
2
7
SO
GND
5
16
GND
Vz
3
6
RES
GND
6
15
GND
CT
4
5
GND
GND
7
14
GND
N.C.
8
13
N.C.
N.C.
9
12
VOUT
RES
10
11
SO
DIP-8/SOP-8
SOP-20
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QW-R102-014,A
UTC L2949E
LINEAR INTEGRATED CIRCUIT
BLOCK DIAGRAM
Vz
VS
VOUT
CT
PREREGULATOR 5V
2μ
RES
+
2V
REG
RESET
VS
SO
SI
REF
1.23V
SENSE
1.23V
GND
ABSOLUTE MAXIMUM RATINGS
PARAMETER
DC Operating Supply Voltage
Transient Supply Voltage(T<1s)
Output Current
Output Voltage
Output Voltage
Reset Output
Sense Output
Output Current
Reset Output
Sense Output
Preregulator Output Voltage
Preregulator Output Current
Junction Temperature
Storage Temperature Range
UTC
SYMBOL
RATING
UNIT
VCC
VCC TR
Io
Vo
28
40
Internally Limited
20
V
V
VRES
Vso
IRES
Iso
Vz
Iz
Tj
Tstg
UNISONIC TECHNOLOGIES
V
20
20
V
5
5
7
5
-40~+150
-55~+150
mA
V
mA
℃
℃
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QW-R102-014,A
UTC L2949E
LINEAR INTEGRATED CIRCUIT
THERMAL DATA
DESCRIPTION
SYMBOL
Thermal Resistance Junction-ambient
DIP-8
SOP-8
SOP-20
Thermal Resistance Junction-pin (SOP-20)
Thermal Shutdown Junction temperature
SYMBOL
Rth j-pins
TJSD
Output Voltage
Output Voltage
Output Voltage
Vo
Vo
Vo
Dropout voltage
VD
Input to Output Voltage
Difference in Undervoltage
Condition
Max Output Leakage
VIO
Line Regulation
Load Regulation
Current Limit
Iouth **
VOL
VOLO
ILIM
CONDITIONS
Tj=25℃;Io=1mA
6V<VIN<28V,1mA<Io<50mA
VIN=40V;
T<1s 5mA<Io<100mA
Io=10mA
Io=50mA
Io=100mA
VIN=4V,Io=35mA
VIN=25V,Vo=5.5V
6V<VIN<28V, Io=1mA
1mA<Io<100mA
Vo=4.5V
Vo=4.5V,TJ=25℃
Vo=0V(note 1)
Io=0.3mA;TJ<100℃
UNIT
100
200
50
15
165
Rth j-amb
ELECTRICAL CHARACTERISTICS(Vs=14V;-40℃<Tj<125℃
PARAMETER
RATING
℃/W
℃/W
℃
unless otherwise specified)
MIN
TYP.
MAX
UNIT
4.95
4.90
4.75
5
5
5.05
5.10
5.25
V
V
V
0.1
0.2
0.3
0.25
0.4
0.5
0.4
V
V
V
V
20
105
120
50
200
100
Quiescent Current
IQSE
200
Quiescent Current
IQ
Io=100mA
** With this test we guarantee that with no output current the output voltage will not exceed 5.5V
80
μA
20
30
400
400
mV
mV
mA
mA
300
5
μA
MAX
UNIT
200
180
0.4
1
V
mV
ms
V
μA
mV
RESET
PARAMETER
SYMBOL
Reset Thereshold Voltage
Reset Thereshold Hysteresis
Reset Pulse Delay
Reset Output Low Voltage
Reset Output Gigh Leakage
Current
Delay Comparator Thereshold
Delay Comparator Thereshold
Hysteresis
VRT
VRTH
tRD
VRL
IRH
UTC
CONDITIONS
CT=100nF;TR≧100μs
RRES=10KΩ to Vs≧1.5V
MIN
TYP.
50
55
Vo-0.5V
100
100
VRES=5V
VCTth
VCTth,hy
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100
V
mV
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QW-R102-014,A
UTC L2949E
LINEAR INTEGRATED CIRCUIT
SENSE
PARAMETER
SYMBOL
Sense Low Thereshold
Sense Thereshold Hysteresis
Sense Output Low Voltage
Vst
Vsth
VSL
Sense Output Leakage
Sense Input Current
ISH
ISI
CONDITIONS
MIN
TYP.
MAX
UNIT
1.16
20
1.23
100
1.35
200
0.4
V
mV
V
-20
-8
1
-3
μA
μA
MIN
TYP.
MAX
UNIT
4.5
5
6
10
V
μA
VSI≦1.16V;Vs≧3V
Rso=10KΩ to Vo
Vso=5V;VSI≧1.5V
VSI=0
PREREGULATOR
PARAMETER
SYMBOL
Preregulator Output Voltage
Preregulator Output Current
Note 1:Foldback characteristic
Vz
Iz
CONDITIONS
Iz=10μA
APPLICATION CIRCUIT
VOUT
Vz (optional)
VBAT
VS
CT
PREREGULATOR 5V
RES
2μ
+
VOUT
2V
REG
RESET
VS
SI
SO
REF
1.23V
SENSE
1.23V
GND
For stability:Cs≧1μF, Co ≧4.7μF, ESR<10Ωat 10KHz
Recommended for application:Cs=Co=10µF to 100µF
APPLICATION INFORMATION
Suppl Voltage Transient
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.
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UTC L2949E
LINEAR INTEGRATED CIRCUIT
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.
10
5
0
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 300μA.
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.
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QW-R102-014,A
UTC L2949E
LINEAR INTEGRATED CIRCUIT
2.0
IQ
mA
VOUT
1.5
1.0
VOUT
5V
RL=100Ω
0.5
RL=4.7KΩ
0V
2V
5V
Vs
40V
Figure 2: Output Voltage vs.Input voltage
0
5V
28V
Vs
Figure 3: Quiescent Current vs.Supply Voltage
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 tRD,is defined with the charge time of an external capacitor CT:
CT● 2V
TRD=
2μA
The reaction time of the reset circuit originates from the discharge time limitation of the reset capacitor CT 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 internal 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.
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UTC L2949E
LINEAR INTEGRATED CIRCUIT
2V
REF 1.23V
RESET
22K
-
-
CT
+
OUT
+
2.8V
REG
Figure 4
40V
VOUT
VIN
5.0V
VRT+0.1V
VRT
VOUT1
1.5V
t
tR
RESET
tRD
SWITCH ON
tRR
tRD
INPUT DROP
DUMP
OUTPUT
OVERLOAD
SWITCH OFF
Figure 5
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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