Datasheet

UNISONIC TECHNOLOGIES CO., LTD
LR478
LINEAR INTEGRATED CIRCUIT
REGULATOR+RESET IC

DESCRIPTION
The UTC LR478 developed for use in CD-ROM drives,
combines a 3V regulator adapted to low power consumption with
a much-sought reset function (regulator input monitoring),with
internal delay circuit, set to detect 4.2V.

FEATURES
*Large Output Current: 300mA (max.)
*High Ripple Rejection Rate: 80dB(typ.)
*Internal Thermal Shutdown Circuit
*Internal Current Limiting Circuit
*Easy Set Delay Time from Voltage Detection to Reset Release

ORDERING INFORMATION
Order Number
Lead Free
Halogen Free
LR478L-xx-S08-T
LR478G-xx-S08-T
LR478L-xx-S08-R
LR478G-xx-S08-R
Note: XX: Output Voltage, refer to Marking Information.

Packing
SOP-8
SOP-8
Tube
Tape Reel
OUTPUT DETECTION VOLTAGE RANK LIST
PART NUMBER
LR478-3.4V
LR478-3.3V
LR478-2.5V

Package
REGULATOR OUTPUT VOLTAGE (V)
3.40±0.05
3.30±0.05
2.50±0.05
DETECTION VOLTAGE (V)
4.20±0.09
4.20±0.09
4.20±0.09
MARKING INFORMATION
PACKAGE
VOLTAGE CODE
SOP-8
25: 2.5V
33: 3.3V
34: 3.4V
www.unisonic.com.tw
Copyright © 2013 Unisonic Technologies Co., LTD
MARKING
1 of 8
QW-R119-003.C
LR478

PIN CONFIGURATION
N.C
1
8
Cd
RESET
2
7
GND
CONT
3
6
N.C
VIN
4
5
VOUT
PIN DESCRIPTION
PIN NO.
1
PIN NAME
N.C
FUNCTIONS
EQUIVALENT CIRCUIT DIAGRAM
Input voltage detection output
Input voltage detection output pin
RESET pin logic
2
RESET
VIN<VS
VIN>VS
RESET
L
H
Output voltage on/off-control pin
3
4
5
6
7
8
RESET
VCONT
L
H
CONT
VIN
VOUT
N.C
GND
Cd
Output
OFF
ON
Connect cont-terminal with VIN when it
is not used.
Voltage supply input pin
Regulator Output pin
GND pin
Delay time capacitor pin
RESET pin output delay time can be
set by the capacitance connected to
the Cd pin.
tPLH=100000.C
tPLH: transmission delay time[s]
C: capacitor value [F]
UNISONIC TECHNOLOGIES CO., LTD
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CONT
300K
400K
V OUT
Cd
+
-

LINEAR INTEGRATED CIRCUIT
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QW-R119-003.C
LR478

LINEAR INTEGRATED CIRCUIT
BLACK DIAGRAM
4
VIN
5
VOUT
+
CONT
+
Thermal
Protect
3
+
+
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
2 RESET
7
GND
8
Cd
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QW-R119-003.C
LR478

LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS
PARAMETER
SYMBOL
RATINGS
UNIT
Supply Voltage
VIN
-0.3 ~ +10
V
Output Current
IOUT
400
mA
Power Dissipation(note3)
PD
700
mW
Junction Temperature
TJ
+125
C
Operating Temperature
TOPR
-40 ~ +85
C
Storage Temperature
TSTG
-40~+150
C
Note 1. Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
2. The device is guaranteed to meet performance specification within 0℃ ~ +70℃ operating temperature range
and assured by design from –20℃ ~ +85℃.

RECOMMENDED OPERATION CONDITIONS
PARAMETER
Operating Voltage
Output Current

SYMBOL
VOPR
IOUT
RATINGS
0 ~ 10
0 ~ 300
UNIT
V
mA
ELECTRICAL CHARACTERISTICS(VCONT =1.6V, Ta=25C, unless otherwise specified )
PARAMETER
No-load Input Current 1
No-load Input Current 2
Input Current (OFF)
Regulator
Output Voltage
Input-Output Different Voltage
Line Regulation
Load Regulation
VOUT Temperature Coefficient
SYMBOL
TEST CONDITIONS
IQ1
VIN=5V, IOUT=0mA
IQ2
VIN=4V, IOUT=0mA
IQ3
VIN=5V, VCONT=0.4V
MIN
TYP
3
4
250
MAX
8
UNIT
mA
mA
μA
VOUT
VI/O(DIFF)
∆VOUT
∆VOUT
∆VOUT/∆T
3.33
3.40
0.15
10
20
100
3.47
0.3
20
120
V
V
mV
mV
ppm/C
50
80
Ripple Rejection
Output Noise Voltage
CONT Terminal Current
High Threshold Voltage
Low Threshold Voltage
Reset
Detection Voltage
Vs Temperature Coefficient
Hysteresis Voltage
Low-Level Output Voltage
Output Leakage Current
Output Current 1
Output Current 2
“H” Transmission Delay Time
Reset Delay Time
“L” Transmission Delay Time
Threshold Operating Voltage
RR
VIN
ICONT
VTHR(H)
VTHR(L)
VS
∆VS/∆T
VHYS
VOL
ILEAK
IOUT1
IOUT2
tPLH
tPLH 1
tPLH
VTHR(OPR)
VIN=5V, IOUT=30mA
VIN=3.2V, IOUT=150mA
VIN=4.4~5.5V, IOUT=30mA
VIN=5V, IOUT=0~300mA
VIN=5V, IOUT=30mA, TJ= -20~85C
VIN=5V, IOUT=30mA, f=120Hz
VRIPPLE=1VP-P
VIN=5V, IOUT=30mA, f=20~80kHz
VCONT=1.6V
1.6
-0.3
VIN= VTHR(H)→VTHR(L)
TJ= -20~85C
VIN= VTHR(H)→VTHR(L)→VTHR(H)
VIN=3.9V, RL=4.7K
VIN=5V
VIN=3.9V, RL=0
VIN=3.9V, RL=0, Ta= -20~85C
Cd =0.0μF
VIN=4V→5V, Cd =0.1μF
VoL=0.4V
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
40
5
4.11
4.20
100
100
dB
120 μVrms
10
μA
VIN+0.3
V
0.4
V
4.29
100
200
200
±0.1
30
10
30
0.65
90
20
90
0.85
5
3
5
V
ppm/C
mV
mV
μA
mA
mA
μs
ms
μs
V
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QW-R119-003.C
LR478
TEST CIRCUIT
VIN
A
4
5
1µF
VOUT
UTC LR478
4.7kO
2
8
3
RESET
7
A
+

LINEAR INTEGRATED CIRCUIT
6
GND
47µF
Cd
V
0.1µF
CONT
TYPICAL APPLICATION CIRCUIT
VIN
4
5
1µF
4.7kO
VOUT
UTC LR478
+

2
RESET
8
3
7
6
GND
COUT
47µF
Cd
0.1µF
CONT
Note: External output-capacitor(COUT) for stability is necessary due to without internally compensated.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
5 of 8
QW-R119-003.C
LR478

LINEAR INTEGRATED CIRCUIT
TIMING CHART
V IN
5V
? Vs
VS
0V
CONT
H
L
V OUT
5V
0V
RESET
tPLH1
5V
0V
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R119-003.C
LR478
TYPICAL CHARACTERISTICS
Detection Voltage
Output Volttage vs Temperature
IOUT =0mA
4
Output Voltage (V)
Output Voltage (V)
5
VOUT
3
2
RESET
1
0
0
1
2
3
Input Voltage (V)
4
5
Line Regulation
20
Load Regulation (mV)
Line Regulation (mV)
10
5
0
-5
-10
-15
-20
4
6
5
7
8
3.5
3.48
3.46
3.44
3.42
3.4
3.38
3.36
3.34
3.32
3.3
-25
0
9
-20
0
50
Output Voltage (V)
50
40
30
20
100000
Frequency (Hz)
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
100
150
200
Detecting Volttage vs Temperature
70
60
10000
300
-10
Ripple Rejection
1000
250
0
Output Current (mA)
100
90
80
100
125
10
Input Voltage (V)
10
0
10
100
20
-30
10
25
50
75
Temperature (°C)
Load Regulation
30
15
Ripple Rejection (dB)

LINEAR INTEGRATED CIRCUIT
4.3
4.28
4.26
4.24
4.22
4.2
4.18
4.16
4.14
4.12
4.1
-25
0
25
50
75
100
125
Temperature (°C)
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QW-R119-003.C
LR478

LINEAR INTEGRATED CIRCUIT
TYPICAL CHARACTERISTICS(Cont.)
Allowable Loss
1000
Allowable loss (mV)
On board 25×40×1mm
800
600
400
200
0
0
25
50
75
100
125
Temperature (°C)
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.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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QW-R119-003.C
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