UNISONIC TECHNOLOGIES CO., LTD
LR478
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.
LINEAR INTEGRATED CIRCUIT
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
SOP-8
*Pb-free plating product number: LR478L
ORDERING INFORMATION
Order Number
Normal
Lead Free Plating
LR478-xx-S08-R
LR478L-xx-S08-R
LR478-xx-S08-T
LR478L-xx-S08-T
Package
SOP-8
SOP-8
Packing
Tape Reel
Tube
Note: xx: Output Voltage, refer to Rank List as below.
OUTPUT DETECTION VOLTAGE RANK LIST
PART NUMBER
LR478-3.4V
LR478-3.3V
LR478-2.5V
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
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Copyright © 2005 Unisonic Technologies Co., LTD
1 of 8
QW-R112-001,B
LR478
PIN CONFIGURATION
N.C
RESET
CONT
V
IN
1
2
3
4
LINEAR INTEGRATED CIRCUIT
8
7
6
5
Cd
GND
N.C
V
OUT
PIN DESCRIPTION
PIN NO.
1
PIN NAME
N.C
FUNCTIONS
Input voltage detection output
Input voltage detection output pin
RESET pin logic
2
RESET
RESET
V
IN
<V
S
L
V
IN
>V
S
H
Output voltage on/off-control pin
V
CONT
3
CONT
L
H
Output
OFF
ON
EQUIVALENT CIRCUIT DIAGRAM
RESET
CONT
300K
400K
4
5
6
7
V
IN
V
OUT
N.C
GND
Connect cont-terminal with V
IN
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.
t
PLH
=100000.C
t
PLH
: transmission delay time[s]
C: capacitor value [F]
V
OUT
Cd
+
-
8
Cd
UNISONIC TECHNOLOGIES CO., LTD
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QW-R112-001,B
LR478
BLACK DIAGRAM
LINEAR INTEGRATED CIRCUIT
4
V
IN
5
-
+
V
OUT
CONT
3
Thermal
Protect
+
-
-
+
-
+
2 RESET
7
8
GND
Cd
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QW-R112-001,B
LR478
ABSOLUTE MAXIMUM RATINGS
PARAMETER
LINEAR INTEGRATED CIRCUIT
SYMBOL
RATINGS
UNIT
Supply Voltage
V
IN
-0.3 ~ +10
V
Output Current
I
OUT
400
mA
Power Dissipation(note3)
P
D
700
mW
Junction Temperature
T
J
+125
°C
Operating Temperature
T
OPR
-20 ~ +85
°C
Storage Temperature
T
STG
-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
V
OPR
I
OUT
RATINGS
0 ~ 10
0 ~ 300
UNIT
V
mA
ELECTRICAL CHARACTERISTICS
(V
CONT
=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
V
OUT
Temperature Coefficient
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
SYMBOL
TEST CONDITIONS
I
Q
1
V
IN
=5V, I
OUT
=0mA
I
Q
2
V
IN
=4V, I
OUT
=0mA
I
Q
3
V
IN
=5V, V
CONT
=0.4V
V
IN
=5V, I
OUT
=30mA
V
I/O(DIFF)
V
IN
=3.2V, I
OUT
=150mA
∆V
OUT
V
IN
=4.4~5.5V, I
OUT
=30mA
∆V
OUT
V
IN
=5V, I
OUT
=0~300mA
∆V
OUT
/∆T V
IN
=5V, I
OUT
=30mA, T
J
= -20~85°C
V
IN
=5V, I
OUT
=30mA, f=120Hz
RR
V
RIPPLE
=1V
P-P
V
IN
V
IN
=5V, I
OUT
=30mA, f=20~80kHz
I
CONT
V
CONT
=1.6V
V
THR(H)
V
THR(L)
VS
∆V
S
/∆T
V
HYS
V
OL
I
LEAK
I
OUT
1
I
OUT
2
t
PLH
t
PLH
1
t
PLH
V
THR(OPR)
V
IN
= V
THR(H)
→V
THR(L)
T
J
= -20~85°C
V
IN
= V
THR(H)
→V
THR(L)
→V
THR(H)
V
IN
=3.9V, R
L
=4.7K
V
IN
=5V
V
IN
=3.9V, R
L
=0
V
IN
=3.9V, R
L
=0, Ta= -20~85°C
Cd =0.0µF
V
IN
=4V→5V, Cd =0.1µF
V
oL
=0.4V
V
OUT
MIN
TYP
3
4
250
3.40
0.15
10
20
100
80
40
5
1.6
-0.3
4.11
100
100
5
3
5
30
10
30
0.65
90
20
90
0.85
4.20
100
MAX
8
UNIT
mA
mA
µA
V
V
mV
mV
ppm/°C
dB
120 µVrms
10
µA
V
IN
+0.3
V
0.4
V
4.29
200
200
±0.1
V
ppm/°C
mV
mV
µA
mA
mA
µs
ms
µs
V
3.33
3.47
0.3
20
120
50
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QW-R112-001,B
LR478
TEST CIRCUIT
LINEAR INTEGRATED CIRCUIT
A
1μF
V
IN
4
UTC LR478
5
V
OUT
A
+
47μF
V
4.7kΩ
RESET
2
3
7
GND
CONT
6
8
Cd
0.1μF
TYPICAL APPLICATION CIRCUIT
V
IN
1μF
4.7kΩ
4
UTC LR478
2
5
V
OUT
C
OUT
47μF
8
3
7
6
GND
Cd
RESET
CONT
0.1μF
Note: External output-capacitor(C
OUT
) for stability is necessary due to without internally compensated.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
+
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QW-R112-001,B
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