Datasheet

UNISONIC TECHNOLOGIES CO., LTD
LR9273
Preliminary
CMOS IC
SUPER LOW ON
RESISTANCE/LOW VOLTAGE
1A LDO REGULATOR

DESCRIPTION
The UTC LR9273 is a typical LDO (linear regulator) with features of
super low dropout, 1A output current capability, and -3mV typical load
regulation at 1A.
During operation of the UTC LR9273, the dropout voltage is very
low and the response of line transient and load transient are very well.
Internally, there’re many functions of UTC LR9273 which can be
seen in the block figure. There are a voltage reference unit, an error
amplifier, resistor-net for voltage setting, a current limit circuit, and a
chip enable circuit in each UTC LR9273.
The UTC LR9273 can be used as an ideal of the power supply for
hand-held communication equipment, such as: power source for
portable communication equipment, power source for electrical
appliances, for example, cameras, VCRs and camcorders and power
source for battery-powered equipment.

SOP-8
1
SOT-89-5
FEATURES
* Ultra Supply Current:
* Standby Mode:
* Very Low Dropout Voltage:
* Ripple Rejection:
60µA (Typ.)
0.1µA (Typ.)
0.18V (Typ.)
@IOUT =1A, VOUT =2.85V
70dB (Typ.)
@f=1kHz,VOUT=2.85V
±100ppm/°C (Typ.)
* Temperature-Drift Coefficient
of Output Voltage:
* Well Line Regulation:
0.02%/ V (Typ.)
* Output Voltage Accuracy:
±1.5% (Typ.)
* Internal Fold Back Protection
250mA (Typ.) @ short mode
Circuit:
* CIN=COUT=4.7µF or more (Ceramic capacitors) are recommended
to be used with this IC
www.unisonic.com.tw
Copyright © 2015 Unisonic Technologies Co., Ltd
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LR9273

Preliminary
CMOS IC
ORDERING INFORMATION
Ordering Number
LR9273xG-xx-S08-R
LR9273xG-xx-AB5-R
Package
SOP-8
SOT-89-5
Packing
Tape Reel
Tape Reel
Notes: 1. x: The auto discharge function at off state are options as follows.
2. xx: Output Voltage, refer to Marking Information.

MARKING INFORMATION
PACKAGE
VOLTAGE CODE
5
MARKING
4
XX
Date Code
SOT-89-5
Active Code
28 :2.8V
35 :3.5V
AD: ADJ
LR9273
G
1
3
2
Voltage Code
SOP-8
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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LR9273
Preliminary

PIN CONFIGURATION

PIN DESCRIPTION
SOT-89-5
PIN NO.
1
2
3
4
5
PIN NAME
ADJ
NC
GND
CE
VIN
VOUT
CMOS IC
DESCRIPTION
ADJUST Pin (For Adjustable Version)
No Connection (For Fixed Version)
Ground Pin
Chip Enable Pin. Active when this Pin is high.
Input Pin
Output Pin
HSOP-8J
PIN NO.
PIN NAME
1
VOUT
Output Pin
2
ON/OFF
ON/OFF Pin
3, 5, 6, 7
NC
No connection (Note)
4
VSS
GND Pin
8
VIN
Input Pin
Note: The NC pin is electrically open.
The NC pin can be connected to VIN or VSS.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
DESCRIPTION
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LR9273

Preliminary
CMOS IC
BLOCK DIAGRAM
For Fixed Version
For Adjustable Version
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www.unisonic.com.tw
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LR9273

Preliminary
CMOS IC
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
RATINGS
UNIT
Input Voltage
VIN
6.5
V
Input Voltage (CE Pin)
VCE
-0.3~6.5
V
Output Voltage
VOUT
-0.3~ VIN+0.3
V
Power Dissipation
PD
900
mW
Operating Temperature
TOPT
-40~+85
°С
Storage Temperature
TSTG
-55~+125
°С
Note: 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.

ELECTRICAL CHARACTERISTICS
LR9273B/D-xx (Fixed Output Voltage Type)
PARAMETER
SYMBOL
TEST CONDITIONS
Input Voltage
VIN
Supply Current
ISS
VIN−VOUT=1.0V, VCE=VIN, IOUT=0A
Standby Current
Istandby VIN=6.0V, VCE=0V
VIN−VOUT=1.0V,
VOUT>1.5V
Output Voltage
VOUT
IOUT=100mA
VOUT≤1.5V
VIN−VOUT=0.3V, 1mA≤IOUT≤300mA, If
∆VOUT
VOUT≤1.1V, then VIN=1.4V
Load Regulation
∆IOUT
VIN−VOUT=0.3V, 1mA≤IOUT≤1A, If
VOUT≤1.1V, then VIN=1.7V
0.8≤VOUT<0.9
0.9≤VOUT<1.0
I OUT=300mA
1.0≤VOUT<1.5
1.5≤VOUT<2.6
Dropout Voltage
2.6≤VOU
VDIF
(TOPT=25°C)
0.8≤VOUT<0.9
0.9≤VOUT<1.0
IOUT=1A
1.0≤VOUT<1.5
1.5≤VOUT<2.6
2.6≤VOU
∆VOUT IOUT=100mA, VOUT+0.5V≤VIN ≤6.0V,
Line Regulation
∆VIN
If VOUT≤0.9V, 1.4V≤VIN≤6.0V
Ripple Rejection
RR
Output Voltage Temperature
Coefficient
∆VOUT
∆TOPT
Output Current
Short Current Limit
Pull-Down Resistance for
CE PIn
High
CE Input Voltage
Low
Thermal Shutdown Detector
Threshold Temperature
Thermal Shutdown
Released Temperature
Output Noise
ILIM
ISC
MIN
1.4
60
0.1
×0.98
-30
-15
-2
MAX UNIT
6.0
V
100
µA
1.0
µA
×1.02
V
+30
mV
15
-3
f=1kHz (VOUT≤4.0V)
f=1kHz (VOUT>4.0V)
Ripple 0.5Vp-p,VIN−VOUT=1.0V,
IOUT=100mA, If VOUT≤1.2V, VIN−VOUT=1.5V,
IOUT=100mA
IOUT=100mA, -40°С≤TOPT≤85°С
VIN-VOUT=1.0V
VOUT=0V
TYP
mV
0.33
0.22
0.18
0.10
0.05
0.72
0.64
0.56
0.32
0.18
0.57
0.47
0.32
0.15
0.10
V
V
V
V
V
V
V
V
V
V
0.05
0.20
%/V
70
dB
60
dB
±100
ppm/°С
250
A
mA
1
RPD
1.9
VCEH
VCEL
1.0
0
mV
5.0
15.0
MΩ
6.0
0.4
V
V
TTSD
Junction temperature
150
°С
TTSR
Junction temperature
120
°С
BW=10Hz~100kHz
30
µVrms
en
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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
Preliminary
CMOS IC
ELECTRICAL CHARACTERISTICS
LR9273B/D-xx (Adjustable Output Voltage Type)
PARAMETER
SYMBOL
TEST CONDITIONS
Input Voltage
VIN
Supply Current
ISS
VOUT=VADJ, VIN=2.0, VCE=VIN
Standby Current
Istandby VIN=6.0V, VCE=0V
Reference Voltage for
VOUT
VOUT=VADJ, VIN=2.0V, IOUT=100mA
Adjustable Voltage Regulator
Output Voltage Range
RVOUT
∆VOUT
VIN=1.4V, 1mA≤IOUT≤300mA
Load Regulation
∆IOUT
VIN=1.7V, 1mA≤IOUT≤1A
Dropout Voltage
VDIF
Line Regulation
∆VOUT
∆VIN
Ripple Rejection
RR
Output Voltage Temperature
Coefficient
∆VOUT
∆TOPT
Output Current
Short Current Limit
Pull-Down Resistance for
CE PIn
High
CE Input Voltage
Low
Thermal Shutdown Detector
Threshold Temperature
Thermal Shutdown
Released Temperature
Output Noise
ILIM
ISC
VOUT=VADJ
MIN
1.4
60
0.1
0.970
1.0
-15
MAX
6.0
100
1.0
1.000 1.030
-2
VIN
15
-3
IOUT=300mA
IOUT=1A
VOUT=VADJ, IOUT=100mA, 1.5V≤VIN ≤6.0V
f=1kHz Ripple 0.5Vp-p, VOUT=VADJ,
VIN=2.5V, IOUT=100mA
IOUT=100mA, -40°С≤TOPT≤85°С
VOUT=VADJ, VIN=2.0
VOUT=VADJ=0V
TYP
1.9
VCEH
VCEL
1.0
0
V
V
mV
mV
0.18
0.56
0.32
V
V
0.05
0.20
%/V
70
dB
±100
ppm/°С
250
A
mA
1
RPD
UNIT
V
µA
µA
5.0
15.0
MΩ
6.0
0.4
V
V
TTSD
Junction temperature
150
°С
TTSR
Junction temperature
120
°С
BW=10Hz~100kHz
30
µVrms
en
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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LR9273

Preliminary
CMOS IC
TEST CIRCUIT
VIN
C1
4.7µF
CE
VIN
VOUT
UTC
LR9273
C2
4.7µF
V
VOUT
GND
Basic Test Circuit
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
IOUT
A ISS
VOUT
UTC
LR9273
C1
4.7µF
CE
C2
4.7µF
GND
Test Circuit for Supply Current
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LR9273

Preliminary
CMOS IC
TYPICAL APPLICATION CIRCUIT
Example of the Typical Application of UTC LR9273 (Fixed Output Type)
Phase Compensation
In these ICs, phase compensation is made with the output capacitor for securing stable operation even if the load
current is varied. For this purpose, use as much as a capacitor as C2. Recommendation value is as follows:
Mounting on PCB
Make VDD and GND lines sufficient. If their impedance is high, a current flows, the noise picked up or unstable
operation may result. Further use a 4.7μF or more value capacitor between VDD pin and GND pin as close as
possible.
Set an Output capacitor between VOUT pin and GND pin for phase compensation as close as possible.
Technical Notes on Output Voltage Setting of Adjustable Output type
VOUT
R2
I2
ADJ
RIC
GND
UNISONIC TECHNOLOGIES CO., LTD
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VOUT
IIC
R3
I3
1.0V
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LR9273
Preliminary
CMOS IC
TYPICAL APPLICATION CIRCUIT(Cont.)

The Output Voltage may be adjustable for any output voltage between its 1.0V reference and its VDD setting level.
An external pair of resistors is required, as shown above.
The complete equation for the output voltage is described step by step as follows;
I2=IIC+I3 ………… (1)
I3=1.0/R3 ………… (2)
Thus,
I2=IIC+1.0/R3 ………… (3)
Therefore,
VOUT=1.0+R2×I2 ………… (4)
Put Equation (3) into Equation (4), then
VOUT=1.0+R2(IIC+1.0/R3)
=1.0(1+R2/R3)+R2×IIC ………… (5)
In 2nd term, or R2×IIC will produce an error in VOUT.
In Equation (5),
IIC=1.0/RIC ………… (6)
R2×IIC=R2×1.0/RIC
=1.0×R2/RIC ………… (7)
RIC (MΩ)
For better accuracy, choosing R2(<<RIC) reduces this error.
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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