RICHTEK RT9172_08

RT9172
3A Fixed Output Voltage LDO Regulator
Ordering Information
RT9172
-
Package Type
T5 : TO-220-5
M5 : TO-263-5
T : TO-220
M : TO-263
G : SOT-223
S : SOP-8
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commercial Standard)
Output Voltage
15 : 1.5V
16 : 1.6V
:
32 : 3.2V
33 : 3.3V
Low Dropout Voltage
Low Ground Pin Current
Load Regulation of 0.4% at 3A
0.5mA Quiescent Current in Shutdown Mode
Guaranteed Output Current of 3A DC
Available in TO-263 and TO-220 Packages
Output Voltage Accuracy ±1.5%
Error Flag Indicates Output Status
Sense Option Improves Better Load Regulation
Extremely Low Output Capacitor Requirements
Over-Temperature/Over- Current Protection
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Microprocessor Power Supplies
GTL, GTL+, BTL, and SSTL Bus Terminators
Power Supplies for DSPs
SCSI Terminator
Post Regulators
High Efficiency Linear Regulators
Battery Chargers
Other Battery Powered Applications
Pin Configurations
(TOP VIEW)
VIN GND VOUT
(TAB)
The RT9172 series of low-dropout linear regulators operate
from a +2.25V to +6.0V input supply. A wide range of preset
output voltage options is available. These low dropout linear
regulators respond very fast to step changes in load, which
are suitable for low voltage microprocessor applications.
The RT9172 uses an internal PMOS as the pass device,
which does not cause extra GND current in heavy load
and dropout condition. The shutdown mode of low operation
current makes the IC suitable for power-saving systems.
The other features include current limiting and over
temperature protection.
Features
3
General Description
1
2
S : Pin Out Exchange
N : Pin 5 bond SENSE
F : Pin 5 bond FLG
1
TO-220
Note :
2
3
VIN GND VOUT
(TAB)
TO-263
Richtek Pb-free and Green products are :
`RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`Suitable for use in SnPb or Pb-free soldering processes.
`100%matte tin (Sn) plating.
1
2
3
VIN GND VOUT
(TAB)
VOUT
SENSE
GND
NC
2
3
4
8
7
6
5
VIN
GND
GND
EN
SOP-8
SOT-223
DS9172-15 April 2008
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1
RT9172
5
SENSE/FLG
5
SENSE/FLG
4
VOUT
4
VOUT
3
GND (TAB)
3
GND (TAB)
2
VIN
2
VIN
1
EN
1
EN
TO-220-5
RT9172NRT9172F-
TO-263-5
xT5
xT5
RT9172NRT9172F-
xM5
xM5
5
VOUT
5
VOUT
4
SENSE
4
SENSE
3
GND (TAB)
3
GND (TAB)
2
EN
2
EN
1
VIN
1
VIN
TO-220-5
RT9172S-
TO-263-5
xT5
RT9172S-
xM5
Functional Pin Description
Pin No.
RT9172F
RT9172N
RT9172S
RT9172-
xT
RT9172-
xM
RT9172-
xG
Pin Nam e
Pin Function
1
1
2
--
EN
Chip Enable (Active Hight)
2
2
1
1
VIN
Power Input Voltage
3
3
3
2
GND
Ground
4
4
5
3
VOUT
Output Voltage
5
--
--
--
FLG
ERROR Flag
--
5
4
--
SENSE
Remote Sense
Typical Application Circuit
RT9172-25
CIN
10uF
VIN
VOUT
GND
+
+
VIN = 3.3V
VOUT
2.5V, 3A
COUT
Figure 1
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2
DS9172-15 April 2008
RT9172
Trace resistance = Rt
RT9172N-25
VIN
+
VIN = 3.3V
CIN
10uF
VOUT
VLOAD = 2.5V
+
10K
EN
ILOAD
L
O
A
D
COUT
SENSE
GND
Figure 2
Trace resistance = Rt
RT9172F-25
VIN
+
VIN = 3.3V
VOUT
10K
10K
EN
VLOAD = 2.5V -ILOADRt
+
CIN
10uF
VOUT = 2.5V
ILOAD
COUT
FLG
GND
L
O
A
D
Figure 3
Recommend COUT: Please note that the part must be paralleled with the least a 100μF electrolytic capacitor when
using a 10μF (or greater) ceramic type as the output capacitor to prevent the output oscillating.
Function Block Diagram
RT9172F
VOUT
VIN
Buffer
Amlifier
Thermal
EN
+
Current
Limiting
Sensor
-
+
FLG
VREF
GND
DS9172-15 April 2008
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3
RT9172
RT9172N/RT9172S
VOUT
VIN
Buffer
Amlifier
Thermal
SENSE
-
EN
+
Current
Limiting
Sensor
VREF
GND
RT9172
VOUT
VIN
Buffer
Amlifier
Thermal
+
Current
Limiting
Sensor
-
VREF
GND
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DS9172-15 April 2008
RT9172
Absolute Maximum Ratings
Input Voltage ------------------------------------------------------------------------------------------------------------ 6V
Power Dissipation, PD @ TA = 25°C
SOT-223 ----------------------------------------------------------------------------------------------------------------- 0.741W
SOP-8 -------------------------------------------------------------------------------------------------------------------- 0.625W
TO-263 ------------------------------------------------------------------------------------------------------------------- 2.222W
TO-220 ------------------------------------------------------------------------------------------------------------------- 1.820W
Package Thermal Resistance (Note 4)
SOT-223, θJC ----------------------------------------------------------------------------------------------------------- 23°C/W
SOT-223, θJA ------------------------------------------------------------------------------------------------------------ 135°C/W
SOP-8, θJC -------------------------------------------------------------------------------------------------------------- 45°C/W
SOP-8, θJA -------------------------------------------------------------------------------------------------------------- 160°C/W
TO-263, θJC ------------------------------------------------------------------------------------------------------------- 7.8°C/W
TO-263, θJA ------------------------------------------------------------------------------------------------------------- 45°C/W
TO-220, θJC ------------------------------------------------------------------------------------------------------------- 15°C/W
TO-220, θJA ------------------------------------------------------------------------------------------------------------- 55°C/W
ESD Rating ------------------------------------------------------------------------------------------------------------- 3 kV
Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C
Junction Temperature Range ---------------------------------------------------------------------------------------- −40°C to +125°C
Electrical Characteristics
(Limits in standard typeface are for TA = 25°C, unless otherwise specified: VIN = VO(NOM) + 1.0V, IL = 10mA,
COUT = 10uF(Electrolytic), VEN = VIN)
Param eter
Symbol
Test Conditions
Min
Typ
Max
Units
-1.5
0
+1.5
%
2.25
--
5.5
V
VOUT + 0.4V < VIN < 5.5V
--
0.35
1
%
Note 1
--
0.4
1
Note 2
--
0.1
0.4
Note 3
--
0.1
0.4
IL = 3A
--
400
700
mV
--
1.2
3
mA
--
0.5
5
μA
Output Voltage Tolerance
Input Voltage Range
V IN
Line Regulation
ΔV LINE
Load Regulation
ΔV LOAD
%
Dropout Voltage
V DROP
Quiescent Current
IQ
Shutdown Supply Current
IGS D
Peak Output Current
IO(P EAK)
3.5
5
--
A
ILIMIT
3.5
5
--
A
Guaranteed by design
--
170
--
°C
Guaranteed by design
--
10
--
°C
VEN = 0V
Short Circuit Protection
Current Limit
Over Temperature Protection
Shutdown Threshold
Thermal Shutdown Hysteresis
TSD
To be continued
DS9172-15 April 2008
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5
RT9172
Param eter
Symbol
Test Conditions
Min
Typ
Max
Units
Output = High
1.2
V IN
--
Output = Low
--
0
0.4
VEN = VIN
--
0.1
--
nA
--
1
--
nA
2
--
--
mA
Shutdown Function
EN Pin Shutdown Threshold
V EN
EN Input Current
FLG Pin Leakage Current
ILE AKAGE
FLG Pin Sink Current
VFLG = 0.5V
V
Note 1. RT9172-xX, RT9172F-XXxX5, 10mA < IL < 3A
Note 2. RT9172S-XXxX5, RT9172N-XXxX5, 10mA < IL < 3A
Note 3. RT9172xS, 10mA < IL < 1.5A
Note 4. θJA is measured in the natural convection at T A = 25°C on a low effective thermal conductivity test board of
JEDEC 51-3 thermal measurement standard. The case point of θJC is on the center of the exposed pad. The pad size
is 125mm2 on TO-263 packages.
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DS9172-15 April 2008
RT9172
Typical Operating Characteristics
Temperature Stability
Quiescent Current vs. Load Current
1.4
Quiescent Current (mA)
2.60
Output Voltage (V)
2.56
2.52
2.48
VOUT = 2.5V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
VIN = VO + 1.0V
ILOAD = 10mA
2.44
1.2
1.0
0.8
0.6
0.4
VOUT = 2.5V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
VIN = VO + 1.0V
0.2
0.0
2.40
-35
-15
5
25
45
65
85
105
0.0
125
0.5
1.0
Temperature (° C)
2.5
3.0
Quiescent Current vs. Supply Voltage
Quiescent Current vs. Temperature
1.5
1.2
Quiescent Current (mA)
Quiescent Current (mA)
2.0
Load Current (A)
1.4
1.0
0.8
0.6
VOUT = 2.5V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
VIN = VO + 1.0V
ILOAD = 10mA
0.4
0.2
1.2
0.9
0.6
VOUT = 2.5V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
VIN = 2V to 6V
ILOAD = 10mA
0.3
0.0
0.0
-35
-15
5
25
45
65
85
105
2.0
125
2.5
3.0
Temperature (° C)
4.0
4.5
5.0
5.5
6.0
Current Limit vs. Temperature
6.0
VOUT = 2.5V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
5.2
Current Limit (A)
0.6
3.5
Supply Voltage (V)
Dropout Voltage (VIN - VOUT)
0.7
Dropout Voltage (V)
1.5
0.5
0.4
TJ = 125°C
0.3
0.2
VOUT = 2.5V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
VIN = VOUT + 1.0V
4.4
3.6
2.8
TJ = 25°C
0.1
2.0
0
0.0
0.5
1.0
1.5
2.0
Load Current (A)
DS9172-15 April 2008
2.5
3.0
-35
-15
5
25
45
65
85
105
125
Temperature (° C)
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RT9172
PSRR
VOUT = 2.5V
COUT = 10uF (Electrolytic)
-20
ILOAD = 100mA
ILOAD = 10mA
-25
PSRR (dB)
Load Regulation Deviation
0.00
Output Voltage Deviation (%) A
-15
-30
-35
-40
-45
-50
-0.03
-0.06
-0.09
VOUT = 2.5V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
ILOAD = 10mA
-0.12
-0.15
-55
10
100
1K
10K
100K
1M
-35
-15
5
Frequency (Hz)
25
45
65
85
105
125
Temperature (° C)
EN Pin Shutdown Response
Range of Stable ESR Values
2
1
0
Shutdown
Voltage (V)
≈
VOUT = 1.8V
CIN = 1uF (Ceramic)
COUT = 10uF (Tantalum)
ILOAD = 100mA
≈
TA = 25°C
2
1
0
Output Capacitor ESR( Ω ).
Output
Voltage (V)
100
CIN = 1uF (MLCC)
COUT = 10uF (MLCC)
10
Stable Region
1
0.1
Reqion of Instability
0.01
2
3
4
6
7
8
9
10
1.5
2
2.5
Line Transient Response
COUT = 10uF (Electrolytic)
ILOAD = 100mA
≈
≈
5.5
4.5
3.5
1
1.5
2
2.5
3
Time (ms)
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1
Line Transient Response
0
0.5
0.5
Time (ms)
20
0
0
Output Current (A)
CIN = 1uF (Ceramic)
VOUT = 2.5V
TA = 25°C
40
5
Output Voltage
Deviation(mV)
1
3.5
4
4.5
5
Input Voltage
Deviation (V)
Input Voltage
Deviation (V)
Output Voltage
Deviation(mV)
0
CIN = 1uF (Ceramic)
VOUT = 2.5V
TA = 25°C
40
3
COUT = 10uF (Tantalum)
ILOAD = 100mA
20
0
≈
≈
5.5
4.5
3.5
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Time (ms)
DS9172-15 April 2008
RT9172
0
≈
≈
6
3
0
0.1
0.2 0.3 0.4 0.5 0.6 0.7
0.9
COUT = 10uF (Tantalum)
ILOAD : 100mA 3A
100
0
≈
≈
6
3
0
10
0
0.1
0.2 0.3 0.4 0.5 0.6 0.7
Time (ms)
Time (ms)
Noise Signal
Noise Signal
CIN = 1uF (Ceramic)
VOUT = 2.5V
TA = 25°C
1.5
0.8
CIN = 1uF (Ceramic)
VOUT = 2.5V
TA = 25°C
200
↓
Output Voltage
Deviation(mV)
100
0
COUT = 10uF (Tantalum)
ILOAD :10mA
CIN = 1uF (Ceramic)
VOUT = 2.5V
TA = 25°C
1.5
1.0
Output Voltage (mV)
Output Voltage (mV)
COUT = 100uF (Electrolytic)
ILOAD :100mA 3A
↓
CIN = 1uF (Ceramic)
VOUT = 2.5V
TA = 25°C
200
Load Transient Response
Load Current
Deviation (A)
Load Current
Deviation (A)
Output Voltage
Deviation(mV)
Load Transient Response
0.5
0
-0.5
-1.0
-1.5
0.8
0.9
10
COUT = 10uF (Tantalum)
ILOAD :100mA
1.0
0.5
0
-0.5
-1.0
-1.5
0
1
2
3
4
5
6
Time (ms)
DS9172-15 April 2008
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
Time (ms)
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RT9172
Application Information
Capacitor Selection
An output capacitor as part of the device frequency
compensation to maintain stability and improve
transient response.
Proper capacitor selection is important to ensure proper
operation. When the output capacitor is 10μF or greater,
the output capacitor should have an ESR less than 2Ω.
This will improve transient response as well as promote
stability.
Ultra-low-ESR capacitor (<100mΩ), such as ceramic
chip capacitors, may promote instability. These very
low ESR levels may cause an oscillation and/or
underdamped transient response. A low-ESR solid
tantalum capacitor works extremely well and provides
good transient response and stability over temperature.
Aluminum electrolytics can also be used, as long as
the ESR of the capacitor is <2Ω. The value of the output
capacitor can be increased without limit. Higher
capacitor values help to improve transient response
and ripple rejection and reduce output noise.
The RT9172 requires a minimum input capacitance of
1μF between the input and ground pins to prevent any
impedance interactions with the supply. The RT9172
requires a minimum of 10μF (tantalum, or electrolytic)
capacitance between the output and ground pins for
proper operation. Please note that the part must be
paralleled with the least a 100μF electrolytic capacitor
when using a 10μF (or greater) ceramic type as the
output capacitor to prevent the output oscillating.
Error Operation (FLG)
The RT9172 produces a logic low signal at the FLG pin
when the output drops out of regulation due to low input
voltage, current limiting, or thermal limiting.
The internal error FLG comparator has an open drain
output stage. Hence, the FLG pin should be pulled high
through a pull up resistor.
Sense Pin
In applications where the regulator output is not very close
to the load, RT9172 can provide better remote load
regulation using the SENSE pin. Figure 2. and Figure 3.
depict the advantage of the SENSE option. RT9172
regulates the voltage at the output pin. Hence, the voltage
at the remote load will be the regulator output voltage
minus the drop across the trace resistance. For example,
in the case of a 3.3V output, if the trace resistance is
100mΩ, the voltage at the remote load will be 3V with 3A
of load current, ILOAD. The RT9172 regulates the voltage
at the sense pin. Connecting the sense pin to the remote
load will provide regulation at the remote load, as shown
in Figure 2. and Figure 3.
Chip Enable Operation
A CMOS logic level signal at the chip enable (EN) pin will
turn-off the regulator. Pin EN must be actively terminated
through a 10kΩ pull-up resistor for a proper operation. If
this pin is driven from a source that actively pulls high
and low (such as a CMOS rail to rail comparator), the
pull-up resistor is not required. This pin must be tied to
VIN if not used.
Dropout Voltage
The dropout voltage of a regulator is defined as the minimum
input-to-output differential required to stay within 2% of
the output voltage. The RT9172 uses an internal MOSFET
with an RDS(ON) 160mΩ. For CMOS LDOs, the dropout
voltage is the product of the load current and the RDS(ON)
of the internal MOSFET.
Maximum Output Current Capability
RT9172 can deliver a continuous current of 1.5 A over the
full operating temperature range. A heatsink may be required
depending on the maximum power dissipation and
maximum ambient temperature of the application. Under
all possible conditions, the junction temperature must be
within the range specified under operating conditions. The
total power dissipation of the device is given by : PD = (VIN
- VOUT) IOUT+ (VIN) IGND
where IGND is the operating ground current of the device
(specified under Electrical Characteristics).
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DS9172-15 April 2008
RT9172
Outline Dimension
C
D
F
M
E1
L1
E
b1
A1
L2
e
b
b2
A
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
4.064
4.826
0.160
0.190
A1
2.032
2.921
0.080
0.115
b
0.635
1.016
0.025
0.040
b1
1.143
1.524
0.045
0.060
b2
0.305
0.559
0.012
0.022
C
1.143
1.397
0.045
0.055
D
9.779
10.668
0.385
0.420
E
7.620
9.398
0.300
0.370
e
2.286
2.794
0.090
0.110
E1
11.176
12.954
0.440
0.510
F
2.616
2.870
0.103
0.113
L1
17.526
18.542
0.690
0.730
L2
7.544
8.636
0.297
0.340
M
3.708
3.962
0.146
0.156
3-Lead TO- 220 Plastic Package
DS9172-15 April 2008
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11
RT9172
C
D
U
B
V
E
L1
b1
L2
e
b2
b
A
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
4.064
4.826
0.160
0.190
B
1.143
1.676
0.045
0.066
b
0.660
0.914
0.026
0.036
b1
1.143
1.397
0.045
0.055
b2
0.305
0.584
0.012
0.023
C
1.143
1.397
0.045
0.055
D
9.652
10.668
0.380
0.420
E
8.128
9.652
0.320
0.380
e
2.286
2.794
0.090
0.110
L1
14.605
15.875
0.575
0.625
L2
2.286
2.794
0.090
0.110
U
6.223 Ref.
0.245 Ref.
V
7.620 Ref.
0.300 Ref.
3-Lead TO- 263 Surface Mount
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DS9172-15 April 2008
RT9172
D
D1
H
C
B
L
e
L1
e
A
A1
b
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
1.450
1.803
0.057
0.071
A1
0.020
0.100
0.0008
0.0047
b
0.610
0.787
0.024
0.031
B
3.302
3.708
0.130
0.146
C
6.706
7.290
0.264
0.287
D
6.299
6.706
0.248
0.264
D1
2.896
3.150
0.114
0.124
e
2.261
2.362
0.089
0.093
H
0.229
0.330
0.009
0.013
L
1.550
1.950
0.061
0.077
L1
0.800
1.100
0.009
0.013
3-Lead SOT-223 Surface Mount Package
DS9172-15 April 2008
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13
RT9172
C
D
M
F
E1
E
P
A1
e
b
b2
A
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
4.064
4.826
0.160
0.190
A1
2.032
2.921
0.080
0.115
b
0.635
1.016
0.025
0.040
b2
0.305
0.559
0.012
0.022
C
1.143
1.397
0.045
0.055
e
1.524
1.829
0.060
0.072
D
9.779
10.668
0.385
0.420
E
7.620
9.398
0.300
0.370
E1
11.176
12.954
0.440
0.510
F
14.224
15.113
0.560
0.595
M
3.708
3.962
0.146
0.156
P
24.689
26.416
0.972
1.040
5-Lead TO-220 Plastic Package
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14
DS9172-15 April 2008
RT9172
C
D
U
B
V
E
L1
L2
b
e
b2
A
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
4.064
4.826
0.160
0.190
B
1.143
1.676
0.045
0.066
b
0.660
0.914
0.026
0.036
b2
0.305
0.584
0.012
0.023
C
1.143
1.397
0.045
0.055
D
9.652
10.668
0.380
0.420
E
8.128
9.652
0.320
0.380
e
1.524
1.829
0.060
0.072
L1
14.605
15.875
0.575
0.625
L2
2.286
2.794
0.090
0.110
U
6.223 Ref.
0.245 Ref.
V
7.620 Ref.
0.300 Ref.
5-Lead TO-263 Plastic Surface Mount Package
DS9172-15 April 2008
www.richtek.com
15
RT9172
H
A
M
J
B
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
3.988
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.508
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.050
0.254
0.002
0.010
J
5.791
6.200
0.228
0.244
M
0.400
1.270
0.016
0.050
8-Lead SOP Plastic Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465
Email: [email protected]
www.richtek.com
16
DS9172-15 April 2008