RT9198/A
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DS9198/A-14 April 2011 www.richtek.com
300mA, Low Noise, Ultra-Fast CMOS LDO Regulator
General Description
The RT9198/A is designed for portable RF and wireless
applications with demanding performance and space
requirements. The RT9198/A performance is optimized for
battery-powered systems to deliver ultra low noise and
low quiescent current. Regulator ground current increases
only slightly in dropout, further prolonging the battery life.
The RT9198/A also works with low-ESR ceramic
capacitors, reducing the amount of board space necessary
for power applications, critical in hand-held wireless
devices. The RT9198/A consumes less than 0.01uA in
shutdown mode and has fast turn-on time less than 50us.
The other features include ultra low dropout voltage, high
output accuracy, current limiting protection, and high ripple
rejection ratio. Available in the SOT-23-3, SOT-23-5,
TSOT-23-3, TSOT-23-5, SC-70-5, SC-82, MSOP-8 and
WDFN-6L 2x2 packages, the RT9198/A also offers a range
from 1.5V to 5.0V with 0.1V per step.
Applications
zCDMA/GSM Cellular Handsets
zBattery-Powered Equipment
zLaptop, Palmtops, Notebook Computers
zHand-Held Instruments
zPCMCIA Cards
zPortable Information Appliances
Ordering Information
Features
zz
zz
zLow-Noise for RF Application
zz
zz
zFast Response in Line/Loa d Tra nsient
zz
zz
zQuick Start-Up (T ypically 50us)
zz
zz
z< 0.01uA Standby Current When Shutdown
zz
zz
zLow Dropout : 220mV @ 300mA
zz
zz
zWide Operating Voltage Ranges : 2.5V to 5.5V
zz
zz
zTTL-Logic-Controlled Shutdown Input
zz
zz
zLow Temperature Coefficient
zz
zz
zCurrent Limiting Protection
zz
zz
zThermal Shutdown Protection
zz
zz
zOnly 1uF Output Capa citor Required f or Sta bility
zz
zz
zHigh Power Supply Rejection Ratio
zz
zz
zCustom Voltage Available
zz
zz
zRoHS Compliant and 100% Lead (Pb)-Free
Note :
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
RT9198/A-
Package Type
U5 : SC-70-5
U5R : SC-70-5 (R-Type)
Y : SC-82
V : SOT-23-3
B : SOT- 23-5
BR : SOT- 23-5 (R-Type)
BG : SOT- 23-5 (G-Type)
J3 : TSOT- 23-3
J5 : TSOT- 23-5
J5R : TSOT- 23-5 (R-Type)
J5G : TSOT- 23-5 (G-Type)
F : MSOP-8
QW : WDFN-6L 2x2 (W-Type)
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Output Voltage
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
1H : 1.85V
2H : 2.85V
4G : 4.75V
Chip Enable Function (Active Low)
Chip Enable Function (Active High)
RT9198/A
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DS9198/A-14 April 2011www.richtek.com
Typical Application Circuit
Pin Configurations
(TOP VIEW)
TSOT-23-5/SOT-23-5/
SC-70-5 (R-Type)
TSOT-23-5/SOT-23-5/
SC-70-5
WDFN-6L 2x2
TSOT-23-3/
SOT-23-3
SC-82MSOP-8
TSOT-23-5/
SOT-23-5(G-Type)
VIN
GND
VOUT
RT9198
COUT
1uF
CIN
1uF
VIN VOUT
ENChip Enable
On
Off
VIN
GND
VOUT
RT9198A
COUT
1uF
CIN
1uF
VIN VOUT
Chip Enable
Off
On
EN
VIN VOUT
GND
3
2
4
EN/EN
GND VOUT
VIN
2
3
VIN GND
VOUT NC
4
23
5
EN/EN VIN
GND
NC VOUT
4
23
5
EN/EN
NC GND
VIN VOUT
4
23
5
EN/EN
5
6
7
8
4
3
2
NC
NC
NC
VOUT
VIN
NC
GND
EN/EN
GND
NC
NC
VOUTVIN
5
4
1
2
3
6
EN/EN
GND
7
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Function Block Diagram
Functional Pin Description
Pin Name Pin Function
EN Chip Enable (Active High). Note that this pin is high impedance. There should be a pull low
100kΩ resistor connected to GND when the control signal is floating.
EN Chip Enable (Active Low). Note that this pin is high impedance. There should be a pull high
100kΩ resistor connected to VIN when the control signal is floating.
NC No Internal Connection.
GND, Exposed Pad Ground. The exposed pad must be soldered to a large PCB and connected to GND for
maximum power dissipation.
VOUT Output Voltage.
VIN Input Voltage.
Current-Limit
and
Thermal
Protection
MOS Driver
-
+
VOUT
Shutdown
and
Logic Control
VIN
Error
Amplifier
VREF
GND
EN/EN
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Absolute Maximum Ratings (Note 1)
zSupply Input Voltage ---------------------------------------------------------------------------------------------------- 6V
z Power Dissipation, PD @ TA = 25°C
TSOT-23-3/TSOT-23-5/SOT-23-3/SOT-23-5 ------------------------------------------------------------------------ 400mW
SC-70-5, SC-82 ---------------------------------------------------------------------------------------------------------- 300mW
MSOP-8 ------------------------------------------------------------------------------------------------------------------- 625mW
WDFN-6L 2x2 ------------------------------------------------------------------------------------------------------------- 606mW
zPackage Thermal Resistance (Note 2)
TSOT-23-3/TSOT-23-5/SOT-23-3/SOT-23-5, θJA ------------------------------------------------------------------- 250°C/W
SC-70-5, SC-82, θJA ----------------------------------------------------------------------------------------------------- 333°C/W
MSOP-8, θJA -------------------------------------------------------------------------------------------------------------- 160°C/W
WDFN-6L 2x2, θJA ------------------------------------------------------------------------------------------------------- 165°C/W
WDFN-6L 2x2, θJC ------------------------------------------------------------------------------------------------------- 20°C/W
zJunction Temperature --------------------------------------------------------------------------------------------------- 150°C
zLead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------------------- 260°C
zStorage Temperature Range ------------------------------------------------------------------------------------------- −65°C to 150°C
zESD Susceptibility (Note 3)
HBM (Human Body Mode) --------------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ---------------------------------------------------------------------------------------------------- 200V
Electrical Characteristics
(VIN = VOUT + 1V, CIN = COUT = 1μF, T A = 25°C, unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
Output Voltage Accuracy ΔVOUT I
OUT = 1mA −2 -- +2 %
Current Limit ILIM R
LOAD = 1Ω 360 400 -- mA
Quiescent Current IQ RT9198, VEN ≧ 1.2V, IOU T = 0mA
RT9198A, VEN ≦ 0.4V, IOUT = 0mA -- 90 130 μA
IOUT = 200mA -- 170 200
Dropout Voltage (Note 5) VDROP IOUT = 300mA -- 220 330 mV
Line Regulation ΔVLINE VIN = (VOUT + 1V) to 5.5V,
IOUT = 1mA -- -- 0.3 %
Load Regulation ΔVLOAD 1mA < IOUT < 300mA -- -- 0.6 %
Shutdown Current ISHDN RT9198, VEN = GND, Shutdown
RT9198A, VEN = VIN, Shutdown -- 0.01 1 μA
EN Input Bias Current IIBEN V
EN = GND or VIN -- 0 100 nA
Recommended Operating Conditions (Note 4)
zSupply Input Voltage ---------------------------------------------------------------------------------------------------- 2.5V to 5.5V
zEN Input Voltage --------------------------------------------------------------------------------------------------------- 0V to 5.5V
zJunction Temperature Range ------------------------------------------------------------------------------------------ −40°C to 125°C
zAmbient Temperature Range ------------------------------------------------------------------------------------------ −40°C to 85°C
To be continued
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Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2. θJA is measured in the natural convection at TA = 25°C on a low effective single layers thermal conductivity test board
of JEDEC 51-3 thermal measurement standard. The case point of θJC is on the exposed pad for the package.
Note 3. Devices are ESD sensitive. Handling precaution is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
Parameter Symbol Test Conditions Min Typ Max Unit
Logic-Low
Voltage VIL RT9198, VIN = 3V to 5.5V , Shut down
RT9198A, VIN = 3V to 5.5V, Enable -- -- 0.4
EN Threshold Logic-High
Voltage VIH RT9198, VIN = 3V to 5.5V, Enable
RT9198A, VIN = 3V to 5.5V, Shutdown 1.2 -- --
V
f = 100Hz -- −60 --
Power Supply
Rejection Rate f = 10kHz PSRR COUT = 1μF, IOUT = 100mA -- −30 -- dB
Thermal Shutdown
Temperature TSD -- 165 -- °C
Thermal Shutdown
Temperature Hysteresis ΔTSD -- 30 -- °C
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Typical Operating Characteristics
PSRR
-80
-60
-40
-20
0
20
0.01 0.1 1 10 100 1000
Frequency (kHz)
PSRR (dB)
VOUT = 2.5V
ILOAD = 10mA
ILOAD = 100mA
CIN = COUT = 1uF, X7R
10 100 1K 10K 100K 1M
(Hz)
Current Lim it vs. Input Vo ltage
300
350
400
450
500
550
600
22.533.544.555.566.5
Input Voltage (V)
Current Limit (mA)
RT9198/A-15
CIN = COUT = 1uF
Quiesent Current vs. Tempera ture
60
65
70
75
80
85
90
95
100
-50 -25 0 25 50 75 100 125
Temperature
Quiescent Current (uA)
(°C)
RT9198/A-15
VIN = 3.3V
CIN = COUT = 1uF
Output Voltage vs. Te mperature
1.6
1.7
1.8
1.9
2
-50 -25 0 25 50 75 100 125
Temperature
Output Voltage (V)
(°C)
VIN = 5V
CIN = COUT = 1uF
No Load
Dropout Voltage vs. Load Current
0
50
100
150
200
250
300
0 0.05 0.1 0.15 0.2 0.25 0.3
Load Current (A)
Dropout Voltage (mV)
RT9198/A-33
CIN = COUT = 1uF TJ = 125°C
TJ = 25°C
TJ = -40°C
EN Pin Shutdown Threshold vs. Temperature
0.25
0.5
0.75
1
1.25
1.5
-50 -25 0 25 50 75 100 125
Temperature
EN Pin Threshold Voltage (V)
(°C)
RT9198/A-15
VIN = 3.3V
CIN = COUT = 1uF
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Time (100μs/Div)
CIN = COUT = 1uF
Line Transient Response
Output Voltage
Deviation (mV)
Input Voltage
Deviation (V)
ILOAD = 50mA
5
4
3
20
0
-20
Time (100μs/Div)
VIN = 3.3V
CIN = COUT = 1uF
Load Transient Response
Output Voltage
Deviation (mV)
Load Current
(mA)
VOUT = 1.5V
ILOAD = 1mA to 250mA
400
200
0
50
0
-50
Time (100μs/Div)
CIN = COUT = 1uF
Line Transient Response
Output Voltage
Deviation (mV)
Input Voltage
Deviation (V)
ILOAD = 250mA
5
4
3
50
0
-50
Time (1ms/Div)
RT9198-18, VIN = 5V
CIN = COUT = 1uF
EN Pin Shutdown Response
EN Pin Voltage
(V)
Output Voltage
(V)
VOUT = 1.8V
ILOAD = 1mA
10
5
0
2
1
0
Time (10μs/Div)
RT9198-18, VIN = 5V
CIN = COUT = 1uF
Start Up
EN Pin Voltage
(V)
Output Voltage
(V)
VOUT = 1.8V
ILOAD = 1mA
10
5
0
2
1
0
Time (100μs/Div)
VIN = 3.3V
CIN = COUT = 1uF
Load Transient Response
Output Voltage
Deviation (mV)
Load Current
(mA)
VOUT = 1.5V
ILOAD= 1mA to 50mA
100
50
0
50
0
-50
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Time (5ms/Div)
VIN = 4.5V
CIN = COUT = 1uF
Noise
Noise (μV)
VOUT = 1.8V
ILOAD = 150mA
400
200
0
-200
-400
f = 10Hz to 100kHz
Time (5ms/Div)
VIN = 4.5V
CIN = COUT = 1uF
Noise
Noise (μV)
VOUT = 1.8V
No Load
400
200
0
-200
-400
f = 10Hz to 100kHz
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Applications Information
Like any low-dropout regulator, the external capacitors used
for the RT9198/A must be carefully selected for regulator
stability and performance. Using a capacitor whose value
is > 1μF on the RT9198/A input and the amount of
capacitance can be increased without limit. The input
capacitor must be located a distance of not more than
0.5 inch from the input pin of the IC and returned to a
clean analog ground. Any good quality ceramic or tantalum
can be used for this capacitor. The capacitor with larger
value and lower ESR (equivalent series resistance) provides
better PSRR and line-transient response.
The output capacitor must meet both requirements for
minimum amount of capacitance and ESR in all LDOs
application. The RT9198/A is designed specifically to work
with low ESR ceramic output capacitor in space-saving
and performance consideration. Using a ceramic capacitor
whose value is at least 1μF with ESR is more than 20mΩ
on the RT9198/A output ensures stability. The RT9198/A
still works well with output capacitor of other types due to
the wide stable ESR range. Figure 1. shows the curves of
allowable ESR range as a function of load current for various
output capacitor values. Output capacitor of larger
capacitance can reduce noise and improve load transient
response, stability, and PSRR. The output capacitor should
be located with in 0.5 inch from the VOUT pin of the
RT9198/A and returned to a clean analog ground.
Thermal Considerations
Thermal protection limits power dissipation in RT9198/A.
When the operating junction temperature exceeds 165°C,
the OTP circuit starts the thermal shutdown function and
turns the pass element off. The pass element turns on
again after the junction temperature cools by 30°C.
For continuous operation, do not exceed absolute
maximum operatiog junction temperature 125°C. The
power dissipation definition in device is shown as following
formula :
PD = (VIN − VOUT) x IOUT + VIN x IQ
The maximum power dissipation depends on the thermal
resistance of IC package, PCB layout, the rate of
surroundings airflow and temperature difference between
junction to ambient. The maximum power dissipation can
be calculated by following formula :
PD(MAX) = ( TJ(MAX) - TA ) / θJA
Where TJ(MAX) is the maximum operating junction
temperature 125°C, TA is the ambient temperature and the
θJA is the junction to ambient thermal resistance.
Instable
Enable Function
The RT9198/A features an LDO regulator enable/disable
function.
To assure the RT9198 LDO regulator will switch on, the
EN turn on control level must be greater than 1.2V. The
RT9198 LDO regulator will go into shutdown mode when
the voltage on the EN pin falls below 0.4V. For RT9198A,
the EN turn on control level must be lower than 0.4V to
assure the RT9198A LDO regulator switch on. The
RT9198A LDO regulator will go into shutdown mode when
the voltage on the EN pin is higher than 1.2 V. The RT9198A
equips a quick-discharge function to protect the system.
When the regulator is turned off by EN pin, the internal
MOSFET between VOUT and GND will be turned on to
discharge output voltage quickly. If the enable function is
not needed in a specific application, it may be tied to
GND/VIN to keep the LDO regulator in a continuously on
state.
Figure 1
Region of Stable COUT ESR vs . L o a d Cu rre n t
0.00
0.01
0.10
1.00
10.00
100.00
0 50 100 150 200 250 300
Load Current (mA)
COUT ESR (Ω)
COUT = 1uF
Instable
Stable
100
10
1
RT9198/A-15xU5
COUT = 1μF, X7R Simulation Verify
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For recommended operating conditions specification of
RT9198/A, where TJ(MAX) is the maximum junction
temperature of the die (125°C) and TA is the maximum
ambient temperature. The junction to ambient thermal
resistance (θJA is layout dependent) for TSOT-23-3/TSOT-
23-5/SOT-23-3/SOT-23-5 package is 250°C/W, SC-70-5
and SC-82 package is 333°C/W and WDFN-6L 2x2
package is 165°C/W on standard JEDEC 51-3 thermal
test board. The maximum power dissipation at TA = 25°C
can be calculated by following formula :
PD(MAX) = (125°C − 25°C)/250 = 400mW (TSOT-23-3/
TSOT-23-5/SOT-23-3/SOT-23-5)
PD(MAX) = (125°C − 25°C)/333 = 300mW (SC-70-5/SC-82)
PD(MAX) = (125°C − 25°C) / 165 = 606mW (WDFN-6L 2x2)
The maximum power dissipation depends on operating
ambient temperature for fixed TJ(MAX) and thermal
resistance θJA. For RT9198/A packages, the Figure 2. of
derating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
allowed.
Figure 2. Derating Curve for Packages
0
100
200
300
400
500
600
700
0 153045607590105120135
Ambient Temperature (°C)
Maximum Power Dissipation (mW) 1
SOT-23-3/SOT-23-5
TSOT-23-3/TSOT-23-5
SC 70-5
SC-82
WDFN-6L 2x2
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Outline Dimension
A
bA1
B
D
C
e
H
L
SOT-23-3 Surfa ce Mount Package
Dim e nsions In Mill imet e rs Dime nsions In I nche s
Symbol Min Max Min Max
A 0.889 1.295 0.035 0.051
A1 0.000 0.152 0.000 0.006
B 1.397 1.803 0.055 0.071
b 0.356 0.508 0.014 0.020
C 2.591 2.997 0.102 0.118
D 2.692 3.099 0.106 0.122
e 1.803 2.007 0.071 0.079
H 0.080 0.254 0.003 0.010
L 0.300 0.610 0.012 0.024
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AA1
e
b
B
D
C
H
L
SOT-23-5 Surface Mount Pa ckage
Dime nsions In Mi llimete rs Dimen sions In Inches
Symbol Min Max Min Max
A 0.889 1.295 0.035 0.051
A1 0.000 0.152 0.000 0.006
B 1.397 1.803 0.055 0.071
b 0.356 0.559 0.014 0.022
C 2.591 2.997 0.102 0.118
D 2.692 3.099 0.106 0.122
e 0.838 1.041 0.033 0.041
H 0.080 0.254 0.003 0.010
L 0.300 0.610 0.012 0.024
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TSOT-23-3 Surface Mount Package
Dime nsions In Mill imete rs Dimensions In Inch e s
Symbol Min Max Min Max
A 0.700 1.000 0.028 0.039
A1 0.000 0.100 0.000 0.004
B 1.397 1.803 0.055 0.071
b 0.300 0.510 0.012 0.020
C 2.591 3.000 0.102 0.118
D 2.692 3.099 0.106 0.122
e 1.803 2.007 0.071 0.079
H 0.080 0.254 0.003 0.010
L 0.300 0.610 0.012 0.024
A
bA1
B
D
C
e
H
L
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TSOT-23-5 Surface Mount Pa ckage
Dimensions In Millimeters Dimensions In Inches
Symbol Min Max Min Max
A 0.700 1.000 0.028 0.039
A1 0.000 0.100 0.000 0.004
B 1.397 1.803 0.055 0.071
b 0.300 0.559 0.012 0.022
C 2.591 3.000 0.102 0.118
D 2.692 3.099 0.106 0.122
e 0.838 1.041 0.033 0.041
H 0.080 0.254 0.003 0.010
L 0.300 0.610 0.012 0.024
AA1
e
b
B
D
C
H
L
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AA1
e
b
B
D
C
H
L
SC-70-5 Surface Mount Package
Dim e nsions In Mill imet e rs Dime nsions In I nche s
Symbol Min Max Min Max
A 0.800 1.100 0.031 0.044
A1 0.000 0.100 0.000 0.004
B 1.150 1.350 0.045 0.054
b 0.150 0.400 0.006 0.016
C 1.800 2.450 0.071 0.096
D 1.800 2.250 0.071 0.089
e 0.650 0.026
H 0.080 0.260 0.003 0.010
L 0.210 0.460 0.008 0.018
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Dimensions In Millimeters Dimension s In Inch es
Symbol Min Max Min Max
A 0.800 1.100 0.031 0.043
A1 0.000 0.100 0.000 0.004
B 1.150 1.350 0.045 0.053
b 0.150 0.400 0.006 0.016
b1 0.350 0.500 0.014 0.020
C 1.800 2.450 0.071 0.096
D 1.800 2.200 0.071 0.087
e 1.300 0.051
H 0.080 0.260 0.003 0.010
L 0.200 0.460 0.008 0.018
SC-82 Surface Mount Package
e
D
A
C
b
A1
L
B
b1
H
e
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L
D
EE1
e
A
bA1 A2
Dim e nsions In Mill imet ers Dimensions In I nche s
Symbol Min Max Min Max
A 0.810 1.100 0.032 0.043
A1 0.000 0.150 0.000 0.006
A2 0.750 0.950 0.030 0.037
b 0.220 0.380 0.009 0.015
D 2.900 3.100 0.114 0.122
e 0.650 0.026
E 4.800 5.000 0.189 0.197
E1 2.900 3.100 0.114 0.122
L 0.400 0.800
0.016 0.031
8-Lead MSOP Plastic Package
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Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit
design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be
guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek.
Richtek Technology Corporation
Headquarter
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Richtek Technology Corporation
Taipei Office (Marketing)
5F, No. 95, Minchiuan Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8862)86672399 Fax: (8862)86672377
Email: marketing@richtek.com
Dim e nsions In Mill imete rs Dimensions In I nc he s
Symbol Min Max Min Max
A 0.700 0.800 0.028 0.031
A1 0.000 0.050 0.000 0.002
A3 0.175 0.250
0.007 0.010
b 0.200 0.350 0.008 0.014
D 1.950 2.050 0.077 0.081
D2 1.000 1.450 0.039 0.057
E 1.950 2.050 0.077 0.081
E2 0.500 0.850 0.020 0.033
e 0.650 0.026
L 0.300 0.400
0.012 0.016
W-Type 6L DFN 2x2 Package
D
1
E
A3
A
A1
eb
L
D2
E2
SEE DETAIL A
11
2
2
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
DETAIL A
Pin #1 ID and Tie Bar Mark Options
