RT9198/A
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 0.01μA in shutdown mode and has fast turn-on time less than 50μs. 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, SC-70-5, SC-82 and WDFN-6L 2x2 packages, the RT9198/ A also offers a range from 1.5V to 5.0V with 0.1V per step.
Features
Low-Noise for RF Application Fast Response in Line/Load Transient Quick Start-Up (Typically 50μs) < 0.01μA Standby Current When Shutdown Low Dropout : 220mV @ 300mA Wide Operating Voltage Ranges : 2.5V to 5.5V TTL-Logic-Controlled Shutdown Input Low Temperature Coefficient Current Limiting Protection Thermal Shutdown Protection Only 1μF Output Capacitor Required for Stability High Power Supply Rejection Ratio Custom Voltage Available RoHS Compliant and 100% Lead (Pb)-Free
Ordering Information
RT9198/APackage 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) QW : WDFN-6L 2x2 (W-Type) Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) 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)
Applications
CDMA/GSM Cellular Handsets Battery-Powered Equipment Laptop, Palmtops, Notebook Computers Hand-Held Instruments PCMCIA Cards Portable Information Appliances
Marking Information
For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail.
Note : 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. DS9198/A-10 November 2006 www.richtek.com 1
RT9198/A
Pin Configurations
(TOP VIEW)
VIN 4 VOUT 3 2 GND
1 GND VIN 3 2 VOUT
VIN GND EN/EN
1 2 3
5
VOUT
EN/EN NC
1 2
5
VIN
1
4
NC
GND
3
4
VOUT
EN/EN
SOT-23-5/SC-70-5 (R-Type)
SOT-23-5/SC-70-5
SC-82
SOT-23-3
EN/EN GND VIN
1 2 3
6 5 4
NC NC VOUT
Note : There is no pin1 indicator on top mark for SC-82 type, and pin 1 will be lower left pin when reading top mark from left to right. Pin2 of SC-82 is wider than other pins.
WDFN-6L 2x2
Typical Application Circuit
RT9198 V IN C IN 1uF VIN VOUT C OUT 1uF EN GND V OUT
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GND
Chip Enable On Off
RT9198A V IN C IN 1uF VIN VOUT C OUT 1uF EN GND V OUT
Chip Enable Off On
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Functional Pin Description
Pin Name EN EN NC GND, Exposed Pad VOUT VIN Pin Function 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. 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. No Internal Connect. Ground. Exposed pad should be soldered to PCB board and connected to GND. Output Voltage. Input Voltage.
Function Block Diagram
EN/EN Shutdown and Logic Control VREF
+ Error Amplifier
VIN
MOS Driver VOUT Current-Limit and Thermal Protection GND
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RT9198/A
Absolute Maximum Ratings
(Note 1) 6V 400mW 300mW 606mW 250°C/W 333°C/W 165°C/W 20°C/W 150°C 260°C −65°C to 150°C 2kV 200V Supply Input Voltage -----------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOT-23-3/SOT-23-5 ------------------------------------------------------------------------------------------------------SC-70-5, SC-82 -----------------------------------------------------------------------------------------------------------WDFN-6L 2x2 -------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 4) SOT-23-3/SOT-23-5, θJA ------------------------------------------------------------------------------------------------SC-70-5, SC-82, θJA -----------------------------------------------------------------------------------------------------WDFN-6L 2x2, θJA --------------------------------------------------------------------------------------------------------WDFN-6L 2x2, θJC -------------------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 2) HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------
Recommended Operating Conditions
(Note 3) 2.5V to 5.5V 0V to 5.5V −40°C to 125°C −40°C to 85°C
Supply Input Voltage -----------------------------------------------------------------------------------------------------EN Input Voltage ----------------------------------------------------------------------------------------------------------Junction Temperature Range -------------------------------------------------------------------------------------------Ambient Temperature Range --------------------------------------------------------------------------------------------
Electrical Characteristics
(VIN = VOUT + 1V, CIN = COUT = 1μF, TA = 25°C, unless otherwise specified)
Parameter Output Voltage Accuracy Current Limit Quiescent Current Dropout Voltage (Note 5) Line Regulation Load Regulation Shutdown Current EN Input Bias Current Logic-Low Voltage Logic-High Voltage
Symbol ΔVOUT ILIM IQ VDROP ΔVLINE ΔVLOAD ISHDN IIBEN VIL VIH
Test Conditions IOUT = 1mA RLOAD = 1Ω RT9198, VEN ≧ 1.2V, IOUT = 0mA RT9198A, VEN ≦ 0.4V, IOUT = 0mA IOUT = 200mA IOUT = 300mA VIN = (VOUT + 1V) to 5.5V, IOUT = 1mA 1mA < IOUT < 300mA RT9198, VEN = GND, Shutdown RT9198A, VEN = VIN, Shutdown VEN = GND or VIN RT9198, VIN = 3V to 5.5V, Shutdown RT9198A, VIN = 3V to 5.5V, Enable RT9198, VIN = 3V to 5.5V, Enable RT9198A, VIN = 3V to 5.5V, Shutdown
Min −2 360 --------1.2
Typ -400 90 170 220 --0.01 0 ---
Max +2 -130 200 330 0.3 0.6 1 100 0.4
Units % mA μA mV % % μA nA
EN Threshold
V --
To be continued
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Parameter Power Supply f = 100Hz Rejection Rate f = 10kHz Thermal Shutdown Temperature Thermal Shutdown Temperature Hysteresis Symbol PSRR TSD ΔTSD Test Conditions COUT = 1μF, IOUT = 100mA Min ----Typ −60 −30 165 30 Max ----Units dB °C °C
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. Devices are ESD sensitive. Handling precaution recommended. Note 3. The device is not guaranteed to function outside its operating conditions. Note 4. 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 5. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
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RT9198/A
Typical Operating Characteristics
Output Voltage vs. Temperature
2
Quiesent Current vs. Temperature
100 95
VIN = 5V CIN = COUT = 1uF
RT9198/A-15 VIN = 3.3V CIN = COUT = 1uF
Quiescent Current (uA)
Output Voltage (V)
1.9
90 85 80 75 70 65
1.8
No Load
1.7
1.6 -50 -25 0 25 50 75 100 125
60 -50 -25 0 25 50 75 100 125
Temperature (°C)
Temperature (°C)
EN Pin Shutdown Threshold vs. Temperature
1.5
Current Limit vs. Input Voltage
600 550
EN Pin Threshold Voltage (V)
1.25
RT9198/A-15 VIN = 3.3V CIN = COUT = 1uF
RT9198/A-15 CIN = COUT = 1uF
Current Limit (mA)
500 450 400 350 300
1
0.75
0.5
0.25 -50 -25 0 25 50 75 100 125
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
Temperature (°C)
Input Voltage (V)
Dropout Voltage vs. Load Current
300 250 200 150
RT9198/A-33 CIN = COUT = 1uF
20
PSRR
VOUT = 2.5V CIN = COUT = 1uF, X7R
TJ = 125°C
0
Dropout Voltage (mV)
PSRR (dB)
TJ = 25°C
-20
TJ = -40°C
100 50 0 0 0.05 0.1 0.15 0.2 0.25 0.3
-40
ILOAD = 100mA
-60
ILOAD = 10mA
-80
10 0.01
100 0.1
11 K
10K 10
1100 00K
1M 1000
Load Current (A)
Frequency (kHz) (Hz)
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Line Transient Response
Input Voltage Deviation (V)
5 4 3
Line Transient Response
Input Voltage Deviation (V)
CIN = COUT = 1uF 5 4 3 ILOAD = 250mA
CIN = COUT = 1uF
ILOAD = 50mA
Output Voltage Deviation (mV)
20 0 -20
Output Voltage Deviation (mV)
50 0 -50
Time (100μs/Div)
Time (100μs/Div)
Load Transient Response
Load Current (mA)
100 50 0
Load Transient Response
Load Current (mA)
400 200 0 VIN = 3.3V CIN = COUT = 1uF VOUT = 1.5V ILOAD = 1mA to 250mA
VIN = 3.3V CIN = COUT = 1uF
VOUT = 1.5V ILOAD= 1mA to 50mA
Output Voltage Deviation (mV)
50 0 -50
Output Voltage Deviation (mV)
50 0 -50
Time (100μs/Div)
Time (100μs/Div)
Start Up
EN Pin Voltage (V)
10 5 0
EN Pin Shutdown Response
EN Pin Voltage (V)
VOUT = 1.8V ILOAD = 1mA 10 5 0 RT9198-18, VIN = 5V CIN = COUT = 1uF VOUT = 1.8V ILOAD = 1mA
RT9198-18, VIN = 5V CIN = COUT = 1uF
Output Voltage (V)
2 1 0
Output Voltage (V)
2 1 0
Time (10μs/Div)
Time (1ms/Div)
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RT9198/A
Noise
VIN = 4.5V CIN = COUT = 1uF 400 VOUT = 1.8V ILOAD = 150mA 400 VIN = 4.5V CIN = COUT = 1uF
Noise
VOUT = 1.8V No Load
Noise (μV)
0 -200 -400
Noise (μV)
200
200 0 -200 -400 f = 10Hz to 100kHz
f = 10Hz to 100kHz
Time (5ms/Div)
Time (5ms/Div)
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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. 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. 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
COUT = 1uF
Region of Stable COUT ESR vs. Load Current
100.00 100
10 10.00
Instable
1.00 1
0.10
Stable
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
C OUT ESR (Ω)
0.01
0.00
RT9198/A-15CU5 COUT = 1μF, X7R
0 50 100
Simulation Verify
150 200 250 300
Load Current (mA)
Where T J(MAX) i s the maximum operating junction temperature 125°C, TA is the ambient temperature and the θJA is the junction to ambient thermal resistance.
Figure 1
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Instable
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RT9198/A
For recommended operating conditions specification of RT9198/A, where T J(MAX) i s the maximum junction temperature of the die (125°C) and TA is the maximum ambient temperature. The junction to ambient thermal resistance ( θJA i s layout dependent) for 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 (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 T J(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.
Maximum Power Dissipation (mΩ1 )
700 600 500 400 300 200 100 0 0 15 30 45 60 75 90 105 120 135
WDFN-6L 2x2
SOT-23-3 SOT-23-5
SC 70-5 SC-82
Ambient Temperature (°C)
Figure 2. Derating Curve for Packages
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Outline Dimension
D
H L
C
B
e
A A1 b
Symbol A A1 B b C D e H L
Dimensions In Millimeters Min 0.889 0.000 1.397 0.356 2.591 2.692 1.803 0.080 0.300 Max 1.295 0.152 1.803 0.508 2.997 3.099 2.007 0.254 0.610
Dimensions In Inches Min 0.035 0.000 0.055 0.014 0.102 0.106 0.071 0.003 0.012 Max 0.051 0.006 0.071 0.020 0.118 0.122 0.079 0.010 0.024
SOT-23-3 Surface Mount Package
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RT9198/A
H D L C B
b A A1 e
Symbol A A1 B b C D e H L
Dimensions In Millimeters Min 0.889 0.000 1.397 0.356 2.591 2.692 0.838 0.080 0.300 Max 1.295 0.152 1.803 0.559 2.997 3.099 1.041 0.254 0.610
Dimensions In Inches Min 0.035 0.000 0.055 0.014 0.102 0.106 0.033 0.003 0.012 Max 0.051 0.006 0.071 0.022 0.118 0.122 0.041 0.010 0.024
SOT-23-5 Surface Mount Package
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H D L C B
b A A1 e
Symbol A A1 B b C D e H L
Dimensions In Millimeters Min 0.800 0.000 1.150 0.150 1.800 1.800 0.650 0.080 0.210 0.260 0.460 Max 1.100 0.100 1.350 0.400 2.450 2.250
Dimensions In Inches Min 0.031 0.000 0.045 0.006 0.071 0.071 0.026 0.003 0.008 0.010 0.018 Max 0.044 0.004 0.054 0.016 0.096 0.089
SC-70-5 Surface Mount Package
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RT9198/A
D e
H L
C
B
b
b1
A e A1
Symbol A A1 B b b1 C D e H L
Dimensions In Millimeters Min 0.800 0.000 1.150 0.150 0.350 1.800 1.800 1.300 0.080 0.200 0.260 0.460 Max 1.100 0.100 1.350 0.400 0.500 2.450 2.200
Dimensions In Inches Min 0.031 0.000 0.045 0.006 0.014 0.071 0.071 0.051 0.003 0.008 0.010 0.018 Max 0.043 0.004 0.053 0.016 0.020 0.096 0.087
SC-82 Surface Mount Package
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D
D2 L
E
E2 SEE DETAIL A
1 e A A1 A3
b
2
1
2
1
DETAIL A Pin #1 ID and Tie Bar Mark Options Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated.
Symbol A A1 A3 b D D2 E E2 e L
Dimensions In Millimeters Min 0.700 0.000 0.175 0.200 1.950 1.000 1.950 0.500 0.650 0.300 0.400 Max 0.800 0.050 0.250 0.350 2.050 1.450 2.050 0.850
Dimensions In Inches Min 0.028 0.000 0.007 0.008 0.077 0.039 0.077 0.020 0.026 0.012 0.016 Max 0.031 0.002 0.010 0.014 0.081 0.057 0.081 0.033
W-Type 6L DFN 2x2 Package
RICHTEK TECHNOLOGY CORP.
Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611
RICHTEK TECHNOLOGY CORP.
Taipei Office (Marketing) 8F-1, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com
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