Richtek RT9198T-18PBR, RT9198T-25PB, RT9198T-25PV, RT9198T-28PU5R, RT9198T-33PU5 Schematic [ru]
RT9198T
300mA, Thermal Folded Back CMOS LDO Regulator
General Description
The RT9198T is designed for portable RF and wireless
applications with demanding performance and space
requirements. The RT9198T 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 RT9198T also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in hand-held wireless devices. The
RT9198T consumes less than 0.01uA in shutdown mode
and has fast turn-on time less than 50μs. RT9198T is short
circuit thermal folded back protected. RT9198T lowers its
OTP trip point from 165°C to 110°C when output short
circuit occurs (V
< 0.4V) providing maximum safety to
OUT
end users. 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 and SC-70-5 packages, the RT9198T also offers
a range of 1.5V to 3.5V with 0.1V per step.
Ordering Information
RT9198T-
Package Type
U5 : SC-70-5
U5R : SC-70-5 (R-Type)
V : SOT-23-3
B : SOT- 23-5
BR : SOT- 23-5 (R-Type)
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Output Voltage
15 : 1.5V
16 : 1.6V
:
34 : 3.4V
35 : 3.5V
1H : 1.85V
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.
2H : 2.85V
Features
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Short Circuit Thermal Folded Back Protection
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z Low-Noise for RF Application
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z Fast Response in Line/Load Tran sient
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z Quick Start-Up (T ypically 50us)
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z < 0.01uA Standby Current When Shutdown
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z Low Dropout : 220mV @ 300mA
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z Wide Operating Voltage Ranges : 2.5V to 5.5V
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z TTL-Logic-Controlled Shutdown Input
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z Low Temperature Coefficient
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z Current Limiting Protection
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z Thermal Shutdown Protection
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z Only 1uF Output Capacitor Required for Stability
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z High Power Supply Rejection Ratio
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z Custom Voltage Available
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z RoHS Compliant and 100% Lead (Pb)-Free
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Applications
z CDMA/GSM Cellular Handsets
z Battery-Powered Equipment
z Laptop, Palmtops, Notebook Computers
z Hand-Held Instruments
z PCMCIA Cards
z Portable Information Appliances
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
Pin Configurations
(TOP VIEW)
VIN
3
2
GND VOUT
SOT-23-3
DS9198T-04 April 2011 www.richtek.com
1
RT9198T
VIN VOUT
5
EN NC GND
4
23
Typical Application Circuit
V
IN
Chip Enable
Functional Pin Description
C
1uF
VOUT NC
5
VIN GND EN
4
23
SOT-23-5/SC-70-5 (R-Type)SOT-23-5/SC-70-5
RT9198T
VIN
VOUT
IN
EN
GND
C
1uF
OUT
V
OUT
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.
NC No Connection
GND Ground
VOUT Output Voltage
VIN Input Voltage
Function Block Diagram
EN
V
REF
Shutdown
and
Logic Control
+
-
Error
Amplifier
VIN
MOS Driver
VOUT
Current-Limit
and
Thermal
Protection
GND
DS9198T-04 April 2011www.richtek.com
2
RT9198T
Absolute Maximum Ratings (Note 1)
z Supply Input Voltage ---------------------------------------------------------------------------------------------------- 6V
z Power Dissipation, P
SOT-23-3------------------------------------------------------------------------------------------------------------------- 0.4W
SOT-23-5------------------------------------------------------------------------------------------------------------------- 0.4W
SC-70-5 -------------------------------------------------------------------------------------------------------------------- 0.3W
z Package Thermal Resistance (Note 2)
SOT-23-3, θJA------------------------------------------------------------------------------------------------------------- 250°C/W
SOT-23-5, θJA------------------------------------------------------------------------------------------------------------- 250°C/W
SC-70-5, θJA--------------------------------------------------------------------------------------------------------------- 333°C/W
z Junction Temperature --------------------------------------------------------------------------------------------------- 150°C
z Lead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------------------- 260°C
z Storage Temperature Range ------------------------------------------------------------------------------------------- −65°C to 150°C
z ESD Susceptibility (Note 3)
HBM (Human Body Mode) --------------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ---------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 4)
@ TA = 25°C
D
z Supply Input Voltage ---------------------------------------------------------------------------------------------------- 2.5V to 5.5V
z Operation Ambient Temperature Range -----------------------------------------------------------------------------
z Operation Junction Temperature Range -----------------------------------------------------------------------------
−40°C to 85°C
−40°C to 125°C
Electrical Characteristics
(V
= V
OUT
+ 1V, C
IN
Output Voltage Accuracy ΔV
Current Limit I
Quiescent Current IQ
Dropout Voltage (Note 5) V
Line Regulation ΔV
Load Regulation ΔV
Standby Current I
EN Input Bias Current I
EN Threshold
Power Supply
Rejection Rate
= C
IN
= 1uF, TA = 25°C, unless otherwise specified)
OUT
Parameter Symbol Test Conditions Min Typ Max Unit
I
OUT
R
LIM
DROP
LINE
LOAD
VEN = GND, Shutdown -- 0.01 1 uA
STBY
VEN = GND or VIN -- 0 100 nA
IBS D
Logic-Low Voltage VIL V
Logic-High Voltage V
VIN = 3V to 5.5V, Start-Up 1.2 -- --
IH
= 1mA −2 -- +2 %
OUT
= 1Ω 360 400 -- mA
LOAD
V
>= 1.2V, I
EN
I
= 200mA -- 170 200
OUT
= 300mA -- 220 330
I
OUT
= (V
V
IN
OUT
= 1mA
I
OUT
1mA < I
OUT
= 3V to 5.5V, Shutdown -- -- 0.4
IN
= 0mA
OUT
+ 1V) to 5.5V,
< 300mA -- -- 0.6 %
-- 90 130 uA
-- -- 0.3 %
mV
f = 100Hz -- −60 --
f = 10kHz
PSRR C
OUT
= 1uF, I
= 100mA
OUT
-- −30 --
dB
V
Thermal Shutdown Temperature TSD -- 165 -- °C
Thermal Shutdown Temperature
Hysteresis
-- 30 -- °C
ΔT
SD
Thermal Folded Back -- 110 -- °C
DS9198T-04 April 2011 www.richtek.com
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RT9198T
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. θ
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 V
is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of
JA
JEDEC 51-3 thermal measurement standard.
-V
IN
, which is measured when V
OUT
OUT
is V
OUT(NORMAL)
− 100mV.
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4
Typical Operating Characteristics
RT9198T
Output Voltage vs. Temperature
2
V
= 5V
IN
CIN = C
1.9
1.8
No Load
1.7
Output Voltage (V)
1.6
-50 -25 0 25 50 75 100 125
OUT
= 1uF
Temperature
(°C)
EN Pin Shutdown Threshold vs. Temperature
1.5
RT9198T-15PU5
V
= 3.3V
IN
CIN = C
1.25
1
0.75
0.5
EN Pin Threshold Voltage (V)
0.25
-50 -25 0 25 50 75 100 125
OUT
= 1uF
Temperature
(°C)
Quiesent Current vs. Temperature
100
RT9198T-15PB
V
= 3.3V
IN
95
CIN = C
90
85
80
75
70
OUT
= 1uF
Quiescent Current (uA)
65
60
-50 -25 0 25 50 75 100 125
Temperature
(°C)
Current Limit vs. Input Voltage
600
RT9198T-15PB
CIN = C
550
500
450
400
Current Limit (mA)
350
300
22.533.544.555.566.5
OUT
= 1uF
Input Voltage (V)
Dropout Voltage vs. Load Current
300
RT9198T-33PB
CIN = C
250
200
150
100
Dropout Voltage (mV)
50
0
0 0.05 0.1 0.1 5 0.2 0.25 0.3
OUT
= 1uF
Load Current (A)
T
J
= 25°C
T
= 125°C
J
T
= -40°C
J
20
V
= 2.5V
OUT
CIN = C
0
-20
-40
PSRR (dB)
I
LOAD
-60
I
LOAD
-80
10 100 1K 10K 100K 1M
0.01 0.1 1 10 100 1000
= 1uF, X7R
OUT
= 100mA
= 10mA
PSRR
Frequency (kHz)
(Hz)
DS9198T-04 April 2011 www.richtek.com
5
RT9198T
CIN = C
5
4
3
Deviation (V)
Input Voltage
20
0
-20
Output Voltage
Deviation (mV)
V
IN
CIN = C
100
50
(mA)
0
Load Current
Line Transient Response
= 1uF
OUT
Time (100μs/Div)
Load Transient Response
= 3.3V
OUT
= 1uF
V
OUT
I
LOAD
= 1.5V
I
= 50mA
LOAD
= 1mA to 50mA
CIN = C
5
4
Deviation (V)
Input Voltage
3
50
0
-50
Output Voltage
Deviation (mV)
V
IN
CIN = C
400
200
(mA)
0
Load Current
Line Transient Response
= 1uF
OUT
Time (100μs/Div)
Load Transient Response
= 3.3V
OUT
= 1uF
V
= 1.5V
OUT
I
= 1mA to 250mA
LOAD
I
LOAD
= 250mA
50
0
-50
Output Voltage
Deviation (mV)
V
CIN = C
10
5
(V)
0
EN Pin Voltage
2
1
(V)
0
Output Voltage
IN
= 5V
OUT
Time (100μs/Div)
Start Up
= 1uF
Time (10μs/Div)
V
OUT
I
LOAD
= 1.8V
= 1mA
50
0
-50
Output Voltage
Deviation (mV)
V
CIN = C
10
5
(V)
0
EN Pin Voltage
2
1
(V)
0
Output Voltage
Time (100μs/Div)
EN Pin Shutdown Response
= 5V
IN
OUT
= 1uF
Time (1ms/Div)
V
OUT
I
LOAD
= 1.8V
= 1mA
DS9198T-04 April 2011www.richtek.com
6
RT9198T
-200
Noise (μV)
400
200
0
-400
V
= 4.5V
IN
CIN = C
OUT
= 1uF
Time (5ms/Div)
Noise
V
= 1.8V
OUT
I
= 150mA
LOAD
f = 10Hz to 100kHz
-200
Noise (μV)
400
200
0
-400
V
= 4.5V
IN
CIN = C
OUT
= 1uF
Time (5ms/Div)
Noise
V
= 1.8V
OUT
No Load
f = 10Hz to 100kHz
DS9198T-04 April 2011 www.richtek.com
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RT9198T
Applications Information
Like any low-dropout regulator, the external capacitors used
with the RT9198T must be carefully selected for regulator
stability and performance. Using a capacitor whose value
is > 1μF on the RT9198T 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 RT9198T 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 > 20mΩ on the
RT9198T output ensures stability. The RT9198T 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
not more than 0.5 inch from the V
pin of the RT9198T
OUT
and returned to a clean analog ground.
Region of Stable C
100.00
100
ESR vs. Load Current
OUT
Enable Function
The RT9198T features an LDO regulator enable/disable
function. To assure the LDO regulator will switch on, the
EN turn on control level must be greater than 1.2 volts.
The LDO regulator will go into the shutdown mode when
the voltage on the EN pin falls below 0.4 volts. For to
protecting the system, the RT9198T have a quick-
discharge function. If the enable function is not needed in
a specific application, it may be tied to VIN to keep the
LDO regulator in a continuously on state.
Thermal Considerations
Thermal protection limits power dissipation in RT9198T.
When the operation junction temperature exceeds 165°C,
the OTP circuit starts the thermal shutdown function and
turns the pass element off. The pass element turn on again
after the junction temperature cools by 30°C.
RT9198T lowers its OTP trip level from 165°C to 110°C
when output short circuit occurs (V
< 0.4V) as shown
OUT
in Figure 2. This limits IC case temperature under 100°C
and provides maximum safety to end users when output
short circuit occurs.
V
Short to GND
OUT
0.4V
V
OUT
I
OUT
TSD
°
165 C
110 C
OTP Trip Point
IC Temperature
°
°
110 C
80 C
°
Figure 2. Short Circuit Thermal Folded Back Protection
when Output Short Circuit Occurs
ESR (Ω)
OUT
C
10
10.00
1.00
1
0.10
0.01
RT9198T-15PU5
C
= 1μF, X7R
0.00
IN
0 50 100 150 200 250 300
Instable
Stable
Simulation Verify
Load Current (mA)
C
OUT
= 1uF
Figure 1
DS9198T-04 April 2011www.richtek.com
8
RT9198T
)
For continuous operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is :
PD = (V
− V
OUT
) x I
IN
+ VIN x I
OUT
Q
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 :
P
Where T
temperature 125°C, T
θ
= ( T
D(MAX)
J(MAX)
is the junction to ambient thermal resistance.
JA
- TA ) / θ
J(MAX)
JA
is the maximum operation junction
is the ambient temperature and the
A
For recommended operating conditions specification of
RT9198T, where T
is the maximum junction
J(MAX)
temperature of the die (125°C) and TA is the maximum
ambient temperature. The junction to ambient thermal
resistance (θJA is layout dependent) for SC-70 package is
333°C/W, 250°C/W is for SOT-23-3 and SOT-23-5 package
on standard JEDEC 51-3 thermal test board. The
maximum power dissipation at TA = 25°C can be calculated
by following formula :
450
SOT-23-3, SOT-23-5
400
350
SC 70-5
300
250
200
150
100
Maxi mum Power Di ssipation (mW
50
0
0 25 50 75 100 125
Ambient Temperature (°C )
Figure 3. Derating Curve for Packages
P
= (125°C−25°C)/250 = 400 mW (SOT-23-3/
D(MAX)
SOT-23-5)
P
= (125°C−25°C)/333 = 300 mW (SC-70-5)
D(MAX)
The maximum power dissipation depends on operating
ambient temperature for fixed T
and thermal
J(MAX)
resistance θJA. For RT9198T packages, the Figure 3. of
derating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
allowed.
DS9198T-04 April 2011 www.richtek.com
9
RT9198T
Outline Dimension
D
C
e
A
b
Dimensions In Millimeters Dimensions 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
A1
H
L
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
SOT-23-3 Surface Mount Package
10
DS9198T-04 April 2011www.richtek.com
RT9198T
H
D
L
C
b
A
e
Dimensio ns In Millim eters Dimensions 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
B
A1
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
SOT-23-5 Surface Mount Package
DS9198T-04 April 2011 www.richtek.com
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RT9198T
H
D
L
C
b
A
e
B
A1
Dimensions In Millimeters Dimensions In Inches
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
SC-70-5 Surface Mount Package
Richtek Technology Corporation
Headquarter
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
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.
12
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
DS9198T-04 April 2011www.richtek.com
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