RT9001
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DS9001-06 April 2011 www.richtek.com
Pin Configurations
600mA, Ultra-Fast Transient Response LDO Regulator
Marking Information
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area.
Ordering Information
General Description
The RT9001 series are CMOS low dropout regulators
optimized for ultra-fast transient response. The devices are
capable of supplying 600mA of output current with a dropout
voltage of 580mV respectively.
The RT9001 series are is optimized for CD/DVD-ROM,
CD/RW or wireless communication supply applications.
The RT9001 regulators are stable with output capacitors
as low as 1μF. The other features include ultra low dropout
voltage, high output accuracy, current limiting protection,
and high ripple rejection ratio.
The devices are available in fixed output voltages range of
1.2V to 4.5V with 0.1V per step. The RT9001 regulators
are available in 3-lead SOT-223 package.
Features
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zLow Quie scent Current (Typically 220μμ
μμ
μA)
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zGuaranteed 600mA Output Current
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zLow Dropout Voltage : 580mV at 600mA
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zWide Operating Voltage Ranges : 3V to 5.5V
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zUltra-Fast T ransient Response
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zTight Load and Line Regulation
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zCurrent Limiting Protection
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zThermal Shutdown Protection
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zOnly low-ESR Ceramic Capacitor Required for
Stability
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zCustom Voltage Available
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zRoHS Compliant and 100% Lead (Pb)-Free
Applications
zCD/DVD-ROM, CD/RW
zWireless LAN Card/Keyboard/Mouse
zBattery-Powered Equipment
zXDSL Router
zPCMCIA Card
(TOP VIEW)
123
GND VOUT
(TAB)
VIN
SOT-223
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.
RT9001-
Package Type
G : SOT-223
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Output Voltage
12 : 1.2V
13 : 1.3V
:
45 : 4.5V
RT9001
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DS9001-06 April 2011www.richtek.com
Typical Application Circuit
Functional Pin Description
Function Block Diagram
Note: To prevent oscillation, a 1μμ
μμ
μF minimum X7R or X5R dielectric is strongly recommended if cera mics are used
as input/output capacitors. When using the Y5V dielectric, the minimum value of the input/output ca pacitance
that can be used for stable over full operating temperature range is 3.3μμ
μμ
μF. (see Application Information
Section for further details)
Pin Nam e Pi n Funct ion
VIN Supply Input.
VOUT Regulator Output.
GND Common Ground.
Current
Limiting
Sensor
Thermal
Shutdown
+
-
Error
Amplifier
1.2V
Reference
VIN
GND
VOUT
VIN
GND
VOUT
RT9001
COUT
1uF
CIN
1uF
VIN VOUT
RT9001
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Electrical Characteristics
Absolute Maximum Ratings (Note 1)
zSupply Input Voltage -------------------------------------------------------------------------------------------------- 6.5V
zPower Dissipation, PD @ TA = 25°C
SOT-223 ----------------------------------------------------------------------------------------------------------------- 0.625W
zPackage Thermal Resistance (Note 2)
SOT-223, θJA ------------------------------------------------------------------------------------------------------------ 160°C/W
zLead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C
zJunction Temperature ------------------------------------------------------------------------------------------------- 150°C
zStorage Temperature Range ---------------------------------------------------------------------------------------- – 65°C to 150°C
zESD Susceptibility (Note 3)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions (Note 4)
zSupply Input Voltage -------------------------------------------------------------------------------------------------- 2.8V to 5.5V
zJunction Temperature Range ---------------------------------------------------------------------------------------- – 40°C to 125°C
(VIN = VOUT + 1V or VIN = 2.8V whichever is greater, CIN = 1μF, C OUT = 1μF, TA = 25°C, unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
Output Voltage Accuracy ΔVOUT I
OU T = 1mA −1 -- 3 %
Current Limit ILIM R
LOAD = 1Ω 600 -- -- mA
Quiescent Current (Note 5) IQ I
OU T = 0mA -- 220 300 μA
Dropout Voltage (Note 6) VDROP I
OU T = 600mA -- 580 -- mV
Line Regulation ΔVLINE VIN = (VOUT + 0.3V) to 5.5V,
IOU T = 1mA -- 0.2 -- %/V
Load Regulation (Note 7) ΔVLOAD 1mA < IOUT < 600mA -- 30 55 mV
Power Supply Rejection Rate PSRR f = 1kHz, COUT = 1μF -- −55 -- dB
Thermal Shutdown Temperature TSD -- 170 -- °C
Thermal Shutdown Hysteresis ΔTSD -- 40 -- °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. θ
JA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of
JEDEC 51-3 thermal measurement standard.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. Quiescent, or ground current, is the difference between input and output currents. It is defined by IQ = IIN - IOUT under
no load condition (IOUT = 0mA). The total current drawn from the supply is the sum of the load current plus the ground
pin current.
Note 6. The dropout voltage is defined as VIN − VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
Note 7. Regulation is measured at constant junction temperature by using a 20ms current pulse. Devices are tested for load
regulation in the load range from 1mA to 600mA respectively.
RT9001
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DS9001-06 April 2011www.richtek.com
Typical Operating Characteristics
Power Supply Rejection Ratio
-60
-50
-40
-30
-20
-10
0
Frequency (Hz)
PSRR (dB)
VIN = 5V
CIN = 1uF
COUT = 1uF
100mA
1mA
10 100 1k 10k 100k 1M
Current Limit vs . Input voltage
700
750
800
850
900
33.544.555.5
Input voltage (V)
Current Limit (mA)
VIN = 5V
CIN = 1uF
COUT = 1uF
RL = 0.5Ω
Current Limit vs . Te m pe rature
700
750
800
850
900
-50 -25 0 25 50 75 100 125
Temperature
Current Limit (mA)
VIN = 5V
CIN = 1uF
COUT = 1uF
RL = 0.5Ω
(°C)
-40
Dropout Voltage vs . Loa d Current
0
100
200
300
400
500
600
700
0 100 200 300 400 500 600
Load Current (mA)
Dropout Voltage (mV)
CIN = 1uF
COUT = 1uF TJ = 125°C
TJ = 25°C
TJ = −40°C
Output Voltage vs. Temperature
3.1
3.15
3.2
3.25
3.3
3.35
3.4
3.45
3.5
-50 -25 0 25 50 75 100 125
Temperature
Output Voltage (V)
(°C)
Quiescent Current v s . Temperature
150
170
190
210
230
250
-50 -25 0 25 50 75 100 125
Temperature
Quiescent Current (uA)
VIN = 5V
(°C)
RT9001
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DS9001-06 April 2011 www.richtek.com
Load Transient Response
Time (100us/Div)
Load
Current (mA)
200
100
0
Output Voltage
Deviation (mV)
20
0
-20
VIN = 5V, ILOAD = 1 to 150mA
CIN = COUT = 1uF (Ceramic, X7R)
Line Transient Response
Time (100us/Div)
Output Voltage
Deviation (mV)
20
0
-20
Input Voltage
Deviation (V)
5
4
VIN = 4 to 5V
CIN = 1uF
COUT = 1uF
Output Noise
Output Noise Signal (μV)
Time (1ms/DIV)
400
200
0
-200
-400
VIN = 5V
CIN = 1uF
ILOAD = 100mA
COUT = 1uF
f = 10Hz to 100kHz
Region of Stable COUT ESR v s . Load Current
0.00
0.01
0.10
1.00
10.00
100.00
0 100 200 300 400 500 600
Load Current (mA)
COUT ESR (Ω)
Instable
Instable
Stable
COUT = 1uF to 4.7uF
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DS9001-06 April 2011www.richtek.com
Application Information
Like any low-dropout regulator, the RT9001 series requires
input and output decoupling capacitors. These capacitors
must be correctly selected for good performance (see
Capacitor Characteristics Section). Please note that linear
regulators with a low dropout voltage have high internal
loop gains which require care in guarding against oscillation
caused by insufficient decoupling capacitance.
Input Capacitor
An input capacitance of ≅ 1μF is required between the
device input pin and ground directly (the amount of the
capacitance may be increased without limit). The input
capacitor MUST be located less than 1 cm from the device
to assure input stability. A lower ESR capacitor allows the
use of less capacitance, while higher ESR type (like
aluminum electrolytic) require more capacitance.
Capacitor types (aluminum, ceramic and tantalum) can be
mixed in parallel, but the total equivalent input capacitance/
ESR must be defined as above to stable operation.
There are no requirements for the ESR on the input
capacitor, but tolerance and temperature coefficient must
be considered when selecting the capacitor to ensure the
capacitance will be ≅ 1μF over the entire operating
temperature range.
Output Ca pa citor
The RT9001 is designed specifically to work with very small
ceramic output capacitors. The recommended minimum
capacitance (temperature characteristics X7R or X5R) is
from 1μF to 4.7μF ceramic capacitor between LDO output
and GND for transient stability, but it may be increased
without limit. Higher capacitance values help to improve
transient. The output capacitor's ESR is critical because it
forms a zero to provide phase lead which is required for
loop stability. (When using the Y5V dielectric, the minimum
value of the input/output capacitance that can be used for
stable over full operating temperature range is 3.3μF.)
No Load Stability
The device will remain stable and in regulation with no
external load. This is specially important in CMOS RAM
keep-alive applications.
Input-Output (Dropout) Voltage
A regulator's minimum input-to-output voltage differential
(dropout voltage) determines the lowest usable supply
voltage. In battery-powered systems, this determines the
useful end-of-life battery voltage. Because the device uses
a PMOS, its dropout voltage is a function of drain-to-source
on-resistance, RDS(ON), multiplied by the load current :
VDROPOUT = VIN − VOUT = RDS(ON) x IOUT
Current Limit
The RT9001 monitors output current and controls the
PMOS' gate voltage to limit the output current to 600mA
(MIN). The output can be shorted to ground for an indefinite
period of time without damaging the part.
Short-Circuit Protection
The device is short circuit protected and in the event of a
peak over-current condition, the short-circuit control loop
will rapidly drive the output PMOS pass element off. Once
the power pass element shuts down, the control loop will
rapidly cycle the output on and off until the average power
dissipation causes the thermal shutdown circuit to respond
to servo the on/off cycling to a lower frequency. Please
refer to the section on thermal information for power
dissipation calculations.
Ca pacitor Chara cteristics
It is important to note that capacitance tolerance and
variation with temperature must be taken into consideration
when selecting a capacitor so that the minimum required
amount of capacitance is provided over the full operating
temperature range. In general, a good tantalum capacitor
will show very little capacitance variation with temperature,
but a ceramic may not be as good (depending on dielectric
type).
No Load Stability
The device will remain stable and in regulation with no
external load. This is specially important in CMOS RAM
keep-alive applications.
Aluminum electrolytics also typically have large
temperature variation of capacitance value.
RT9001
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DS9001-06 April 2011 www.richtek.com
Equally important to consider is a capacitor's ESR change
with temperature: this is not an issue with ceramics, as
their ESR is extremely low. However, it is very important in
Tantalum and aluminum electrolytic capacitors. Both show
increasing ESR at colder temperatures, but the increase
in aluminum electrolytic capacitors is so severe they may
not be feasible for some applications.
Ceramic:
For values of capacitance in the 10μF to 100μF range,
ceramics are usually larger and more costly than tantalums
but give superior AC performance for by-passing high
frequency noise because of very low ESR (typically less
than 10mΩ). However, some dielectric types do not have
good capacitance characteristics as a function of voltage
and temperature.
Z5U and Y5V dielectric ceramics have capacitance that
drops severely with applied voltage. A typical Z5U or Y5V
capacitor can lose 60% of its rated capacitance with half of
the rated voltage applied to it. The Z5U and Y5V also
exhibit a severe temperature effect, losing more than 50%
of nominal capacitance at high and low limits of the
temperature range.
X7R and X5R dielectric ceramic capacitors are strongly
recommended if ceramics are used, as they typically
maintain a capacitance range within ±20% of nominal over
full operating ratings of temperature and voltage. Of course,
they are typically larger and more costly than Z5U/Y5U
types for a given voltage and capacitance.
Tantalum:
Solid tantalum capacitors are recommended for use on
the output because their typical ESR is very close to the
ideal value required for loop compensation. They also work
well as input capacitors if selected to meet the ESR
requirements previously listed.
Tantalums also have good temperature stability: a good
quality tantalum will typically show a capacitance value
that varies less than 10 to 15% across the full temperature
range of 125°C to −40°C. ESR will vary only about 2X going
from the high to low temperature limits.
The increasing ESR at lower temperatures can cause
oscillations when marginal quality capacitors are used (if
the ESR of the capacitor is near the upper limit of the
stability range at room temperature).
Aluminum:
This capacitor type offers the most capacitance for the
money. The disadvantages are that they are larger in
physical size, not widely available in surface mount, and
have poor AC performance (especially at higher
frequencies) due to higher ESR and ESL.
Compared by size, the ESR of an aluminum electrolytic is
higher than either Tantalum or ceramic, and it also varies
greatly with temperature. A typical aluminum electrolytic
can exhibit an ESR increase of as much as 50X when going
from 25°C down to −40°C.
It should also be noted that many aluminum electrolytics
only specify impedance at a frequency of 120Hz, which
indicates they have poor high frequency performance. Only
aluminum electrolytics that have an impedance specified
at a higher frequency (between 20kHz and 100kHz) should
be used for the device. Derating must be applied to the
manufacturer's ESR specification, since it is typically only
valid at room temperature.
Any applications using aluminum electrolytics should be
thoroughly tested at the lowest ambient operating
temperature where ESR is maximum.
Thermal Considerations
Thermal protection limits power dissipation in RT9901.
When the operation junction temperature exceeds 170°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 40°C. For
continuous loading operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is:
PD = (VIN − VOUT) IOUT + VIN IGND
The final operating junction temperature for any set of
conditions can be estimated by the following thermal
equation :
PD (MAX) = ( TJ (MAX) − TA ) / θJA
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Where TJ(MAX) is the maximum junction temperature of the
die (125°C) and TA is the ambient temperature. The junction
to ambient thermal resistance (θJA) for SOT-223 package
at recommended minimum footprint is 160°C/W (θJA is
layout dependent). Visit our website in which
“Recommended Footprints for Soldering Surface Mount
Packages” for detail.
RT9001
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DS9001-06 April 2011 www.richtek.com
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
Outline Dimension
Dimens ions In M i llimeters Dimens ions In Inches
Symbol Min Max Min Max
A 1.400 1.800 0.055 0.071
A1 0.020 0.100
0.001 0.004
b 0.600 0.840 0.024 0.033
B 3.300 3.700 0.130 0.146
C 6.700 7.300 0.264 0.287
D 6.300 6.700 0.248 0.264
b1 2.900 3.100 0.114 0.122
e 2.300 0.091
H 0.230 0.350 0.009 0.014
L 1.500 2.000 0.059 0.079
L1 0.800 1.100 0.031 0.043
3-Lead SOT-223 Surface Mount Package
