®
RT9065
500mA, Low Dropout, Low Noise, Ultra-Fast Linear Regulator
General Description
Features
The RT9065 is designed for portable RF and wireless
applications with demanding performance and space
requirements. The RT9065 performance is optimized for
battery powered systems to deliver ultra low noise and
low quiescent current. A noise bypass pin is available for
further reduction of output noise. Regulator ground current
increases only slightly in dropout, further prolonging the
battery life. The RT9065 also works with low-ESR ceramic
capacitors, reducing the amount of board space necessary
for power applications, critical in hand held wireless
devices. The RT9065 consumes less than 0.01μA in
shutdown mode and has fast turn-on time less than 10μs.
The other features include low dropout voltage, high output
accuracy, current limiting protection, and high ripple
rejection ratio. The RT9065 is available in the SOT-23-6
package.
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Ultra-Low-Noise for RF Application
Ultra-Fast Response in Line/Load Transient
Quick Start-Up (Typically 10μ
μs)
0.01μ
μA Shutdown Current
Low Dropout : 370mV @ 500mA
Wide Input Voltage Range : 2.2V to 5.5V
Adjustable Output Voltage
TTL Logic Controlled Shutdown Input
Low Temperature Coefficient
Current Limiting Protection
Thermal Shutdown Protection
Only 1μ
μF Output Capacitor Required for Stability
High Power Supply Rejection Ratio
RoHS Compliant and Halogen Free
Applications
Ordering Information
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RT9065
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Package Type
E : SOT-23-6
Lead Plating System
G : Green (Halogen Free and Pb Free)
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CDMA/GSM Cellular Handsets
Battery Powered Equipment
Laptop, Palmtops, Notebook Computers
Hand Held Instruments
PCMCIA Cards
Portable Information Appliances
Note :
Richtek products are :
`
Marking Information
RoHS compliant and compatible with the current require-
0B= : Product Code
ments of IPC/JEDEC J-STD-020.
`
0B=DNN
DNN : Date Code
Suitable for use in SnPb or Pb-free soldering processes.
Simplified Application Circuit
RT9065
VIN
VOUT
VIN
VOUT
CIN
R1
COUT
ADJ
Chip Enable
EN
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9065-01
December 2012
R2
BP
GND
CBP
is a registered trademark of Richtek Technology Corporation.
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1
RT9065
Pin Configurations
(TOP VIEW)
VOUT ADJ BP
6
5
4
2
3
VIN GND EN
SOT-23-6
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
VIN
Power Input.
2
GND
Ground.
3
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.
4
BP
Reference Noise Bypass.
5
ADJ
Feedback Input. Connect a resistive divider to adjust the output voltage.
6
VOUT
Output of the Regulator.
Function Block Diagram
EN
Shutdown
and
Logic Control
Quick
Start
BP
VREF
+
ADJ
Error
Amplifier
MOS
Driver
Current Limit
and
Thermal Protection
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
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2
VIN
VOUT
GND
is a registered trademark of Richtek Technology Corporation.
DS9065-01
December 2012
RT9065
Operation
The RT9065 is a low dropout voltage linear regulator
designed for RF and wireless applications which require
low noise and high PSRR performance. The RT9065 builds
in a P-type P-MOSFET with current capability up to
500mA. In normal operation, the Error Amplifier adjusts
the gate voltage of the power MOSFET to regulate the
ADJ voltage being equal to the internal 0.8V reference
voltage.
P-MOSFET current is detected and current limit function
will work to limit the output current to a designed value
when short circuit happens. Furthermore, the P-MOSFET
will be shutdown if the junction temperature is higher than
typically 165°C, and released to normal operation until
the temperature falls below typically 135°C.
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9065-01
December 2012
Quick Start
This function is designed to achieve internal reference
voltage quick ramping up during chip turning on or power
on.
Shutdown and Logic Control
This function block includes chip Enable/Disable and UVLO
circuits. When chip is disabled, VOUT is pulled to GND
through the auto-discharge MOSFET.
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3
RT9065
Absolute Maximum Ratings
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(Note 1)
Supply Voltage, VIN -----------------------------------------------------------------------------------------------------Chip Enable Input Voltage, EN ----------------------------------------------------------------------------------------Output Voltage, VOUT --------------------------------------------------------------------------------------------------Adjust Output, ADJ ------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
SOT-23-6 -------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
SOT-23-6, θJA --------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Model) ---------------------------------------------------------------------------------------------MM (Machine Model) -----------------------------------------------------------------------------------------------------
Recommended Operating Conditions
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−0.3V to 6V
−0.3V to 6V
−0.3V to 6V
−0.3V to 6V
0.48W
208.2°C/W
260°C
−65°C to 150°C
150°C
2kV
200V
(Note 4)
Supply Voltage, VIN ------------------------------------------------------------------------------------------------------ 2.2V to 5.5V
Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C
Electrical Characteristics
(VIN = VOUT + 1V, CIN = 2.2μF, COUT = 1μF, CBP =22nF, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
0.788
0.8
0.812
V
ADJ Reference Voltage
VADJ
VIN = 5V, IOUT = 100mA
Shutdown Current
ISHDN
VEN = GND
--
0.01
1
μA
Quiescent Current
IQ
IOUT = 0mA
--
90
120
μA
Dropout Voltage
VDROP
IOUT = 300mA
--
220
300
IOUT = 500mA
--
370
500
Line Regulation
ΔVLINE
VIN = (VOUT + 1V) to 5.5V, IOUT = 1mA
--
--
0.3
%
Load Regulation
ΔVLOAD
1mA < IOUT < 500mA
--
--
0.6
%
EN Input Bias Current
IIBSD
VEN = GND or VIN
--
0
100
nA
Logic-High VIH
1.2
--
--
Logic-Low VIL
--
--
0.4
--
100
--
--
70
--
--
50
--
1.6
1.8
2
EN Input
Voltage
Output Noise Voltage
eNO
10kHz to 100kHz, IOUT = 200mA,
COUT = 1μF
Power Supply f = 100Hz
Rejection Rate f = 10kHz
PSRR
COUT = 1μF, IOUT = 10mA
Under Voltage Lockout
Threshold
VUVLO
VIN Rising
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
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4
mV
V
μVRMS
dB
V
is a registered trademark of Richtek Technology Corporation.
DS9065-01
December 2012
RT9065
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
0.1
0.15
--
V
500
650
--
mA
Under Voltage Lockout
Hysteresis
ΔVUVLO
Current Limit
ILIM
Thermal Shutdown
Threshold
TSD
--
165
--
°C
Hysteresis
ΔTSD
--
30
--
°C
RLOAD = 1Ω
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and 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 may
affect device reliability.
Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9065-01
December 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
5
RT9065
Typical Application Circuit
VIN
CIN
2.2µF X7R
1
RT9065
6
VOUT
VIN
R1
ADJ
Chip Enable
3 EN
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
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6
5
BP 4
GND
2
VOUT
COUT
1µF X7R
R2
CBP
22nF
is a registered trademark of Richtek Technology Corporation.
DS9065-01
December 2012
RT9065
Typical Operating Characteristics
ADJ Reference Voltage vs. Temperature
Quiescent Current vs. Temperature
120
Quiescent Current (µA)
ADJ Reference Voltage (V)
1.0
0.9
0.8
0.7
0.6
100
80
60
40
20
VIN = 2.2V
0.5
VIN = 2.2V
0
-50
-25
0
25
50
75
100
125
-50
-25
0
25
50
75
Temperature (°C)
Temperature (°C)
Dropout Voltage vs. Temperature
Start-Up
100
125
Dropout Voltage (mV)
500
400
IOUT = 500mA
VEN
(5V/Div)
300
200
IOUT = 300mA
100
VOUT
(500mV/Div)
VIN = 2.2V, ILOAD = 0mA
0
-50
-25
0
25
50
75
100
125
Time (20μs/Div)
Temperature (°C)
Line Transient Response
Line Transient Response
VIN
(2V/Div)
VIN
(2V/Div)
VOUT
(10mV/Div)
VOUT
(10mV/Div)
VIN = 3.5V to 5.5V, ILOAD = 1mA
Time (4ms/Div)
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9065-01
December 2012
VIN = 3.5V to 5.5V, ILOAD = 100mA
Time (4ms/Div)
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7
RT9065
Load Transient Response
Load Transient Response
VOUT
(10mV/Div)
VOUT
(10mV/Div)
IOUT
(200mV/Div)
IOUT
(200mV/Div)
VIN = 2.2V, ILOAD = 0mA to 300mA
VIN = 2.2V, ILOAD = 0mA to 500mA
Time (200μs/Div)
Time (200μs/Div)
PSRR
Noise
90
80
PSRR (dB)
70
Noise
(100μV/Div)
60
50
VOUT = 3.3V
VOUT = 1.2V
VOUT = 1.8V
VOUT = 2.5V
40
30
20
10
VIN = 3V (By Battery), ILOAD = 10mA
IOUT = 100mA
0
10
Time (10ms/Div)
100
1000
10000
100000
1000000
Frequency (Hz)
Dropout Voltage vs. Output Current
350
Dropout Voltage (mV)
300
250
200
150
100
50
0
0
100
200
300
400
500
Output Current (mA)
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
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is a registered trademark of Richtek Technology Corporation.
DS9065-01
December 2012
RT9065
Application Information
The RT9065 requires input and output decoupling
capacitors. These capacitors must be correctly selected
for good performance and insufficient decoupling
capacitance may cause oscillation.
Adjustable Output Voltage
Input Capacitor
Bypass Capacitor and Low Noise
The value of input capacitor should be ≥ 2.2μF. The input
capacitor must be placed within 1cm from the device to
assure input stability. There are no requirements for the
ESR (equivalent series resistance) on the input capacitor,
but low-ESR ceramic capacitor with larger value provides
better PSRR and line transient response.
Connecting a 22nF capacitor between the BP pin and the
GND pin significantly reduces noise on the regulator
output, and it is critical that the capacitor should be placed
close to the IC and PCB traces should be as short as
possible. DC leakage on this pin can affect the LDO
regulator output noise and voltage regulation performance.
Output Capacitor
Enable Function
The output capacitor must meet both requirements for
minimum amount of capacitance and ESR for the LDO
application. The RT9065 is designed specifically to work
with low-ESR ceramic output capacitor in consideration
of space-saving and performance. To ensure the stability,
the value of ceramic capacitor should be at least 1μF and
ESR should be > 5mΩ. The RT9065 can also work well
with other types of output capacitors. Figure 1 shows the
stable range of ESR as a function of load current for various
output capacitor values. Output capacitor with larger
capacitance can reduce noise and improve load transient
response, stability, and PSRR. The output capacitor should
be located no more than 0.5 inches from the VOUT pin.
The RT9065 features an enable/disable function. The
enable control level must be greater than 1.2V to turn-on
the device. When the voltage on the EN pin falls below
0.4V, the LDO will be shut down and will reduce quiescent
current to less than 1μA. If the enable function is not
needed in a specific application, it should be tied to VIN
to keep the LDO in a continuously on state.
Region of Stable COUT ESR vs. Output Current
100
Stable (High)
ESR Range (Ω)
10
1
0.1
Stable (Low)
0.01
0.001
0
50
100 150 200 250 300 350 400 450 500
Output Current (mA)
The output voltage is set by the ratio of two external
resistors as follow :
VOUT = 0.8 × (1+ R1 / R2)
Current Limit
The RT9065 contains an independent current limiter, which
monitors and controls the pass transistor's gate voltage,
limiting the output current to 0.65A (typ.). The output can
be shorted to ground without damaging the part.
Thermal Considerations
For continuous operation, do not exceed absolute
maximum junction temperature. The maximum power
dissipation depends on the thermal resistance of the IC
package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature. The
maximum power dissipation can be calculated by the
following formula :
PD(MAX) = (TJ(MAX) − TA) / θJA
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction to ambient
thermal resistance.
Figure 1. Region of Stable COUT ESR
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9065-01
December 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
9
RT9065
PD(MAX) = (125°C − 25°C) / (208.2°C/W) = 0.48W for
SOT-23-6 package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. The derating curve in Figure 2 allows the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
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10
0.6
Maximum Power Dissipation (W)1
For recommended operating condition specifications, the
maximum junction temperature is 125°C. The junction to
SOT-23-6 package, the thermal resistance, θ JA, is
208.2°C/W on a standard JEDEC 51-7 four-layer thermal
test board. The maximum power dissipation at TA = 25°C
can be calculated by the following formula :
Four-Layer PCB
0.5
0.4
0.3
0.2
0.1
0.0
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 2. Derating Curve of Maximum Power Dissipation
is a registered trademark of Richtek Technology Corporation.
DS9065-01
December 2012
RT9065
Outline Dimension
H
D
L
C
B
b
A
A1
e
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
0.889
1.295
0.031
0.051
A1
0.000
0.152
0.000
0.006
B
1.397
1.803
0.055
0.071
b
0.250
0.560
0.010
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
SOT-23-6 Surface Mount Package
Richtek Technology Corporation
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
DS9065-01
December 2012
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