DS9049 01

RT9049
500mA, Low Dropout, Low Noise Ultra-Fast Without Bypass
Capacitor CMOS LDO Regulator
General Description
Features
The RT9049 is a high-performance, 500mA LDO regulator,
offering extremely high PSRR and ultra-low dropout. The
RT9049 is designed for portable RF and wireless
applications with demanding performance and space
requirements. The RT9049 quiescent current is as low as
115μA, further prolonging the battery life. The RT9049 also
works with low-ESR ceramic capacitors, reducing the
amount of board space necessary which is critical for
power applications in hand-held wireless devices. The
RT9049 consumes typical 1.35μA in shutdown mode and
has fast turn-on time less than 40μs. The other features
include ultra-low dropout voltage, high output accuracy,
current limiting protection, and high ripple rejection ratio.
The RT9049 is available in the SOT-23-5 package.
z
Wide Operating Voltage Ranges : 2.2V to 5.5V
z Low Dropout : 250mV at 500mA
z Ultra-Low-Noise for RF Application
z Ultra-Fast Response in Line/Load Transient
z Current Limiting Protection
z Thermal Shutdown Protection
z High Power Supply Rejection Ratio
z Only 10μ
μF Output Capacitor Required for Stability
z 1.35μ
μA Shutdown Current
z TTL-Logic-Controlled Shutdown Input
z RoHS Compliant and Halogen Free
Applications
CDMA/GSM Cellular Handsets
Portable Information Appliances
z Laptop, Palmtops, Notebook Computers
z HandHeld Instruments
z Mini PCI & PCI-Express Cards
z PCMCIA & New Cards
z
z
Ordering Information
RT9049 Package Type
B : SOT-23-5
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
Pin Configurations
Fixed Output Voltage
12 : 1.2V
(TOP VIEW)
VOUT
Richtek products are :
`
NC
5
RoHS compliant and compatible with the current require-
4
2
3
ments of IPC/JEDEC J-STD-020.
`
VIN GND EN
Suitable for use in SnPb or Pb-free soldering processes.
SOT-23-5
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
Typical Application Circuit
1 VIN
VIN
CIN
1µF/X7R
VOUT 5
VOUT
COUT
10µF/X7R
RT9049
Chip Enable
3 EN
Rpull_down
100k
DS9049-01 April 2011
NC 4
GND
2
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RT9049
Function Block Diagram
EN
Current
Limit
POR
OTP
VIN
VREF
+
MOS
Driver
VOUT
GND
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
VIN
Supply Input.
2
GND
3
EN
4
NC
Common Ground.
Chip Enable (Active High). When the EN goes to a logic low, the device will be in
shutdown mode.
No Internal Connection.
5
VOUT
Regulator Output.
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DS9049-01 April 2011
RT9049
Absolute Maximum Ratings
z
z
z
z
z
z
z
z
(Note 1)
Input Voltage, VIN ---------------------------------------------------------------------------------------------------------EN, VEN ---------------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
SOT-23-5 -------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
SOT-23-5, θJA --------------------------------------------------------------------------------------------------------------SOT-23-5, θJC -------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------
Recommended Operating Conditions
z
z
6V
6V
0.4W
250°C/W
25°C/W
260°C
150°C
−65°C to 150°C
2kV
200V
(Note 4)
Junction Temperature Range -------------------------------------------------------------------------------------------Ambient Temperature Range --------------------------------------------------------------------------------------------
−40°C to 125°C
−40°C to 85°C
Electrical Characteristics
(VIN = 2.7V, VEN = VIN, CIN = 1μF, COUT = 10μF(Ceramic, X7R), TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Input Voltage Range
VIN
2.2
--
5.5
V
Output Noise Voltage
VON
--
30
--
μV RMS
Output Voltage Accuracy
ΔV OUT
IOUT = 10mA
−2
0
+2
%
Quiescent Current
IQ
IOUT = 0mA
--
115
125
μA
Shutdown Current
ISHDN
VEN = 0V
--
1.35
2
μA
Current Limit
ILIM
RLOAD = 0 Ω
1mA < IOUT < 400mA
VIN = 2.5V
0.5
0.6
0.85
A
--
--
0.6
%
Load Regulation
(Note 5)
(Note 6)
ΔV LOAD
Logic-High
VIH
1.6
--
--
Logic-Low
VIL
--
--
0.6
Enable Pin Current
IEN
--
0.1
1
μA
Power Supply Rejection Rate
PSRR
IOUT = 100mA, f = 10kHz
--
−50
--
dB
Line Regulation
ΔV LINE
VIN = 2.2V to 5.5V,
IOUT = 1mA
--
0.01
0.2
%/V
Thermal Shutdown
Temperature
TSD
--
170
--
°C
Thermal Shutdown Hysteresis
ΔT SD
--
30
--
°C
EN Threshold
Voltage
DS9049-01 April 2011
V
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RT9049
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 thermal conductivity single layer test board
of JEDEC 51-3 thermal measurement standard. The case position of θJC is on the package top of 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. 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. Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for
loadregulation in the load range from 10mA to 500mA.
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DS9049-01 April 2011
RT9049
Typical Operating Characteristics
Output Voltage vs. Temperature
Quiescent Current vs. Temperature
1.300
140
Quiescent Current (μA)
Output Voltage(V)
1.275
1.250
1.225
1.200
1.175
1.150
130
120
110
100
1.125
90
VIN = 2.75V, VOUT = 1.2V, No Load
1.100
VIN = 2.75V, VOUT = 1.2V, No Load
80
-50
-25
0
25
50
75
100
125
-50
Temperature (°C)
0
25
50
75
100
125
Temperature (°C)
Line Transient Response
Power On-Off from EN
VIN
(1V/Div)
VEN
(1V/Div)
-25
3.6
2.6
20
VOUT
(20mV/Div) 0
VOUT
(0.5V/Div)
−20
VIN = 2.75V, VOUT = 1.2V, IOUT = 50mA
VIN
(1V/Div)
VIN = 2.6V to 3.6V, VOUT = 1.2V, IOUT = 10mA
Time (100μs/Div)
Time (100μs/Div)
Line Transient Response
Load Transient Response
VOUT
(5mV/Div)
3.6
2.6
20
VOUT
(20mV/Div) 0
−20
VIN = 2.6V to 3.6V, VOUT = 1.2V, IOUT = 100mA
Time (100μs/Div)
DS9049-01 April 2011
IOUT
(50mA/Div)
VIN = 2.75V, VOUT = 1.2V, IOUT = 10mA to 100mA
Time (500μs/Div)
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RT9049
Load Transient Response
Noise
VOUT
(5mV/Div)
VOUT
(100μV/Div)
IOUT
(100mA/Div)
VIN = 2.75V, VOUT = 1.2V, IOUT = 10mA to 300mA
VIN = 4.5V (By Battery), VOUT = 1.2V, No Load
Time (500μs/Div)
Time (10msDiv)
Noise
PSRR
20
10
PSRR(dB)
0
VOUT
(100μV/Div)
-10
-20
-30
IOUT = 100mA
-40
IOUT = 300mA
-50
VIN = 4.5V (By Battery), VOUT = 1.2V, IOUT = 10mA
Time (10msDiv)
IOUT = 10mA
-60
VIN = 2.5V to 2.6V
-70
10
100
1000
10000
100000
1000000
Frequency (Hz)
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DS9049-01 April 2011
RT9049
Applications Information
Like any low-dropout regulator, the external capacitors used
with the RT9049 must be carefully selected for regulator
stability and performance. Using a capacitor more than
1μF on the RT9049 is suitable. The input capacitor must
be located at a distance of not more than 0.5 inch from
the input pin of the IC and returned to a clean analog ground.
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 capacitance and ESR in all LDOs application.
The RT9049 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 10μF with ESR is > 45mΩ on the RT9049 output
ensures stability. The RT9049 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 at less than 0.5
inch from the VOUT pin of the RT9049 and returned to a
clean analog ground.
Region of Stable COUT ESR (Ω )
Region of Stable COUT ESR vs. Load Current
Enable
The RT9049 goes into sleep mode when the Enable pin is
in a logic low condition. During this condition, the pass
transistor, error amplifier, and bandgap are turned off,
reducing the supply current to 1.35μA typical. The Enable
pin may be directly tied to VIN to keep the part on. The
Enable input is CMOS logic and cannot be left floating.
PSRR
The power supply rejection ratio (PSRR) is defined as the
gain from the input to output divided by the gain from the
supply to the output. The PSRR is found to be
⎛ ΔGain Error ⎞
⎟⎟
PSRR = 20 × log⎜⎜
⎝ ΔSupply ⎠
Note that when heavy load measuring, Δsupply will cause
Δtemperature. And Δtemperature will cause Δoutput
voltage. So the heavy load PSRR measuring is includes
temperature effect.
Current Limit
The RT9049 contains an independent current limiter, which
monitors and controls the pass transistor's gate voltage,
limiting the output current to 0.6A (typ.). The output can
be shorted to ground indefinitely without damaging the
part.
100
Thermal Considerations
Unstable Range
For continuous operation, do not exceed absolute
maximum operation junction temperature. 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 :
10
1
RT9049 -12GB
VIN = 2.75V
COUT = 10μF/X7R
0.1
Stable Range
Unstable Range
PD(MAX) = (TJ(MAX) − TA) / θJA
0.01
0
0.1
0.2
0.3
0.4
0.5
Load Current (mA)
Figure 1.Region of Stable COUT ESR vs. Load Current
DS9049-01 April 2011
Where T J(MAX) is the maximum operation junction
temperature, TA is the ambient temperature and the θJA is
the junction to ambient thermal resistance.
For recommended operating conditions specification of
RT9049, the maximum junction temperature is 125°C. The
junction to ambient thermal resistance θJA is layout
dependent. For SOT-23-5 package, the thermal resistance
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RT9049
θJA is 250°C/W on the standard JEDEC 51-3 single layer
thermal test board. The maximum power dissipation at
TA = 25°C can be calculated by following formula :
P D(MAX) = (125°C − 25°C) / (250°C/W) = 0.4W for
SOT-23-5 package
Maximum Power Dissipation (W)1
The maximum power dissipation depends on operating
ambient temperature for fixed T J(MAX) and thermal
resistance θJA. For RT9049 package, the Figure 2 of
derating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
dissipation allowed.
0.50
Single Layer PCB
0.45
0.40
0.35
SOT-23-5
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 2. Derating Curves for RT9049 Package
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DS9049-01 April 2011
RT9049
Outline Dimension
H
D
L
B
C
b
A
A1
e
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
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
SOT-23-5 Surface Mount Package
Richtek Technology Corporation
Richtek Technology Corporation
Headquarter
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
5F, No. 95, Minchiuan Road, Hsintien City
Hsinchu, Taiwan, R.O.C.
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)86672399 Fax: (8862)86672377
Email: [email protected]
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.
DS9049-01 April 2011
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