RICHTEK RT9166B

RT9166B
600mA, Ultra-Fast Transient Response Linear Regulator
General Description
Features
The RT9166B is a CMOS linear regulator optimized for
ultra-fast transient response. The device is capable of
supplying up to 600mA of output current and is optimized
for CD/DVD-ROM, CD/RW or wireless communication
applications. The RT9166B regulator is stable with output
capacitor as low as 3.3μF. The other features include high
output accuracy, current limiting protection, and high ripple
rejection ratio. The RT9166B regulator is available in a
3-lead SOT-89 package.
z
z
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z
z
z
z
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z
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Ordering Information
RT9166B -
μA)
Low Quiescent Current (Typically 220μ
Guaranteed 600mA Output Current
Wide Operating Voltage Ranges : 2.8V to 5.5V
Ultra-Fast Transient Response
Tight Load and Line Regulation
Current Limiting Protection
Thermal Shutdown Protection
Only Low-ESR Ceramic Capacitor Required for
Stability
Custom Voltage Available
RoHS Compliant and Halogen Free
Applications
Package Type
X : SOT-89
z
Lead Plating System
G : Green (Halogen Free and Pb Free)
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Output Voltage
12 : 1.2V
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Note :
CD/DVD-ROM, CD/RW
Wireless LAN Card/Keyboard/Mouse
Battery-Powered Equipment
XDSL Router
PCMCIA Card
Richtek products are :
`
RoHS compliant and compatible with the current require-
`
Suitable for use in SnPb or Pb-free soldering processes.
Pin Configurations
ments of IPC/JEDEC J-STD-020.
(TOP VIEW)
Marking Information
1
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
2
GND VOUT
(TAB)
3
VIN
SOT-89
Typical Application Circuit
RT9166B
VIN
VIN
CIN
1µF
DS9166B-01 April 2011
VOUT
GND
VOUT
COUT
3.3µF
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RT9166B
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
GND
Common Ground.
2
VOUT
Regulator Output.
3
VIN
Supply Input.
Function Block Diagram
VIN
VOUT
Thermal
Shutdown
Error
Amplifier
-
+
Current
Limiting
Sensor
1.2V
Reference
GND
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DS9166B-01 April 2011
RT9166B
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage ---------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
SOT-89 --------------------------------------------------------------------------------------------------------------------z Package Thermal Resistance (Note 2)
SOT-89, θJA ---------------------------------------------------------------------------------------------------------------SOT-89, θJC --------------------------------------------------------------------------------------------------------------z Junction Temperature --------------------------------------------------------------------------------------------------z Lead Temperature (Soldering, 10 sec.) ----------------------------------------------------------------------------z Storage Temperature Range ------------------------------------------------------------------------------------------z ESD Susceptibility (Note 3)
HBM (Human Body Mode) --------------------------------------------------------------------------------------------MM (Machine Mode) ---------------------------------------------------------------------------------------------------z
6.5V
z
Recommended Operating Conditions
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z
z
0.847W
118°C/W
58°C/W
150°C
260°C
−65°C to 150°C
2kV
200V
(Note 4)
Supply Input Voltage ---------------------------------------------------------------------------------------------------- 2.8V to 5.5V
Junction Temperature Range ------------------------------------------------------------------------------------------ −40°C to 125°C
Ambient Temperature Range ------------------------------------------------------------------------------------------ −40°C to 85°C
Electrical Characteristics
(VIN = 2.8V whichever is greater; CIN = 1μF, COUT = 3.3μF, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
Output Voltage Accuracy
ΔVOUT
IOUT = 1mA
-1
--
3
%
Current Limit
ILIM
RLOAD = 1Ω
600
--
--
mA
Quiescent Current
(Note 5)
IQ
IOUT = 0mA
--
220
300
μA
Line Regulation
ΔVLINE
VIN = 2.8V to 5.5V, IOUT = 1mA
--
0.2
--
%V
ΔVLOAD
1mA < IOUT < 600mA
--
30
55
mV
PSRR
f = 1kHz, COUT = 1μF
--
−55
--
dB
--
170
--
°C
--
40
--
°C
Load Regulation
(Note 6)
Power Supply Rejection
Rate
Thermal Shutdown
Temperature
Thermal Shutdown
Hysteresis
DS9166B-01 April 2011
TSD
ΔTSD
ISW = 0.2A
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RT9166B
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 high effective four-layer thermal conductivity test board
of JEDEC 51-7 thermal measurement standard. The measurement case position of θJC is on the expose pad 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 20ms current pulse. Devices are tested for
load regulation in the load range from 1mA to 600mA respectively.
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DS9166B-01 April 2011
RT9166B
Typical Operating Characteristics
Output Voltage vs. Temperature
1.25
1.24
1.24
1.23
1.23
Output Voltage (V)
Output Voltage (V)
Output Voltage vs. Input Voltage
1.25
1.22
1.21
1.20
1.19
1.18
1.17
1.22
1.21
1.20
1.19
1.18
1.17
1.16
1.16
IOUT = 0A
1.15
2.8
3.1
3.4
3.7
4.0
4.3
4.6
4.9
5.2
VIN = 3.3V, IOUT = 0A
1.15
5.5
-50
-25
0
Quiescent Current vs. Input Voltage
75
100
125
Quiescent Current vs. Temperature
230
230
220
220
Quiescent Current (μA)
Quiescent Current (μA)
50
Temperature (°C)
Input Voltage (V)
210
200
190
180
170
210
200
190
180
170
160
160
VOUT = 1.2V, IOUT = 0A
VIN = 3.3V, VOUT = 1.2V, IOUT = 0A
150
150
2.8
3.1
3.4
3.7
4.0
4.3
4.6
4.9
5.2
-50
5.5
-25
0
25
50
75
100
125
Temperature (°C)
Input Voltage (V)
Current Limit vs. Temperature
Current Limit vs. Input Voltage
1.00
1.00
0.95
0.95
0.90
0.90
Current Limit (A)
Current limit (A)
25
0.85
0.80
0.75
0.85
0.80
0.75
0.70
0.70
0.65
0.65
VOUT = 1.2V
0.60
2.8
3.1
3.4
3.7
4.0
4.3
4.6
Input Voltage (V)
DS9166B-01 April 2011
4.9
5.2
5.5
VIN = 3.3V, VOUT = 1.2V
0.60
-50
-25
0
25
50
75
100
125
Temperature (°C)
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RT9166B
Power Off from VIN
Power On from VIN
VIN
(2V/Div)
VIN
(2V/Div)
VOUT
(0.5V/Div)
VOUT
(0.5V/Div)
I IN
(0.5A/Div)
IOUT
(0.5A/Div)
I IN
(0.5A/Div)
IOUT
(0.5A/Div)
VIN = 3.3V, VOUT = 1.2V, IOUT = 600mA
VIN = 3.3V, VOUT = 1.2V, IOUT = 600mA
Time (2.5ms/Div)
Time (2.5ms/Div)
Load Transient Response
Load Transient Response
VOUT
(20mV/Div)
VOUT
(20mV/Div)
IOUT
(500mA/Div)
IOUT
(500mA/Div)
VIN = 3.3V, VOUT = 1.2V, IOUT = 0A to 600mA
VIN = 3.3V, VOUT = 1.2V, IOUT = 0A to 300mA
Time (250μs/Div)
Time (250μs/Div)
Line Transient Response
0.00
PSRR
VIN = 3V + 0.1VAC, VOUT = 1.2V
-10.00
PSRR (dB)
-20.00
VIN
(1V/Div)
VOUT
(5mV/Div)
IOUT = 0A
IOUT = 300mA
-30.00
-40.00
-50.00
-60.00
VIN = 3V to 4V, VOUT = 1.2V, IOUT = 300mA
-70.00
-80.00
Time (50μs/Div)
0.01
10
CIN = 1μF/X7R, COUT = 3.3μF
0.1
100
1
1000
10
10000
100
100000
1000
1000000
Frequency (kHz)
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DS9166B-01 April 2011
RT9166B
Application Information
Like any linear regulator, the RT9166B requires input and
output decoupling capacitors. These capacitors must be
correctly selected for good performance Please note that
linear regulators 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 capacitance may be
increased without limit). The input capacitor must be
located less than 1cm from the device to assure input
stability A lower ESR capacitor allows the use of less
capacitance, while higher ESR type (like aluminum
electrolytic) requires 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 for 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 1μF
capacitance over the entire operating temperature range.
Output Capacitor
The RT9166B is designed specifically to work with very
small ceramic output capacitors. The recommended
minimum capacitance (temperature characteristics X7R
or X5R) is 3.3μF with 10mΩ to 50mΩ range ceramic
capacitor between LDO output and GND for transient
stability.
Higher capacitance helps to improve the transient
response. The output capacitor's ESR is critical because
it forms a zero to provide phase lead which is required for
loop stability.
Input-Output (Dropout) Voltage
A regulator's minimum input-to-output differential voltage
(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-
DS9166B-01 April 2011
source on-resistance, RDS(ON), multiplied by the load
current :
VDROPOUT = VIN − VOUT = RDS(ON) x IOUT
Current Limit
The RT9166B monitors and controls the PMOS gate
voltage, with a minimum limit of the output current at
600mA. 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 in the event of a peak
over-current condition, such that the short-circuit control
loop rapidly drives 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 by cycling to a lower frequency. Please refer to
the section on thermal information for power dissipation
calculations.
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.
For recommended operating condition specifications of
RT9166B, the maximum junction temperature is 125°C
and TA is the ambient temperature. The junction to ambient
thermal resistance, θJA, is layout dependent. For SOT-89
packages, the thermal resistance, θJA, is 118°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 :
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RT9166B
PD(MAX) = (125°C − 25°C) / (60°C/W) = 0.847W for
SOT-89 package
The maximum power dissipation depends on operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. For RT9166B packages, the derating curve
in Figure 1 allows the designer to see the effect of rising
ambient temperature on the maximum power dissipation.
Maximum Power Dissipation (W)1
1.00
Four-Layer PCB
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 1. Derating Curve for RT9166B Package
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DS9166B-01 April 2011
RT9166B
Outline Dimension
D
D1
A
B
C
C1
e
e
H
A
b
b1
b
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
1.397
1.600
0.055
0.063
b
0.356
0.483
0.014
0.019
B
2.388
2.591
0.094
0.102
b1
0.406
0.533
0.016
0.021
C
3.937
4.242
0.155
0.167
C1
0.787
1.194
0.031
0.047
D
4.394
4.597
0.173
0.181
D1
1.397
1.753
0.055
0.069
e
1.448
1.549
0.057
0.061
H
0.356
0.432
0.014
0.017
3-Lead SOT-89 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.
DS9166B-01 April 2011
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