RT9167A-33GB [RICHTEK]
Low-Noise, Fixed Output Voltage,300mA/500mA LDO Regulator;型号: | RT9167A-33GB |
厂家: | RICHTEK TECHNOLOGY CORPORATION |
描述: | Low-Noise, Fixed Output Voltage,300mA/500mA LDO Regulator |
文件: | 总13页 (文件大小:230K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
RT9167/A
Low-Noise, Fixed Output Voltage,300mA/500mA LDO Regulator
General Description
Features
z Stable with Low-ESR Output Capacitor
z Low Dropout Voltage (350mV @ 300mA)
z Low Operation Current −80μA Typical
z Shutdown Function
The RT9167/A is a 300mA/500mA low dropout and low
noise micropower regulator suitable for portable
applications. The output voltages range from 1.5V to 5.0V
in 100mV increments and 2% accuracy. The RT9167/Ais
designed for use with very low ESR capacitors. The output
remains stable even with 1μF ceramic output capacitor.
z Low Noise Output
z Low Temperature Coefficient
z Current and Thermal Limiting
z Custom Voltage Available
The RT9167/Auses an internal PMOS as the pass device,
which does not cause extra GND current in heavy load
and dropout conditions. The shutdown mode of nearly zero
operation current makes the IC suitable for battery-powered
devices. Other features include a reference bypass pin to
improve low noise performance, current limiting, and over
temperature protection.
z SOT-23-5 and SOP-8 Packages
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Cellular Telephones
z Laptop,Notebook, and Palmtop Computers
z Battery-powered Equipment
z Hand-held Equipment
Ordering Information
RT9167/A-
Package Type
B : SOT-23-5
Marking Information
For marking information, contact our sales representative
directly or through a RichTek distributor located in your
area, otherwise visit our website for detail.
BR : SOT-23-5 (R-Type)
S : SOP-8
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-Pin Configurations
cial Standard)
Output Voltage
15 : 1.5V
16 : 1.6V
:
49 : 4.9V
50 : 5.0V
2H : 2.85V
(TOP VIEW)
VOUT
BP
VOUT
GND
VIN
BP
EN
1
2
3
5
4
1
2
3
5
VIN
GND
EN
4
500mA Output Current
300mA Output Current
SOT-23-5
SOT-23-5 (R-Type)
Note :
RichTek Pb-free and Green products are :
`RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
8
7
6
5
GND
EN
VIN
2
3
4
GND
GND
GND
VOUT
BP
`Suitable for use in SnPb or Pb-free soldering processes.
`100%matte tin (Sn) plating.
SOP-8
DS9167/A-26 March 2007
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1
RT9167/A
Functional Pin Description
Pin Name
VIN
Pin Function
Power Input Voltage
Ground
GND
EN
Chip Enable (Active High)
Reference Noise Bypass
Output Voltage
BP
VOUT
Function Block Diagram
Shutdown
and
VIN
EN
Logic Control
VREF
BP
+
MOS Driver
Error
Amplifier
VOUT
Current-Limit and
Thermal Protection
R1
R2
GND
Typical Application Circuit
RT9167/A
V
IN
OUT
V
IN
OUT
C
1uF
C
1uF
IN
OUT
GND
Chip Enable
EN
BP
C
10nF
BP
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DS9167/A-26 March 2007
RT9167/A
Absolute Maximum Ratings
z Input Voltage------------------------------------------------------------------------------------------------------------ 8V
z Power Dissipation, PD @ TA = 25°C
SOT-23-5 ---------------------------------------------------------------------------------------------------------------- 0.4W
SOP-8 -------------------------------------------------------------------------------------------------------------------- 0.625W
z Package Thermal Resistance (Note1)
SOT-23-5, θJA ----------------------------------------------------------------------------------------------------------- 250°C/W
SOT-23-5, θJC ---------------------------------------------------------------------------------------------------------- 130°C/W
SOP-8, θJA -------------------------------------------------------------------------------------------------------------- 160°C/W
SOP-8, θJC -------------------------------------------------------------------------------------------------------------- 60°C/W
z Operating Junction Temperature Range -------------------------------------------------------------------------- −40°C to 125°C
z Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C
z Lead Temperature (Soldering, 10 sec.)--------------------------------------------------------------------------- 260°C
Electrical Characteristics
(VIN = 5.0V, CIN = 1μF, COUT = 1μF, TA = 25°C, unless otherwise specified)
Parameter
Input Voltage Range
Symbol
Test Conditions
Min Typ Max Units
2.9
2.7
-2
--
--
--
--
--
--
7
7
V
%
V
IN
I = 50mA
L
Output Voltage Accuracy
+2
--
ΔV
I = 1mA
L
OUT
RT9167
300
500
400
Maximum Output
Current
mA
IMAX
RT9167A
RT9167
--
--
Current Limit
mA
I
R
= 1Ω
LOAD
LIM
RT9167A
RT9167/A
RT9167/A
RT9167A
RT9167/A
RT9167/A
RT9167/A
RT9167A
500 700
--
No Load
--
--
80
90
90
1.1
55
150
150
150
5
Quiescent Current
μA
I
G
I
I
I
I
I
I
= 300mA
OUT
OUT
OUT
OUT
OUT
OUT
--
--
= 500mA
= 1mA
(2)
Dropout Voltage
(V = 3.0V
--
100
= 50mA
= 300mA
= 500mA
mV
V
DROP
OUT(Normal)
--
350 450
600 750
Version)
--
Line Regulation
Load Regulation
--
--
--
6
30
35
--
mV/V
mV
ΔV
ΔV
V = (V
+0.15) to 7V, I
=1mA
OUT
LINE
IN
OUT
RT9167/A
RT9167A
--
I
= 0mA to 300mA
= 0mA to 500mA
OUT
OUT
LOAD
--
--
I
EN Input High Threshold
EN Input Low Threshold
EN Bias Current
1.6
--
--
V
V
V
V
V = 3V to 5.5V
IN
IH
--
0.4
100
1
V
IN
= 3V to 5.5V
IL
--
--
nA
μA
°C
I
SD
Shutdown Supply Current
Thermal Shutdown Temperature
--
0.01
155
IGSD
V
OUT
= 0V
--
--
T
SD
To be continued
DS9167/A-26 March 2007
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RT9167/A
Parameter
Output Noise
Symbol
Test Conditions
= 10nF, C = 10μF
Min Typ Max Units
--
--
350
58
--
--
nV
e
NO
C
BP
Hz
dB
OUT
Ripple Rejection
PSRR
F = 100Hz, C = 10nF, C
= 10μF
BP
OUT
Note 1. θJA 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. Pin 1 of SOP-8 and pin4 of SOT-23-5 packages are the case position for
θJA measurement.
Note 2. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
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DS9167/A-26 March 2007
RT9167/A
Typical Operating Characteristics
Output Voltage vs. Temperature
Quiescent Current vs. Temperature
120
105
90
75
60
45
30
15
0
3.33
3.32
3.31
3.30
3.29
3.28
3.27
3.26
VOUT = 3.3V
VOUT = 3.3V
100 125 150
3.25
-50
-25
0
25
50
75
100 125 150
-50
-25
0
25
50
75
Temperature
Temperature
(°C)
(°C)
Dropout Voltage vs. Load Current
Dropout Voltage vs. Load Current
250
200
150
100
50
600
500
400
300
200
100
0
125°C
125°C
25°C
25°C
-40°C
-40°C
RT9167
RT9167A
VOUT = 5.0V
VOUT = 3.3V
0
0
0.05
0.1
0.15
0.2
0.25
0.3
0
0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5
Load Current (A)
Load Current (A)
Current Limit vs. Temperature
Current Limit vs. Temperature
900
700
650
600
550
500
450
400
350
300
800
700
600
500
400
300
200
RT9167
VOUT = 5.0V
RT9167A
VOUT = 3.3V
-50
-25
0
25
50
75
100
125
-50
-25
0
25
50
75
100
125
Temperature
(°C)
Temperature
(°C)
DS9167/A-26 March 2007
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RT9167/A
Load Transient Response
Load Transient Response
60
40
20
0
60
40
20
0
C
= 10uF
V
= 4V
IN
IN
C
= 10uF
V
= 4V
IN
IN
COUT = 1uF
BP = 10nF
VOUT = 3.0V
C
OUT = 4.7uF
BP = 10nF
VOUT = 3.0V
C
C
-20
-20
≈
≈
≈
≈
50
1
50
1
-50
-50
Time (50us/Div)
Time (50us/Div)
Line Transient Response
Line Transient Response
150
100
50
150
Loading = 1mA
VOUT = 3.0V
Loading = 50mA
VOUT = 3.0V
COUT = 1uF
CBP = 10nF
100 COUT = 1uF
C
BP = 10nF
50
0
0
-50
-50
≈
≈
≈
≈
5
5
4
4
Time (1ms/Div)
Time (1ms/Div)
Line Transient Response
Line Transient Response
150
60
40
20
0
VOUT = 3.0V
OUT = 4.7uF
CBP = 10nF
VOUT = 3.0V
OUT = 4.7uF
CBP = 10nF
Loading = 1mA
Loading = 50mA
C
C
100
50
0
-50
-20
≈
≈
≈
≈
5
4
5
4
Time (500us/Div)
Time (500us/Div)
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DS9167/A-26 March 2007
RT9167/A
PSRR
70
60
50
40
30
20
10
0
VOUT = 3.3V, ILOAD = 1mA
OUT = 4.7uF, CBP = 10nF
10K 100K 1M
C
10
100
1K
Frequency (kHz)
DS9167/A-26 March 2007
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RT9167/A
Application Information
Capacitor Selection and Regulator Stability
capacitor should be located not more than 0.5" from the
VOUT pin of the RT9167/A and returned to a clean analog
ground.
Like any low-dropout regulator, the external capacitors used
with the RT9167/A must be carefully selected for regulator
stability and performance.
Note that some ceramic dielectrics exhibit large
capacitance and ESR variation with temperature. It may
be necessary to use 2.2μF or more to ensure stability at
temperatures below -10°C in this case. Also, tantalum
capacitors, 2.2μF or more may be needed to maintain
capacitance and ESR in the stable region for strict
application environment.
Using a capacitor whose value is > 1μF on the RT9167/A
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" 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.
Tantalum capacitors maybe suffer failure due to surge
current when it is connected to a low-impedance source
of power (like a battery or very large capacitor). If a tantalum
capacitor is used at the input, it must be guaranteed to
have a surge current rating sufficient for the application
by the manufacture.
The output capacitor must meet both requirements for
minimum amount of capacitance and ESR in all LDOs
application. The RT9167/Ais 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 > 5mΩ on the
RT9167/A output ensures stability. The RT9167/A 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 voltages and capacitor values. Output capacitor of
larger capacitance can reduce noise and improve load-
transient response, stability, and PSRR. The output
Use a 10nF bypass capacitor at BP for low output voltage
noise. The capacitor, in conjunction with an internal 200kΩ
resistor, which connects bypass pin and the band-gap
reference, creates an 80Hz low-pass filter for noise
reduction. Increasing the capacitance will slightly decrease
the output noise, but increase the start-up time. The
capacitor connected to the bypass pin for noise reduction
must have very low leakage. This capacitor leakage current
causes the output voltage to decline by a proportional
amount to the current due to the voltage drop on the internal
200kΩ resistor. Figure 2 shows the power on response.
Region of Stable COUT ESR vs. Load Current
100
COUT = 1uF
Unstable Region
Stable Region
CBP = 10nF
10
CBP = 10nF
1
0.1
Unstable Region
0.01
0.001
VOUT = 3.0V
0
50
100
150
200
250
300
0
5.0
Time (ms)
10.0
15.0
Load Current (mA)
Figure 1
Figure 2
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DS9167/A-26 March 2007
RT9167/A
Load-Transient Considerations
Input-Output (Dropout) Voltage
The RT9167/Aload-transient response graphs (see Typical
Operating Characteristics) show two components of the
output response: a DC shift from the output impedance
due to the load current change, and the transient response.
The DC shift is quite small due to the excellent load
regulation of the IC. Typical output voltage transient spike
for a step change in the load current from 0mAto 50mAis
tens mV, depending on the ESR of the output capacitor.
Increasing the output capacitor's value and decreasing the
ESR attenuates the overshoot.
A regulator's minimum input-output voltage differential
(or dropout voltage) determines the lowest usable supply
voltage. In battery-powered systems, this will determine
the useful end-of-life battery voltage. Because the RT9167/
Auses a P-Channel MOSFET pass transistor, the dropout
voltage is a function of drain-to-source on-resistance
[RDS(ON)] multiplied by the load current.
Reverse Current Path
The power transistor used in the RT9167/Ahas an inherent
diode connected between the regulator input and output
(see Figure 3). If the output is forced above the input by
more than a diode-drop, this diode will become forward
biased and current will flow from the VOUT terminal to VIN.
This diode will also be turned on by abruptly stepping the
input voltage to a value below the output voltage. To prevent
regulator mis-operation, a Schottky diode should be used
in any applications where input/output voltage conditions
can cause the internal diode to be turned on (see Figure4).
As shown, the Schottky diode is connected in parallel
with the internal parasitic diode and prevents it from being
turned on by limiting the voltage drop across it to about
0.3V. < 100mA to prevent damage to the part.
Shutdown Input Operation
The RT9167/A is shutdown by pulling the EN input low,
and turned on by driving the input high. If this feature is
not to be used, the EN input should be tied to VIN to keep
the regulator on at all times (the EN input must not be left
floating).
To ensure proper operation, the signal source used to
drive the ENinput must be able to swing above and below
the specified turn-on/turn-off voltage thresholds which
guarantee an ON or OFF state (see Electrical
Characteristics). The ON/OFF signal may come from
either CMOS output, or an open-collector output with pull-
up resistor to the RT9167/Ainput voltage or another logic
supply. The high-level voltage may exceed the
RT9167/A input voltage, but must remain within the
absolute maximum ratings for the EN pin.
VIN
VOUT
Internal P-Channel Pass Transistor
The RT9167/Afeatures a typical 1.1Ω P-Channel MOSFET
pass transistor. It provides several advantages over similar
designs using PNP pass transistors, including longer
battery life. The P-channel MOSFET requires no base
drive, which reduces quiescent current considerably. PNP-
based regulators waste considerable current in dropout
when the pass transistor saturates. They also use high
base-drive currents under large loads. The RT9167/Adoes
not suffer from these problems and consume only 80μA of
quiescent current whether in dropout, light-load, or heavy-
load applications.
Figure 3
VIN
VOUT
Figure 4
DS9167/A-26 March 2007
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9
RT9167/A
Operating Region and Power Dissipation
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 :
The maximum power dissipation of RT9167/A depends
on the thermal resistance of the case and circuit board,
the temperature difference between the die junction and
ambient air, and the rate of airflow. The power dissipation
across the device is P = IOUT (VIN - VOUT). The maximum
power dissipation is: PMAX = (TJ - TA) /θJA
PD(MAX) = ( TJ(MAX) - TA ) / θJA
Where TJ(MAX) is the maximum operation junction
temperature 125°C, TA is the ambient temperature and
the θJA is the junction to ambient thermal resistance.
where TJ - TA is the temperature difference between the
RT9167/Adie junction and the surrounding environment,
θJA is the thermal resistance from the junction to the
surrounding environment. TheGNDpin of the RT9167/A
performs the dual function of providing an electrical
connection to ground and channeling heat away. Connect
theGNDpin to ground using a large pad or ground plane.
For recommended operating conditions specification of
RT9167/A, where TJ(MAX) is the maximum junction
temperature of the die (125°C) and TA is the operated
ambient temperature. The junction to ambient thermal
resistance θJA is layout dependent. For SOT-23-5 package,
the thermal resistance 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 :
Current Limit and Thermal Protection
T9167 includes a current limit which monitors and controls
the pass transistor's gate voltage limiting the output current
to 350mA Typ. (700mA Typ. for RT9167A). Thermal-
overload protection limits total power dissipation in the
RT9167/A. When the junction temperature exceeds
TJ = +155°C, the thermal sensor signals the shutdown
logic turning off the pass transistor and allowing the IC to
cool. The thermal sensor will turn the pass transistor on
again after the IC's junction temperature cools by 10°C,
resulting in a pulsed output during continuous thermal-
overload conditions. Thermal-overloaded protection is
designed to protect the RT9167/A in the event of fault
conditions.Do not exceed the absolute maximum junction-
temperature rating of TJ = +150°C for continuous operation.
The output can be shorted to ground for an indefinite
amount of time without damaging the part by cooperation
of current limit and thermal protection.
PD(MAX) = (125°C − 25°C) / 250 = 0.4W for SOT-23-5
package
PD(MAX) = (125°C - 25°C) / 160 = 0.625W for SOP-8
package
The maximum power dissipation depends on operating
ambient temperature for fixed TJ(MAX) and thermal
resistance θJA. For RT9167/A packages, the Figure 5 of
derating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
allowed.
700
SOP-8
600
500
SOT-23-5
400
Thermal Considerations
Thermal protection limits power dissipation in RT9167/A.
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.
300
200
100
0
For continuous operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is:
0
20
40
60
80
100
120
140
Ambient Temperature
Figure 5. Derating Curves for RT9167/APackages
DS9167/A-26 March 2007
PD = (VIN − VOUT) x IOUT + VIN x IQ
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RT9167/A
The value of junction to case thermal resistance θJC is
popular for users. This thermal parameter is convenient
for users to estimate the internal junction operated
temperature of packages while IC operating. It’ s
independent of PCB layout, the surroundings airflow effects
and temperature difference between junction to ambient.
The operated junction temperature can be calculated by
following formula :
TJ = TC + PD x θJC
Where TC is the package case temperature measured by
thermal sensor, PD is the power dissipation defined by
user’ s function and the θJC is the junction to case thermal
resistance provided by IC manufacturer. Therefore it’ s easy
to estimate the junction temperature by any condition.
For example, how to calculate the junction temperature
of RT9167A-28CB SOT-23-5 package? If we use input
voltage VIN = 3.3V at an output current IO = 500mA and
the case temperature (pin 4 of SOT-23-5 package)
TC = 70°C measured by thermal couple while operating,
then our power dissipation is as follows:
PD = (3.3V − 2.8V) x 500mA + 3.3V x 90μA ≅ 250mW
And the junction temperature TJ could be calculated as
following :
TJ = TC + PD x θJC
TJ = 70°C + 0.25W x 130°C/W
= 70°C + 32.5°C
= 102.5°C < TJ(MAX) =125°C
For this operation application, TJ is lower than absolute
maximum operation junction temperature 125°C and it’s
safe to use.
DS9167/A-26 March 2007
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11
RT9167/A
Outline Dimension
H
D
L
B
C
A
b
A1
e
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
A1
B
0.889
0.000
1.397
0.356
2.591
2.692
0.838
0.080
0.300
1.295
0.152
1.803
0.559
2.997
3.099
1.041
0.254
0.610
0.035
0.000
0.055
0.014
0.102
0.106
0.033
0.003
0.012
0.051
0.006
0.071
0.022
0.118
0.122
0.041
0.010
0.024
b
C
D
e
H
L
SOT-23-5 Surface Mount Package
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DS9167/A-26 March 2007
RT9167/A
H
A
M
J
B
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
B
C
D
F
H
I
4.801
3.810
1.346
0.330
1.194
0.170
0.050
5.791
0.400
5.004
3.988
1.753
0.508
1.346
0.254
0.254
6.200
1.270
0.189
0.150
0.053
0.013
0.047
0.007
0.002
0.228
0.016
0.197
0.157
0.069
0.020
0.053
0.010
0.010
0.244
0.050
J
M
8-Lead SOP Plastic Package
Richtek Technology Corporation
Headquarter
Richtek Technology Corporation
Taipei Office (Marketing)
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
8F, No. 137, Lane 235, Paochiao Road, Hsintien City
Taipei County, Taiwan, R.O.C.
Tel: (8863)5526789 Fax: (8863)5526611
Tel: (8862)89191466 Fax: (8862)89191465
Email: marketing@richtek.com
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13
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