DS9012 09

RT9012
300mA Dual LDO Regulator with POR
General Description
Features
RT9012 is a dual channel, low noise, and low dropout with
the sourcing ability up to 300mA and power-on reset
function. The range of output voltage is from 1.2V to 3.6V
by operating from 2.5V to 5.5V input.
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Wide Operating Voltage Ranges : 2.5V to 5.5V
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Low-Noise for RF Application
No Noise Bypass Capacitor Required
Fast Response in Line/Load Transient
TTL-Logic-Controlled Shutdown Input
Low Temperature Coefficient
Dual LDO Outputs (300mA/300mA)
Ultra-low Quiescent Current 27uA/LDO
High Output Accuracy 2%
Short Circuit Protection
Thermal Shutdown Protection
Current Limit Protection
Short Circuit Thermal Folded Back Protection
Tiny 8-Lead WDFN Package
RoHS Compliant and 100% Lead (Pb)-Free
The RT9012 offers 2% accuracy, extremely low dropout
voltage (240mV @ 300mA), and extremely low ground
current, only 27uA per LDO. The shutdown current is near
zero current which is suitable for battery-power devices.
Other features include current limiting, over temperature,
output short circuit protection.
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The RT9012 is short circuit thermal folded back protected.
The IC lowers its OTP trip point from 165°C to 110°C when
output short circuit occurs (VOUT < 0.4V) providing
maximum safety to end users.
The RT9012 can operate stably with very small ceramic
output capacitors, reducing required board space and
component cost. The RT9012 is available in fixed output
voltages in the WDFN-8L 2x2 package.
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Applications
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Ordering Information
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RT9012-
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Package Type
QW : WDFN-8L 2x2 (W-Type)
Lead Plating System
P : Pb Free
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
Pin Configurations
(TOP VIEW)
VIN 1
EN1 2
EN2 3
SET 4
Output Voltage : VOUT1/VOUT2
VOUT2 > VOUT1 is Recommended
Note :
8
9
7
6
5
VOUT1
VOUT2
POR
GND
WDFN-8L 2x2
Richtek products are :
`
RoHS compliant and compatible with the current require-
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Suitable for use in SnPb or Pb-free soldering processes.
ments of IPC/JEDEC J-STD-020.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS9012-09 April 2011
Available Voltage Version
Code
Voltage
Code
Voltage
Code
Voltage
A
D
G
K
N
R
V
Y
3.5
1.85
1.8
2.6
2.85
3.2
2.9
1.9
B
E
H
L
P
S
W
1.3
2.1
2
2.7
3
3.3
1.6
C
F
J
M
Q
T
X
1.2
1.5
2.5
2.8
3.1
2.65
3.15
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1
RT9012
Typical Application Circuit
100K
VIN
VIN
CIN
1uF
POR
RT9012
Chip Enable
EN1
VOUT1
COUT1
1uF
VOUT1
EN2
VOUT2
SET
GND
COUT2
1uF
VOUT2
CDELAY
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
VIN
Supply Input.
2
EN1
Chip Enable1 (Active High).
3
EN2
Chip Enable2 (Active High).
4
SET
Delay Set Input. Connect external capacitor to GND to set the internal delay.
5
GND
Common Ground.
6
POR
Power-On Reset Output : Open-drain output. Active low indicates an output
under-voltage condition on regulator 2.
7
VOUT2
Channel 2 Output Voltage.
8
VOUT1
Channel 1 Output Voltage.
9 (Exposed Pad)
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2
GND
The exposed pad must be soldered to a large PCB and connected to GND
for maximum power dissipation.
DS9012-09 April 2011
RT9012
Function Block Diagram
EN1
Shutdown
and
Logic Control
0.2uA
VIN
-
VREF
MOS Driver
+
Error
Amplifier
VOUT1
Current-Limit
and
Thermal
Protection
GND
EN2
Shutdown
and
Logic Control
0.2uA
-
VREF
+
Error
Amplifier
MOS Driver
VOUT2
Current-Limit
and
Thermal
Protection
GND
SET
DS9012-09 April 2011
POR& Delay
POR
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3
RT9012
Absolute Maximum Ratings
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(Note 1)
Supply Input Voltage -----------------------------------------------------------------------------------------------------Other I/O Pin Voltages --------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
WDFN-8L 2x2 -------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
WDFN-8L 2x2, θJA --------------------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------
Recommended Operating Conditions
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6V
6V
0.606W
165°C/W
150°C
260°C
−65°C to 150°C
2kV
200V
(Note 4)
Supply Input Voltage ------------------------------------------------------------------------------------------------------ 2.5V to 5.5V
Enable Input Voltage ------------------------------------------------------------------------------------------------------ 0V to 5.5V
Operation Junction Temperature Range ------------------------------------------------------------------------------ −40°C to 125°C
Operation Ambient Temperature Range ------------------------------------------------------------------------------ −40°C to 85°C
Electrical Characteristics
(VIN = VOUT + 1V, VEN = VIN, CIN = COUT = 1μF, TA = 25°C, unless otherwise specified.)
Parameter
Input Voltage
Dropout Voltage
Symbol
VIN
(Note 5)
VDROP
Test Conditions
Min
Typ
Max
Unit
2.5
--
5.5
V
IOUT = 150mA
--
120
--
mV
IOUT = 300mA
--
240
--
mV
1.2
--
3.6
V
VIN = 2.5V to 5.5V
Output voltage range
VOUT
V OUT Accuracy
ΔV
IOUT = 1mA
-2
--
+2
%
Line Regulation
ΔVLINE
VIN = (V OUT + 0.3V) to 5.5V or
VIN > 2.5V, whichever is larger
--
--
0.2
%/V
Load Regulation
ΔVLOAD 1mA < IOUT< 300mA
--
--
0.6
%
RLOAD = 1Ω
330
450
700
mA
Current Limit
Quiescent Current
IQ
VEN > 1.5V
--
58
80
μA
Shutdown Current
IQ_SD
VEN < 0.4V
--
--
1
μA
VIH
VIN = 2.5V to 5.5V, Power On
1.5
--
--
VIL
VIN = 2.5V to 5.5V, Shutdown
--
--
0.4
--
100
--
ppm/°C
EN Threshold
Output Voltage TC
V
Thermal Shutdown
T SD
--
170
--
°C
Thermal Shutdown Hysteresis
ΔTSD
--
40
--
°C
To be continued
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DS9012-09 April 2011
RT9012
Parameter
Min
Typ
Max
f =100Hz
--
65
--
f =1kHz
--
60
--
f =10kHz
--
50
--
f =100Hz
--
65
--
f =1kHz
--
50
--
f =10kHz
--
50
--
VTHL
Low Threshold, % of nominal
VOUT2 (Flag On)
90
--
--
%
VTHH
High Threshold, % of nominal
VOUT2 (Flag Off)
--
--
96
%
POR Output Logic Low Voltage
VOL
ILOW = 250uA
--
0.02
0.1
V
POR Leakage Current
IPOR
Flag Off
-1
0.01
1
μA
Set pin Current Source
VSET = 0
0.60
1.25
1.70
μA
Set pin Threshold
POR = high
--
1.4
--
V
PSRR
ILOAD = 10mA
PSRR
ILOAD = 150mA
Symbol
PSRR
PSRR
Test Conditions
Unit
dB
dB
Power Good
Reset Threshold
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 T A = 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 is recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
Note 5. The dropout voltage is defined as VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
DS9012-09 April 2011
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RT9012
Typical Operating Characteristics
Output Voltage vs. Temperature
Output Voltage vs. Temperature
3.4
RT9012-GS, VOUT1
1.85
Output Voltage (V)
Output Voltage (V)
1.9
1.8
1.75
RT9012-GS, VOUT2
3.35
3.3
3.25
3.2
1.7
-50
-25
0
25
50
75
100
-50
125
-25
0
Temperature (°C)
RT9012-GS
VIN = VEN = 4.3V
CIN = COUT1 = COUT2 = 1uF/X7R
100
125
RT9012-GS, VOUT2
TJ = 125°C
300
60
55
250
TJ = 25°C
200
150
TJ = -40°C
100
50
50
0
-50
-25
0
25
50
75
100
0
125
50
Temperature (°C)
0
PSRR
10000
RT9012-FM, VOUT1
VIN = 4.3V ± 0.1V
CIN = COUT1 = COUT2 = 1uF/X7R
ILOAD = 100mA
ILOAD = 50mA
-20
-40
ILOAD = 10mA
-60
-80
0.01
10
0.1
100
1
1000
10k
10000
Frequency (Hz)
(Hz)
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100
150
200
250
300
Load Current (mA)
100k
100000
1000k
1000000
POR Delay Time (ms)
20
PSRR (dB)
75
Dropout Voltage vs. Load Current
350
Dropout Voltage (mV)
Quiescent Current (uA)
65
50
Temperature (°C)
Quiescent Current vs. Temperature
70
25
POR Delay
RT9012-FM
1000
100
10
1
0.1
0.01
0.0001
0.0010
0.0100
0.1000
1.0000
POR Setting Capacitance (uF)
DS9012-09 April 2011
RT9012
Line Transient Response
Line Transient Response
RT9012-GS, Both ILOAD = 10mA
VIN = 3.8V to 4.8V
RT9012-GS, Both ILOAD = 1mA
VIN = 3.8V to 4.8V
VIN 4.8
(V)
VIN 4.8
(V)
VOUT2
(10mV/Div)
VOUT2
(10mV/Div)
VOUT1
(10mV/Div)
VOUT1
(10mV/Div)
3.8
3.8
Time (100μs/Div)
Time (100μs/Div)
Line Transient Response
Line Transient Response
RT9012-GS, Both ILOAD = 50mA
VIN = 3.8V to 4.8V
RT9012-GS, Both ILOAD = 100mA
VIN = 3.8V to 4.8V
VIN 4.8
(V)
VIN 4.8
(V)
VOUT2
(10mV/Div)
VOUT2
(10mV/Div)
VOUT1
(10mV/Div)
VOUT1
(10mV/Div)
3.8
3.8
Time (100μs/Div)
Time (100μs/Div)
Load Transient Response
Load Transient Response
RT9012-GS, ILOAD = 10mA to 100mA
VIN = VEN = 4.3V
CIN = COUT1 = COUT2 = 1uF/X7R
RT9012-GS, ILOAD = 10mA to 50mA
VIN = VEN = 4.3V
CIN = COUT1 = COUT2 = 1uF/X7R
IOUT
(50mA/Div)
IOUT
(100mA/Div)
VOUT1
(20mV/Div)
VOUT1
(20mV/Div)
VOUT2
(20mV/Div)
VOUT2
(20mV/Div)
Time (250μs/Div)
DS9012-09 April 2011
Time (250μs/Div)
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RT9012
Start Up
EN Pin Shutdown Response
RT9012-FM, VIN = 5V
IOUT1 = IOUT2 = 50mA
RT9012-FM, VIN = 5V
IOUT1 = IOUT2 = 50mA
(5V/Div)
V EN
(5V/Div)
V EN
V OUT2
V OUT2
V OUT1
V OUT1
(1V/Div)
(1V/Div)
Time (5μs/Div)
Time (50μs/Div)
Power-On
Noise
RT9012-FM
Both ILOAD = 10mA
RT9012-GS, No LOAD
VIN = VEN = 4.5V(By battery)
150
CIN = COUT1 = COUT2 = 1uF/X7R
100
Noise (μV/Div)
VEN
(5V/Div)
VOUT1
(1V/Div)
VOUT2
(2V/Div)
POR
(5V/Div)
50
0
-50
-100
-150
Time (10μs/Div)
Time (10ms/Div)
Noise
300
RT9012-GS, ILOAD = 50mA
VIN = VEN = 4.5V(By battery)
CIN = COUT1 = COUT2 = 1uF/X7R
Noise (μV/Div)
200
100
0
-100
-200
-300
Time (10ms/Div)
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DS9012-09 April 2011
RT9012
Applications Information
Like any low-dropout regulator, the external capacitors used
with the RT9012 must be carefully selected for regulator
stability and performance. Using a capacitor whose value
is > 1μF on the RT9012 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
inch 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.
The output capacitor must meet both requirements for
minimum amount of capacitance and ESR in all LDOs
application. The RT9012 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 1μF with ESR is > 20mΩ on the
RT9012 output ensures stability. The RT9012 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
not more than 0.5 inch from the VOUT pin of the RT9012
and returned to a clean analog ground.
Region of Stable COUT ESR vs. Load Current
Region
ESR (Ω)
(Ω)
OUT ESR
RegionofofStable
StableCCOUT
100
RT9012-FM, VIN = 5V
CIN = COUT1 =
COUT2 = 1uF/X7R
10
Unstable Range
1
Thermal Considerations
Thermal protection limits power dissipation in RT9012.
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 turn on again
after the junction temperature cools by 40°C. RT9012
lowers its OTP trip level from 170°C to 110°C when output
short circuit occurs (VOUT < 0.4V) as shown in Figure 2. It
limits IC case temperature under 100°C and provides
maximum safety to customer while output short circuit
occurring.
VOUT Short to GND
0.4V
VOUT
IOUT
TSD
170 °C
110 °C
OTP Trip Point
110 °C
IC Temperature
80 °C
Figure 2. Short Circuit Thermal Folded Back Protection
when Output Short Circuit Occurs (Patent)
For continuous operation, do not exceed absolute
maximum operation junction temperature 125°C. The
power dissipation definition in device is :
PD = (VIN − VOUT) x IOUT + VIN x IQ
Stable Range
0.1
0.01
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 :
Simulation Verify
0.001
0
50
100
150
200
Load Current (mA)
Figure 1. Stable Cout ESR Range
DS9012-09 April 2011
250
300
PD(MAX) = ( TJ(MAX) − TA ) /θJA
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.
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RT9012
For recommended operating conditions specification of
RT9012, the maximum junction temperature is 125°C. The
junction to ambient thermal resistance (θJA is layout
dependent) for WDFN-8L 2x2 package is 108°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 ) / 108 = 0.926W for
WDFN-8L 2x2 packages
The maximum power dissipation depends on operating
ambient temperature for fixed T J(MAX) and thermal
resistance θJA . For RT9012 packages, the Figure 3 of
derating curves allows the designer to see the effect of
rising ambient temperature on the maximum power
allowed.
0.8
Power Dissipation (W)
0.7
0.6
WDFN-8L 2x2
0.5
0.4
0.3
0.2
0.1
0
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 3. Derating Curves for RT9012 Packages
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DS9012-09 April 2011
RT9012
Outline Dimension
D2
D
L
E
E2
1
e
SEE DETAIL A
b
2
1
2
1
A
A1
A3
DETAIL A
Pin #1 ID and Tie Bar Mark Options
Note : The configuration of the Pin #1 identifier is optional,
but must be located within the zone indicated.
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
0.175
0.250
0.007
0.010
b
0.200
0.300
0.008
0.012
D
1.950
2.050
0.077
0.081
D2
1.000
1.250
0.039
0.049
E
1.950
2.050
0.077
0.081
E2
0.400
0.650
0.016
0.026
e
L
0.500
0.300
0.020
0.400
0.012
0.016
W-Type 8L DFN 2x2 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: marketing@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.
DS9012-09 April 2011
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