RT9002A/B/C
Dual Low-Dropout Regulator with Detector
General Description
The RT9002A/B/C is a dual-channel, low noise, and low
dropout regulator. The first regulator is capable of sourcing
240mA, while the second regulator can source up to
500mA and includes a voltage detection function. The
RT9002A/B/C performance is optimized for CD/DVD-ROM,
CD/RW or wireless communication supply applications.
The RT9002A/B/C regulator is stable with output capacitors
as low as 1μF. The other features include high output
accuracy, ultra-fast transient response, tight load and line
regulation, current limiting/thermal protection and high
ripple rejection ratio. The RT9002A/B/C is
available in
SOP-8 package requiring minimum board space and
smallest components.
Features
μ
Low Quiescent Current (Typically 70μA)
Wide Operating Voltage Ranges : 2.5V to 5.5V
Ultra-Fast Transient Response
Tight Load and Line Regulation
Current Limiting Protection
Thermal Shutdown Protection
Only low-ESR Ceramic Capacitors Required for
Stability
Custom LDO V
OUT1
, V
OUT2
Voltage Available from
1.5V to 3.3V
Custom V
IN
Detector Available from 3.5V to 4.0V
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Ordering Information
RT9002A/B/C
-
Package Type
S : SOP-8
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
Output Voltage : VOUT1/VOUT2
A : 2.5V/3.3V
B : 1.5V/2.8V
C : 2.5V/3.3V
CD/DVD-ROM, CD/RW
Wireless LAN Card/Keyboard/Mouse
Battery-Powered Equipment
XDSL Router
Pin Configurations
(TOP VIEW)
VIN1
VOUT1
Cd
VIN2
2
3
4
8
7
6
5
EN1
GND
VDOUT
VOUT2
Note :
RichTek Pb-free and Green products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
100% matte tin (Sn) plating.
SOP-8
Typical Application Circuit
V
IN1
1
C
IN1
1uF
8
VIN1
VOUT1
2
3
Cd
6
5
C
OUT2
1uF
C
OUT1
1uF
R1
100k
V
OUT1
RT9002A/B/C
Cd
EN1
VDOUT
Chip Enable
V
IN2
V
DOUT
V
OUT2
V
IN2
4
C
IN2
1uF
VIN2
GND
7
VOUT2
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1
RT9002A/B/C
Functional Pin Description
Pin No.
1
2
3
4
5
6
7
8
Pin Name
VIN1
VOUT1
Cd
VIN2
VOUT2
VDOUT
GND
EN1
Channel 1 Supply Input.
Channel 1 Output Voltage.
Delay Capacitor.
Channel 2 Supply Voltage.
Channel 2 Output Input.
Detector Output Voltage. (RT9002A = Active High, RT9002B and RT9002C = Active Low)
Common Ground.
Chip Enable (Active High) for Channel 1.
Pin Function
Function Block Diagram
EN1
Shutdown
and
Logic Control
V
REF
+
-
Error
Amplifier
VIN1
MOS Driver
VOUT1
Current-Limit
and
Thermal
Protection
VIN2
+
Cd
Error
Amplifier
MOS Driver
Current-Limit
and
Thermal
Protection
VOUT2
-
V
REF
VDOUT
-
+
VD
Comparator
GND
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DS9002ABC-03 March 2007
RT9002A/B/C
Absolute Maximum Ratings
Package Thermal Resistance (Note 4)
SOP-8,
θ
JA
-------------------------------------------------------------------------------------------------------------- 110°C/W
Power Dissipation, P
D
@ T
A
= 25°C
SOP-8 -------------------------------------------------------------------------------------------------------------------- 0.909W
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C
Junction Temperature ------------------------------------------------------------------------------------------------- 150°C
Storage Temperature Range ----------------------------------------------------------------------------------------
−
65°C to 150°C
ESD Susceptibility (Note 2)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V
(Note 1)
Supply Input Voltage -------------------------------------------------------------------------------------------------- 6V
Recommended Operating Conditions
(Note 3)
Supply Input Voltage -------------------------------------------------------------------------------------------------- 2.5V to 5.5V
Chip Enable Input Voltage ------------------------------------------------------------------------------------------- 0V to 5.5V
Junction Temperature Range ----------------------------------------------------------------------------------------
−
40°C to 125°C
Ambient Temperature Range ----------------------------------------------------------------------------------------
−40°C
to 125°C
Electrical Characteristics
(V
IN
= V
OUT
+ 1V, whichever is greater, C
IN
= 1μF, C
OUT
= 1μF, T
A
= 25°C, unless otherwise specified)
Parameter
Regulator 1
RT9002A
Output Voltage Accuracy RT9002B
RT9002C
Maximum Output Current
Load Regulation
Dropout Voltage
Quiescent Current
Standby Current
Line Regulation
Power Supply Rejection Rate
Current Limit
EN Threshold
Logic-Low Voltage
Logic-High Voltage
(Note 5)
(Note 6)
(Note 7)
Symbol
Test Conditions
Min
2.45
Typ
2.50
1.50
2.50
--
1
50
150
30
0.1
0.01
−60
450
--
--
170
Max
2.55
1.53
2.55
--
--
--
--
--
1
0.2
--
--
0.6
--
--
Units
ΔV
OUT1
I
OUT1_MAX
ΔV
LOAD1
V
DROP1_1
V
DROP1_2
I
Q1
I
STB1
ΔV
LINE1
PSRR1
I
LIM1
V
IL
V
IH
T
SD1
I
OUT1
= 30mA
1.47
2.45
240
V
mA
mV
mV
μA
μA
%/V
dB
mA
V
°C
1mA
<
I
OUT1
<
100mA
I
OUT1
= 30mA
I
OUT1
= 100mA
V
IN1
= V
EN1
= 3.5V,
I
OUT1
= 0mA
V
IN1
= 3.5V, V
EN1
= 0V
V
IN1
= 3.5V to 5.5V,
V
IN1
= V
EN1
, I
OUT1
= 30mA
f = 100Hz, I
OUT1
= 100mA
V
IN1
= V
EN1
= 5V
--
--
--
--
--
--
--
--
--
1.8
--
Thermal Shutdown Protection
To be continued
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RT9002A/B/C
Parameter
Thermal Shutdown Hysteresis
Enable Pin Current
Regulator 2
RT9002A
Output Voltage Accuracy RT9002B
RT9002C
Maximum Output Current
Load Regulation
Dropout Voltage
Quiescent Current
Line Regulation
Power Supply Rejection Rate
Current Limit
Thermal Shutdown Protection
Thermal Shutdown Hysteresis
Detector
RT9002A
Detect Fall Voltage
RT9002B
RT9002C
Hysteresis
RT9002A
Sink Current
RT9002B
RT9002C
I
DOUT
ΔV
HYS
V
DOUT
= 0.5V, V
IN2
= 5.0V
V
DOUT
= 0.5V, V
IN2
= 2.0V
V
DF
3.528
3.822
3.528
V
DF
x0.02
7.0
4.0
4.0
3.60
3.9
3.60
V
DF
x0.05
12.0
8.0
8.0
3.672
3.978
3.672
V
DF
x0.08
--
--
--
mA
V
V
(Note 5)
(Note 6)
(Note 7)
I
OUT2_MAX
ΔV
LOAD2
V
DROP2_1
V
DROP2_2
I
Q2
ΔV
LINE2
PSRR2
I
LIM2
T
SD2
ΔT
SD2
1mA
<
I
OUT2
<
100mA
I
OUT2
= 30mA
I
OUT2
= 100mA
V
IN2
= 4.3V, I
OUT2
= 0mA
V
IN2
= 4.3V to 5.5V,
I
OUT2
= 30mA
f = 100Hz, I
OUT2
= 100mA
V
IN2
= 5V
ΔV
OUT2
I
OUT2
= 30mA
3.234
2.744
3.234
500
--
--
--
--
--
--
--
--
--
3.30
2.80
3.30
--
15
50
150
40
0.01
−60
800
170
40
3.366
2.856
3.366
--
50
90
200
--
0.2
--
--
--
--
mA
mV
mV
μA
%/V
dB
mA
°C
°C
V
Symbol
ΔT
SD1
I
EN
V
IN
= 3.5V, Enable
Test Conditions
Min
--
--
Typ
40
0.1
Max
--
1
Units
°C
μA
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DS9002ABC-03 March 2007
RT9002A/B/C
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.
Devices are ESD sensitive. Handling precaution recommended.
Note 3.
The device is not guaranteed to function outside its operating conditions.
Note 4.
θ
JA
is measured in the natural convection at T
A
= 25°C on a high effective thermal conductivity test board of JEDEC
51-7 2S2P 4-layer thermal measurement standard.
Note 5.
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 100mA.
Note 6.
The dropout voltage is defined as V
IN
-V
OUT
, which is measured when V
OUT
is V
OUT(NORMAL)
−
100mV.
Note 7.
Quiescent, or ground current, is the difference between input and output currents. It is defined by I
Q
= I
IN
- I
OUT
under no
load condition (I
OUT
= 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin
current.
DS9002ABC-03 March 2007
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