Download

RT9002A/B/C
Dual Low Dropout Regulator with Detector
General Description
Features
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.
z
z
z
z
z
z
z
z
z
z
μA)
Low Quiescent Current (Typically 70μ
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 VOUT1, VOUT2 Voltage Available from
1.5V to 3.3V
Custom VIN Detector Available from 3.5V to 4V
RoHS Compliant and 100% Lead (Pb)-Free
Applications
Ordering Information
z
RT9002A/B/C -
z
Package Type
S : SOP-8
z
z
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Note :
CD/DVD-ROM, CD/RW
Wireless LAN Card/Keyboard/Mouse
Battery-Powered Equipment
XDSL Router
Pin Configurations
Output Voltage : VOUT1/VOUT2
A : 2.5V/3.3V
B : 1.5V/2.8V
C : 2.5V/3.3V
(TOP VIEW)
EN1
2
7
GND
Cd
3
6
VDOUT
VIN2
4
5
VOUT2
VIN1
Richtek products are :
`
8
VOUT1
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`
SOP-8
Suitable for use in SnPb or Pb-free soldering processes.
Typical Application Circuit
VIN1
1
CIN1
1uF
Chip Enable
VIN1
VOUT1
RT9002A/B/C
Cd
8
EN1
VDOUT
VIN2
DS9002ABC-04 April 2011
4
CIN2
1uF
VIN2
VOUT2
GND
7
2
3
Cd
COUT1
1uF
R1
100k
6
VOUT1
VIN2
VDOUT
5
COUT2
1uF
VOUT2
www.richtek.com
1
RT9002A/B/C
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
VIN1
Channel 1 Supply Input.
2
VOUT1
Channel 1 Output Voltage.
3
Cd
Delay Capacitor.
4
VIN2
Channel 2 Supply Voltage.
5
VOUT2
Channel 2 Output Input.
6
VDOUT
Detector Output Voltage. (RT9002A = Active High, RT9002B and RT9002C = Active Low)
7
GND
Common Ground.
8
EN1
Chip Enable (Active High) for Channel 1.
Function Block Diagram
EN1
Shutdown
and
Logic Control
VIN1
VREF
+
MOS Driver
-
Error
Amplifier
VOUT1
Current-Limit
and
Thermal
Protection
VIN2
+
MOS Driver
-
Cd
Error
Amplifier
VREF
Current-Limit
and
Thermal
Protection
VOUT2
VDOUT
+
GND
VD
Comparator
www.richtek.com
2
DS9002ABC-04 April 2011
RT9002A/B/C
Absolute Maximum Ratings
z
z
z
z
z
z
z
(Note 1)
Supply Input Voltage ------------------------------------------------------------------------------------------------ 6V
Package Thermal Resistance (Note 2)
SOP-8, θJA ------------------------------------------------------------------------------------------------------------ 110°C/W
Power Dissipation, PD @ TA = 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 3)
HBM (Human Body Mode) ----------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------ 200V
Recommended Operating Conditions
z
z
z
z
(Note 4)
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
(VIN = VOUT + 1V, whichever is greater, CIN = 1μF, COUT = 1μF, TA = 25° C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
2.45
2.5
2.55
1.47
1.5
1.53
2.45
2.5
2.55
240
--
--
mA
mV
Regulator 1
RT9002A
Output Voltage
Accuracy
RT9002B
ΔVOUT1
IOUT1 = 30mA
RT9002C
V
Maximum Output Current
IOUT1_MAX
Load Regulation
(Note 5)
ΔVLOAD1
1mA < IOUT1 < 100mA
--
1
--
Dropout Voltage
(Note 6)
VDROP1_1
IOUT1 = 30mA
--
50
--
VDROP1_2
IOUT1 = 100mA
--
150
--
IQ1
VIN1 = VEN1 = 3.5V,
IOUT1 = 0mA
--
30
--
μA
Standby Current
ISTB1
VIN1 = 3.5V, VEN1 = 0V
--
0.1
1
μA
Line Regulation
ΔVLINE1
--
0.01
0.2
%/V
Power Supply Rejection Rate
PSRR1
f = 100Hz, IOUT1 = 100mA
--
−60
--
dB
Current Limit
ILIM1
VIN1 = VEN1 = 5V
--
450
--
mA
Quiescent Current
(Note 7)
EN Threshold Voltage
VIN1 = 3.5V to 5.5V,
VIN1 = VEN1, I OUT1 = 30mA
Logic-Low
VIL
--
--
0.6
Logic-High
VIH
1.8
--
--
--
170
--
Thermal Shutdown Protection
TSD1
mV
V
°C
To be continued
DS9002ABC-04 April 2011
www.richtek.com
3
RT9002A/B/C
Parameter
Symbol
Thermal Shutdown Hysteresis
ΔTSD1
Enable Pin Current
IEN
Test Conditions
VIN = 3.5V, Enable
Min
Typ
Max
Unit
--
40
--
°C
--
0.1
1
μA
3.234
3.3
3.366
2.744
2.8
2.856
3.234
3.3
3.366
500
--
--
mA
mV
Regulator 2
RT9002A
Output Voltage
Accuracy
RT9002B
ΔVOUT2
IOUT2 = 30mA
RT9002C
V
Maximum Output Current
IOUT2_MAX
Load Regulation
(Note 5)
ΔVLOAD2
1mA < IOUT2 < 100mA
--
15
50
Dropout Voltage
(Note 6)
VDROP2_1
IOUT2 = 30mA
--
50
90
VDROP2_2
IOUT2 = 100mA
--
150
200
IQ2
VIN2 = 4.3V, IOUT2 = 0mA
--
40
--
μA
Line Regulation
ΔVLINE2
VIN2 = 4.3V to 5.5V,
IOUT2 = 30mA
--
0.01
0.2
%/V
Power Supply Rejection Rate
PSRR2
f = 100Hz, IOUT2 = 100mA
--
−60
--
dB
Current Limit
ILIM2
VIN2 = 5V
--
800
--
mA
Thermal Shutdown Protection
T SD2
--
170
--
°C
--
40
--
°C
3.528
3.6
3.672
3.822
3.9
3.978
3.528
3.6
3.672
VDF
x0.02
V DF
x0.05
VDF
x0.08
7
12
--
4
8
--
4
8
--
Quiescent Current
(Note 7)
Thermal Shutdown Hysteresis
ΔTSD2
mV
Detector
RT9002A
Detect Fall Voltage
RT9002B
VDF
RT9002C
ΔVHYS
Hysteresis
RT9002A
Sink Current
RT9002B
RT9002C
www.richtek.com
4
VD OUT = 0.5V, V IN2 = 5.0V
IDOUT
VD OUT = 0.5V, V IN2 = 2.0V
V
V
mA
DS9002ABC-04 April 2011
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. θJA is measured in the natural convection at TA = 25°C on a high effective thermal conductivity test board of JEDEC
51-7 2S2P 4-layer thermal measurement standard.
Note 3. Devices are ESD sensitive. Handling precaution recommended.
Note 4. The device is not guaranteed to function outside its operating conditions.
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 VIN -VOUT, which is measured when VOUT is VOUT(NORMAL) − 100mV.
Note 7. 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.
DS9002ABC-04 April 2011
www.richtek.com
5
RT9002A/B/C
Typical Operating Characteristics
Input Voltage vs. Detector Voltage
Input Voltage vs. Detector Voltage
7
RT9002A
6
6
5
5
Reset Voltage (V)
Reset Voltage (V)
7
4
3
2
RT9002B
4
3
2
1
1
0
0
0
1
2
3
4
5
125
6
0
1
2
Output Voltage vs. Temperature
RT9002A
Output Voltage (V)
Output Voltage (V)
RT9002B
3.2
3.0
2.8
V OUT1
2.4
2.6
2.4
2.2
2.0
1.8
1.6
2.2
V OUT1
1.4
-50
-25
0
25
50
75
100
125
-50
-25
Temperature (°C)
25
50
75
100
125
Quiescent Current vs. Input Voltage
45
RT9002A
RT9002B
42.5
Quiescent Current (uA)
42.5
Quiescent Current (uA)
0
Temperature (°C)
Quiescent Current vs. Input Voltage
45
6
V OUT2
2.8
V OUT2
2.6
5
Output Voltage vs. Temperature
3.0
3.4
4
Input Voltage (V)
Input Voltage (V)
3.6
3
40
V OUT2
37.5
35
32.5
V OUT1
30
V OUT2
40
37.5
35
V OUT1
32.5
30
27.5
27.5
25
25
2.5
3
3.5
4
4.5
Input Voltage (V)
www.richtek.com
6
5
5.5
2.5
3
3.5
4
4.5
5
5.5
Input Voltage (V)
DS9002ABC-04 April 2011
RT9002A/B/C
Nch Driver Sink Current vs. Input Voltage
Nch Driver Sink Current vs. Input Voltage
60
RT9002A
-40°C
Nch Driver Output Current (mA)
Nch Driver Output Current (mA)
60
50
25°C
40
125°C
30
20
10
RT9002B
50
-40°C
40
25°C
30
125°C
20
10
0
0
0
1
2
3
4
5
0
6
1
2
RT9002A
VDD = 5V
Nch Driver Output Current (mA)
Nch Driver Output Current (mA)
110
VDD = 5.5V
150
125
VDD = 4.5V
100
75
50
25
0
RT9002B
100
VDD = 3.5V
90
80
VDD = 3V
70
60
VDD = 2.5V
50
VDD = 2V
40
30
VDD = 1.5V
20
10
VDD = 0.5V
1
2
3
4
5
0
6
1
2
VDD = 1V
1000
RT9002A
Output Delay Time (us)
100
10
1
0.1
0.0001
0.0010
0.0100
Load Capacitance (uF)
DS9002ABC-04 April 2011
4
5
6
Output Delay Time vs. Load Capacitance
Output Delay Time vs. Load Capacitance
0.01
0.0000
3
VDS (V)
VDS (V)
Output Delay Time (ms)
6
0
0
1000
5
Nch Driver Sink Current vs. VDS
Nch Driver Sink Current vs. VDS
175
4
Input Voltage (V)
Input Voltage (V)
200
3
0.1000
RT9002B
100
10
1
0.1
0.01
0.0000
0.0001
0.0010
0.0100
0.1000
Load Capacitance (uF)
www.richtek.com
7
RT9002A/B/C
Dropout Voltage vs. Load Current
400
RT9002A, VOUT1 = 2.5V
125°C
300
25°C
250
200
-40°C
150
100
50
0
125°C
25°C
400
300
-40°C
200
100
0
0
50
100
150
200
250
300
0
0.1
0.2
0.3
0.4
Load Current (mA)
Load Current (A)
EN Pin Shutdown Response
Line Transient Response
0.5
RT9002A
Boost ILOAD = 50mA
RT9002A, VOUT1
ILOAD = 75mA
5
VOUT
(1V/Div) 4
VOUT1
(20mV/Div)
VOUT
(1V/Div)
VOUT2
(20mV/Div)
Time (100μs/Div)
Time (250μs/Div)
Load Transient Response
Start Up
RT9002A
ILOAD = 10mA to 100mA
IOUT1
(100mA/Div)
VOUT2
(50mV/Div)
Time (500μs/Div)
www.richtek.com
8
RT9002A, VOUT1
ILOAD = 75mA
VOUT
(1V/Div)
VOUT1
(5mV/Div)
Shutdown Voltage
(5V/Div)
Shutdown Voltage
(5V/Div)
RT9002C, VOUT2 = 3.3V
500
Dropout Voltage (mV)
350
Dropout Voltage (mV)
Dropout Voltage vs. Load Current
600
Time (10μs/Div)
DS9002ABC-04 April 2011
RT9002A/B/C
Noise
600
Noise
RT9002B, VOUT1
IOUT1 = 100mA
600
400
Noise (μV/Div)
Noise (μV/Div)
400
RT9002B, VOUT1
No Load
200
0
-200
200
0
-200
-400
-400
-600
-600
Time (10ms/Div)
DS9002ABC-04 April 2011
Time (10ms/Div)
www.richtek.com
9
RT9002A/B/C
Applications Information
Like any low-dropout regulator, the external capacitors used
with the RT9002A/B/C must be carefully selected for
regulator stability and performance. Using a capacitor
whose value is > 1μF on the RT9002A/B/C 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 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 RT9002A/B/C is designed specifically to
work with low ESR ceramic output capacitor in spacesaving and performance consideration. Using a ceramic
capacitor whose value is at least 1μF with ESR is > 20mΩ
on the RT9002A/B/C output ensures stability. The
RT9002A/B/C 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 RT9002A/B/C and returned to a clean
analog ground.
Region of Stable COUT ESR vs. Load Current
Region of
Region
of Stable
Stable C
COUT
ESR(Ω)
(Ω)
OUTESR
100
RT9002APS
VIN = 4.0V, VOUT2 = 3.3V
CIN = COUT = 1uF/X7R
10
Unstable Region
1
Stable Region
0.1
0.01
Unstable Region (Simulation Verify)
0.001
0
50
100
150
200
250
Enable
The RT9002A/B/C 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 0.1μA 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
⎛
⎞
PSRR = 20 × log ⎜ Δ Gain Error ⎟
Δ
Supply
⎝
⎠
Note that when heavy load measuring, Δsupply will cause
Δtemperature. And Δtemperature will cause Δoutput
voltage. So the heavy load PSRR measuring is include
temperature effect.
Current Limit
The RT9002A/B/C contains an independent current limiter,
which monitors and controls the pass transistor's gate
voltage, limiting the output1/2 current to 0.45/0.8A (typ.).
The output can be shorted to ground indefinitely without
damaging the part.
Thermal-Shutdown Protection
Thermal-shutdown protection limits total power dissipation
in the RT9002A/B/C. When the junction temperature
exceeds TJ = +170°C, the thermal sensor signals the
shutdown logic, turning off the pass transistor and allowing
the IC to cool. The thermal sensor turns the pass transistor
on again after the IC's junction temperature cools by 40°C,
resulting in a pulsed output during continuous thermal
overload conditions. Thermal-shutdown protection is
designed to protect the RT9002A/B/C in the event of fault
conditions. For continual operation, do not exceed the
absolute maximum junction temperature rating of TJ =
+125°C.
300
Load Current (mA)
Figure 1
www.richtek.com
10
DS9002ABC-04 April 2011
RT9002A/B/C
Outline Dimension
H
A
M
J
B
F
C
I
D
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
4.801
5.004
0.189
0.197
B
3.810
3.988
0.150
0.157
C
1.346
1.753
0.053
0.069
D
0.330
0.508
0.013
0.020
F
1.194
1.346
0.047
0.053
H
0.170
0.254
0.007
0.010
I
0.050
0.254
0.002
0.010
J
5.791
6.200
0.228
0.244
M
0.400
1.270
0.016
0.050
8-Lead SOP Plastic 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.
DS9002ABC-04 April 2011
www.richtek.com
11
Similar pages