RICHTEK RT9701B_11

RT9701B
100mΩ
Ω Power Distribution Switches
General Description
Features
The RT9701B is an integrated 100mΩ power switch for
self-powered and bus-powered Universal Series Bus
(USB) applications. A built-in charge pump is used to
drive the N-MOSFET that is free of parasitic body diode to
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eliminate any reversed current flow across the switch when
it is powered off. Its low quiescent current (23uA) and
small package (SOT-23-5) is particularly suitable in
battery-powered portable equipment.
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Several protection functions include soft start to limit inrush
current during plug-in, current limiting at 1.5A to meet
USB power requirement, and thermal shutdown to protect
damage under over current conditions.
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Applications
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Ordering Information
RT9701B
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Package Type
B : SOT-23-5
BL : SOT-23-5 (L-Type)
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
100mΩ
Ω Typ. High-Side N-MOSFET
Guaranteed 1.1A Continuous Current
1.5A Current Limit
Small SOT-23-5 Package Minimizes Board Space
Soft Start
Thermal Protection
Low 23uA Supply Current
Wide Input Voltage Range : 3.5V to 6V
UL Approved - #E219878
RoHS Compliant and 100% Lead (Pb)-Free
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Battery-Powered Equipment
Motherboard USB Power Switch
USB Device Power Switch
Hot-Plug Power Supplies
Battery-Charger Circuits
Pin Configurations
(TOP VIEW)
VOUT
EN
5
4
Note :
Richtek products are :
`
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
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2
3
VOUT GND VIN
Suitable for use in SnPb or Pb-free soldering processes.
SOT-23-5
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
VOUT
VIN
5
4
2
3
VOUT GND VIN
SOT-23-5 (L-Type)
DS9701B-06 April 2011
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RT9701B
Typical Application Circuit
VIN
CIN
1uF
VIN
RT9701B
VOUT
VIN
VOUT
VOUT
* COUT
470uF
GND
* 470uF, Low ESR Electrolytic
Test Circuits
IIN
VIN_SW
VIN
+
EN
VOUT
VOUT
+
CIN
1uF
IL
IOUT
RT9701B
VIN
VOUT
GND
COUT
IL
RL
Chip Enable
Functional Pin Description
Pin Name
Pin Function
VIN
Power Input Voltage
VOUT
Output Voltage
GND
Ground
EN
Chip Enable (Active High)
Function Block Diagram
VIN
EN
Current
Limit
Bias
Charge
Pump
Control
NMOSFET
RS
(VIN)
(VOUT)
VOUT
Oscillator
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Thermal
Detection
GND
DS9701B-06 April 2011
RT9701B
Absolute Maximum Ratings
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(Note 1)
Supply Voltage ------------------------------------------------------------------------------------------------------------Chip Enable ----------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
SOT-23-5 -------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 3)
SOT-23-5, θJA --------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Operating Junction Temperature Range -----------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 2)
HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------
7V
−0.3V to 7V
0.4W
250°C /W
260°C
−20°C to 100°C
−65°C to 150°C
8kV
700V
Electrical Characteristics
(VIN = 5V, CIN = COUT = 1μF, TA = 25°C, unless otherwise specified)
Parameter
Symbol
Input Voltage Range
Output NMOSFET RDS(ON)
Test Conditions
Min
Typ
Max
Units
3.5
--
6
V
IL = 1A
--
85
100
IL = 1A
--
87
100
VIN = 5V
--
23
45
μA
--
400
--
μs
1.1
1.5
2
A
--
1.0
--
A
VIN
RT9701BCBL
RT9701BCB
RDS(ON)
Quiescent Current
Output Turn-On Rising Time
TR
RL = 10Ω, 90% Settling
Current Limit Threshold
ILIM
RL = 2Ω
Short-circuit Fold Back Current
IOS
VOUT = 0V, measured
prior to thermal shutdown
mΩ
EN Input High Threshold
RT9701BCB
2.0
--
--
V
EN Input Low Threshold
RT9701BCB
--
--
0.8
V
Shutdown Supply Current
RT9701BCB
IOFF
EN = “0”
--
0.1
1
μA
Output Leakage Current
RT9701BCB
ILEAKAGE EN = “0”, VOUT = 0V
--
0.5
10
μA
2.8
3
--
V
--
100
--
mV
VIN Under Voltage Lockout
UVLO
VIN Under Voltage Hysteresis
Thermal Limit
TSD
--
130
--
°C
Thermal Limit Hysteresis
ΔTSD
--
20
--
°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 is recommended.
Note 3. 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.
DS9701B-06 April 2011
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RT9701B
Typical Operating Characteristics
(Refer to Test Circuit)
Quiescent Current vs. Temperature
40
Quiescent Current vs. Input Voltage
40
VIN = 5V
Quiescent Current (uA)
Quiescent Current (uA)
TA = 25°C
35
35
30
25
20
15
10
30
25
20
15
10
5
5
0
0
-20
-5
10
25
40
55
70
85
3.5
100
3.8
4.0
4.3
On-Resistance vs. Temperature
200
5.0
5.3
5.5
5.8
6.0
On-Resistance vs. Input Voltage
VIN = 5V
TA = 25°C
95
150
On-Resistance (mΩ)
On-Resistance (mΩ)
4.8
100
175
RT9701BCBL
125
100
RT9701BCB
75
50
25
0
90
RT9701BCB
85
RT9701BCBL
80
75
70
-20
-5
10
25
40
55
70
85
100
3.5
3.8
4.0
4.3
Temperature (°C)
(℃)
4.5
4.8
5.0
5.3
5.5
5.8
6.0
Input Voltage(V)
Current Limit vs. Temperature
2.20
Current Limit vs. Input Voltage
1.80
VIN = 5V
2.00
1.58
1.80
1.35
Current Limit (A)
Current Limit (A)
4.5
Input Voltage (V)
Temperature (°C)
1.60
1.40
1.20
1.00
TA = 25°C
1.13
0.90
0.68
0.45
0.23
0.80
0.00
0.60
-20
-5
10
25
40
55
Temperature (°C)
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70
85
100
3.5
3.8
4.0
4.3
4.5
4.8
5.0
5.3
5.5
5.8
6.0
Input Voltage (V)
DS9701B-06 April 2011
RT9701B
Short Circuit Current vs. Input Voltage
Short Circuit Current vs. Temperature
1950
1.950
VIN = 5V
1300
1.3
Short Circuit Current (A)
Short Circuit Current (A) 1
1400
1.4
1200
1.2
1100
1.1
1000
1.0
900
0.9
800
0.8
700
0.7
TA = 25°C
1700
1.7
1450
1.45
1200
1.2
950
0.95
700
0.7
450
0.45
600
0.6
200
0.2
0.5
500
-20
-5
10
25
40
55
70
85
3.5
100
3.8
4.0
4.3
Temperature (°C)
5.0
5.3
5.5
5.8
6.0
EN Threshold vs. Input Voltage
EN Threshold vs. Temperature
2.4
VIN = 5V
TA =25°C
2.0
EN Threshold (V)
2.0
EN Threshold (V)
4.8
Input Voltage (V)
2.4
1.6
Rising
1.2
Falling
0.8
1.6
Rising
1.2
Falling
0.8
0.4
0.4
0.0
0.0
-20
-5
10
25
40
55
70
85
3.5
100
3.8
4.0
4.3
Temperature (°C)
4.5
4.8
5.0
5.3
5.5
5.8
6.0
Input Voltage (V)
Turn On Rising Time vs. Temperature
400
Shutdown Supply Current vs. Temperature
0.9
VIN = 5V
Shutdown Supply Current (uA)
Turn On Rising Time (us)
4.5
350
300
250
200
150
100
VIN = 5V
0.8
0.6
0.5
0.3
0.2
0.0
-20
-5
10
25
40
55
Temperature (°C)
DS9701B-06 April 2011
70
85
100
-20
-5
10
25
40
55
70
85
100
Temperature (°C)
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RT9701B
UVLO Threshold vs. Temperature
4.5
VIN = 5V
VIN = 5V
3.0
UVLO Threshold (V)
Turn-Off Leakage Current (uA)
A
Turn-Off Leakage Current vs. Temperature
3.5
2.5
2.0
1.5
1.0
0.5
0.0
4
3.5
3
2.5
2
-20
-5
10
25
40
55
70
85
100
-20
-5
Temperature (°C)
10
25
40
55
70
85
100
Temperature (°C)
Turn - Off Response
Turn - On Response
VIN = 5V
VIN = 5V
CH1
CH1
CH1: VEN: 5V/Div
CH2: IL: 100mA/Div
CH3: VOUT: 2V/Div
CH2
CH1: VEN: 5V/Div
CH2: VOUT: 1V/Div
RL = 10Ω, COUT = 1uF
CH2
CH3
Time (100us/Div)
Time (50us/Div)
UVLO at Rising
UVLO at Falling
CH1: VIN: 1V/Div
CH2: VOUT: 1V/ Div
RL = 30Ω, COUT = 1uF
CH1: VIN: 1V/Div
CH2: VOUT: 1V/Div
RL = 30Ω, COUT = 1uF
CH1
CH1
CH2
CH2
Time (500us/Div)
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RL = 30Ω, COUT = 1uF
Time (10ms/Div)
DS9701B-06 April 2011
RT9701B
Inrush Short Circuit Response
Soft - start Short Circuit Response
CH1: VIN: 2V/Div
CH1: VIN: 2V/Div
VDROP=1.2V, depend on CIN ESR
IPEAK : depend on ESR & ESL
CH1
CH1
CH2: IL: 1A/Div
CH2
CH1
CIN = 1uF, COUT = 1000uF
CH2: IL: 1A/Div
CH2
CIN = 1uF
Time (25us/Div)
Time (50us/Div)
Ramped Load Response
Thermal Shut Dowm Response
VOUT = 4.6V
VOUT =
4.9V
CH1
Current Limit Threshold
CH3
Thermal Shut Down
1.1A
CH2
CH2
CH2: IOUT: 500mA/Div
CH1: VEN = 5V/Div, CH3:[email protected]Ω:1A/Div
CH2: [email protected]:1A/DiV, VIN = 5V
VIN = 5V, COUT = 1uF
Time (1ms/Div)
Time (50ms/Div)
Current Limit Response
Current Limit Response
COUT = 1uF
COUT = 1uF
COUT = 33uF
COUT = 100uF
COUT = 33uF
COUT = 100uF
IL
(1A/Div)
IOUT
(1A/Div)
VIN = 5V, RL = 1Ω
Time (100us/Div)
DS9701B-06 April 2011
VIN = 5V, RL = 1Ω
Time (100us/Div)
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RT9701B
Current Limit Response
Loading trigger
CH1
CH2
CH2: IOUT: 1A/Div
VIN = 5V, COUT = 0.1uF
RL = 1Ω
Time (5us/Div)
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DS9701B-06 April 2011
RT9701B
Application Information
The RT9701B is a high-side single N-Channel MOSFET
switch with active-high enable input.
Input and Output
VIN (input) is the power supply connection to the circuitry
and the drain of the output MOSFET. VOUT (output) is
the source of the output MOSFET. In a typical circuit,
current flows through the switch from VIN to VOUT toward
the load. Both VOUT pins must be short on the board
and connected to the load and so do both VIN pins but
connected to the power source.
Thermal Shutdown
Thermal shutdown shuts off the output MOSFET if the
die temperature exceeds 130°C and 20°C of hysteresis
forces the switch turning off until the die temperature
drops to 110°C.
Soft Start
In order to eliminate the upstream voltage droop caused
by the large inrush current during hot-plug events, the
“ soft-start” feature effectively isolates power supplies
from such highly capacitive loads.
Connect a sufficient capacitor from VOUT to GND. This
capacitor helps to prevent inductive parasitics from pulling
VOUT negative during turn-off or EMI damage to other
components during the hot-detachment. It is also
necessary for meeting the USB specification during hot
plug-in operation. If RT9701B is implanted in device end
application, minimum 1μF capacitor from VOUT to GND
is recommended and higher capacitor values are also
preferred.
In choosing these capacitors, special attention must be
paid to the Effective Series Resistance, ESR, of the
capacitors to minimize the IR drop across the capacitor
ESR. A lower ESR on this capacitor can get a lower IR
drop during the operation.
Ferrite beads in series with all power and ground lines are
recommended to eliminate or significantly reduce EMI. In
selecting a ferrite bead, the DC resistance of the wire
used must be kept to a minimum to reduce the voltage
drop.
Reverse current preventing
The output MOSFET and driver circuitry are also designed
to allow the MOSFET source to be externally forced to a
UVLO prevents the MOSFET switch from turning on until
input voltage exceeds 3V (typical). If input voltage drops
below 3V (typical), UVLO shuts off the MOSFET switch.
higher voltage than the drain (VOUT > VIN ≥ 0). To prevent
reverse current from such condition, disable the switch
(RT9701BCB) or connect VIN to a fixed voltage under
UVLO.
Current Limiting and Short Protection
Layout and Thermal Dissipation
Under-voltage Lockout
The current limit circuit is designed to protect the system
supply, the MOSFET switch and the load from damage
caused by excessive currents. The current limit threshold
is set internally to allow a minimum of 1.1A through the
MOSFET but limits the output current to approximately
1.5A typical. When the output is short to ground, it will
limit to a constant current 1A until thermal shutdown or
short condition removed.
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Place the switch as close to the USB connector as
possible. Keep all traces as short as possible to reduce
the effect of undesirable parasitic inductance.
Place the ot capacitor and ferrite beads asclose to the
USB connector as possible.
If ferrite beads are used, use wires with minimum
resistance and large solder pads to minimize connection
resistance.
Filtering
To limit the input voltage drop during hot-plug events,
connect a 1μF ceramic capacitor from VIN to GND.
However, higher capacitor values will further reduce the
voltage drop at the input.
DS9701B-06 April 2011
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RT9701B
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If the package is with dual VOUT or VIN pins, short both the same function pins as Figure 1 or Figure 2 to reduce the
internal turn-on resistance. If the output power will be delivered to two individual ports, it is specially necessary to
short both VOUT pin at the switch output side in order to protect the switch when each port are plug-in separately.
Under normal operating conditions, the package can dissipate the channel heat away. Wide power-bus planes connected
to VIN and VOUT and a ground plane in contact with the device will help dissipate additional heat.
RT9701BCBL
VIN
VOUT
VIN
VIN
CIN
1uF
VOUT
VOUT2
VOUT1
GND
COUT
COUT
CIN = 1uF, COUT = 470uF (Low ESR) on M/B
CIN = 1uF, COUT = 330uF (Low ESR) on Notebook
CIN = 10uF, COUT = 1uF on USB device
Figure 1. High Side Power Switch
VIN
CIN
RT9701BCB
VIN
VOUT
EN
VOUT
GND
Chip Enable
VOUT1
COUT
VOUT2
COUT
Figure 2. High Side Power Switch with Chip Enable Control
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DS9701B-06 April 2011
RT9701B
Outline Dimension
H
D
L
B
C
b
A
A1
e
Symbol
Dimensions In Millimeters
Dimensions In Inches
Min
Max
Min
Max
A
0.889
1.295
0.035
0.051
A1
0.000
0.152
0.000
0.006
B
1.397
1.803
0.055
0.071
b
0.356
0.559
0.014
0.022
C
2.591
2.997
0.102
0.118
D
2.692
3.099
0.106
0.122
e
0.838
1.041
0.033
0.041
H
0.080
0.254
0.003
0.010
L
0.300
0.610
0.012
0.024
SOT-23-5 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.
DS9701B-06 April 2011
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