RT9702/A
80mΩ, 500mA/1.1A High Side Power Switches with Flag
Ω
General Description
The RT9702 and RT9702A are cost-effective, low voltage,
single N-Channel MOSFET high-side power switches,
optimized for self-powered and bus- powered Universal
Serial Bus (USB) applications. The RT9702/A equipped
with a charge pump circuitry to drive the internal MOSFET
switch; the switch's low R
DS(ON)
, 80mΩ, meets USB
voltage drop requirements; and a flag output is available
to indicate fault conditions to the local USB controller.
Additional features include soft-start to limit inrush current
during plug-in, thermal shutdown to prevent catastrophic
switch failure from high current loads, under-voltage
lockout (UVLO) to ensure that the device remains off
unless there is a valid input voltage present, fault current
is limited to typically 800mA for RT9702 in single port and
1.5A for RT9702A in dual ports in accordance with the
USB power requirements, lower quiescent current as 25μA
making this device ideal for portable battery-operated
equipment.
The RT9702/A is available in SOT-23-5 and
TSOT-23-5
packages requiring minimum board space and smallest
components.
Features
Compliant to USB Specifications
Built-In (Typically 80mΩ) N-Channel MOSFET
Ω
Output Can Be Forced Higher Than Input (Off-State)
Low Supply Current :
25uA Typical at Switch On State
1uA Typical at Switch Off State
Guaranteed 500mA/RT9702 and 1.1A/RT9702A
Continuous Load Current
Wide Input Voltage Ranges : 2V to 5.5V
Open-Drain Fault Flag Output
Hot Plug-In Application (Soft-Start)
1.7V Typical Under Voltage Lockout (UVLO)
Current Limiting Protection
Thermal Shutdown Protection
Reverse Current Flow Blocking (no body diode)
Smallest
SOT-23-5 and
TSOT-23-5 Packages
Minimizes Board Space
UL Approved
−
E219878
TUV
IEC60950-1 : 2005
Certified
RoHS Compliant and 100% Lead (Pb)-Free
Applications
USB Bus/Self Powered Hubs
USB Peripherals
ACPI Power Distribution
PC Card Hot Swap
Notebook, Motherboard PCs
Battery-Powered Equipment
Hot-Plug Power Supplies
Battery-Charger Circuits
Ordering Information
RT9702/A
Package Type
B : SOT-23-5
J5 : TSOT-23-5
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
1.1A Output Current
500mA Output Current
Note :
Richtek 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.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
DS9702/A-15 April 2011
www.richtek.com
1
RT9702/A
Pin Configurations
(TOP VIEW)
VOUT
5
2
Functional Pin Description
Pin Name
VIN
VIN
4
3
Pin Function
Power Input Voltage
Output Voltage
Ground
Chip Enable (Active High)
Open-Drain Fault Flag Output
VOUT
GND
EN
FLG
EN GND FLG
SOT-23-5/TSOT-23-5
Typical Application Circuit
Pull-Up Resistor (10k to 100k) (Optional)
Flag Transient Filtering) USB Controller
Supply Voltage 5V
VIN
1µF
FLG
RT9702/A
VOUT
GND
10µF
150µF
V
BUS
D+
D-
GND
Ferrite
Beades
10k
0.1µF
Over -Current
Chip Enable
EN
Note:
A low-ESR 150μF aluminum electrolytic or tantalum between V
OUT
and GND is strongly recommended to meet the
330mV maximum droop requirement in the hub V
BUS
. (see Application Information Section for further details)
+
Data
Function Block Diagram
VIN
EN
Bias
UVLO
Current
Limiting
Gate
Control
Output Voltage
Detection
Oscillator
Charge
Pump
Thermal
Protection
VOUT
FLG
Delay
GND
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2
DS9702/A-15 April 2011
RT9702/A
Test Circuits
1
R
FG
+
2
I
Supply
A
VIN
FLG
V
FLG
I
LEAK AGE
V
IN
C
IN
Chip Enable
VIN
FLG
V
FLG
S1
I
OUT
V
OUT
V
IN
C
IN
+
RT9702/A
VOUT
GND
RT9702/A
VOUT
GND
EN
A
C
OUT
Chip Enable
EN
A
R
L
+
R
L
I
L
3
V
RDS(ON)
4
R
FG
V
I
OUT
VIN
VOUT
VIN
+
+
+
FLG
V
IN
C
IN
V
FLG
V
OUT
RT9702/A
FLG
GND
C
OUT
V
IN
C
IN
RT9702/A
VOUT
GND
C
OUT
Chip Enable
EN
EN
V
CE
+
R
L
I
L
5
S2
VIN
R
FG
FLG
V
FLG
I
OUT
V
OUT
+
V
IN
C
IN
RT9702/A
VOUT
GND
C
OUT
EN
A
S3
R
L
I
L
Note:
Above test circuits reflected the graphs shown on “ Typical Operating Characteristics ” are as follows:
1
−
Turn-On Rising & Falling Time vs. Temperature, Turn-On & Off Response, Flag Response
vs. Temperature
3
−
On-Resistance vs. Input Voltage & Temperature
4
−
EN
Threshold Voltage vs. Input Voltage & Temperature, Flag Delay Time vs. Input Voltage & Temperature, UVLO
Threshold vs. Temperature, UVLO at Rising & Falling
5
−
Current Limit vs. Input Voltage/Temperature, Short Circuit Current Response, Short Circuit Current vs. Temperature,
Inrush Current Response, Soft-start Response, Ramped Load Response, Current Limit Transient Response, Thermal
Shutdown Response
DS9702/A-15 April 2011
www.richtek.com
3
2
−
Supply Current vs. Input Voltage & Temperature, Switch Off Supply Current vs. Temperature, Turn-Off Leakage Current
+
RT9702/A
Absolute Maximum Ratings
(Note 1)
Supply Voltage --------------------------------------------------------------------------------------------------------- 6.5V
Chip Enable Input Voltage -------------------------------------------------------------------------------------------
−
0.3V to 6.5V
Flag Voltage ------------------------------------------------------------------------------------------------------------ 6.5V
Power Dissipation, P
D
@ T
A
= 25°C
SOT-23-5, TSOT-23-5 ------------------------------------------------------------------------------------------------- 0.4W
Package Thermal Resistance (Note 2)
SOT-23-5, TSOT-23-5,
θ
JA
------------------------------------------------------------------------------------------- 250°C/W
Junction Temperature ------------------------------------------------------------------------------------------------- 150°C
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C
Storage Temperature Range ----------------------------------------------------------------------------------------
−
65°C to 150°C
ESD Susceptibility (Note 3)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 8kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------- 800V
Recommended Operating Conditions
(Note 4)
Supply Input Voltage -------------------------------------------------------------------------------------------------- 2V 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 85°C
Electrical Characteristics
(V
IN
= 5V, C
IN
= C
OUT
= 1μF, T
A
= 25°C, unless otherwise specified)
Parameter
Switch On Resistance
RT9702
RT9702A
Symbol
R
DS(ON)
I
SW_ON
I
SW_OFF
Logic-Low
V
IL
I
EN
Logic-High V
IH
Test Conditions
I
OUT
= 500mA
I
OUT
= 1.1A
switch on, V
OUT
= Open
switch off, V
OUT
= Open
V
IN
= 2V to 5.5V, switch off
V
IN
= 2V to 5.5V, switch on
V
EN
= 0V to 5.5V
Min
--
--
--
--
2.0
--
--
--
0.5
1.1
--
--
--
--
2
Typ
80
25
0.1
--
--
0.01
0.5
400
0.8
1.5
0.8
1.0
20
0.01
10
Max
100
45
1
0.8
--
--
10
--
1.1
2.0
--
--
400
1
15
Unit
mΩ
μA
V
V
μA
μA
μs
A
A
Ω
μA
ms
Supply Current
EN Threshold Voltage
EN Input Current
Output Leakage Current
Output Turn-On Rise Time
Current Limit
Short Circuit Fold-
Back Current
RT9702
RT9702A
RT9702
RT9702A
I
LEAKAGE
V
EN
= 0V, R
LOAD
= 0Ω
T
ON_RISE
10% to 90% of V
OUT
rising
I
LIM
I
SC_FB
R
FLG
I
FLG_OFF
R
LOAD
= 1Ω
V
OUT
= 0V, measured prior to
thermal shutdown
I
SINK
= 1mA
V
FLG
= 5V
From fault condition to FLG
assertion
FLAG Output Resistance
FLAG Off Current
FLAG Delay Time
(Note 5)
t
D
To be continued
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4
DS9702/A-15 April 2011
RT9702/A
Parameter
Under Voltage Lockout
Under Voltage Hysteresis
Thermal Shutdown Protection
Thermal Shutdown Hysteresis
Symbol
V
UVLO
ΔV
UVLO
T
SD
ΔT
SD
Test Conditions
V
IN
Increasing
V
IN
Decreasing
Min
1.3
--
--
--
Typ
1.7
0.1
130
20
Max
--
--
--
--
Unit
V
V
°C
°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.
θ
JA
is measured in the natural convection at T
A
= 25°C on a low effective thermal conductivity single layer 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 FLAG delay time is input voltage dependent, see“ Typical Operating Characteristics” graph for further details.
DS9702/A-15 April 2011
www.richtek.com
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