RT9703
80mΩ, 3A Smart Universal Power Switch with Flag
Ω
General Description
The RT9703 is a low voltage, high performance single
N-MOSFET power switch, designed for power rail on/off
control with low R
DS(ON)
≈
80mΩ and full protection
functions. The RT9703 equipped with a charge pump
circuitry to drive the internal MOSFET switch and a flag
output is available to indicate fault conditions against large
di/dt which may cause the supply to fall out of regulation.
In order to fit different application, an IP pin is offered for
current limit point setting, a resistor from IP to ground
sets the current limit for the switch.
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, a precision
resistor-programmable output current limit up to 3.5A.
Besides, the lower quiescent current as 30μA making this
device ideal for portable battery-operated equipment.
The RT9703 is available in SOP-8 package requiring
minimum board space and smallest components.
Features
Adjustable Current Limiting up to 3.5A
Built-In (Typically 80mΩ) N-MOSFET
Ω
Reverse Current Flow Blocking (no body diode) i.e.
Output Can Be Forced Higher than Input (Off-State)
Low Supply Current :
30μA Typical at Switch on State
μ
Less than 1μA Typical at Switch Off State
μ
Guaranteed 3A 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)
Thermal Shutdown Protection
Smallest SOP-8 Package Minimizes Board Space
RoHS Compliant and 100% Lead (Pb)-Free
Applications
LCD Monitor, LCD-TV
USB Power Module for ADSL
Information Appliance and Set-Top Box
Battery-Powered Equipment
Hot-Plug Power Supplies
ACPI Power Distribution
PCI Bus Power Switching
Motherboard & Notebook PCs
PC Card Hot Swap Application
Ordering Information
RT9703
Package Type
S : SOP-8
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
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.
Pin Configurations
(TOP VIEW)
FLG
VOUT
VOUT
GND
2
3
4
8
7
6
5
IP
VIN
VIN
EN
SOP-8
DS9703-09 April 2011
www.richtek.com
1
RT9703
Typical Application Circuit
Pull-Up Resistor (10K to 100K)
Supply Voltage
10µF
Chip Enable
EN
VIN
FLG
R
SET
IP
RT9703
VOUT
GND
33µF
+
Peripheral
Fault Flag
Functional Pin Description
Pin Name
VIN
VOUT
GND
EN
FLG
IP
Pin Function
Power Input Voltage.
Output Voltage.
Ground.
Chip Enable (Active High).
Open-Drain Fault Flag Output.
Current Limit Programming Input.
Function Block Diagram
VIN
+
-
EN
Bias
UVLO
-
+
Gate
Control
Output Voltage
Detection
V
REF
IP
Oscillator
Charge
Pump
Thermal
Protection
VOUT
FLG
Delay
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2
DS9703-09 April 2011
RT9703
Test Circuits
1
R
FG
I
SUPPLY
V
IN
2
I
SUPPLY
VIN
FLG
V
FLG
V
OUT
A
C
IN
S1
I
OUT
RT9703
VOUT
V
IN
C
IN
A
VIN
FLG
I
LEAKAGE
+
+
RT9703
VOUT
A
R
L
R
SET
Chip Enable
EN
GND
A
R
SET
C
OUT
Chip Enable
R
L
I
L
EN
+
IP
GND IP
3
V
RDS(ON)
4
R
FG
V
I
OUT
VIN
VOUT
+
VIN
V
IN
C
IN
RT9703
FLG
EN
GND
IP
C
OUT
V
IN
C
IN
FLG
VOUT
C
OUT
V
FLG
+
V
OUT
I
L
Note: Above test circuits reflected the graphs shown on
“
Typical Operating Characteristics
”
are as follows:
1
–
Turn-On Rising & Turn-Off Falling Time vs. Temperature, Turn-On & Off Response, Flag Response at Chip Enable, Flag
Response (Enable into Current Limit)
2
–
On-State & Off-State Supply Current vs. Input Voltage/Temperature, Turn-Off Leakage Current 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/R
SET
, Current Limit Factor vs. R
SET
, Short Circuit Current vs. Input Voltage,
Inrush Current Response, Soft-Start Response, Current-Limit & Short Circuit with Thermal Shutdown, Short-Circuit
Response
DS9703-09 April 2011
www.richtek.com
3
+
R
SET
+
RT9703
EN
V
CE
GND
IP
R
L
R
SET
5
S2
C
IN
VIN
FLG
RT9703
VOUT
EN
GND IP
R
SET
C
OUT
+
+
I
OUT
V
IN
V
OUT
A
S3
R
L
I
L
RT9703
Absolute Maximum Ratings
(Note 1)
6.5V
−
0.3V to 6.5V
6.5V
0.95W
104°C/W
Supply Voltage -------------------------------------------------------------------------------------------------------
Chip Enable Input Voltage -----------------------------------------------------------------------------------------
Flag Voltage -----------------------------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
SOP-8 ------------------------------------------------------------------------------------------------------------------
Package Thermal Resistance
SOP-8,
θ
JA
------------------------------------------------------------------------------------------------------------
Junction Temperature ----------------------------------------------------------------------------------------------- 125°C
Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------- 260°C
Storage Temperature Range ---------------------------------------------------------------------------------------
−
65°C to 150°°C
ESD Susceptibility (Note 2)
HBM (Human Body Mode) ----------------------------------------------------------------------------------------- 8kV
MM (Machine Mode) ------------------------------------------------------------------------------------------------ 800V
Recommended Operating Conditions
(Note 3)
Supply Input Voltage ------------------------------------------------------------------------------------------------ 2V to 5.5V
Chip Enable Input Voltage ----------------------------------------------------------------------------------------- 0V to 5.5V
Junction Temperature Range --------------------------------------------------------------------------------------
−
20°C to 100°C
Electrical Characteristics
(V
IN
= 5V, C
IN
= C
OUT
= 1μF, T
A
= 25°C, unless otherwise specified)
Parameter
Switch On Resistance
Supply Current
Symbol
R
DS(ON)
I
SW_ON
I
SW_OFF
Test Conditions
I
OUT
= 3A (Note 8)
Switch On, V
OUT
= Open
Switch Off, V
OUT
= Open
Switch Off
Switch On
V
CE
= 0V to 5.5V
V
CE
= 0V, R
LOAD
= 0Ω
10% to 90% of V
OUT
rising
I
LIM
x R
SET
V
IN
= 3.3V to 5.5V, R
SET
= 60kΩ
I
LIMSET
= 0.5A to 3A
(R
SET
= 420kΩ to 70kΩ)
I
SINK
= 1mA
Form fault condition to FLG assertion
V
IN
increasing
V
IN
decreasing
Min
--
--
--
--
2.0
--
--
--
--
--
−20
--
--
2
1.3
--
Typ
80
30
0.1
--
--
0
0.5
1.5
210k
--
--
15
0.01
4.6
1.7
0.1
Max
100
50
1
0.8
--
--
10
--
--
3.5
+20
400
1
8
--
--
Unit
mΩ
μA
V
V
μA
μA
ms
A
Ω
A
%
Ω
μA
ms
V
V
CE Threshold Logic-Low Voltage V
IL
(Note 7)
Logic-High Voltage V
IH
CE Input Current
Output Leakage Current
Output Turn-On Rise Time
Current Limit Factor (Note 5)
Max. Current Limit Setting (Note 6) I
LIMSET
Current Limit Setting Accuracy
FLAG Output Resistance
FLAG Off Current
FLAG Delay Time (Note 4)
Under-Voltage Lockout
Under-Voltage Hysteresis
ΔI
LIMSET
R
FLG
t
D
V
UVLO
ΔV
UVLO
I
CE
I
LEAKAGE
T
ON_RISE
I
FLG_OFF
V
FLG
= 5V
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4
DS9703-09 April 2011
RT9703
Parameter
Thermal Shutdown Protection
Thermal Shutdown Hysteresis
Symbol
T
SD
ΔT
SD
Test Conditions
Min
--
--
Typ
130
10
Max
--
--
Unit
°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.
Devices are ESD sensitive. Handling precaution recommended.
Note 3.
The device is not guaranteed to function outside its operating conditions.
Note 4.
The FLAG delay time is input voltage dependent, see
“
Typical Operating Characteristics
”
graph for further details.
Note 5.
Current limit is determined by: I
LIMIT
=
210k/R
SET
, where R
SET
is in ohms.
Note 6.
It is important to note that the maximum current limit value shall be set properly in accordance with its supply voltage
otherwise which it may result in the failure occurrence. See
“
Maximum Current Limit vs. Supply Voltage
”
graph shown
on the applications information section for further details.
Note 7.
For input voltage lower than 5V, the threshold level will subject to
±
0.6V deviation throughout the operating junction
temperature range. Refer to the
“
Typical Operating Characteristics
”
graph for further details.
Note 8.
R
DS(ON)
is measured at constant junction temperature by using a 1ms current pulse.
DS9703-09 April 2011
www.richtek.com
5
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