UTC-IC US205

UNISONIC TECHNOLOGIES CO., LTD
US205
Preliminary
CMOS IC
100mΩ, 2A SLEW RATE
CONTROLLED LOAD SWITCH
„
DESCRIPTION
The UTC US205 is a cost-effective, low-voltage, low switch-on
resistance (typ. 100mΩ) high-side Power Switch IC. It has a 20μA
low quiescent supply current that meets the requirements of
battery-powered portable equipment.
The UTC US205 incorporates protection circuits, such as an
over-current protection circuit, a short fold back circuit, a thermal
shutdown circuit and an under-voltage lockout circuit for overall
protection. Besides, a slew rate controlled function is embedded for
turn-on rising time control.
The UTC US205 can be usedin applications, such as Cellular
Phones, Digital still Camera, Hot swap Supplies, Notebook
Computers, Personal Communication Devices, Personal Digital
Assistants and so on.
The UTC US205 is available in SOP-8 package.
„
FEATURES
* High-Side NMOSFET: 100mΩ (TYP)
* Input Voltage Varies From 2.7V to 5.5V
* Low Supply Current: 20μA
* Over Current Protection
* Short Circuit Protection
* Under Voltage Lockout
* Thermal Protection with Foldback
* Slew Rate Limited Turn-On Time 3ms (5V)
* Reverse Blocking Current
* RoHS Compliant
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ORDERING INFORMATION
Ordering Number
Lead Free
Halogen Free
US205XL-S08-R
US205XG-S08-R
www.unisonic.com.tw
Copyright © 2011 Unisonic Technologies Co., Ltd
Package
Packing
SOP-8
Tape Reel
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US205
Preliminary
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PIN CONFIGURATION
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PIN DESCRIPTION
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PIN NO.
1
2
3
PIN NAME
NC
VOUT
EN
4
GND
5, 6, 7, 8
VIN
CMOS IC
DESCRIPTION
No Internal Connection.
Power-Switch Output.
Chip Enable (Active High).
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
Power Input Voltage.
BLOCK DIAGRAM
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Preliminary
CMOS IC
ABSOLUTE MAXIMUM RATING (TA=25°C, unless otherwise specified)
PARAMETER
SYMBOL
RATINGS
UNIT
Supply Voltage
VIN
6
V
Enable Input Voltage
EN
-0.3~6
V
Power Dissipation, @TA=25°C
PD
0.3
W
Junction Temperature
TJ
150
°C
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.
„
RECOMMENDED OPERATING CONDITIONS (TA=25°C, unless otherwise specified) (Note)
PARAMETER
SYMBOL
RATINGS
Supply Voltage
VIN
2.7~5.5
Enable Input Voltage
EN
0~5.5
Junction Temperature
TJ
-40~100
Ambient Temperature
TA
-40~85
Note: The device is not guaranteed to function outside its operating conditions.
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UNIT
V
V
°C
°C
ELECTRICAL CHARACTERISTICS
(VIN=5V, CIN=1uF, COUT=0.1uF, TA=25°C, unless otherwise specified)
PARAMETER
SYMBOL
TEST CONDITIONS
Operation Voltage
VIN
Under Voltage Lookout
VUVLO
VIN Falling
Under Voltage Lockout Hysteresis
ΔVUVLO
Quiescent Current
IQ
EN=High
Off Supply Current
ISHDN
EN=Low, VOUT=Open
Off Switch Current
ILEAKAGE EN=Low, VOUT=0
On-Resistance
RDS(ON)
VIN=3.3V, IOUT=1.3A
Current Limiting
ILIM
VIN=3.3V, VOUT=2.3V
VOUT=0V, Measured Prior
Short Circuit Current
ISC_FB
to Thermal Shutdown
Thermal shutdown Threshold
TSD
Thermal shutdown Hysteresis
ΔTSD
Low
VIL
VIN=2.7V ~ 5.5V
EN Threshold
High
VIH
VIN=2.7V ~ 5.5V
Enable Input Leakage
IEN
VEN=5.5V
Output Turn-On Delay Time
TD_ON
VIN=5V, RLOAD=10Ω
Output Turn-On Rise Time
TON
VIN=5V, RLOAD=10Ω
Output Turn-Off Fall Time
TD_OFF
VIN=5V, RLOAD=10Ω
Output Pull-Down Resistance During OFF RDISCHARGE EN=Low
UNISONIC TECHNOLOGIES CO., LTD
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MIN
2.7
1.3
TYP
1.7
50
20
MAX
5
2.1
1.5
100
2
70
1
1
120
2.5
0.4
0.8
1.5
130
20
0.8
2
1
60
3
4
150
1
100
10
UNIT
V
V
mV
μA
μA
μA
mΩ
A
A
°C
°C
V
V
μA
μs
ms
μs
Ω
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Preliminary
CMOS IC
APPLICATION INFORMATION
The UTC US205 is an enable input single N-MOSFET high-side power switches, optimized for self-powered and
bus-powered Universal Serial Bus (USB) applications. A charge pump circuitry is contained to drive the internal
MOSFET switch, the switch on resistance is 100mΩ, meets USB voltage droop requirements.
Input and Output
VIN (Input) is both the power supply connection for the internal circuitry driving the switch and the input (Drain
connection) of the power MOSFET switch. VOUT (Output) is the Source connection of the MOSFET and supplies
power to the load. In a typical circuit, current flows from VIN to VOUT toward the load. Since the switch is bidirectional
when enabled, if VOUT is greater than VIN, current will flow through the switch from VOUT to VIN.
There is no parasitic body diode between drain and source of the MOSFET, prevents reverse current flow if VOUT
is externally forced to a higher voltage than VIN when the chip is disabled (VEN < 0.8V).
D
S
S
D
G
G
Normal MOSFET
UTC US205
Chip Enable Input
If the EN pin is in a logic low condition the UTC US205 switch will be disabled. During this case, MOSFET and the
internal circuitry will be turned off, and the supply current is reduced to 0.1uA typical. When the EN is floating,
unpredictable operation may be caused. EN goes negative with respect to GND should not be allowed. The EN pin
can be directly tied to VIN.
Soft Start for Hot Plug-In Applications
The UTC US205 “soft-start” feature eliminates the upstream voltage droop caused by the large inrush current
during hot-plug events, and effectively isolates the power source from extremely large capacitive load, meets the
USB voltage droop requirements.
Under-Voltage Lockout
The UTC US205 internal Under-voltage lockout (UVLO) circuit prevents the MOSFET switch from turning on until
the input voltage exceeds approximately 1.75V. The internal MOSFET switch will be turned off if input voltage drops
below approximately 1.7V. Under-voltage detection functions only when the chip is enabled.
Current Limiting and Short-Circuit Protection
The UTC US205 protects the power supply and the load from damage by the current limit circuitry, but can deliver
load current up to the current limit threshold (typically 2A). If an enabled switch encounters a heavy load or short
circuit case, a large transient current may flow until the current limit circuitry responds. Once this current limit
threshold level is exceeded, the device enters constant current mode until the fault is removed or thermal shutdown
occurs.
Supply Filter/Bypass Capacitor
To prevent the input voltage drooping during hot-plug events, a 1uF low-ESR ceramic capacitor from VIN to GND is
strongly recommended. But higher capacitor values will further reduce the voltage droop on the input. Furthermore,
without the bypass capacitor, an output short may cause sufficient ringing on the input (from source lead inductance)
to destroy the internal circuitry. The input voltage transient must not exceed the absolute maximum supply voltage
6V even for a short duration.
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Preliminary
CMOS IC
APPLICATION INFORMATION(Cont.)
Output Filter Capacitor
A low-ESR 150uF aluminum electrolytic or tantalum between VOUT and GND is strongly recommended to meet the
330mV maximum droop requirement in the hub VBUS (Per USB 2.0, output ports must have a minimum 120μF of
low-ESR bulk capacitance per hub). The bypass capacitor itself should have a low dissipation factor to allow
decoupling at higher frequencies.
Thermal Shutdown
Thermal shutdown is used to turn off the output MOSFET when the if the temperature is higher than130°C, 20°C
of hysteresis prevents the switch turn on until the die temperature drops to 110°C.
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TYPICAL APPLICATION CIRCUIT
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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