ACE345 - ACE Technology Co., LTD.

ACE345
Adjustable USB Load Current Switch
Description
The ACE345 is Adjustable USB Load Current Switch Current Limited designed for high-side load
switching applications. The internal current-limiting circuit protects the input supply against large output
short circuit current which may cause the supply to fall out of regulation.
The current limit threshold is programmed with an external resistor from ISET Pin to ground. The
quiescent supply current is typically 150μA, making the device ideal for portable battery-operated
equipment. In shutdown mode, the supply current decreases to less than 0.1μA.
Additional features include thermal shutdown and constant current output characteristics if current
exceed its current limit
Features
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


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
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2.5 to 5.5V input voltage range
Controlled turn-on
0.15-1.5A adjustable current limit
+/-6% current limit accuracy
0.1ohm on resistance
Fast current limit response time
Logic Control Shutdown (IQ<1uA)
Thermal shutdown and UVLO
Reverse current blocking
Application



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Portable Devices
MID, MP4…
Set top boxes
Notebook and PC mother board
USB supplied Devices
Absolute Maximum Ratings
Parameter
Max
Unit
Max Input Voltage
6
V
Max Operating Junction Temperature(TJ)
125
℃
Ambient Temperature(TA)
-40~85
℃
Maximum Power Dissipation
250
mW
Storage Temperature(TS)
ESD (HBM)
-40~150 ℃
>4000
V
Note: Exceed these limits to damage to the device. Exposure to absolute maximum rating conditions may affect device reliability.
VER 1.2
1
ACE345
Adjustable USB Load Current Switch
Packaging Type
SOT-23-5
5
1
4
2
3
SOT-23-5 Description
Function
1
VOUT
Switch Output, the output of power switch
2
GND
3
ISET
4
ON
Ground
Current limit setting pin. Connecting a resistor (R_Iset) from this pin to ground
will adjust the current limit
Control input, enable pin, active high
5
VIN
Supply input voltage
Ordering information
ACE345 XX +
H
Halogen - free
Pb - free
BN : SOT-23-5
Recommended Work Conditions
Parameter
Max
Unit
Input Voltage Range
5.5
V
Operating Junction Temperature (TJ) -20~125 ℃
Typical Application
ACE345
VER 1.2
2
ACE345
Adjustable USB Load Current Switch
Electrical Characteristics (VIN=5V,TA=25℃.)
Parameter
Symbol
Input Voltage Range
Vin
Quiescent Current
Conditions
Min Typ Max Units
2.6
Active, Vfb=0.65, No
Switching
Iq
5.5
150
Shutdown
Switch Rdson
Rdson
Adjustable current limit
Llimit
Reverse Voltage Leakage
Current
Irevlk
ON Input High Voltage
Vh_on
ON Input Low Voltage
Vl_on
Thermal shutdown Temp
Tsd
V
300
uA
1
Iout=500mA
R_Iset=53K ohm
R_Iset=25K ohm
R_Iset=17K ohm
100
0.5
1.0
1.5
150
Vout=5V, Vin=0V
0.1
5
mΩ
A
1.5
uA
V
0.4
V
℃
155
Setting The Current Limit Threshold
RILIM (KΩ) Typical Current Limit (mA) RILIM (KΩ) Typical Current Limit (mA)
200
138
51
520
180
152
43
612
151
179
30
873
100
266
20
1295
82
324
15.1
1705
68
389
VER 1.2
3
ACE345
Adjustable USB Load Current Switch
Electrical Performance
Tested under TA=25℃, unless otherwise noted
VER 1.2
4
ACE345
Adjustable USB Load Current Switch
Electrical Performance
Tested under TA=25℃, unless otherwise noted
VER 1.2
5
ACE345
Adjustable USB Load Current Switch
Block Diagram
Detailed Description
Operation
The ACE345 is a current limited switch that protects systems and loads which can be damaged or
disrupted by the application of high currents. The core of each device is a 0.10Ω P-channel MOSFET and
a controller capable of functioning over a wide input operating range of 2.6-5.5V. The controller protects
against system malfunctions through current limiting, undervoltage lockout and thermal shutdown. The
current limit is adjustable from 0.15A to 1.5A through the selection of an external resistor.
On/Off control
The ON pin controls the state of the switch. When ON is high, the switch is in the on state. Activating ON
continuously holds the switch in the on state so long as there is no fault. An undervoltage on VIN or a
junction temperature in excess of 155°C overrides the ON control to turn off the switch. The ACE345 does
not turn off in response to an over current condition but instead remains operating in a constant current
mode so long as ON is active and the thermal shutdown or undervoltage lockout have not activated. The
ON pin control voltage and VIN pin have independent and recommended operating ranges. The ON pin
voltage can be driven by a voltage level higher than the input voltage.
VER 1.2
6
ACE345
Adjustable USB Load Current Switch
Current limiting
The current limit ensures that the current through the switch doesn't exceed a maximum value while not
limiting at less than a minimum value. The current at which the parts will limit is adjustable through the
selection of an external resistor connected to ISET. Information for selecting the resistor is found in the
Application Info section. The ACE345 has no current limit blanking period so it will remain in a constant
current state until the ON pin is deactivated or the thermal shutdown turns-off the switch.
Thermal Shutdown
The thermal shutdown protects the die from internally or externally generated excessive temperatures.
During an over-temperature condition the switch is turned-off. The switch automatically turns-on again if
temperature of the die drops below the threshold temperature.
Packing Information
SOT-23-5
VER 1.2
7
ACE345
Adjustable USB Load Current Switch
Notes
ACE does not assume any responsibility for use as critical components in life support devices or systems
without the express written approval of the president and general counsel of ACE Electronics Co., LTD.
As sued herein:
1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant
into the body, or (b) support or sustain life, and shoes failure to perform when properly used in
accordance with instructions for use provided in the labeling, can be reasonably expected to result in
a significant injury to the user.
2. A critical component is any component of a life support device or system whose failure to perform can
be reasonably expected to cause the failure of the life support device or system, or to affect its safety
or effectiveness.
ACE Technology Co., LTD.
http://www.ace-ele.com/
VER 1.2
8