ISL54227
11
FN7593.1
September 5, 2013
The ISL54227 is designed to minimize IDD current consumption
when the logic control voltage is lower than the VDD supply
voltage. With VDD = 3.6V and the OE logic pin is at 1.4V the part
typically draws only 25A. With VDD = 4.3V and the OE logic pin
is at 2.6V the part typically draws only 35A. Driving the logic pin
to the VDD supply rail minimizes power consumption.
The OE and LP pin can be driven with a voltage higher than the
VDD supply voltage. It can be driven up to 5.25V with a VDD
supply in the range of 2.7V to 5.25V.
Low Power Mode
If the OE pin = Logic “0”, and the LP pin = Logic “1” the switches
will turn OFF (high impedance) and the part will be put in a low
power mode. In this mode the part draws only 10A (max) of
current across the operating temperature range.
Normal Operation Mode
With a signal level in the range of 0V to 3.6V and with the LP pin =
Logic “0” the switches will be ON when the OE pin = Logic “1” and
will be OFF (high impedance) when the OE pin = Logic “0”.
USB 2.0 VBUS Short Requirments
The USB specification in section 7.1.1 states a USB device must
be able to withstand a VBUS short (4.4V to 5.25V) or a -1V short to
the D+ or D- signal lines when the device is either powered off or
powered on for at least 24 hours.
The ISL54227 part has special power-off protection and OVP
detection circuitry to meet these short circuit requirements. This
circuitry allows the ISL54227 to provide protection to the USB
down-stream transceiver connected at its signal pins (D-, D+) to
meet the USB specification short circuit requirements.
The power-off protection and OVP circuitry allows the COM pins
(COM-, COM+) to be driven up to 5.25V or down to -5V while the
VDD supply voltage is in the range of 0V to 5.25V. In these
overvoltage conditions with a 500 external VDD resistor the part
draws <55A of current into the COM pins and causes no
stress/damage to the IC. In addition all switches are OFF and the
shorted VBUS voltage will be isolated from getting through to the
other side of the switch channels, thereby protecting the USB
transceiver.
TABLE 2. LOGIC CONTROL VOLTAGE LEVELS
VDD SUPPLY
RANGE
LOGIC = “0” (LOW)
LOGIC = “1” (HIGH)
OE
LP
OE
LP
2.7V to 3.6V
≤ 0.5V
or
floating
≤ 0.5V
or
floating
≥1.4V
3.7V to 4.2V
≤ 0.7V
or
floating
≤ 0.7V
or
floating
≥1.7V
4.3V to 5.25V
≤ 0.8V
or
floating
≤ 0.8V
or
floating
≥2.0V
Typical Performance Curves T
A = +25°C, Unless Otherwise Specified
FIGURE 11. ON-RESISTANCE vs SUPPLY VOLTAGE vs SWITCH
VOLTAGE
FIGURE 12. ON-RESISTANCE vs SUPPLY VOLTAGE vs SWITCH
VOLTAGE
2.9
3.0
3.1
3.2
3.3
3.4
0
0.1
0.2
0.3
0.4
r ON
(W
)
VCOM (V)
2.7V
3.3V
ICOM = 17mA
3.6V
4.3V
5.25V
3.0V
0
2
4
6
8
10
12
14
16
0
0.6
1.2
1.8
2.4
3.0
3.6
r ON
(W
)
VCOM (V)
ICOM = 17mA
2.7V
3.0V
3.3V
5.25V