FAN3989MLP8X Fairchild Semiconductor, FAN3989MLP8X Datasheet - Page 8

• Manufacturer Part Number: FAN3989MLP8X
• Description: IC USB CONNECTION MONITOR 8MLP
• Manufacturer: Fairchild Semiconductor

Specifications of FAN3989MLP8X

• Function: Over/Under Voltage Protection
• Voltage - Supply: 2.7 V ~ 20 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-MLP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: FAN3989MLP8XTR

© 2007 Fairchild Semiconductor Corporation
FAN3989 • Rev. 1.0.8
Applications Information
The FAN3989 sets the FLAG1 pin to logic HIGH or
LOW as an indicator to the system controller that a
standard USB device or a charger is connected to the
USB port. The FAN3989 also monitors the V
over- or under-voltage conditions. If V
3.3V or greater than 6.0V, the FLAG2 pin is set LOW
and the internal load switch control pin is set HIGH,
turning off the PMOS switch.
In a standard USB configuration, there is a switch in
the USB transceiver that is always on in full-speed
mode. It is on during the transition from full-speed to
high-speed mode and turned off after enumeration is
USB
Devic e
15 K
U S B
V BUS
D -
D +
G nd
Figure 12.
Mobile Phone Battery Charging System with USB Interface
V
BUS
GND
D+
D-
BUS
Std 15K pull-dow n
on D- input by US B
device and 1.5K pull-u p
on D+ by USB transceiver .
is less than
1.5K
USB Transceive r
BUS
for
Comparato r
OVP
UVP
8
V
Std USB /
Charge r
Detec t
DD
complete. If D+ and D- are shorted when a charger is
plugged into the USB port, the USB switch is on and
pulled to V
D- HIGH. Flag1 is also set HIGH, indicating that a
charging device is connected to the port. If D+ and D-
are connected to a standard USB device, the D+ is
pulled to V
down resistor on the USB device) and flag1 is LOW. If
D+ and D- are open (floating), D+ is pulled to V
D- floats LOW, which makes flag1 LOW.
DD
DD
LSctrl
, which is about 3V, making both D+ and
and D- is set low (due to the 15KΩ pull-
Contro l
Batter y
Logi c
Logi c
V
R s en s e
OUT
Flag 2
Flag 1
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DD
and