Datasheet

MAX3346E
±15kV ESD-Protected USB Transceiver
in UCSP
8 _______________________________________________________________________________________
Applications Information
Power-Supply Configurations
Normal Operating Mode
Connect V
L
and V
CC
to system power supplies (Table
1). Connect V
L
to a +1.65V to +3.6V supply. Connect
V
CC
to a +4.0V to +5.5V supply. Alternatively, the
MAX3346E can derive power from a single Li+ battery.
Connect the battery to V
CC
. VTRM remains above
+3.0V for V
CC
as low as +3.1V.
Additionally, the MAX3346E can derive power from a
3.3V ±10% voltage regulator. Connect V
CC
and VTRM
to an external +3.3V voltage regulator.
Disable Mode
Connect V
CC
to a system power supply and leave V
L
unconnected or connect to GND. D+ and D- enter a tri-
state mode and V
CC
consumes less than 20µA of sup-
ply current. D+ and D- withstand external signals up to
+5.5V in disable mode (Table 2).
Sharing Mode
Connect V
L
to a system power supply and leave V
CC
(or V
CC
and V
VTRM
) unconnected or connect to GND.
D+ and D- enter a tri-state mode, allowing other circuit-
ry to share the USB D+ and D- lines, and V
L
consumes
less than 20µA of supply current. D+ and D- withstand
external signals up to +5.5V in sharing mode (Table 2).
Device Control
OE
OE controls the direction of communication through the
device. With OE low, the MAX3346E transfers data from the
system side to the USB side. With OE high, the MAX3346E
transfers data from the USB side to the system side.
ENUM
The MAX3346E allows software control of USB enumera-
tion. USB specification 1.1 requires a 1.5kΩ pullup resistor
to D+ or D- to set the transmission speed (see the SPEED
section). Enumerating the USB requires removing the 1.5kΩ
resistor from the circuit, and is accomplished with the
MAX3346E by driving ENUM low. With ENUM high, the volt-
age at SPEED determines how the internal resistor is con-
nected (see the Functional Diagram).
MODE
MODE is a control input that selects whether differential
or single-ended logic signals are recognized by the
system side of the MAX3346E (Table 3).
If MODE is forced high, differential input is selected. With
differential input selected, outputs D+ and D- follow the
differential inputs at VP and VM. If VP and VM are both
forced low, an SE0 condition is forced on the USB.
Drive MODE and VM low for single-ended input mode.
With single-ended input selected, the differential sig-
nal on D+ and D- is controlled by VP. If VM is high
when MODE is low, D- and D+ are both low, forcing
an SE0 condition.
V
CC
(V) VTRM (V) V
L
(V) CONFIGURATION NOTES
+4.0 to +5.5 +3.3 Output +1.65 to +3.6 Normal mode —
+3.1 to +4.5 +3.3 Output +1.65 to +3.6 Battery supply —
+3.0 to +3.6 +3.0 to +3.6 Input +1.65 to +3.6
Voltage regulator supply
—
GND or floating Output +1.65 to +3.6 Sharing mode Table 2
+3.0 to +5.5 Output GND or floating Disable mode Table 2
Table 1. Power-Supply Configurations
INPUTS/OUTPUTS DISABLE MODE SHARING MODE
V
CC
/VTRM
• +5V input/+3.3V output
• +3.3V input/+3.3V output
• +3.7V input/+3.3V output
Floating or connected to GND
V
L
Floating or connected to GND +1.65V to +3.6V input
D+ and D- High impedance High impedance
SPEED, SUSP, OE, ENUM High impedance High impedance
Table 2. Disable-Mode and Sharing-Mode Configurations