MAX3345E Просмотр технического описания (PDF) - Maxim Integrated
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MAX3345E Datasheet PDF : 15 Pages
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±15kV ESD-Protected USB Transceivers
in UCSP with USB Detect
Power-Supply Configurations
Normal Operating Mode
Connect VL and VCC to system power supplies (Table
1). Connect VL to a +1.65V to +3.6V supply. Connect
VCC to a +4.0V to +5.5V supply. Alternatively, the
MAX3344E/MAX3345E can derive power from a single
Li+ battery. Connect the battery to VCC. VVTRM remains
above +3.0V for VCC as low as +3.1V.
Additionally, the MAX3344E/MAX3345E can derive
power from a 3.3V ±10% voltage regulator. Connect VCC
and VTRM to an external +3.3V voltage regulator.
Disable Mode
Connect VCC to a system power supply and leave VL
unconnected or connect to GND. D+ and D- enter a tri-
state mode and VCC consumes less than 20µA of supply
current. D+ and D- withstand external signals up to
+5.5V in disable mode (Table 2).
Sharing Mode
Connect VL to a system power supply and leave VCC (or
VCC and VTRM) unconnected or connect to GND. D+
and D- enter a tri-state mode, allowing other circuitry to
share the USB D+ and D- lines, and VL consumes less
than 20µA of supply current. D+ and D- withstand exter-
nal signals up to +5.5V in sharing mode (Table 2).
Device Control
D+ and D-
D+ and D- are the USB-side transmitter I/O connec-
tions, and are ESD protected to ±15kV using the
Human Body Model, ±10kV using IEC 1000-4-2 Air-
Gap Discharge, and ±8kV using IEC 1000-4-2 Contact
Discharge, making the MAX3344E/MAX3345E ideal for
applications where a robust transmitter is required. A
23.7Ω resistor is required on D+ and D- for normal
operation (see the External Resistors section).
ENUM
USB specification 2.0 requires a 1.5kΩ pullup resistor
on D+ for full-speed (12Mbps) operation. Controlled by
enumerate (ENUM), the MAX3344E/MAX3345E provide
this internal 1.5kΩ resistor. Drive ENUM high to connect
the pullup resistor from D+ to VTRM. Drive ENUM low to
disconnect the pullup resistor from D+ to VTRM.
VPO/VMO, VPI/VMI, and OE
The MAX3344E/MAX3345E system-side inputs are VPO
and VMO. Data comes into the MAX3344E/MAX3345E
through VPO and VMO. VPO and VMO operate either
differentially with VPO as the positive terminal and VMO
as the negative terminal, or single ended with VPO as
the data input (see the MODE section).
Table 1. Power-Supply Configurations
VCC (V)
+4.0 to +5.5
+3.1 to +4.5
+3.0 to +3.6
GND or floating
+3.0 to +5.5
VTRM (V)
+3.3 Output
+3.3 Output
+3.0 to +3.6 Input
Output
Output
VL (V)
+1.65 to +3.6
+1.65 to +3.6
+1.65 to +3.6
+1.65 to +3.6
GND or floating
CONFIGURATION
Normal mode
Battery supply
Voltage regulator supply
Sharing mode
Disable mode
NOTES
—
—
—
Table 2
Table 2
Table 2. Disable-Mode and Sharing-Mode Configurations
INPUTS/OUTPUTS
VCC/VTRM
VL
D+ and D-
VPI and VMI
RCV
SPEED, SUSP, OE, ENUM
*High Impedance or low.
**High or low.
DISABLE MODE
• +5V input/+3.3V output
• +3.3V input/+3.3V input
• +3.7V input/+3.3V output
Floating or connected to GND
High impedance
Invalid*
Invalid*
High impedance
SHARING MODE
• Floating or connected to GND
• < +3.6V (MAX3344E)
• < +1.0V (MAX3345E)
+1.65V to +3.6V input
High impedance
High impedance for OE = Low
High for OE = High
Undefined**
High impedance
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