4
USB
Signal
Description
D-
Input/Output with 22 Ohm series termination resistor; USB D- differential data signal.
D+
Input/Output with 22 Ohm series termination resistor; USB D+ differential data signal. A USB speed indication
resistor (menu selectable based on terminal ID) is also incorporated.
DC Characteristics
Operating Voltage (T=23°C)
Parameter
Min
Typ
Max
VIN
3.2
5.0
5.5
Operating Current (VIN=3.3V, T=23°C)
Parameter
Typ
Unit
Max Working Current
450
mA
Average Working Current
330
mA
Idle Current
75
mA
Deep Sleep Current
900
uA
DC Operating (VDD=3.3V, VSS=0V, T=23°C)
Parameter
Min
Typ
Max
Unit
VIL
VSS-0.1
-
VDD*0.2
V
VIH
VDD*0.8
-
VDD+0.1
V
VOL
VSS
-
VSS+0.3
V
VOH
VDD-0.3
-
VDD
V
Interface Circuit
EM2037 supports two kinds of interfaces, i.e. TTL Level 232 and USB. Users can select either one as per need.
TTL Level 232
This is the illustration of interface circuit based on TTL Level 232.
