User's Manual

<ACR122T> <Feasibility Study>
Version <1.00> <31/03/2009>
Page
6
of
10
<
ACR122
T
>
3.0. Hardware Interfaces
3.1. USB Interface
The ACR122T is connected to a Host through the USB as specified in the USB Specification 1.1. The
ACR122T is working in Full speed mode, i.e. 12Mbps.
Pin Signal Function
1 VCC
+5V power supply for the reader (Max 200mA, Normal 100mA)
2 D-
Differential signal transmits data between Host and ACR122T
3 D+
Differential signal transmits data between Host and ACR122T
4 GND
Reference voltage level for power supply
3.2. Bi-Color LED
•
User-controllable Bi-Color LED. Red and Green Color.
3.3. Built-in Antenna
• 6 turns symmetric loop antenna.
•
The estimated size = 19mm x 19mm.
• The loop inductance should be around ~ 1.6uH to 2.5uH
• Operating Distance for different Tags ~ up to 10mm (depend on the Tag)
• No anti-collision. Only one Tag can be accessed at any one time.