U2270B_08 Datasheet, PDF (12/18 Pages) ATMEL Corporation – Read/Write Base Station

4.2 Application 2
Basic application using diode feedback. This application allows higher communication distances
than .“Application 1”
Figure 4-2. Application Circuit 2
BC639
4×
1N4148
75 kΩ
68 kΩ
4.7 nF
+
22 µF
100 kΩ
43 kΩ
1.2 nF
1.35 mH 82Ω
Antenna
1N4148
470 kΩ
1.5 nF
C_IN
C_HP
V_S V_EXT DV_S V_Batt
RF
MS
COIL2
CFE
U2270B
COIL1
Standby
Input
Output
HIPASS
OE
DGND GND
360Ω
+
22 µF
+
22 µF
V_DD
12V
GND
Micro-
controller
I/O
V_SS
12 U2270B
4684E–RFID–02/08