BC41B143A-DS-001PE Datasheet, PDF (51/102 Pages) List of Unclassifed Manufacturers – BlueCpre 4-ROM Single Chip Bluetooth v2.0 System with EDR

Device Terminal Descriptions
10 Device Terminal Descriptions
10.1 RF Ports
The BlueCore4-ROM RF_IN terminal can be configured as either a single ended or differential input. The
operational mode is determined by the setting the PS Key PSKEY_TXRX_PIO_CONTROL (0x20).
10.1.1 TX_A and TX_B
TX_A and TX_B form a complementary balanced pair. On transmit; their outputs are combined using a balun into
the single-ended output required for the antenna. Similarly, on receive their input signals are combined internally.
Both terminals present similar complex impedances that require matching networks between them and the balun.
Starting from the substrate (chip side), the outputs can each be modelled as an ideal current source in parallel
with a lossy resistance and a capacitor. The bond wire can be represented as series inductance.
BlueCore4-ROM
_
L2
1.5nH
PA
TX_A
+
RF
Switch
R2
10
0.9pF
+
LNA
_
RF
Switch
R3
10
0.9pF
L3
1.5nH
TX_B
Figure 10.1: Circuit TX/RX_A and TX/RX_B
BC41B143A-ds-001Pe
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© Cambridge Silicon Radio Limited 2005
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