BC41B143A-DS-002PD Datasheet, PDF (57/89 Pages) List of Unclassifed Manufacturers – BlueCore 4-ROM CSP EDR Single Chip Bluetooth v2.0 + EDR System

Device Terminal Descriptions
This formula shows the negative resistance of the BlueCore4-ROM CSP driver as a function of its drive strength.
The value of the driver negative resistance can be easily measured by placing an additional resistance in series
with the crystal. The maximum value of this resistor (oscillation occurs) is the equivalent negative resistance of
the oscillator.
11.3.6 Crystal PS Key Settings
See tables in Section 11.2.5.
11.3.7 Crystal Oscillator Characteristics
1000.0
Crystal Load Capacitance and Series Resistance Limits with Crystal Frequency
100.0
10.0
2.5
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10.5
11.5
12.5
Load Capacitance (pF)
8 MHz
20 MHz
32 MHz
12 MHz
24 MHz
16 MHz
28 MHz
Figure 11.7: Crystal Load Capacitance and Series Resistance Limits with Crystal Frequency
Figure 11.7 shows results for BlueCore4-ROM CSP crystal driver at maximum drive level.
Conditions:
C_trim = 3.4pF centre value
Crystal C_o = 2pF
Transconductance setting = 2mA/V
Loop gain = 3
C_t1/C_t2 = 3
BC41B143A-ds-002Pd
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Production Information
© Cambridge Silicon Radio Limited 2005
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