TL16C754 Datasheet, PDF (16/39 Pages) Texas Instruments – QUAD UART WITH 64-BYTE FIFO

TL16C754
QUAD UART WITH 64-BYTE FIFO
SLLS279A – OCTOBER 1998 – REVISED OCTOBER 1999
programmable baud generator (continued)
Figure 10 and Figure 11 shows the crystal clock circuit reference.
External
Clock
Driver
XTAL1
Optional
Clock
Output
Optional
Driver
XTAL2
VCC
C1
RP
Oscillator Clock
to Baud Generator
Logic
C2
XTAL1
Crystal
RX2
XTAL2
VCC
Oscillator Clock
to Baud Generator
Logic
CRYSTAL
3.072 MHz
1.8432 MHz
TYPICAL CRYSTAL OSCILLATOR NETWORK
RP
1 MΩ
RX2
15 kΩ
C1
10 – 30 pF
1 MΩ
15 kΩ
10 – 30 pF
C2
40 – 60 pF
40 – 60 pF
† _{For crystal with fundamental frequency from 1 MHz to 24 MHz}
Figure 10. Typical Crystal Clock Circuits^†
Oscillator
Cell
XTAL1
Crystal
C1
XTAL2
R1
L1
1000 pF
L2
C2
FREQUENCY
C1
C2
L1
L2
R1
(MHz)
(pF)
(pF)
(µH)
(µH)
(kΩ)
25
5
15
3.9
15
18
30
6
15
2.7
10
18
35
6
15
3.3
8.2
18
‡ _{For crystal with third-overtune frequency between 24 MHz and maximum clock speed specified in recommended operating conditions.}
Recommend to use a series-mode crystal with series resistance no larger than 40 Ω.
Figure 11. Typical Third-Overtune Crystal Clock Circuits^‡
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