Document No.: FT_000288
FT232H SINGLE CHANNEL HI-SPEED USB TO MULTIPURPOSE UART/FIFO IC
Datasheet Version 1.8
Clearance No.: FTDI #199
6.3 Oscillator Configuration
Figure 6.4 Recommended FT232H Oscillator Configuration
Figure 6.4 illustrates how to connect the FT232H with a 12MHz ± 0.003% crystal. In this case loading
capacitors should to be added between OSCI, OSCO and GND as shown. A value of 27pF is shown as the
capacitor in the example – this will be good for many crystals but it is recommended to select the loading
capacitor value based on the manufacturer’s recommendations wherever possible. It is recommended to
use a fundamental mode, parallel cut type crystal.
It is also possible to use a 12 MHz Oscillator with the FT232H. In this case the output of the oscillator
would drive OSCI, and OSCO should be left unconnected. The oscillator must have a CMOS output drive
capability.
Parameter
Description
Minimum
Typical
Maximum
Units
Conditions
OSCI Vin
Input Voltage
Input Frequency
Cycle to cycle jitter
2.97
3.3V
12MHz
<150
3.63
V
Fin
Ji
MHz
pS
± 30ppm
Table 6.1 OSCI Input characteristics
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