Rainbow Electronics DS2188 - Manual (Page 6)

DS2188
021997 6/11
CRYSTAL REQUIREMENTS
The DS2188 must have a crystal connected to the
XTAL1 and XTAL2 pins. For T1 environments, the fre-
quency of this crystal should be 6.176 MHz. For CEPT
environments, the frequency of this crystal should be
8.192 MHz. Table 2 lists some suggested crystal man-
ufacturers that are recommended for use with the
DS2188. Also, see DS2188 Application Note, “Opera-
tion at Speeds Greater than E1” for additional informa-
tion.
CRYSTAL MANUFACTURERS Table 2
MANUFACTURER PART # FREQUENCY
JAN Crystal 6323–00, JC6A14
6323–00, JC8A14 6.176 MHz
8.192 MHz
M–TRON 4575–001
4575–002 6.176 MHz
8.192 MHz
CRYSTAL SELECTION GUIDELINES FOR THE DS2188
PARAMETER SPECIFICATION
Parallel resonant frequency 6.176 MHz (T1) or 8.192 MHz (CEPT)
Mode Fundamental
Load capacitance 14 to 20 pF (16 pF preferred)
Tolerance ± 50 ppm over 0 to 70 ° C
Pullability CL = 10 pF, delta_f = +175 to +250 ppm
CL = 45 pF, delta_f = –175 to –250 ppm
Effective series resistance 40 ohms maximum for 6.176 MHz
30 ohms maximum for 8.192 MHz
Crystal cut AT