Cirrus Logic CS61880 - Manual (Page 52)

CS61880
52 DS450PP3
18.1 Transformer Specifications
Recommended transformer specifications are
shown in
Table 15 . Any transformer used with the
CS61880 should meet or exceed these specifica-
tions.
18.2 Crystal Oscillator Specifications
When a reference clock signal is not available, a
CMOS crystal oscillator may be used as the refer-
ence clock signal. The oscillator must have a mini-
mum symmetry of 40-60% and minimum stability
of + 100 ppm.
18.3 Line Protection
Secondary protection components can be added to
the line interface circuitry to provide lightning
surge and AC power-cross immunity. For addition-
al information on the different electrical safety
standards and specific applications circuit recom-
mendations, refer to Application Note AN034, Sec-
ondary Line Protection for T1 and E1 Cards.
Table 15. Transformer Specifications
Descriptions Specifications
Turns Ratio Receive 1:2
Turns Ratio Transmit 1:1.15
Primary Inductance 1.5 mH min @ 1024 kHz
Primary Leakage Induc-
tance 0.3
µ
H max @ 1024 kHz
Secondary leakage Induc-
tance 0.4
µ
H max @ 1024 kHz
Inter winding Capacitance 18 pF max, primary to
secondary
ET-Constant 16 V -
µ
s min