PCA1070 datasheet(26/36 Pages) PHILIPS

26 / 36 page

1997 Jun 20

Philips Semiconductors

Product speciﬁcation

Multistandard programmable analog

CMOS transmission IC

PCA1070

23. The internal balance impedance Zoss to match the external load impedance at pin LN (Zline =Zoss) for optimum

sidetone suppression; Zoss =Rsa +(Rsb // Cs); without clock the sidetone balance impedance is automatically set to

Zoss = 600 Ω (typical).

24. Other values can be found in Tables 14, 15 and 16.

25. Value Cs = 5 nF can also be programmed.

26. Gain sending channel GM = default (typical 41 dB); gain receiving channel Grec = default (typical −6 dB); sidetone

gain GSTS minimum sidetone suppression at f = 300 Hz and 3400 Hz is: GM +GR − Gst(max) =41 − 6 − 15=20dB.

GSTA, the sidetone gain for asymmetrical drive equals GSTS −6 (in dB).

27. Indication only; exact values can be found in Table 16.

28. Standard I2C-bus specifications are valid for VDD ≥ 2.5 V. Relaxed specifications for VDD = 1.8 to 2.5 V.

29. Recommended accuracy of input frequency; a higher tolerance will cause parameters to deviate from their specified

values; note that all parameters are specified with the reference input clock frequency fclk = 3.579545 MHz.

PCA1070 Datasheet(PDF) 26 Page - NXP Semiconductors