Nortel Networks 553-3001-211 manual Digital pad

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Digital pad

The digital pad is an EPROM whose address-input to data-output transfer function meets the characteristics of a digital attenuator. The digital pad accommodates both µ255-law and A-Law coding. There are 32 combinations

each for µ255 to µ255, µ255 to A-Law, A-Law to µ255, and A-Law to A-Law. These values are selected to meet the EIA loss and level plan. See Table 226.

Table 226

Digital pad values and offset allocations

Offset	PAD set 0	PAD set 1
0	0dB	–7db
1	2dB	–8db
2	3dB	–9db
3	4dB	–10db
4	5dB	0.6db
5	6.1dB	7db
6	8dB	9db
7	–1dB	10db
8	–3dB	11db
9	–4dB	12db
A	idle code, 7F	3db
B	unassigned code, FF	14db
C	1dB	spare
D	–2dB	spare
E	–5db	spare
F	–6db	spare

553-3001-211 Standard 2.00 September 2004