Nortel Circuit Card Installation Manual page 716

Page 716 of 906
Digital pad
553-3001-211 Standard 3.00
NTAK09 1.5 Mb DTI/PRI card
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 231.
Table 231
Digital pad values and offset allocations
Offset
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
August 2005
PAD set 0
0dB
2dB
3dB
4dB
5dB
6.1dB
8dB
–1dB
–3dB
–4dB
idle code, 7F
unassigned code, FF
1dB
–2dB
–5db
–6db
PAD set 1
–7db
–8db
–9db
–10db
0.6db
7db
9db
10db
11db
12db
3db
14db
spare
spare
spare
spare