tda8757hl NXP Semiconductors, tda8757hl Datasheet - Page 18

• Manufacturer Part Number: tda8757hl
• Description: Triple 8-bit Adc 170 Msps
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 09457
Preliminary data
9.1.3 Coarse and Fine registers
Table 5:
The default programmed value is:
These two registers enable the gain control: the AGC gain with the coarse register,
and the reference voltage with the fine register. The coarse register programming
equation is as follows:
Where: V
The gain correspondence is given in
programming code (N
Table 6:
The default programmed value is as follows:
GAIN
Programmed code
0
1
2
...
127
...
254
255
256
...
287
N
32
99
•
•
•
•
•
•
COARSE
Programmed code = 127
Clamp code = 0
ADC output = 0.
N
Gain = 0.825
V
i
COARSE
to be full-scale = 1.212.
=
ref
Coding
Typical gain correspondence (COARSE)
----------------------------------------------- -
V
= 2.5 V.
= 32
ref
N
COARSE
Rev. 07 — 28 February 2002
1
–
----------------- -
32 16
N
FINE
+
FINE
1
= 0).
Clamp code
...
0
...
63.5
64
120
...
136
Gain
0.825
2.5
63.5
63
62.5
----- -
16
1
=
Table
----------------------------------------------- -
V
ref
N
6. The gain is linear with reference to the
. 512 N
COARSE
–
+
FINE
1
© Koninklijke Philips Electronics N.V. 2002. All rights reserved.
ADC output
0
...
63 or 64
64
120
...
136
V
1.212
0.4
Triple 8-bit ADC 170 Msps
i
to be full-scale (V)
32
TDA8757
underflow
18 of 37
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