Datasheet

PGA870
SBOS436A –DECEMBER 2009–REVISED FEBRUARY 2011 www.ti.com
Table 2. PGA870 Gain and Corresponding Gain Word Values
Gain Gain
State Gain (MSB) (LSB) State Gain (MSB) (LSB)
NG (dB) B5 B4 B3 B2 B1 B0 NG (dB) B5 B4 B3 B2 B1 B0
63 20 1 1 1 1 1 1 31 4 0 1 1 1 1 1
62 19.5 1 1 1 1 1 0 30 3.5 0 1 1 1 1 0
61 19 1 1 1 1 0 1 29 3 0 1 1 1 0 1
60 18.5 1 1 1 1 0 0 28 2.5 0 1 1 1 0 0
59 18 1 1 1 0 1 1 27 2 0 1 1 0 1 1
58 17.5 1 1 1 0 1 0 26 1.5 0 1 1 0 1 0
57 17 1 1 1 0 0 1 25 1 0 1 1 0 0 1
56 16.5 1 1 1 0 0 0 24 0.5 0 1 1 0 0 0
55 16 1 1 0 1 1 1 23 0 0 1 0 1 1 1
54 15.5 1 1 0 1 1 0 22 -0.5 0 1 0 1 1 0
53 15 1 1 0 1 0 1 21 -1 0 1 0 1 0 1
52 14.5 1 1 0 1 0 0 20 -1.5 0 1 0 1 0 0
51 14 1 1 0 0 1 1 19 -2 0 1 0 0 1 1
50 13.5 1 1 0 0 1 0 18 -2.5 0 1 0 0 1 0
49 13 1 1 0 0 0 1 17 -3 0 1 0 0 0 1
48 12.5 1 1 0 0 0 0 16 -3.5 0 1 0 0 0 0
47 12 1 0 1 1 1 1 15 -4 0 0 1 1 1 1
46 11.5 1 0 1 1 1 0 14 -4.5 0 0 1 1 1 0
45 11 1 0 1 1 0 1 13 -5 0 0 1 1 0 1
44 10.5 1 0 1 1 0 0 12 -5.5 0 0 1 1 0 0
43 10 1 0 1 0 1 1 11 -6 0 0 1 0 1 1
42 9.5 1 0 1 0 1 0 10 -6.5 0 0 1 0 1 0
41 9 1 0 1 0 0 1 9 -7 0 0 1 0 0 1
40 8.5 1 0 1 0 0 0 8 -7.5 0 0 1 0 0 0
39 8 1 0 0 1 1 1 7 -8 0 0 0 1 1 1
38 7.5 1 0 0 1 1 0 6 -8.5 0 0 0 1 1 0
37 7 1 0 0 1 0 1 5 -9 0 0 0 1 0 1
36 6.5 1 0 0 1 0 0 4 -9.5 0 0 0 1 0 0
35 6 1 0 0 0 1 1 3 -10 0 0 0 0 1 1
34 5.5 1 0 0 0 1 0 2 -10.5 0 0 0 0 1 0
33 5 1 0 0 0 0 1 1 -11 0 0 0 0 0 1
32 4.5 1 0 0 0 0 0 0 -11.5 0 0 0 0 0 0
Table 3. Gain Control Signals and Latch Modes
Latch Mode GAIN STROBE LATCH MODE CONDITION
Device gain follows and latches gain control word (B0
Edge-triggered latch Falling edge Low
to B5) only on GAIN STROBE falling edge.
Device gain follows gain control word (B0 to B5) when
Level-triggered latch Low High GAIN STROBE and LATCH MODE are both high.
Device gain latches when GAIN STROBE goes low.
Device gain is level-triggered on the gain-control word
No latch High High (B0 to B5) when LATCH MODE is high and GAIN
STROBE remains high.
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