XE8000EV101 Semtech, XE8000EV101 Datasheet - Page 94

• Manufacturer Part Number: XE8000EV101
• Description: EVAL BOARD FOR XE8801AMI027LF
• Manufacturer: Semtech
• Type: MCUr

Specifications of XE8000EV101

• Contents: Fully Assembled Evaluation Board
• For Use With/related Products: XE88LC01AMI027
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

16.6
As seen in Figure 16-1, the zooming function is implemented with three programmable gain amplifiers (PGA). These
are:
•
•
•
All gain and offset settings are realized with ratios of capacitors. The user has control over each PGA activation and
gain, as well as the offset of stages 2 and 3. These functions are examined hereafter.
© Semtech 2005
PGA1: coarse gain tuning
PGA2: medium gain and offset tuning
PGA3: fine gain and offset tuning
Programmable Gain Amplifiers
PGA2_OFFSET[3:0]
PGA2_GAIN[1:0]
ENABLE[3:0]
PGA1_GAIN
Table 16-13 ADC & PGA enabling
Table 16-16 PGA2 offset settings
Table 16-14 PGA1 Gain Settings
0000
0001
0010
0011
0100
0101
1001
1010
1011
1100
1101
xxx0
xxx1
xx0x
xx1x
x0xx
x1xx
0xxx
1xxx
Table 16-15 PGA2 gain settings
00
01
10
11
0
1
16-9
PGA1 disabled
PGA2 disabled
PGA3 disabled
PGA1 enabled
PGA2 enabled
PGA3 enabled
ADC disabled
ADC enabled
PGA2 Offset
GDoff
PGA1 Gain
PGA2 Gain
GD
GD
Block
+0.2
+0.4
+0.6
+0.8
-0.2
-0.4
-0.6
-0.8
1
2
10
10
+1
-1
1
1
2
5
0
(V/V)
(V/V)
2
(V/V)
XE8801A – SX8801R
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