SN8P2977
8-Bit Micro-Controller with Regulator, PGIA, 24-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 106
Version 1.7
13.4 PGIA -Programmable Gain Instrumentation Amplifier
SN8P2977 includes a low noise chopper-stabilized programmable gain instrumentation amplifier (PGIA) with selection
gains of 1x, 4x, 8x, 16x, 32x, 64x, 128x and 200x controlled by register AMPM1. The PGIA also provides two
multiplexers. One for positive input channel, the other one is for negative input channel. It was defined by register
AMPM1.
Channel Selection
+
-
PGIA Input channel Selection and Structure
X+
X-
Channel Selection
MUXP [2:0]
000: AI1
101:
110: Temp+
Gain Selection
x1 ~ x200
PGIA
ADC
001: AI2
010: AI3
011: AI4
100: AVE
111: Gnd
MUXN
AI1 000
AVE 100
Temp- 110
2/8*VDD 101
AI2 001
AI3 010
AI4 011
Gnd 111
MUXP
AI1 000
AVE 100
Temp+ 110
3/8*VDD 101
AI2 001
AI3 010
AI4 011
Gnd 111
MUXN [2:0]
000: AI1
101: VDD_DET-
110: Temp-
001: AI2
010: AI3
011: AI4
100: AVE
111: Gnd
PGIA Gain Selection
GS[2:0]
000: x1
001: x4
010: x8
011: x16
100: x32
(Buff Mode)
101: x64
110: x128
111: x200
PGIA Off
PGIA Off
13.4.1
CHS- Analog input signal channel selection Register
091H
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
Bit1
Bit0
CHS
-
MUXP2
MUXP1
MUXP0
-
MUXN2
MUXN1
MUXN0
R/W
-
R/W
R/W
R/W
-
R/W
R/W
R/W
After Reset
-
0
0
0
-
0
0
1
Bit[6:4]: MUXP[2:0]: PGIA Positive input channel selection.
Bit[2:0]: MUXN[2:0]: PGIA Negative input channel selection.
MUXP [2:0]
Positive channel
MUXN [2:0]
Negative channel
000
AI1
000
AI1
001
AI2
001
AI2
010
AI3
010
AI3
011
AI4
011
AI4
100
AVE
100
AVE
101
101
VDD_DET-
110
Temp
110
Temperature-
111
GND
111
GND