Microchip Technology MCP6S22 PGA PICtail, Руководство пользователя

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2004 Microchip Technology Inc. DS51327B-page 9
1.3 HOW IT IS USED
1.3.1 Application Procedure - Stand-Alone Mode
1. Apply a 2.5V to 5.5V supply voltage to the V
DD
and ground (GND) terminals of
J1. Place the V
DD
SELECT jumper (JP2) at the bottom (nearest J1).
For additional information on powering-up the MCP6S2X Evaluation Board (Rev.
4), refer to
Section 1.4.2 “Applying Power” . During power-up, the MCP6S2X
PGA's default settings are Channel 0 (CH0) and gain = 1 V/V.
2. Connect a voltage-measuring device (such as an oscilloscope) to V
OUT_1
for the
MCP6S26 and/or V
OUT_2
for the MCP6S21.
3. Select the desired reference voltage using JP1. If the adjustable reference
voltage is selected, adjust this voltage using the potentiometer (ADJ_V
REF
). A
test point is available to measure the reference voltage.
Refer to
Section 1.4.5 “Reference Voltage” for additional information.
4. Apply the input signal source at V
IN_0
and/or V
IN_1
. V
IN_0
is connected to
Channel 0 and V
IN_1
is connected to Channel 1 of the MCP6S26 (refer to
Section 1.4.4 “Analog Interface” ). Make sure that the input signal range is at
the proper level to avoid railing the amplifier output when the signal is gained.
Refer to
Section 1.4.5 “Reference Voltage” for additional information.
5. Refer to the Table 1-1 and select the desired gain, channel or shutdown using the
on-board DIP switch. Press and release the
READ push button switch to pro-
gram the PGA and notice the change in the output voltage. Refer to
Section 1.4.6 “Programming The PGA” for further explanation.
TABLE 1-1: DIP SWITCH CONFIGURATION TABLE
Note: If jumper JP2 is incorrectly placed, there may be a conflict between power
supplies.
Note:
Do
NOT
use the ICSP connector while in this mode (disconnect the cable).
The results may be unpredictable and damage might occur due to
conflicting voltage sources.
Note: There are soldering pads available across each input terminal for termina-
tion resistors (R
4
and R
5
). If these resistors (e.g., 50
Ω
) are needed for your
application, solder them across the pads.
Register
MCP6S26
MSB
→
LSB
MCP6S21
MSB
→
LSB
Gain 1
00000 01000
Gain 2
00001 01001
Gain 4
00010 01010
Gain 5
00011 01011
Gain 8
00100 01100
Gain 10
00101 01101
Gain 16
00110 01110
Gain 32
00111 01111
Channel 0
10000
—
Channel 1
10001
—
Channel 2
10010
—
Channel 3
10011
—
Channel 4
10100
—
Channel 5
10101
—
SHDN
11000
—
SHDN —
11001
SHDN
11010 11010