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1
2
3
4
5
6
JP4
1
2
3
4
5
6
7
8
9
10
Pin #
Signal
+VA
-VA
+5VA
-5VA
DGND
AGND
+1.8VD
VD1
+3.3VD
+5VD
MMB0 Signals
1
2
3
4
5
6
7
8
9
1
0
J5
DAUGHTER-POWER
+5V
GND
-5V
+3.3V
(Bottom Connects to MMB0)
Top and Bottom Side
AVDD
AVSS
DVDD
+3.3V
Power Measurement
TPS72325DBVT
-2.5V
IN
2
EN
3
OUT
5
BYP
4
GND
1
U3
TPS79225DBVT
+2.5V
IN
1
EN
3
OUT
5
BYP
4
GND
2
U2
GND
GND
+5V
GND
-5V
GND
+5V
GND
GND
GND
AVDD
AVSS
DVDD
AVDD
AVSS
Positive Supply
Negative Supply
(-5V Supply must be supplied by user)
10uF
C29
10uF
C30
10uF
C31
1uF
C27
1uF
C32
100nF
C28
1
6
3
2
5
4
Pos 1
Pos 2
S2
CAS-220TB
Switch
Supply Polarity
AVDD
AVSS
DVDD
1
2
D1
DDZ6V2B-7
100nF
C33
GND
GND
GND1
GND2
-5V Input
or EXT Supply Jumpers
ADS126xEVM Hardware
2.3
Power Supply
The ADS126x operates either from a single 5-V supply or from bipolar ±2.5V supplies. By default, the
MMB0 and ADS126xEVM are configured for single 5-V supply operation using the included 6-V wall-
adapter power supply. An additional –5-V supply voltage is required when using the ADS126xEVM with
bipolar supplies. Configuring the EVM and MMB0 for each of these cases is demonstrated in
and
.
The ADS126xEVM is powered by the MMB0 motherboard, through the J5 header. The MMB0 is powered
through the 6-V wall adapter connected to J2. The MMB0 does not use USB power. Additional supplies
can be connected to the MMB0 through the J14 header.
shows the relevant power supply
circuitry on the ADS126xEVM.
Figure 4. Power Supply Circuitry Schematic
The JP4 jumpers are required to power the ADS126x. Removing these jumpers allows for an external
power supply connection or an ammeter connection to monitor the supply currents. Mini-clip test points
may also be used to connect to the ADS126xEVM supplies.
shows the JP4 jumpers, switch S2,
and the power-supply test points.
Figure 5. Power-Supply Circuitry (Default Jumper Settings)
7
SBAU206 – April 2015
ADS126xEVM-PDK
Copyright © 2015, Texas Instruments Incorporated