Power Supply; Power Supply Circuitry Schematic; Power-Supply Circuitry (Default Jumper Settings) - Texas Instruments ADS126 EVM-PDK Series User Manual

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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 Section 2.3.2.
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.
circuitry on the ADS126xEVM.
+5V
GND
+5V
1
3
C27
1uF
GND
-5V
2
C32 3
1uF
GND
(-5V Supply must be supplied by user)
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.
and the power-supply test points.
SBAU206 – April 2015
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Supply Polarity
Switch
S2
6
Pos 2
3
4
Pos 1
1
CAS-220TB
U2 +2.5V
5
IN OUT
4
BYP
2
EN GND C28
100nF
TPS79225DBVT
GND
U3 -2.5V
5
IN OUT
4
BYP
1
EN GND C33
100nF
TPS72325DBVT
GND
-5V Input
Top and Bottom Side
(Bottom Connects to MMB0)
Figure 4. Power Supply Circuitry Schematic
Figure 5. Power-Supply Circuitry (Default Jumper Settings)
Copyright © 2015, Texas Instruments Incorporated
Figure 4 shows the relevant power supply
AVDD
AVDD
5
1 2
Positive Supply
3 4
2
Negative Supply 5 6
+3.3V JP4
Power Measurement
or EXT Supply Jumpers
AVDD
C29
10uF
GND1 GND2
GND
GND GND
+5V MMB0 Signals
+3.3V
Signal Pin #
+VA 1
-5V
-VA 2
+5VA 3
-5VA 4
DGND 5
AGND 6
+1.8VD 7
VD1 8
+3.3VD 9
J5 DAUGHTER-POWER +5VD 10
Figure 5
ADS126xEVM Hardware
Section 2.3.1
AVSS DVDD
AVSS
DVDD
AVSS DVDD AVDD
D1
C30 C31
DDZ6V2B-7
10uF 10uF
AVSS
GND GND
shows the JP4 jumpers, switch S2,
ADS126xEVM-PDK
7