EVM Power Supply Inputs
4
EVM Power Supply Inputs
J3 is the power-supply input connector.
lists the configuration details for J3.
Table 4. J3: Power-Supply Interface Header
Pin Number
Pin Name
Function
Required
J3.3
+5VA
5-V analog supply
Yes
J3.5
GND
Digital ground input
Yes
J3.6
GND
Analog ground input
Yes
J3.7
1.8 VD
1.8-V digital supply
Optional
J3.9
3.3 VD
3.3-V digital supply
Yes
J3.10
5 VD
5-V digital supply
No
P3.1-2, P3.4, and P3.7-
Unused
Unused
No
8
4.1
Analog Power Options
The ADS8881EVM board is designed to work with a 5-V analog power supply connected to J3.3. The
ADS8881 is limited to 3.6 V as analog supply, so the board regulates down the 5-V analog supply with an
on-board 3.3-V LDO (TPS78833).
4.2
Digital Power Options
The ADS8881EVM connects the digital power supply of the ADS8881 to 3.3 VD (J3.10) with a 0-
Ω
resistor. This matches the logic level of the MMB0 motherboard.
4.3
Analog and Digital Grounds
The EVM only has one ground plane for analog and digital supplies, so pins J3.5 and J3.6 are tied
together to this ground plane. Therefore, both supply grounds should be connected to pins J3.5–6 so they
share the same ground.
7
SBAU211 – June 2013
ADS8881EVM-PDK
Copyright © 2013, Texas Instruments Incorporated
