Power Supplies - Texas Instruments ADS7043EVM-PDK User Manual

Power Supplies

3 Power Supplies
The ADS7043 supports a wide range of operation on its analog supplies. The AVDD can operate from 1.8
V to 3.6 V. The DVDD operates from 1.65 V to 3.6 V, independent of the AVDD supply.
The analog portion of the ADS7043EVM-PDK operates from a 5-V supply. The ADS7043EVM-PDK is
configured to use the onboard regulated analog 5-V supply that in turn generates an AVDD analog supply
using the low-noise TPS79101 LDO. This supply is nominally set to 3.3 V at the factory, but this voltage
maybe changed to any value within the valid range, by modifying the value of R15 as per
any intermediate value needs to be set, the detailed formula to arrive at these values are available in the
TPS79101 (SGLS160) datasheet.
AVDD Voltage
1.8 V
2.0 V
2.5 V
3.0 V
3.3 V (default)
3.6 V
By default, the OPA316 amplifier supplies, VDD_OPA and VSS_OPA, are tied to AVDD (supplied from the
same LDO) and GND, respectively. DVDD_ADC is set at 3.3 V from the controller. These three supplies
may be externally supplied by making the modifications described in
Supply Supply Option
VDD_OPA Onboard
External
VSS_OPA Onboard
External
DVDD_ADC Onboard
External
The external AVDD supply applied to external connector P3 must not exceed
3.6 V as this may damage the device. The external AVDD supply must be in
the range of 1.8 V to 3.6 V for proper operation of the ADS7043EVM.
The digital portion of the ADS7043 ADC operates from a 3.3-V supply from the Simple Capture Card. The
buffer U12 is included to ensure that the SDO can be driven to the controller with minimal distortion.
4
ADS7043EVM-PDK
Table 3. AVDD Voltage Settings
R15
14.2 kΩ
19.1 kΩ
31.6 kΩ
43.7 kΩ
51.1 kΩ
59.0 kΩ
Table 4. Voltage Supply Options
Source
AVDD LDO (U5)
J7/pin1
GND
J7/pin3
3V3_SDCC supply from connector
J9/pin1
CAUTION
Copyright © 2014, Texas Instruments Incorporated
R19 C9
30.1 kΩ 33 pF
30.1 kΩ 27 pF
30.1 kΩ 22 pF
30.1 kΩ 15 pF
30.1 kΩ 15 pF
30.1 kΩ 15 pF
Table 4.
Component
R47
R47
R48
R48
R49
R49
Submit Documentation Feedback
www.ti.com
Table 3. In case
Setting
Assembled
Disassembled
Assembled
Disassembled
Assembled
Disassembled
SBAU241 – November 2014