Evm Power Supply Options - Texas Instruments ADS5400EVM-CVAL User Manual

Circuit Description
EVM Banana Jack
PWR
5 to 36 V
EVM Option
1
2
(Default)
3
2.2.1.1 Power Supply Option 1
Option 1 supplies the power to the ADC using cascaded topology of the TPS5420D and the
TPS79501DCQ. The TPS5420 is a step-down converter which works with the input voltage in the range of
6 V to 36 V. The switching supply increases efficiency for higher input voltages but does create noise on
the voltage supplies. To reduce the noise, an ultralow-noise, high-PSSR LDO TPS79501DCQ is used to
clean the power supply. The TPS5420D is designed for output of 5.3 V, which acts as input for TPS79501.
The TPS79501 is designed to output a 5-V output, which is the AVDD for the ADC. This voltage rail is
8
ADS5400EVM-CVAL
Downloaded from Elcodis.com electronic components distributor
Table 2. EVM Power Supply Jumper Description (continued)
Description
JP17 TS5420 INPUT SELECT
U7
JP17
open TPS5420D
J5
Switching
Regulator to
3.5 V
J6
GND
Figure 2. ADS5400EVM-CVAL Distribution
Table 3. EVM Power Supply Options
Evaluation Goal Jumper Changes Required
Evaluate ADC JP12 → 1-2; JP13 → 1-2; JP14 → 1-2;
performance using JP15 → 1-2; JP16 → 1-2; JP17 → 1-2;
a cascaded
switching power
supply
(TPS5420D) and
LDO solution
(TPS79501DCQ)
Evaluate ADC JP12 → 1-2; JP13 → 1-2; JP14 → 1-2;
performance using JP15 → 1-2; JP16 → 2-3, JP17 → No
a LDO-based shunt;
solution.
Evaluate ADC JP12 → connect 3.3V to pin 2 of
performance using Jumper; JP13 →connect 3.3V to pin 2 of on J5.
an isolated ADC Jumper; JP14 → connect 5 V to pin 2 of
AVDD and DVDD Jumper and ground to J6; JP15 →No
for current shunt ; JP16 →No shunt ; JP17 → No
consumption shunt;
measurements
Copyright © 2012, Texas Instruments Incorporated
Shunt → J5 connected to TPS5420D
5 V
TPS79633
LDO 3.3V
U8
1
TPS79501
LDO
1
Regulator to
5 V
1
TPS79633
LDO 3.3V
Jumper setting
U5
Analog
1
3.3V VDD
L6
To ADC
Digital
1
3.3V VDD
L9
To ADC
Analog
1
5V VDD
L11
U14 To ADC
To USB
Port
To USB
Port
Voltage on J5
6 V to 36 V Isolates input voltage from
the requirement for a clean
analog supply input
5 V to 5.5 V Requires clean input supply
as this connects to
ADS5400 5-V analog supply
input
Do not apply power Separates power inputs for
analog and digital for
individual current
consumption measurements
SLAU471 – December 2012
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