Evm Power Supply Jumper Description; Evm Power Supply Options - Texas Instruments ADS62P EVM Series User Manual

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EVM Banana Jack
J10
JP16
JP19
JP17
EVM
Evaluation Goal
Option
Evaluate ADC performance using
a cascaded switching power
1
supply (TPS5420D) and LDO
solution (TPS79501DCQ)
Evaluate ADC performance using
2
a LDO based solution
Evaluate ADC performance using
an isolated ADC AVDD and
3
DVDD for current consumption
measurements
2.2.2.1 Power Supply Option 1
Option 1 supplies the power to the ADC using cascaded topology of the TPS5420D switching power
regulator and the TPS79501DCQ Low Drop-Out regulator. The TPS5420 is a step-down converter which
works with the input voltage in the range 6V to 36V. The switching supply increases efficiency for higher
input voltages but does create noise on the voltage supplies. To reduce the noise, an ultra-low-noise,
high-PSSR LDO TPS79501DCQ is used to clean the power supply. The TPS5420D is designed for 5.3V
output, which acts as a supply for the TPS79501. The TPS79501 is designed to output 5V, which is the
AVDD for the ADC. This voltage rail is input to the LDO TPS79633, which outputs 3.3V, used for DVDD
for the ADC. A separate TPS79633 is designed to output 3.3V for the CDCE72010 supply rail. This
solution adds two features to the EVM: one is to increase the range of the power supply on jumper J10
from 6V to 36V, allowing the user to choose any power supply source in the specified range without
causing significant power dissipation. The other feature is that the output-voltage rail has a much lower
ripple, allowing better performance of the part even when the power source is fluctuating.
2.2.2.2 Power Supply Option 2
Option 2 supplies power to the ADC using the LDOs TPS79633DCQ and TPS79601DCQ. The LDOs take
a maximum input of 5.5V. When using this option, take care powering up the EVM, because higher
voltage or reverse polarity can damage it. This is the default power-supply configuration for the
ADS62PXXEVM.
SLAU237A – May 2008 – Revised April 2009
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Table 2. EVM Power Supply Jumper Description
Description
Input
TPS79501 INPUT SELECT
5V_AUX
TPS5420 INPUT SELECT
Table 3. EVM Power Supply Options
Jumper Changes Required
JP16 → 1-2
JP19 → 2-3
JP17 → 1-2
JP15 → 1-2
JP18 → 1-2
JP16 → 1-2
JP19 → 1-2
JP17→ No Shunt
JP15 → 1-2
JP18 → 1-2
JP16 → No Shunt; JP19 → No
Shunt
JP17 → No Shunt
JP15 → Connect 3.3V to pin 2 of
jumper
JP18 → Connect 1.8V to pin 2 of
jumper
Jumper
Setting 6V to 36V power supply
default-apply just 5V
1-2 → Connects 5.3V to input of TPS79501
2-3 → TPS79501 Input connected to J10
2-3 → TPS79501 output as 5V_AUX rails
1-2 → 5V_AUX rail connected to J10
Shunt → J10 connected to TPS5420D
Voltage on J10
6V - 36V
5.1V - 5.5V
Do not apply power
on J10
ADS62PXXEVM
Circuit Description
Comments
Maximum
performance and
efficiency
Maximum
Performance
Isolated power supply
for current
consumption
measurements
11