Texas Instruments TPS3809, Руководство пользователя

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EVM Setup
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8 SPRUI96 – October 2016
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Copyright © 2016, Texas Instruments Incorporated
TPS3813xxxQ1EVM for Processor Voltage Supervisor With Window-
Watchdog User’s Guide
3.1 Recommended Test Equipment
The following is the recommended test equipment:
• Two-channel storage oscilloscope
• Current probe
• Voltage probe
• Adjustable DC power supply with at least 2.5-V to 6.5-V output and 10-A current limit
• Digital Multimeter or Volt-Ohmmeter
• A passive or active load capable of handling up to 3 A
3.2 Measuring Delay Time and Rise/Fall Time
An internal clock delays the return of the output to the inactive (high) state to ensure proper system reset.
The delay time, t
d
= 25 ms typical, begins after the VDD1 voltage rises above the threshold voltage (V
IT
)
as specified in the TPS3813-Q1 datasheet. To perform this test, the user must set the jumpers according
to Jumper Settings,
Table 5 . A stable 5-V DC supply must also be readily available.
Table 5. Jumper Settings
Jumper Setting
J1 to J5 VDD1
J2 to J6 VDD1
J3 to J7 VDD1
J4 to J8 OFF
The jumper settings previously described will pull the WDT and WDR pin up to VDD, setting the Watchdog
window to a default with window frame minimum of 15.6 ms and maximum of 3000 ms.
Figure 9 through
Figure 14 display the delay time as well for the rise and fall time of the RESETN pin when the VDD
voltage falls above or below the negative going threshold voltage as outlined in the EVM Electrical
Characteristics,
Table 4 .
Figure 9. Delay Time TPS3813K33-Q1 Figure 10. Delay Time TPS3813I50-Q1