Texas Instruments bq24295EVM-549, Руководство пользователя

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Test Summary
2.4.4 Verify Device ID Using GUI Software and Table 5 .
Table 5. Device ID
Assembly Number EVM Part Number Device ID
PWR549-001 bq24295EVM-549 bq24295
2.4.5 Switch to Boost Mode
1. Turn off and disconnect PS#1. May be used in step 2, if needed.
2. Move the voltmeter from J2 (VBUS/GND) to J1 (PMID/GND).
3. If the constant voltage supply connected between BAT+ and GND, from above, is not a 4 quadrant
supply (can source current) then this needs to be replaced with a power source set to 3.7 VDC that
can source current. Connect new power source, if necessary, that is set to 3.7 V and turn on.
4. Apply 10 ohms (5 W or greater) across J1 (PMID(+) to GND(–))
5. Click the GUI read button two times to make sure the latest data is read.
6. Disable the “I2C watchdog timer Limit” if set to a time.
7. Uncheck the “Enable Charge” Box if checked.
8. Uncheck the “OTG Low” box in the GUI.
9. Check the “Enable OTG” if un-checked.
10. Verify switch node waveform
11. Verify PMID to GND on J1 is between 4.9 V and 5.3 V (See Figure 9 ).
CH2 (5 V/div): SW Node – (Left Side of inductor to GND)
Measure → SW Frequency (TP2) - Frequency between 1.1 MHz and 1.5 MHz, (Period = 1 / f
sw
)
Measure
→
SW Duty cycle (TP2) - Duty cycle between 26 and 33%. (tV
SW_LOW
/ period)
Figure 9. Boost Mode Ripple and Duty Cycle; VBAT = 3.7 V
2.4.6 Turn off Power Source connected to BAT+ and GND.
9 SLUUAO5B – August 2013 – Revised April 2014 bq24295EVM-549 (PWR549) User’s Guide
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