BQ2000: bq2000 EVM circuit question

Ann_Lien

Genius 14430 points

Part Number: BQ2000

Hi expert,

My customerf has some questions on bq2000 EVM circuit.

A. How can we choose this diode? (why 5.6V?)

B. Why needs 100uH? Is there any concern on inductor current ripple?

D. If we don't need to sense charging current, could we remove sense resitor?

E. How can we choose this diode? (why 6.5V?)

Best regards,

Ann Lien

over 7 years ago

0 Ann_Lien over 7 years ago

TI__Genius 14430 points

Loop Kyle.

0 Wang5577 over 7 years ago in reply to Ann_Lien

TI__Guru 56650 points

Ann,

A. 5.6V D6 sets Q4's base pin at 5.6V and Q4's emitter pin at 5V which is good for BQ2000's VCC pin.
B. BQ2000 operation frequency is not high which needs 100uH inductor.
D. Sense resistor cannot be removed. If remove it, there is no current control: like input short to output
E. D7 voltage is related to Vin, maximum Q1's gate voltage (MOD pin low), maximum MOD pin voltage at MOD pin off.