LM74700-Q1: driving MOSFET with Logic Level or Standard Level

Josef Warta

Part Number: LM74700-Q1

Hello Team,
my customer has following question:

now we use the NEXPERIA BUK9Y1R9-40H with the LM74700-Q1 for reverse voltage protection. As the BUK9Y1R9-40H is not available yet, NEXPERIA suggested the BUK7J1R0-40H, BUK7J1R4-40H or BUK7J1R7-40H.

Which effects would it have, if we replace the BUK9Y1R9-40H with one of the BUK7J1R… in terms of switch-on Voltage (full functionality should be archieved from 6V to 22V) and temperature behavior (-40°C to 85°C)? Are there any other restrictions if I will change the Transistor?

BUK9Y1R9-40H is logic level

BUK9Y1R9-40H - N-channel 40 V, 1.9 mΩ logic level MOSFET in LFPAK56 | Nexperia

BUK7J1R is standard level family

BUK7J1R0-40H - N-channel 40 V, 1.0 mΩ standard level MOSFET in LFPAK56E | Nexperia

Many Thanks

Josef

over 1 year ago

0 Divyanshu Vadehra over 1 year ago

TI__Expert 3370 points

Hi Josef,

Can you please share the nominal and maximum load current required by the application. Also please share the schematics if possible. We can look into suitable alternative FETs.

Best regards

Divyanshu

0 Markus Lorenz over 1 year ago in reply to Divyanshu Vadehra

Prodigy 30 points

Hi Divyanshu,

The nominal load current should be 9.25A

The maximum load current should be 25A

Best regrads

Markus

0 Divyanshu Vadehra over 1 year ago in reply to Markus Lorenz

TI__Expert 3370 points

Hi Markus,

Please check if this FET would be suitable: RS1G260MNTB : Transistors (rohm.com)

The only concern with the NXP FET is the low Ron, which is recommended to be higher so that the device could operate in regulation mode.

Best regards

Divyanshu

0 Markus Lorenz over 1 year ago in reply to Divyanshu Vadehra

Prodigy 30 points

Hi Divyanshu,

thank you for your reply.

I will use a FET with higher Ron. But it is hard to get automotive FET with logic level VGSth.

My origin question was, if it is possible to use automotive FET with standard level VGSth e.g. BUK7J1R7 or BUK7J3R3 ..

Many thanks

Markus

+1 Divyanshu Vadehra over 1 year ago in reply to Markus Lorenz

TI__Expert 3370 points

Hi Markus,

BUK7J1R7 has 3V threshold voltage, which should be okay when used with LM74700-Q1.

Best regards

Divyanshu

0 Josef Warta over 1 year ago in reply to Divyanshu Vadehra

TI__Expert 3890 points

Many Thanks

Power management

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LM74700-Q1: driving MOSFET with Logic Level or Standard Level