# 3.3v PWM to 10V to drive Power MOSFETS with Low Rds on?

#### muthu05

Joined Apr 21, 2020
1
Hello,

I am designing and developing a low voltage Battery management system . i have designed whole circuit but in one small thing i am stuck. kindly help me answering it.

Battery Pack specifications:

36 V 2.5 AH 10s battery pack.
maximum voltage : 42 v
Minimum voltage : 30v

Power rail: (B- to C- in the diagram)
Voltage: 42v to 30v
Current max : 15 Amps

Microcontroller : STM32F401rct6 https://www.st.com/resource/en/datasheet/stm32f401cb.pdf

Mosfet : https://pdf1.alldatasheet.com/datasheet-pdf/view/399737/INFINEON/IPD088N06N3G.html

I have a Power rail from battery negative to Charger and Load . In This Power Rail i am using two N channel Mosfets as a switch between battery negative to charge negative. The concept is when the charge and discharge current reaches more than the threshold these Mosfets will cutoff the circuit so the battery pack will be protected.

so to control this Mosfets with Low RDs on i need 10 V as per datasheet. but My STM32 microcontrollers PWM maximum output is 3.3v . i would like to amplify this voltage in to 10 v so that i can control the Mosfets.

The Problem is amplification . when it comes to amplify 3.3v to 10 v i thought of using a NPN transistor in common emitter mode. but when i try to simulate it i am not getting the output as 10v .

When i use NPN Transistor the collector voltage is given from battery packs voltage . so when battery is in full charge it gives 42v and when it is discharged it gives 30 v as an input to the collector . when the collector voltage varies the output voltage also varies.

doubts:

using NPN transistor is the correct way to get 3.3v PWM to 10v or not to drive the mosfet .

should i use PWM or normal 3.3 v output from my STM32 microcontroller which is better to drive mosfets.

Am i choosing a wrong Mosfet is there any logic level Power Mosfet which can be driven using 3.3v output.

Kindly Help me in This,

Thanks

#### ericgibbs

Joined Jan 29, 2010
11,645
hi 05,
Welcome to AAC.
Please show the STM32 power and ground connections on the circuit.
E