Other Parts Discussed in Thread: DRV8353
Tool/software:
Hi Team!
I have an issue with the DRV8353SR FET driver. The circuit requires short circuit protection. When I connect 2 phases the one low side gate driver is damaging permanently. The input power increase, the VLGS power supply is not ok, and the charge pump voltage is also not ok (2.5V). The MOSFET itself is not damaging. I can measure 1.5Ohm between the GLB and the GND.
His bits reported active via the SPI interface:
This is my schematic:
This is my configuration:
staticconstexpruint16_t DriverControlReg = 1 << 10 // All three half-bridges are shutdown in response to VDS_OCP and SEN_OCP
| 0 << 9 // undervoltage lockout fault enabled
| 0 << 8 // gate drive fault enabled
| 1 << 7 // thermal warning reported on nFAULT and FAULT bit
| 0 << 5 // 6x PWM Mode
| 0 << 4 // 1x PWM mode uses synchronous rectification, doesn't apply since not using 1x PWM mode
| 0 << 3 // in 1x PWM, this bit is ORed with INHC (DIR) input, doesn't apply since not using 1x PWM mode
| 0 << 2 // don't coast the motor
| 0 << 1 // don't brake the motor
| 0 << 0 // don't clear latched fault bits
;
write(i, DRV8353rsRegister_t::DRIVER_CONTROL, DriverControlReg);
staticconstexpruint16_t GateDriveHigh = 0b000 << 8 // don't lock settings just yet
| 0b0100 << 4 // high side rise drive current = 300mA
| 0b0011 << 0 // high side fall drive current = 300mA
;
write(i, DRV8353rsRegister_t::GATE_DRIVE_HIGH_CONTROL, GateDriveHigh);
staticconstexpruint16_t GateDriveLow = 1 << 10 // For VDS_OCP and SEN_OCP, the fault is cleared when a new PWM input is given or after tRETRY
| 0b11 << 8 // gate current drive time 4000ns
| 0b0100 << 4 // low side rise drive current = 300mA
| 0b0011 << 0 // low side fall drive current = 300mA
;
write(i, DRV8353rsRegister_t::GATE_DRIVE_LOW_CONTROL, GateDriveLow);
// RDS = 7mOhm
// maximum estimated I = 22A
// voltage across the sense resistor is V = IR = 0.2V
// set overcurrent voltage to 0.2V
staticconstexpruint16_t OvercurrentControl = 0 << 10 // overcurrent time is 8ms
| 0b11 << 8 // 400ns dead time (time between switching of high and low MOSFET, prevents shoot-through)
| 0b00 << 6 // Overcurrent causes a latched fault
| 0b10 << 4 // overcurrentdeglitch time (minimum time of overcurrent before detection) = 4us
| 0b0101 << 0 // VDS overcurrent voltage = 0.2V
;
write(i, DRV8353rsRegister_t::OCP_CONTROL, OvercurrentControl);
// maximum estimated I = 23A
// maximum common mode input range is +-0.165V, so max resistor size is 0.15V/15A = 0.007mOhm, power dissipation = I^2R = 1.57W..
// max SPx-SNx = IR = 22*0.0009 = 0.2V
// SOx goes from 0.25 to Vref-0.25 = 3.3-0.25 = 3.05V, so 10V/V gain should be good
// SOx goes from (Vref/2)-(10*0.101) to (Vref/2)+(10*0.101) = 0.6275V to 2.6475V
staticconstexpruint16_t CurrentSenseControl = 0 << 10 // sense amplifier positive is SPx
| 1 << 9 // sense amplifier reference voltage is VREF/2 (bidirectional current sense)
| 1 << 8 // VDS_OCP for the low-side MOSFET is measured across SHx to SNx (Shunt + Rdson)
| 0b01 << 6 // 10-V/V shunt amplifier gain
| 0 << 5 // sense overcurrent fault enabled
| 0 << 4 // normal sense amplifier A operation
| 0 << 3 // normal sense amplifier B operation
| 0 << 2 // normal sense amplifier C operation
| 0 << 0 // Sense OCP 0.25 V
;
write(i, DRV8353rsRegister_t::CSA_CONFIGURATION, CurrentSenseControl);
lock(i);
