TMC603A Datasheet, PDF (11/44 Pages) TRINAMIC Motion Control GmbH & Co. KG. – Three phase motor driver with BLDC back EMF commutation hallFX™ and current sensing

TMC603A DATA SHEET (V. 1.15 / 2009-Nov-19)
11
A zener diode at the gate (range 12V to 15V) protects the high-side MOSFET in case of a short to
GND event: Should the bridge be shorted, the gate driver output is forced to stay at a maximum of the
zener voltage above the source of the transistor. Further it prevents the gate voltage from dropping
below source level.
The maximum permissible MOSFET driver current depends on the motor supply voltage:
Parameter
MOSFET driver current with V_VM < 30V
MOSFET driver current with 30V < V_VM < 50V
MOSFET driver current with V_VM = 50V
Symbol
I_HSX, I_LSX
I_HSX, I_LSX
Max
150
150-2.5*(V_VM-30V)
100
Unit
mA
mA
mA
Pin
LSx
HSx
BMx
RSLP
VLS
VCP
GNDP
BHx
BLx
INV_BL
Comments
Low side MOSFET driver output. The driver current is set by resistor R_SLP. A Schottky
protection diode to GND may be required for MOSFETs, where Q_GD is larger than
Q_GS. Check that LSx voltage does not drop below GND by more than 0.5V.
High side MOSFET driver output. The driver current is set by resistor R_SLP
Bridge center used for current sensing and for control of the high side driver.
For unused bridges, connect BMx pin to GND and leave the driver outputs
unconnected. Place the external protection resistor near the IC pin.
The resistor connected to this pin controls the MOSFET gate driver current. A 40µA
current out of this pin (resistor value of 100k to GND) results in the nominal
maximum current at full supply range. Keep interconnection between IC and resistor
short, to avoid stray capacitance to adjacent signal traces of modulating the set
current.
Resistor range: 60 k to 500 k
Low side driver supply voltage for driving low side gates
Charge pump supply voltage. Provides high side driver supply
Power GND for MOSFET drivers, connect directly to GND
High side driver control signal: A positive level switches on the high side.
For unused bridges, tie to GND.
Low side driver control signal: Polarity can be reversed via INV_BL
Allows inversion of BLx input active level (low: BLx is active high).
When high, each BLx and BHx can be connected in parallel in order to use only 3
PWM outputs for bridge control. Be sure to switch on internal break-before-make logic
(BBM_EN = Vcc) to avoid bridge short circuits in this case.
5.2.2 Break-before-make logic
Each half-bridge has to be protected against cross conduction during switching events. When
switching off the low-side MOSFET, its gate first needs to be discharged, before the high side
MOSFET is allowed to be switched on. The same goes when switching off the high-side MOSFET and
switching on the low-side MOSFET. The time for charging and discharging of the MOSFET gates
depends on the MOSFET gate charge and the driver current set by R_SLP. When the BBM logic is
enabled, the TMC603 measures the gate voltage and automatically delays switching on of the
opposite bridge transistor, until its counterpart is discharged. The BBM logic also prevents
unintentional bridge short circuits, in case both, LSx and HSx, become switched on. The first active
signal has priority.
Copyright © 2009 TRINAMIC Motion Control GmbH & Co. KG