DRV10983ZPWPR datasheet(34/58 Pages) TI1

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Driving

AVS State

Driving State

High Impedance State

DRV10983

SLVSCP6C – JULY 2014 – REVISED MAY 2016

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AVSMMd = 1 – AVS mode becomes active when VCC reaches 24 V. The motor acts as a generator and returns

energy into the power supply until VCC reaches 24 V. This mode can be used to enable faster deceleration of

the motor in applications where returning energy to the power supply is allowed.

9.4.8.2 Inductive AVS Function

When DRV10983 transitions from driving the motor into a high-impedance state, the inductive current in the

motor’s windings continues to flow and the energy returns to the power supply through the intrinsic body diodes

in the FET output stage (see Figure 34).

Figure 34. Inductive Mode Voltage Surge

To prevent the inductive energy from being returned to the power supply, the DRV10983 system transitions from

driving to a high-impedance state by first turning off the active high-side drivers, and then after a fixed period of

time, turning off the low-side drivers (see Figure 35).

Figure 35. Inductive AVS

In this example, current is applied to the motor through the high-side driver on phase U (S1) and returned

through the low-side driver on phase W (S6). The high-side driver on phase U is turned off and after a period of

time (to allow the inductive energy in the resulting LR circuit to decay) the low-side driver on phase W is turned

off.

9.4.9 PWM Output

The DRV10983 has 16 options for PWM deadtime which can be used to configure the time between one of the

bridge FETs turning off and the complementary FET turning on. Deadtime[3:0] can be used to configure

deadtimes between 40 to 640 ns. Take care that the deadtime is long enough to prevent the bridge FETs from

shooting through.

The DRV10983 offers two options for PWM switching frequency. When the configuration bit DoubleFreq is set to

0, the output PWM frequency will be 25 kHz and when DoubleFreq is set to 1, the output PWM frequency will be

50 kHz.

9.4.10 FG Customized Configuration

The DRV10983 provides information about the motor’s speed through the frequency generate (FG) pin. FG also

provides information about the driving state of the DRV10983.

9.4.10.1 FG Output Frequency

The FG output frequency can be configured by FGcycle[1:0]. The default FG toggles once every electrical cycle

(FGcycle = 00). Many applications configure the FG output so that it provides two pulses for every mechanical

rotation of the motor. The configuration bits provided in DRV10983 can accomplish this for 4-pole, 6-pole, 8-pole,

and 12-pole motors, as shown in Figure 36.

DRV10983ZPWPR Datasheet(PDF) 34 Page - Texas Instruments