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ManualsBrandsSTMICROELECTRONICS ManualsPMICsPMIC - motor controllers Pre-driver - half bridge (4) SPI HTSSOP 38
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L6480 Functional description
75
The gate current can be set to one of the following values: 4, 8, 16, 24, 32, 64 and 96 mA
through the IGATE parameter in the GATECFG1 register (see Section 9.1.21 on page 52).
Controlled current time can be programmed within range from 125 ns to 3.75 s with a
resolution of 125 ns (TCC parameter in GATECFG1 register) (see Section 9.1.21 on page
52).
Turn-off overboost time can be set to one of the following values: 0, 62.5, 125, 250 ns
(TBOOST parameter in GATECFG1 register). The 62.5 ns value is only available when
clock frequency is 16 MHz or 32 MHz; when clock frequency is 8 MHz it is changed to 125
ns and when a 24-MHz clock is used it is changed to 83.3 ns. (see Section 9.1.21 on page
52).
6.16 Deadtime and blanking time
During the bridge commutation, a deadtime is added in order to avoid cross conductions.
The deadtime can be programmed within a range from 125 ns to 4 s with a resolution of
125 ns (TDT parameter in the GATECFG2 register) (see Section 9.1.22 on page 53).
At the end of each commutation the overcurrent and stall detection comparators are
disabled (blanking) in order to avoid the respective systems detecting body diodes turn-off
current peaks.
The duration of blanking time is programmable through the TBLANK parameter in the
GATECFG2 register at one of the following values: 125, 250, 375, 500, 625, 750, 875, 1000
ns (see Section 9.1.22 on page 53).
6.17 Integrated analog to digital converter
The L6480 integrates an N
ADC
bit ramp-compare analog to digital converter with a reference
voltage equal to
V
REG
. The analog to digital converter input is available through the ADCIN
pin and the conversion result is available in the ADC_OUT register (Section 9.1.16 on page
49).
Sampling frequency is equal to the programmed PWM frequency.
The ADC_OUT value can be used for motor supply voltage compensation or can be at the
user’s disposal.
Figure 14. Gate driving currents
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&&
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