User Manual
934
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
High-Side Switch
26.3.1.5 Low-VS Feature
The default behaviour of the high-side switch is the following:
The high-side is switched on using Bits HS1_EN and HS1_ON. (Note: This description describes HS1 only, but
applies to HS2 as well accordingly)
In case of VS-undervoltage (detected by ADC2 ch0, at VS < ~4.43V), the high-side is switched off.
The high-side remains switched off, even when VS is increased above the threshold again, until the VS_UV
interrupt and Status bits are cleared in SCUPM_SYS_SUPPLY_IRQ_CLR (VS_UV_ISC and VS_UV_SC).
In case this switch-off of the high-side is not wanted, the high-side low-VS feature can be enabled:
The high-side is switched on using Bits HS1_EN, HS1_ON and HS1_CYC_ON_ACTIVE. (HS1_CYC_ON_ACTIVE
should only be set together with HS1_ON). In that case, the high-side remains switched on down to Vs = 3V.
26.3.2
PWM Operation
In PWM mode the high-side switch has to be first enabled by the corresponding bits in the
HSx_CTRL
register.
The related bits are described below. PWM_CHx in
can be set in register
Figure 215 Combinatorial Control of High-Side Switch in PWM Mode
To avoid any output glitches on the HSx output, the
HSx_PWM
bit should be set first. After the function is
enabled for PWM operation the corresponding PWM unit can be enabled.
For frequencies higher than 10 kHz, the slew rate setting has to be set to 30V/µs. Otherwise the internal
power dissipation of the switch might damage the device.
In PWM mode all protection functions are available.
26.3.3
Cyclic Switching in Low Power Mode
In the cyclic sense power-saving mode the high-side switch cyclically supplies an external switch arrangement
for a short time, just long enough to detect the position of the switch. The configuration procedure to use the
high-side switch for cyclic sense operation, is described in the chapter
Power Management Unit
.
SCU_PM
CCU6 or
GPT12
&
≥
1
1
PWM_CHx
HS_PWM
HS_ON
&
ON
VS
HS
HSS
SFR