Data Sheet
52
Rev. 1.00
2017-07-31
TLE9262BQXV33
External Voltage Regulator 3
8.2
Functional Description
The external voltage regulator can be used as an independent voltage regulator or in load-sharing mode with
VCC1. Setting
VCC3_ON
in the
M_S_CTRL
register in SBC Normal Mode sets the stand-alone configuration of
VCC3 as an independent voltage regulator. The load sharing configuration is set via the SPI bit
VCC3_LS
in the
HW_CTRL
register.
Figure 18 Selecting the Configuration of the VCC3 Regulator
Depending on the configuration the regulator will act in the respective SBC Mode as described in
Table 12
.
After the VCC3 configuration has been selected, it cannot be changed anymore.
In stand-alone configuration the maximum current
I
CC3max
is defined by the current limitation determined by
the used shunt. In load sharing configuration, the shunt is used to determine the current ratio between VCC1
and VCC3. Since the junction temperature of the external PNP transistor cannot be sensed by the SBC, it
cannot be protected against overtemperature by the SBC. Therefore the thermal behavior has to be analyzed
by the application.
For low-quiescent current reasons, the output voltage tolerance is decreased in SBC Stop Mode because a
low-power mode regulator with a lower accuracy will be active for small loads. If the base current on VCC3
exceeds
I
VCC3base
> I
VCC3base,Ipeak,r
then the high-power mode regulator is enabled additionally to support an
optimum dynamic load behavior. If the base current on VCC3 falls below the threshold (I
VCC3base
<
I
VCC3base,Ipeak,f
), then the low-quiescent current consumption is resumed again by disabling the high-power
mode regulator.
Only the high-power mode regulator is active in SBC Normal Mode.
The status of VCC3 is reported in the
SUP_STAT_2
SPI register. The regulator will switch OFF in case of VS
dropping below
VS_UV
regardless of the VCC3 configuration and will be automatically enabled again when
exceeding this threshold voltage unless the control bit
VCC3_VS_ UV_OFF
is set, i.e. in order to keep VCC3
enabled below
VS_UV
the bit
VCC3_VS_ UV_OFF
must be set. VCC3 will also stay active in SBC Stop Mode
Set bit
VCC3_V_CFG = 0
Set bit
VCC3_ON = 0 or 1
Set bit
VCC3_LS = 1
VCC3_V_CFG is
automatically set to 0
VCC3_LS, VCC3_ON and
VCC3_V_CFG cannot be
changed anymore
VCC3_LS and VCC3_V_CFG
cannot be changed anymore
(once VCC3_ON is set for the first time )
VCC3
load sharing?
Default value of
VCC3_LS = ‘0'
VCC3
output voltage
in stand-alone
configuration
Set bit
VCC3_V_CFG = 1
Set bit
VCC3_ON = 0 or 1
stand-alone
configuration
VCC3 = 3.3V
stand-alone
configuration
VCC3 = 1.8V
VCC3 load sharing
VCC3 = VCC1
No
Yes
3.3V
1.8V