Voltage Regulator (S12VREGL3V3V1)
S12XS Family Reference Manual, Rev. 1.13
502
Freescale Semiconductor
17.4
Functional Description
17.4.1
General
Module VREG_3V3 is a voltage regulator, as depicted in
. The regulator functional elements
are the regulator core (REG), a low-voltage detect module (LVD), a control block (CTRL), a power-on
reset module (POR), and a low-voltage reset module (LVR)and a high temperature sensor (HTD).
17.4.2
Regulator Core (REG)
Respectively its regulator core has three parallel, independent regulation loops (REG1,REG2 and REG3).
REG1 and REG3 differ only in the amount of current that can be delivered.
The regulators are linear regulator with a bandgap reference when operated in Full Performance Mode.
They act as a voltage clamp in Reduced Power Mode. All load currents flow from input VDDR to VSS or
VSSPLL. The reference circuits are supplied by VDDA and VSSA.
17.4.2.1
Full Performance Mode
In Full Performance Mode, the output voltage is compared with a reference voltage by an operational
amplifier. The amplified input voltage difference drives the gate of an output transistor.
17.4.2.2
Reduced Power Mode
In Reduced Power Mode, the gate of the output transistor is connected directly to a reference voltage to
reduce power consumption. Mode switching from reduced power to full performance requires a transition
time of t
vup
, if the voltage regulator is enabled.
17.4.3
Low-Voltage Detect (LVD)
Subblock LVD is responsible for generating the low-voltage interrupt (LVI). LVD monitors the input
voltage (V
DDA
–V
SSA
) and continuously updates the status flag LVDS. Interrupt flag LVIF is set whenever
status flag LVDS changes its value. The LVD is available in FPM and is inactive in Reduced Power Mode
or Shutdown Mode.
17.4.4
Power-On Reset (POR)
This functional block monitors VDD. If V
DD
is below V
PORD
, POR is asserted; if V
DD
exceeds V
PORD
,
the POR is deasserted. POR asserted forces the MCU into Reset. POR Deasserted will trigger the power-
on sequence.
17.4.5
Low-Voltage Reset (LVR)
Block LVR monitors the supplies VDD, VDDX and VDDF. If one (or more) drops below it’s
corresponding assertion level, signal LVR asserts; if all VDD,VDDX and VDDF supplies are above their
Содержание MC9S12XS128
Страница 4: ...S12XS Family Reference Manual Rev 1 13 4 Freescale Semiconductor ...
Страница 58: ...Device Overview S12XS Family S12XS Family Reference Manual Rev 1 13 58 Freescale Semiconductor ...
Страница 150: ...Memory Mapping Control S12XMMCV4 S12XS Family Reference Manual Rev 1 13 150 Freescale Semiconductor ...
Страница 168: ...Interrupt S12XINTV2 S12XS Family Reference Manual Rev 1 13 168 Freescale Semiconductor ...
Страница 194: ...Background Debug Module S12XBDMV2 S12XS Family Reference Manual Rev 1 13 194 Freescale Semiconductor ...
Страница 364: ...Periodic Interrupt Timer S12PIT24B4CV1 S12XS Family Reference Manual Rev 1 13 364 Freescale Semiconductor ...
Страница 396: ...Pulse Width Modulator S12PWM8B8CV1 S12XS Family Reference Manual Rev 1 13 396 Freescale Semiconductor ...
Страница 506: ...Voltage Regulator S12VREGL3V3V1 S12XS Family Reference Manual Rev 1 13 506 Freescale Semiconductor ...
Страница 736: ...Ordering Information S12XS Family Reference Manual Rev 1 13 736 Freescale Semiconductor ...
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