LFDAS12XSDT Freescale Semiconductor, LFDAS12XSDT Datasheet - Page 502

• Manufacturer Part Number: LFDAS12XSDT
• Description: HARDWARE MC9S12XS 52-PIN
• Manufacturer: Freescale Semiconductor

Specifications of LFDAS12XSDT

• Module/board Type: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: -

Voltage Regulator (S12VREGL3V3V1)
17.4
17.4.1
Module VREG_3V3 is a voltage regulator, as depicted in
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
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
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
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
17.4.3
Subblock LVD is responsible for generating the low-voltage interrupt (LVI). LVD monitors the input
voltage (V
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
This functional block monitors VDD. If V
the POR is deasserted. POR asserted forces the MCU into Reset. POR Deasserted will trigger the power-
on sequence.
17.4.5
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
502
vup
Functional Description
DDA
, if the voltage regulator is enabled.
General
Regulator Core (REG)
Low-Voltage Detect (LVD)
Power-On Reset (POR)
Low-Voltage Reset (LVR)
Full Performance Mode
Reduced Power Mode
–V
SSA
) and continuously updates the status flag LVDS. Interrupt flag LVIF is set whenever
S12XS Family Reference Manual, Rev. 1.11
DD
is below V
PORD
Figure
, POR is asserted; if V
17-1. The regulator functional elements
Freescale Semiconductor
DD
exceeds V
PORD
,