S912XHZ512F1VAG Datasheet, PDF (726/978 Pages) Freescale Semiconductor, Inc – Covers MC9S12XHZ384, MC9S12XHZ256

Chapter 20 Voltage Regulator (S12VREG3V3V5)
The regulator is active, providing the nominal supply voltage of 2.5 V with full current sourcing
capability at both outputs. Features LVD (low-voltage detect), LVR (low-voltage reset), and POR
(power-on reset) are available. The API is available.
2. Reduced power mode (RPM) (MCU is in stop mode)
The purpose is to reduce power consumption of the device. The output voltage may degrade to a
lower value than in full performance mode, additionally the current sourcing capability is
substantially reduced. Only the POR is available in this mode, LVD and LVR are disabled. The API
is available.
3. Shutdown mode
Controlled by VREGEN (see device level specification for connectivity of VREGEN).
This mode is characterized by minimum power consumption. The regulator outputs are in a
high-impedance state, only the POR feature is available, LVD and LVR are disabled. The API
internal RC oscillator clock is not available.
This mode must be used to disable the chip internal regulator VREG_3V3, i.e., to bypass the
VREG_3V3 to use external supplies.
20.1.3 Block Diagram
Figure 20-1 shows the function principle of VREG_3V3 by means of a block diagram. The regulator core
REG consists of two parallel subblocks, REG1 and REG2, providing two independent output voltages.
MC9S12XHZ512 Data Sheet, Rev. 1.06
726
Freescale Semiconductor