MM912H634DM1AER2 Freescale Semiconductor, MM912H634DM1AER2 Datasheet - Page 63

• Manufacturer Part Number: MM912H634DM1AER2
• Description: 16-bit Microcontrollers - MCU 64KS12 LIN2XLS/HS ISENSE
• Manufacturer: Freescale Semiconductor

Specifications of MM912H634DM1AER2

• Rohs: yes
• Core: HCS12
• Processor Series: MM912F634
• Data Bus Width: 16 bit
• Maximum Clock Frequency: 20 MHz
• Program Memory Size: 32 KB
• Data Ram Size: 2 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 5.5 V to 18 V
• Operating Temperature Range: - 40 C to + 105 C
• Package / Case: LQFP-48
• Mounting Style: SMD/SMT
• A/d Bit Size: 10 bit
• A/d Channels Available: 15
• Interface Type: SPI
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 15
• Number Of Timers: 1
• Program Memory Type: Flash
• Supply Voltage - Max: 18 V
• Supply Voltage - Min: 5.5 V

Functional Description and Application Information
4.4.3
To guarantee safe power up and down behavior, special dependencies are implemented to prevent unwanted MCU execution.
Figure 19
To avoid any critical behavior, it is essential to have the MCU Power On Reset (POR) active when the analog die reset
(RESET_A) is not fully active. As the RESET_A circuity is supplied by VDDX, VDD needs to be below the POR threshold when
VDDX is to low to guarantee RESET_A active (3;6). This is achieved with the following implementation.
Power Up:
Power Down:
Freescale Semiconductor
•
•
•
•
•
The VDD regulator is enabled after VDDX has reached the V
Once VDD reaches V
The MCU is also protected by the MCU_LVR.
Once VDDX has reached the V
pulled down to discharge any VDD capacitance (5). RESET_A is activated as well.
The active discharge guarantees VDD to be below POR level before VDDX discharges below critical level for the reset
circuity.
shows a standard power up and power down sequence.
Range (not to scale)
Power Up Behavior / Power Down Behavior - I64
V
Normal Operating
LVRX
The behavior explained is essential for the MC9S12I64 MCU die used, as this MCU does
have an internal regulator stage, but the LVR function is only active in normal mode
MC9S12I64.
The shutdown behavior should be considered when sizing the external capacitors C
C
VDDX
RESET_A
/ V
V
V
LBI
POR_MCU
LVR_MCU
for extended low voltage operation.
V
V
/ V
POR_A
V
V
ROVX
ROX
5V
LVR
LVI
LRV
, the RESET_A is released (2).
3
LVRX
VSUP
Figure 19. Power Up / Down Sequence
threshold (4), the VDD regulator is disabled and the regulator output is actively
1
2
NOTE
VDDX
LVRX
threshold (1).
VDD
4
5
6
VDD
and
Power Supply
MM912F634
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