S9S12G128F0VLF Freescale Semiconductor, S9S12G128F0VLF Datasheet - Page 264

• Manufacturer Part Number: S9S12G128F0VLF
• Description: 16-bit Microcontrollers - MCU 16BIT 128K FLASH
• Manufacturer: Freescale Semiconductor

Specifications of S9S12G128F0VLF

• Rohs: yes
• Core: S12
• Processor Series: MC9S12G
• Data Bus Width: 16 bit
• Maximum Clock Frequency: 25 MHz
• Program Memory Size: 128 KB
• Data Ram Size: 8 KB
• On-chip Adc: Yes
• Operating Supply Voltage: 5 V
• Operating Temperature Range: - 40 C to + 105 C
• Package / Case: LQFP-48
• Mounting Style: SMD/SMT

Reference Voltage Attenuator (RVAV1)
4.7
The RVA is a prescaler for the ADC reference voltage. If the attenuation is turned off the resistive divider
is disconnected from VSSA, VRH_INT is connected to VRH and VRL_INT is connected to VSSA. In this
mode the attenuation is bypassed and the resistive divider does not draw current.
If the attenuation is turned on the resistive divider is connected to VSSA, VRH_INT and VRL_INT are
connected to intermediate voltage levels:
The attenuated reference voltage difference (VRH_INT - VRL_INT) equals 50% of the input reference
voltage difference (VRH - VSSA). With reference voltage attenuation the resolution of the ADC is
improved by a factor of 2.
266
Functional Description
In attenuation mode the maximum ADC clock is reduced. Please refer to the
conditions in appendix A “ATD Accuracy”, table “ATD Conversion
Performance 5V range, RVA enabled”.
VRH_INT = 0.9 * (VRH - VSSA) + VSSA
VRL_INT = 0.4 * (VRH - VSSA) + VSSA
MC9S12G Family Reference Manual,
NOTE
Rev.1.23
Freescale Semiconductor
Eqn. 4-1
Eqn. 4-2