MC908SR12MFAE Freescale Semiconductor, MC908SR12MFAE Datasheet - Page 224

• Manufacturer Part Number: MC908SR12MFAE
• Description: IC MCU 12K FLASH 8MHZ 48-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908SR12MFAE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SCI
• Peripherals: LVD, POR, PWM, Temp Sensor
• Number Of I /o: 31
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 14x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Analog Module
14.4.2 Two-Stage Amplifier
14.4.3 Amplifier Response Time
Data Sheet
224
The two-stage amplifier is used to amplify small input signals from the
on-chip temperature sensor or external voltage sources such as external
thermistor and current sensing resistor, for temperature and current
monitoring. The amplified signal, OPOUT, is fed to the ADC module for
analog-to-digital conversion. The gain of the two-stage amplifier is
defined by the GAINAx and GAINBx bits in the analog module gain
control register (AMGCR) (see
The two-stage amplifier requires the input signal to be stable for
sampling. This signal hold-time varies with gain setting for stage-1 of the
two-stage amplifier, and is determined by the formula:
The AMCLK clock is the analog amplifier clock, which is divided from the
ADC clock, ADCICLK.
The time for the two-stage amplifier to amplify the input signal to the
desired output is dependent on the gain setting in both stages of the two-
stage amplifier. The amplifier response time is determined by the
formula:
This amplifier response time should be added to the ADC conversion
time to obtain the total time for the small-signal conversion.
Therefore, conversion time for OPINx signals, with amplification is:
70 + (8 × Gain of stage-1) + (6 × Gain of stage-2) AMCLK cycles
10 + [(Gain of stage-1 amplifier – 1) × 2] AMCLK cycles
Amplifier response time + ADC conversion time
Analog Module
MC68HC908SR12•MC68HC08SR12 — Rev. 5.0
Figure
14-1).
Freescale Semiconductor