ZAMC4100 Datasheet, PDF (28/155 Pages) Integrated Device Technology – Actuator and Motor Controller

ZAMC4100 Datasheet
2.2. High-Frequency and Low-Frequency Oscillator
The ZAMC4100 system has two built-in oscillators: OSCH and OSCL. Oscillator OSCH generates the 20 MHz
clock used directly in the MCU chip and divided by 5 in SBC chip. OSCL is a very low-power oscillator which
provides 125kHz clock frequency used by LIN wake-up logic during SLEEP Mode and used as an autonomous
clock for the watchdog timer. When SLEEP Mode is enabled, the SBC switches from OSCH to OSCL clock and
vice versa when SLEEP Mode is exited.
2.3. Watchdog Timer
The SBC features an integrated watchdog timer (WDT), running on an autonomous 125kHz clock provided by
OSCL oscillator. The WDT enables monitoring unresponsive states within the MCU and the SPI bus.
The WDT will generate configurable time-out intervals and when expired will reset the MCU. To avoid this, the
MCU firmware should periodically reset the WDT via the SPI interface.
The WDT has a separate counter that counts the number of MCU resets (N = 4, 8 as configured in the
WDTCONF register; see Table 3.3). When expired, it generates global reset for the whole system. This
guarantees that all drivers are automatically disabled if abnormal MCU behavior occurs (e.g., frozen code).
2.4. Analog-to-Digital Converter
The SBC features a high-accuracy 10-bit successive approximation ADC with a front-end multiplexer (MUX) that
selects one of the external or internal input signals for sampling and further processing by the MCU.
The ADC supports three types of external measurements, depending on the configuration setting in the firmware:
ratiometric mode, absolute mode, or temperature measurement using internal current sources. For more details,
refer to section 3.12.2.
Summary of possible measurements:
• Absolute voltage measurement with internal reference voltage
• Absolute current measurement with internal reference current
• Ratiometric measurement
• Measurements of internal input signals for the ADC:
• Supply voltage; i.e., the voltage between the VDDE and VSSA pins
• Internal temperature: the average temperature of the SBC die
• Current through each half-bridge and high-side driver output (does not include EC mirror driver)
• Actual output voltage of EC mirror driver (at EC_M pin)
• Diagnostic measurements, which are used during the self-diagnostic mode
• External analog inputs AIN1-AIN4. Pins AIN3/TEMP and AIN4/TEMP feature switchable current sources
allowing optional direct connection to external temperature sensors
© 2016 Integrated Device Technology, Inc.
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January 26, 2016