ZAMC4100 Datasheet, PDF (29/155 Pages) Integrated Device Technology – Actuator and Motor Controller

ZAMC4100 Datasheet
2.5. Output Drivers
The ZAMC4100 features three types of drivers:
• Half-bridge drivers – Low-side and high-side switches are connected between the positive supply rail
and the negative supply rail
• High-side drivers – High-side switches connected to the positive supply rail VDDE
• EC mirror control driver (ECM driver) – Output power stage, digital-to-analog converter (DAC) for
controlling the output voltage level, and analog feedback circuit
Each driver provides the following functionalities:
• Low-resistance power switches optimized for high-current operation.
• PWM control available for all half-bridge and high-side drivers.
• The ECM driver is a special type of power driver designed for electrochromatic mirror control. For more
details, refer to section 3.11.
• Integrated diagnostic and protection features.
• Detects high impedance output state.
• Except for the ECM, all switches have an integrated current measurement capability. If selected, these
signals are digitized by the ADC. For the ECM driver, a dedicated internal channel is implemented for
direct measurement of the actual output voltage (potential at EC_M pin).
All switches use an NMOS device for optimal low resistance channels. For driving the high-side switches, an
integrated charge pump provides voltages higher than VDDE.
2.6. Driver’s Power Capability and Package Temperature
One of the features of the ZAMC4100 is very low channel resistance; therefore, the package is less likely to
overheat in performance of high current operations. However it is the responsibility of the application design
engineer to properly evaluate thermal behavior in the application to avoid premature safety shutdown by the
internal temperature protection circuitry.
The thermal behavior of the ZAMC4100 is very dependent on the PCB layout, encapsulate material, and heat
sinking. Poor quality PCB layout resulting in high thermal resistance will likely cause over-heating, which will
trigger an over-temperature event and prematurely shut down the driver. It is likely that there will be a delay
before the package junction returns to a safe temperature level, depending on the rate of heat dispersion into the
ambient environment.
The MCU could incorporate additional firmware referred to as Smart Power Management, depending on the
application; for example for an automotive heater mirror, where demand for a high current level can be reduced
by implementing a low-frequency PWM method when the ZAMC4100’s package temperature exceeds a specified
temperature level. This feature is designed to prolong the operation period and therefore enhanced reliability. For
more information, contact IDT’s technical support.
© 2016 Integrated Device Technology, Inc.
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January 26, 2016