908E626_09 Datasheet, PDF (15/44 Pages) Freescale Semiconductor, Inc – Integrated Stepper Motor Driver with Embedded MCU and LIN Serial Communication

FUNCTIONAL DESCRIPTION
FUNCTIONAL PIN DESCRIPTION
CURRENT LIMITATION FREQUENCY INPUT PIN
(FGEN)
Input pin for the half-bridge current limitation PWM
frequency. This input is not a real PWM input pin; it should
just supply the period of the PWM. The duty cycle will be
generated automatically.
Important The recommended FGEN frequency should
be in the range of 0.1kHz to 20kHz.
BACK ELECTROMAGNETIC FORCE OUTPUT PIN
(BEMF)
This pin gives the user information about back
electromagnetic force (BEMF). This feature allows stall
detection and coil failures in step motor applications. In order
to evaluate this signal the pin must be directly connected to
pin PTD0 / TACH0 / BEMF.
RESET PIN (RST_A)
RST_A is the bidirectional reset pin of the analog die. It is
an open drain with pull-up resistor and must be connected to
the RST pin of the MCU.
INTERRUPT PIN (IRQ_A)
IRQ_A is the interrupt output pin of the analog die
indicating errors or wake-up events. It is an open drain with
pull-up resistor and must be connected to the IRQ pin of the
MCU.
SLAVE SELECT PIN (SS)
This pin is the SPI Slave Select pin for the analog chip. All
other SPI connections are done internally. SS must be
connected to PTB1 or any other logic I /O of the
microcontroller.
LIN BUS PIN (LIN)
The LIN pin represents the single-wire bus transmitter and
receiver. It is suited for automotive bus systems and is based
on the LIN bus specification.
HALF-BRIDGE OUTPUT PINS (HB1: HB4)
The 908E626 device includes power MOSFETs
configured as four half-bridge driver outputs. The HB1: HB4
outputs may be configured for step motor drivers, DC motor
drivers, or as high side and low side switches.
The HB1: HB4 outputs are short-circuit and over-
temperature protected, and they feature current recopy,
current limitation, and BEMF generation. Current limitation
and recopy are done on the low side MOSFETs.
POWER SUPPLY PINS (VSUP1: VSUP3)
VSUP1: VSUP3 are device power supply pins. The
nominal input voltage is designed for operation from 12V
systems. Owing to the low ON-resistance and current
requirements of the half-bridge driver outputs, multiple VSUP
pins are provided.
All VSUP pins must be connected to get full chip
functionality.
POWER GROUND PINS (GND1 AND GND2)
GND1 and GND2 are device power ground connections.
Owing to the low ON-resistance and current requirements of
the half-bridge driver outputs multiple pins are provided.
GND1 and GND2 pins must be connected to get full chip
functionality.
SWITCHABLE V_DD OUTPUT PIN (HVDD)
The HVDD pin is a switchable V_DD output for driving
resistive loads requiring a regulated 5.0V supply; The output
is short-circuit protected.
+ 5.0V VOLTAGE REGULATOR OUTPUT PIN (VDD)
The VDD pin is needed to place an external capacitor to
stabilize the regulated output voltage. The VDD pin is
intended to supply the embedded microcontroller.
Important The VDD pin should not be used to supply
other loads; use the HVDD pin for this purpose. The VDD,
EVDD, VDDA, and VREFH pins must be connected together.
VOLTAGE REGULATOR GROUND PIN (VSS)
The VSS pin is the ground pin for the connection of all non-
power ground connections (microcontroller and sensors).
Important VSS, EVSS, VSSA, and VREFL pins must be
connected together.
LIN TRANSCEIVER OUTPUT PIN (RXD)
This pin is the output of LIN transceiver. The pin must be
connected to the microcontroller’s Enhanced Serial
Communications Interface (ESCI) module (RXD pin).
ADC REFERENCE PINS (VREFL AND VREFH)
VREFL and VREFH are the reference voltage pins for the
ADC. It is recommended that a high quality ceramic
decoupling capacitor be placed between these pins.
Important VREFH is the high reference supply for the
ADC and should be tied to the same potential as VDDA via
separate traces. VREFL is the low reference supply for the
ADC and should be tied to the same potential as VSS via
separate traces.
For details refer to the 68HC908EY16 datasheet.
ADC SUPPLY PINS (VDDA AND VSSA)
VDDA and VSSA are the power supply pins for the analog-
to-digital converter (ADC). It is recommended that a high
quality ceramic decoupling capacitor be placed between
these pins.
Important VDDA is the supply for the ADC and should be
tied to the same potential as EVDD via separate traces.
Analog Integrated Circuit Device Data
Freescale Semiconductor
908E626
15