MC33742 Datasheet, PDF (18/52 Pages) Motorola, Inc – System Basis Chip (SBC) with Enhanced High-Speed CAN Transceiver

Freescale Semiconductor, Inc.
SYSTEM/APPLICATION INFORMATION
INTRODUCTION
The 33742 and the 33742S are integrated circuits dedicated
to automotive applications. Their functions include the
following:
• One fully protected voltage regulator with 200 mA total
output current capability available at the V_DD terminal.
• Driver for external pass transistor for V2 regulator
function.
• V_DD regulator undervoltage reset function, programmable
window or timeout software watchdog function.
• Two running modes: Normal and Standby modes when
the microcontroller is running.
• Sleep and Stop modes for operation in low power mode to
reduce the application current consumption, while offering
wake-up capability from CAN interface, L3:L0 wake-up
input, and automatic timer wake-up.
• Programmable wake-up input and cyclic sense wake-up.
• CAN high-speed physical interface with bus failure
diagnostic and enhanced protection feature for TXD and
RXD failure.
• Interface with micro through SPI. Interrupt output to report
device status, diagnostic, and wake-up event.
FUNCTIONAL TERMINAL DESCRIPTION
RXD and TXD
The RXD and TXD terminals (receive data terminal and
transmit data terminal, respectively) are connected to the
microcontroller CAN protocol handler. TXD is an input and
controls the CANH and CANL line state (dominant when TXD is
LOW, recessive when TXD is HIGH). RXD is an output and
reports the bus state (RXD LOW when CAN bus is dominant,
HIGH when CAN bus is recessive).
V_DD
The V_DD terminal is the output terminal of the 5.0 V internal
regulator. It can deliver up to 200 mA. This output is protected
against overcurrent and overtemperature. It includes an
overtemperature pre-warning flag, which is set when the
internal regulator temperature exceeds 130°C typical. When
the temperature exceeds the overtemperature shutdown
(170°C typical), the regulator is turned off.
V_DD includes an undervoltage reset circuitry, which sets the
RST terminal LOW when V_DD is below the undervoltage reset
threshold.
RST
The Reset terminal RST is an output that is set LOW when
the device is in reset mode. The RST terminal is set HIGH when
the device is not in reset mode. RST includes an internal pullup
current source. When RST is LOW, the sink current capability is
limited, allowing RST to be shorted to 5.0 V for software debug
or software download purposes.
INT
The Interrupt terminal INT is an output that is set LOW when
an interrupt occurs. INT is enabled using the Interrupt Register
(INTR). When INT occurs, INT stays LOW until the INT source
is cleared.
INT output also reports a wake-up event by a 10 µs typical
pulse when the device is in stop mode.
V2
The V2 terminal is the input sense of the V2 regulator. It is
connected to the external ballast transistor. V2 is also the 5.0 V
supply of the internal CAN interface. It is possible to connect V2
to an external 5.0 V regulator or to the V_DD output when no
external ballast transistor is used. In this case, the V2CTRL
terminal must be left open. Refer to Figure 28, 33742 Typical
Application Schematic, page 46.
V2CTRL
The V2CTRL terminal is the output drive of the V2 regulator
connected to the external ballast transistor.
V_SUP
The V_SUP terminal is the battery supply input of the device.
HS
The HS terminal is the internal high-side driver output. It is
internally protected against overcurrent and overtemperature.
L0, L1, L2, and L3
The L0:L3 input terminals can be connected to external
switches or any IC’s output. The state of the inputs can be read
by SPI. Theses inputs can be used as wake-up events when the
device is set in Sleep or Stop mode.
CANH and CANL
The CAN High and CAN Low terminals are the interfaces to
the CAN bus lines. They are controlled by TXD input level, and
the state of CANH and CANL is reported through RXD output.
A 60 Ω impedance termination is connected between CANH
and CANL.
33742
18
MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
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