
33742
18
MOTOROLA ANALOG INTEGRATED CIRCUIT DEVICE DATA
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
 μ
s 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
 
 impedance termination is connected between CANH 
and CANL.
F
Freescale Semiconductor, Inc.
For More Information On This Product,
  Go to: www.freescale.com
n
.