Analog Integrated Circuit Device Data
18
Freescale Semiconductor
33989
FUNCTIONAL DESCRIPTION
INTRODUCTION
FUNCTIONAL DESCRIPTION
INTRODUCTION
The 33989 is an integrated circuit dedicated to automotive applications. Its functions include:
One full protected voltage regulator with 200 mA total output current capability available at the VDD1 external pin
Driver for an external path transistor for the V2 regulator function
Reset, programmable watchdog function, interrupt, and four operational modes
Programmable wake-up input and Cyclic Sense wake-up
CAN high speed physical interface
FUNCTIONAL PIN DESCRIPTION
RECEIVE AND TRANSMIT DATA (RXD AND TXD)
The RX and TX pins (receive data and transmit data pins, respectively) are connected to a microcontroller’s 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).
VOLTAGE DIGITAL DRAIN ONE (VDD1)
The VDD1 pin is the output pin 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.
VDD1 includes an undervoltage reset circuitry, which sets the RST pin LOW when VDD1 is below the undervoltage reset
threshold.
RESET (RST)
The Reset pin RST is an output that is set LOW when the device is in reset mode. The RST pin is set HIGH when the device
is not in reset mode. RST includes an internal pull-up 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.
INTERRUPT (INT)
The Interrupt pin INT is an output that is set LOW when an interrupt occurs. INT is enabled using the Interrupt Register (INTR).
When an interrupt occurs, INT stays LOW until the interrupt source is cleared.
INT output also reports a wake-up event by a 10
s typical pulse when the device is in Stop mode.
VOLTAGE SOURCE TWO (V2)
The V2 pin is the input sense for the V2 regulator. It is connected to the external series pass 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 VDD1 output when no
external series pass transistor is used. In this case, the V2CTRL pin must be left open.
VOLTAGE SOURCE 2 CONTROL (V2CTRL)
The V2CTRL pin is the output drive pin for the V2 regulator connected to the external series pass transistor.
VOLTAGE SUPPLY (VSUP)
The VSUP pin is the battery supply input of the device.
HIGH-SIDE ONE (HS1)
The HS1 pin is the internal high side driver output. It is internally protected against overcurrent and overtemperature.
LEVEL 0-3 INPUTS (L0:L3)
The L0:L3 pins can be connected to contact switches or the output of other ICs for external inputs. The input states can be
read by SPI. These inputs can be used as wake-up events for the SBC when operating in the Sleep or Stop mode.