mc33905s Freescale Semiconductor, Inc, mc33905s Datasheet - Page 29

• Manufacturer Part Number: mc33905s
• Description: System Basis Chip Gen2 With High Speed Can And Lin Interface
• Manufacturer: Freescale Semiconductor, Inc

UNDER-VOLTAGE RESET AND RESET FUNCTION
(RST)
pull-up current source. The low side driver has limited current
capability when asserted low, in order to tolerate a short to
5.0V.The Reset terminal voltage is monitored in order to
detect failure (e.g. RESET pin shorted to 5.0V or GND).
condition at the VDD pin, as well as failure in watchdog
refresh operation. VDD under-voltage reset operate also in
Low Power V
on (typ 4.65V, R
This is selected by the SPI. When “R
Normal Mode, an INT is asserted when VDD falls below “R
TH1-5
mode, for example, with 4.0V V
I/O PINS (I/O-1: I/O-3)
for small load or to drive external transistors. When used as
output drivers, the I/Os are high side or low side type. They
can also be set to high-impedance. I/Os are controlled by
SPIn and at power on, the I/Os are set as inputs. They
include over load protection by temperature or excess of drop
voltage.
off, with extremely low extra consumption (except load).
Protection is disabled in low power mode.
switch, I/O-1, 2 and 3 and the wake inputs.
terminal function.
VSENSE INPUT (VSENSE)
reverse battery protection diode), via a serial resistor and a
Analog Integrated Circuit Device Data
Freescale Semiconductor
The RESET pin is an open drain structure with an internal
The RESET pin reports to the MCU under -voltage
Two VDD under-voltage threshold are included. The upper
I/O s are configurable input output pins. They can be used
In Low Power Mode, state of the I/O can be turned on or
When cyclic sense is used, I/O-0 is the high side/low side
I/O-2 and I/O-3 terminals share also the LIN Master
This pin can be connected to the battery line (before the
“. This will allow the MCU to operate in a degraded
DD
ST-TH1-5
ON Mode.
) can lead to a Reset or an Interrupt.
DD
.
ST-TH2-5
“is selected, in
ST-
capacitor to gnd. It incorporates a threshold detector to sense
the battery voltage and provide a battery early warning. It also
includes a resistor divider to measure the VSENSE voltage
via the MUX OUT pin.
MUX OUTPUT (MUXOUT)
voltage to the MCU A/D input. The voltage to be delivered to
MUX-OUT is selected via the SPI, from one of the following
functions: Vsup1, Vsense, I/O-0, I/O-1, Internal 2.5V
reference, die temperature sensor, VDD current copy.
shown in
MUX OUT pin, to convert current into voltage. Device
includes an internal 2k resistor selectable by SPI.
automatically limited to VDD (max 3.3V for 3.3V part
numbers).
so the 5V-CAN regulator must be ON in order to have:
SPI command that selects one of the analog input is ignored.
CAN turn ON and SPI to select MUX-OUT function. The
delay depends mainly upon the 5V-CAN capacitor and load
on 5V-CAN.
delay = C(
(parameter 5V
The MUX-OUT terminal
Voltage divider or amplifier are inserted in the chain, as
For the VDD current copy, a resistor must be added to the
Voltage range at MUX_OUT is from gnd to VDD. It is
The MUX-OUT buffer is supplied from 5V-CAN regulator,
1) MUX-OUT functionality and
2) SPI selection of the analog function.
If 5V-CAN is OFF, MUX-OUT voltage is near gnd and the
Delay must be respected between SPI commands for 5V-
The delay can be estimated using the following formula:
C = cap at 5V-CAN regulator, U = 5V,
I_lim 5V-CAN = min current limit of 5V-CAN regulator
Figures
5V-CAN
-C ILIM
) x U (
17.
).
5V
) / I_lim 5V-CAN.
(Figures
FUNCTIONAL PIN DESCRIPTION
FUNCTIONAL DESCRIPTION
17) delivers an analog
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