33888 Datasheet, PDF (18/40 Pages) Freescale Semiconductor, Inc – Quad High-Side and Octal Low-Side Switch for Automotive

FUNCTIONAL DESCRIPTION
INTRODUCTION
FUNCTIONAL DESCRIPTION
INTRODUCTION
This 33888 is a single-package combination of a power die
with four discrete high-side MOSFETs and an integrated IC
control die consisting of eight low-side drivers with
appropriate control, protection, and diagnostic features. The
high-side drivers are useful for both internal and external
vehicle lighting applications as well as capable of driving
inductive solenoid loads. The low-side drivers are capable of
controlling low-current on/off type inductive loads, such as
relays and solenoids as well as LED indicators and small
lamps (see Figure 2, page 3). The device is useful in body
control, instrumentation, and other high-power switching
applications and systems.
The 33888 is available in two packages: a power-
enhanced 12 x 12 non-leaded Power QFN package with
exposed tabs and a 64-lead Power QFP plastic package.
Both packages are intended to be soldered directly onto the
printed circuit board.
The 33888 differs from the 33888A as explained in
Table 1, page 2.
FUNCTIONAL PIN DESCRIPTION
FAULT STATUS (FS)
This output pin is an open drain indication that goes active
low when a fault mode is detected by the device. Specific
device fault indication is given via the SO pin.
POSITIVE POWER SUPPLY (V_PWR)
These pin connects to the positive power supply and are
the source input of operational power for the device.
LOW-SIDE OUTPUT (LS4, LS6, LS8, LS10)
Each low-side pin is one 0.6 Ω low-side output MOSFET
drain, which pulls current through the connected loads. Each
of the outputs is actively clamped at 53 V. These outputs are
current and thermal overload protected. Maximum steady
state current through each of these outputs is 500 mA.
GROUND (GND)
These pins serve as the ground for the source of the low-
side output transistors as well as the logic portion of the
device.
LOW-SIDE OUTPUT (LS5, LS7, LS9, LS11)
Each low-side pin is one 0.6 Ω low-side output MOSFET
drain, which pulls current through the connected loads. Each
of the outputs is actively clamped at 53 V. These outputs are
current and thermal overload protected. Maximum steady
state current through each of these outputs is 800 mA.
DIGITAL DRAIN VOLTAGE (V_DD)
This is an external input pin used to supply power to the
SPI circuit.
SERIAL OUTPUT (SO)
This is an output pin connected to the SPI Serial Data Input
pin of the MCU or to the SI pin of the next device in a daisy
chain. This output will remain tri-stated unless the device is
selected by a low CS pin. The output signal generated will
have CMOS logic levels and the output data will transition on
the rising edges of SCLK. The serial output data provides
fault information for each output and is returned MSB first
when the device is addressed. OD11 through OD0 are output
fault bits for outputs 11 through 0, respectively.
CHIP SELECT (CS)
This is an input pin connected to a chip select output of a
microcontroller (MCU). This IC controls which device is
addressed (selected) by pulling the CS pin of the desired
device logic Low, enabling the SPI communication with the
device, while other devices on the serial link keep their serial
outputs tri-stated. This input has an internal active pullup and
requires CMOS logic levels.
SERIAL CLOCK (SCLK)
This input pin is connected to the SCLK pin of the master
MCU, which is a bit (shift) clock for the SPI port. It transitions
one time per bit transferred at an operating frequency, fSPI,
and is idle between command transfers. It is 50% duty cycle
and has CMOS logic levels. This signal is used to shift data
to and from the 33888.
SERIAL INPUT (SI)
This input pin is connected to the SPI Serial Data Output
pin of the MCU from which it receives output command data.
This input has an internal active pull-down and requires
CMOS logic levels. The serial data transmitted on this line is
a 16-bit control command sent MSB first, which controls the
twelve output channels. Bits D3 : D0 control the high-side
outputs HS3 : HS0, respectively. Bits D11: D4 control the low-
side outputs LS11: LS4, respectively. The MUC will ensure
that data is available on the falling edge of SCLK.
LOW-SIDE INPUT (ILS)
This input pin is used to directly control a number of the
low-side devices as configured by SPI. This pin may or may
not be activated depending on the configured state of the
internal logic.
33888
18
Analog Integrated Circuit Device Data
Freescale Semiconductor