33937 Datasheet, PDF (26/47 Pages) Freescale Semiconductor, Inc – Three Phase Field Effect Transistor Pre-driver

FUNCTIONAL INTERNAL BLOCK DESCRIPTION
FUNCTIONAL INTERNAL BLOCK DESCRIPTION
MC33937 - Functional Block Diagram
Integrated Supply
Main Charge Pump Trickle Charge Pump
5V Regulator
VLS Regulator
Sensing & Protection
Hold-off
Under-voltage
Temperature
De-sat
Current Sense
Phase
Over-current
Logic & Control
Fault Register
Dead Time
Phase Control
Mode Control
SPI Communication
High Side
and
Low Side
Output
Pre-drivers
Integrated Supply Sensing & Protection Logic & Control Drivers
Figure 15. Functional Internal Block Description
All functions of the IC can be described as the following
12 µs. Calibration of the delay, because of internal IC
five major functional blocks:
variations, is performed via the SPI.
• Logic Inputs and Interface
• Bootstrap Supply
• Low Side Drivers
• High Side Drivers
• Charge Pump
LOGIC INPUTS AND INTERFACE
This section contains the SPI port, control logic, and shoot-
through timers.
• Enabling of simultaneous operation of High Side and
Low Side FETs—Normally, both FETs would not be
enabled simultaneously. However, for certain applications
where the load is connected between the High Side and
Low Side FETs, this could be advantageous. If this mode
is enabled, the blanking time delay will be disabled. A
sequence of commands may be required to enable this
function to prevent inadvertent enabling. In addition, this
command can only be executed once after reset to enable
or disable simultaneous turn-on.
The IC logic inputs have Schmitt trigger inputs with
hysteresis. Logic inputs are 3.0 V compatible. The logic
outputs are driven from the internal supply of approximately
5.0 V.
The SPI registers and functionality is described completely
in the LOGIC COMMANDS AND REGISTERS section of this
document. SPI functionality includes the following:
• Programming of deadtime delay—This delay is
adjustable in approximately 50 ns steps from 0 ns to
• Setting of various operating modes of the IC and
enabling of interrupt sources.
The 33937 allows different operating modes to be set and
locked by an SPI command (FULLON, Desaturation Fault,
Zero Deadtime). SPI commands can also determine how
the various faults are (or are not) reported.
• Read back of internal registers.
The status of the 33937 Status Registers can be read back
by the Master (DSP or MCU).
33937
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Analog Integrated Circuit Device Data
Freescale Semiconductor