MCZ33800R2 FREESCALE [Freescale Semiconductor, Inc], MCZ33800R2 Datasheet - Page 24

• Manufacturer Part Number: MCZ33800R2
• Description: Engine Control Integrated Circuit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Table 11. PWM Short Fault Timer
33800 will wait for the Short Fault Time period and then shut
down the output drive, setting the fault status bit to a 1 in the
Serial Output Response Register.
Example: Load Measurement Operation
33800 device uses an alternate channel to determine a
differential load voltage and forces a known load current.
With the differential load voltage and the forced current the
load resistance is calculated. As shown in
is used as the battery reference for the load measurement of
channel 1. The current through the channel 1 load is set by
the external resistor. Setting the resistance to 25Ω forces a
current of 100mA. The measurement is sampled within
200µs and is held for 150ms on the Load Resistance
Feedback (L
fixed gain of 2.5V. Hence for this example, a 10Ω load will
produce a 2.5V output. When a second pair is selected for
measurement, the sample and hold is reset and the
measurement is immediately directed to the new load
measurement. The previous pair immediately revert back to
normal operation.
24
33800
FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
Notes: Tolerance on fault timer setting is
PWM FLT Timer
To perform an accurate load resistance measurement the
Bits
210
543
876
000
001
010
011
100
101
110
111
RFDBK
) output. The differential amplifier has a
Fault Timer Select
No Change
No Change
±10%
120µs
240µs
480µs
960µs
30µs
60µs
Table
with calibrated part.
6, channel 2
OCTAL OUTPUT DRIVER (OCTAL SERIAL
SWITCH; OSS)
outputs. Outputs 1 and 2 are specifically designed with higher
current limit to accommodate lamp inrush current. The device
allows for parallel control and/or SPI control through the use
of several input command words. This section describes the
logic operation and commands for the octal driver.
eight commands, and one response as shown in
Bits 11 through 15 determine the specific command and bits
0 through 10 determine how a specific output will operate.
The 33800 operates on the command word on the rising edge
of CS. The Most Significant Bit (MSB) is sent and received
first.
shown in
The 33800 provides flexible control of 8 low side driver
The 33800 Octal Output Driver message set consists of
Note Upon Power-ON Reset all OSS bits are defined as
VCAL
Figure 9. Example of Channel 1 Measurement
Table
+
−
12.
Diagnostics
Diagnostics
Gate Drive
+
−
Gate Drive
Control &
Control &
Analog Integrated Circuit Device Data
Differential
Amplifier
Predriver 1
Predriver 2
V
V
PWR
PWR
Freescale Semiconductor
+
−
Table
VSSNS123
VSSNS123
VDSNS1
GD1
VDSNS2
GD2
REXT
LRFDBK
12.