mcz33800ek/r2 Freescale Semiconductor, Inc, mcz33800ek/r2 Datasheet - Page 29

• Manufacturer Part Number: mcz33800ek/r2
• Description: Engine Control Integrated Circuit
• Manufacturer: Freescale Semiconductor, Inc

greater than 0.0mA. Commands outside of this command
range will automatically lock out dither.
CCD2 Control command. The command consists of an
control address, Diagnostic Pull-up Enable bit (Diag_pu_EN),
Dither Disable bit (DTHR_DIS), and a 9-bits of data for digital
to analog conversion (DAC). The data is received and the
DAC provides bias for a comparator to produce a threshold
level. The comparator drives a switch control circuit which
generates a frequency modulated signal for the output drive.
The differential voltage across the sense resistor provides
the feedback necessary to maintain the desired output
current. The output current is continuously monitored as a
differential voltage across the internal sense resistor. When
the current is recirculation and the driver is in the off state, the
current will decay to the lower limit switch point. When the
current reaches the lower limit, the driver will turn on to
increase the current until the upper limit switch point is
reached. The output current will continue to switch between
the switch points, resulting in the desired average current.
The switch points are set to a fixed +/-5% of the commanded
Table 18. CCD2 Constant Current Controller Commands
Notes
Analog Integrated Circuit Device Data
Freescale Semiconductor
CCD2 Control
0 = Pull-down Current Source
1 = Pull-up Current Source
CCD2 Frequency & Amplitude
Next SO Response (Message 2)
0 = No Fault, 1 = Fault
23.
24.
25.
Programming the solenoid current begins by sending the
Trim Set bit indicates (0 = untrimmed, 1 = trimmed)
VCAL Status bit indicates when internal or external supply is used. VCAL Bit = 0 indicates external, VCAL Bit = 1indicates internal.
Reset Bit indicates the device has performed a POR.
Command
OvrVlt
,TLim
CAL
15
Flt
or
1
1
CCD2 Command Address
CCD2 Command Address
Reset Trim
14
Control Address
1
1
Set
13
0
0
(23)
VCAL
Status
int=0
ext=1
12
0
0
CCD2
Open
Fault
11
0
1
CCD2
CCD2
Retry
Short
Fault
Diag
Pull-
10
up
0
1
current. The switching frequency and accuracy are
dependent upon the load inductance and resistance, battery
voltage, dither amplitude and frequency, switch points, and
the commanded current.
increased and decreased through the solenoid valve. The
33800 allows the user to program the frequency and
amplitude of the dither control. Dither amplitude is
implemented by increasing and decreasing the DAC by the
programmed dither value. The rate at which the value is
changed is set by the programmed dither frequency. When
reprogramming the dither amplitude or dither frequency, the
update will occur on the start of a positive cycle.
less than 232mA. When a greater value is programmed, the
device will disable dither on the output. Similarly, the
minimum value of the output (DAC - Dither) must be greater
than 0.0mA. Requesting a lower value will disable dither on
the output.
DTHR
CCD1
Open
Fault
DIS
Current dither is a method by which the average current is
The maximum value of the output (DAC + Dither) must be
X
9
0
CCD1
Short
Fault
8
0
X
Status
OUT8
Fault
7
0
X
Status
OUT7
Fault
Dither Amplitude
Command Bits
6
0
0
9 BIT DAC Command Data
LOGIC COMMANDS AND REGISTERS
Status
OUT6
Fault
FUNCTIONAL DEVICE OPERATION
5
0
1
Status
OUT5
Fault
4
0
1
Status
OUT4
Fault
3
0
0
Dither Frequency
Status
OUT3
Fault
2
0
1
Status
OUT2
Fault
1
0
0
Status
OUT1
Fault
33800
0
0
0
29