mc33197d ETC-unknow, mc33197d Datasheet - Page 4

• Manufacturer Part Number: mc33197d
• Description: Automotive Wash Wiper Timer
• Manufacturer: ETC-unknow

switching of INT to either V bb or ground after a time T1 (see
T1 Debounce Timing). If INT is disconnected before the end
of T1; no action will be taken. After a time T1, the output will
be switched on for a duration, T3 = 16 x 4 x t b1 and then
switched off for a duration, T4 = 144 x 4 x t b2 . This sequence
will continue to repeat so long as INT is disconnected from
V bb or ground for a time duration greater than T1. If INT is
disconnected during the time T3; the output will remain on for
the remainder of T3. This is illustrated in the diagram on
Figure 2.
Wash Wipe Operation
W/W to V bb after a time T1 (see T1 Debounce Timing). If
W/W is disconnected or connected to ground before the end
of T1; no action will be taken. After a time T1; the circuit will
perform as shown on Figure 3. The output will turn on and
remain on for the duration of W/W. When W/W becomes
inactive, the output will remain on for T2 = 96 x 4 x t b1 .
Continuous Operation
CONT to V bb . If CONT is connected to V bb , the output will
turn on regardless of the state of any other input and remain
on so long as CONT is active. This command operates
directly on the relay output and does not interfere with any
4
In this configuration, the circuit will respond to the
Conditions:
In this condition, the circuit will respond to the switching of
In this condition, the circuit responds to the switching of
T1
INT disconnected.
CONT disconnected or connected to ground.
W/W
INT
Out
Out
T3
Figure 3. Switching Waveform W/W Timing
Figure 2. Switching Waveform INT Timing
T1
T4
T2
MC33197
other timing. Therefore, the circuit will not be reset to a
defined state.
Wash Wiper and Intermittent Operation
the circuit will respond to W/W after a time T1 (see T1
Debounce Timing). The output will turn on after T1, and stay
on for a time T2 + T3 after W/W is deactivated. Following this,
normal operation of INT will occur. This is shown on Figure 4.
T1 Debounce Timing
should be active at two successive negative internal clock
edges. The inputs are sampled on the negative edge of the
internal clock. If two consecutive samples are the same, the
input is detected as being in that state. Hence the time T1 from
a signal becoming active to the time that the circuit responds
can be anytime from 4 x t b1 to 2 x 4 x t b1 (due to synchronizing
the input to the oscillator period) when the oscillator is
oscillating with a time base of t b1 and 4 x t b2 to 2 x 4 x t b2 , when
the oscillator is oscillating with a time base of t b2 .
Two MC33197 Devices Using One Decoupling Resistor
and Capacitor
a common R1 resistor for protection against overvoltages. If
this is done it should be noted that the current flowing
through R1 is increased and hence the voltage drop across
R1 is increased.
INT
W/W
Out
INT Active
INT Inactive
W/W Active When INT Inactive
W/W Active When INT Active During T3
W/W Active When INT Active During T4
If W/W is activated during the time INT is also activated,
The criteria for an input signal to be detected is that it
The following table summarizes all T1 debounce timings:
Two devices may be connected to the power source using
Figure 4. Switching Waveform W/W and INT Active
T1
Condition
MOTOROLA ANALOG IC DEVICE DATA
T2
T3
T4
4 x t b1 to 2 x 4 x t b1
4 x t b1 to 2 x 4 x t b1
4 x t b1 to 2 x 4 x t b1
4 x t b1 to 2 x 4 x t b1
4 x t b2 to 2 x 4 x t b2
Debounce Time
T3