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Электронный компонент: IL33197

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IL33197
1
A
UTOMOTIVE WASH WIPER TIMER
The IL33197A is a standard wiper timer control device designed for harsh automotive applications. The
device can perform the intermittent, after wash, and continuous wiper timer functions. It is designed to
directly drive a wiper motor relay. The IL33197A requires very few external components for full system
implementation. The intermittent control pin can be switched to ground or V
bat
to meet a large variety of
possible applications. The intermittent timing can be fixed or adjustable via an external resistor. The
IL33197A is built using bipolar technology and parametrically specified over the automotive ambient
temperature range and 8.0 to 16 V supply voltage. The IL33197A can operate in both front and rear wiper
applications.
Adjustable Time Interval of Less Than 500 ms to
More Than 30 s
Intermittent Control Pin Can Be Switched to Ground
or V
bat
Adjustable After Wipe Time
Priority to Continuous Wipe
Minimum Number of Timing Components
Integrated Relay Driver With Free Wheeling
Protection Diode
Operating Voltage Range From 8.0 to 16 V
For Front Wiper and Rear Wiper Window
Applications
8
1
PIN CONNECTIONS
This device contains 60 active transistors.
MAXIMUM RATINGS
Rating Symbol
Value
Unit
Continuous Supply Voltage (V
Pin 6
)
V
CC
16
V
Storage Temperature
T
stg
-55 to +150
o
C
Thermal Resistance (Junction-to-
Ambient)
R
JA
100
o
C/W
Operating Ambient Temperature Range T
A
-40 to +125
o
C
Operating Junction Temperature Range T
J
-40 to +150
o
C
Maximum Junction Temperature
T
J(max)
150
o
C

Representative Block Diagram
IL33197
2
ELECTRICAL CHARACTERISTICS (-40
o
C
T
A
+125
o
C, 8.0 V
V
CC
16 V, unless otherwise noted.
Typical values reflect approximate mean at T
A
= 25
o
C with V
CC
= 14 V at the time of initial device
characterization.)
Characteristic Symbol
Min
Typ
Max
Unit
Functional Supply Voltage Range
V
CCF
8.0 - 18
V
Operating Supply Voltage Range
V
CCOP
8.0 - 16 V
Standby Supply Current (V
CC
= 16 V, R2 = 68 k)
I
CC
- 4.0
5.2
mA
Supply Current INT Active (R3 = 2.5 k)
I
CC
- 7.0
8.4
mA
Supply Current Relay "On" (R2 = 68 k)
I
CC
- 7.5
11.2
mA
Supply Current INT and Relay "On" (R2 = 68 k, R3 =
2.5 k)
I
CC
- 10
14.5
mA
Oscillator Variations with Supply Voltage and
Temperature (excluding external component
tolerances, C2 = 100 nF polyester capacitor) (Notes
1 & 2)
K
osc
%
10 V
V
bb
16 V
-
10
-
8.0 V
V
bb
16 V
-
15
-
Relay Resistance
R
L
60
- -
Output Voltage (I
out
= 200 mA)
V
out
- 0.9
1.5
V
Output Clamp Voltage (I
out
= 20 mA)
V
cl
19.5
- 22
V
Oscillator Period Coefficient (T
A
= 25
o
C)
-
V
bb
= 13 V (Note 3)
t
b1
0.98
1.0
1.03
V
bb
= 13 V (INT Connected to Gnd) (Note 4)
t
b2g
15.1 15.5 15.9
V
bb
= 13 V (INT Connected to V
bat
, R1 = 220
)
(Note 4)
t
b2v
11.5 12.1 12.7
CONT Threshold (V
CC
= 13 V)
V
ih
6.0
- 8.5
V
CONT Threshold (V
CC
= 16 V)
V
ih
- V
CC
/2
- V
NOTES:
1. The oscillator frequency is defined by the current flowing through the external resistor R2. The voltage at the INT pin is
(V
CC
/2 - V
be
) and hence the current flowing through R3 is different if R3 is connected to V
bb
or to Gnd because of the voltage
drop across resistor R1. This voltage drop causes the oscillator coefficient for tb2 to be different for the two cases of INT
terminated to Gnd or to V
bb
. Because of this, the oscillator coefficient is specified with a specific value of R1 whenever INT is
connected to V
bb
. If R1 is changed, the coefficient will change. Also, any extra current through the resistor R1 other than the
current used by the device will cause timing deviations in t
b2
timings (as in the case where two devices are sharing a
common R1 resistor).
2. The oscillator stability with temperature is dependent on the temperature coefficients of the external components. If the
capacitance value of the external capacitor varies more than 5% over the parametric temperature range, the figures quoted
for oscillator variation are not valid.
3. The t
b1
duration is given by coefficient 4 x R2 x C2 (tb1 duration = tb1 x 4 x R2 x C2). 4. The t
b2
duration is given by
coefficient x R3 x C2 (t
b2
duration = tb2 x R3 x C2).
IL33197
3
TYPICAL APPLICATION
This application shows the IL33197A with the external wirings and two speed wiper motor. This
application has the Intermittent and Wash Wiper functions.

INTRODUCTION
The IL33197A is a wiper timer control device designed for use in harsh automotive applications. The
device can perform the intermittent, after wash, and continuous wiper timer functions.
The IL33197A is designed to directly drive a wiper motor relay. The IL33197A is suitable for both front
and rear wiper applications. The IL33197A connects directly to the vehicle's battery voltage (V
bat
)
through
a 220
resistor used with a 47F de-coupling filter capacitor. The device has an internal oscillator
controlled by one of two external resistors (R2 and R3) in addition to one external capacitor (C2),
dependent on the application function required. The values of C2 and R2 determine the t
b1
time base. T
b1
is used to generate the relay wiper activation during the INT function (T3) and the after wash timing (T2)
during the wash wipe mode. The values C2 and R3 determine the t
b2
time base. The t
b2
time base is used
to generate the pause or intermittent time (T4).
The intermittent wiper function can generate intermittent timing (T4) from less than 500 ms to more
than 30 seconds. The intermittent function of the device can be activated by the INT input connected to
either ground or
V
bat
. The intermittent
timing is externally adjustable by changing the value of resistor R3.
The wash wiper timer function detects the water pump motor's operation. When the pump motor
activation is detected, the IL33197A turns the wiper on for the entire duration of the pump motor's
activation. When the motor is turned off, it generates an after wash timing (T2) to maintain the wiping
action. The W/W pin is connected to the water pump motor through a protection resistor (R4).
The IL33197A also has a continuous function, which activates the wiper relay whenever the CONT
input is activated. The CONT input is connected to a switch through a protection resistor (R5). The CONT
input comparator has an input threshold of V
bb
/2 with hysteresis.
The device has internal debounce circuitry, based on the oscillator period. This provides filtering of the
intermittent (INT) and wash wipe (W/W) input signals (see T1 Debounce Timing paragraph that follows).
The device directly drives the wiper motor relay. It internally incorporates a 20 V free wheeling zener
diode to protect the device against overvoltage spikes produced when relay is switched off.
Intermittent Operation
Conditions:

W/W not connected or connected to ground.

CONT not connected or connected to ground.

INT connected to V
bb
or to ground.
In this configuration, the circuit will respond to the 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
IL33197
4
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.
Figure 2. Switching Waveform INT Timing
Wash Wipe Operation
Conditions:

INT disconnected.

CONT disconnected or connected to ground.
In this condition, the circuit will respond to the switching of 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
.
Figure 3. Switching Waveform W/W Timing
Continuous Operation
In this condition, the circuit responds to the switching of 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 other timing.
Therefore, the circuit will not be reset to a defined state.
Wash Wiper and Intermittent Operation
If W/W is activated during the time INT is also activated, 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.
Figure 4. Switching Waveform W/W and INT Active
T1 Debounce Timing
The criteria for an input signal to be detected is that it 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
.
IL33197
5
The following table summarizes all T1 debounce timings:
Condition Debounce
Time
INT Active
4 x t
b1
to 2 x 4 x t
b1
INT Inactive
4 x t
b1
to 2 x 4 x t
b1
W/W Active When INT Inactive
4 x t
b1
to 2 x 4 x t
b1
W/W Active When INT Active During T3 4 x t
b1
to 2 x 4 x t
b1
W/W Active When INT Active During T4 4 x t
b2
to 2 x 4 x t
b2
Two IL33197A Devices Using One Decoupling Resistor and Capacitor
Two devices may be connected to the power source using 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.
Overvoltage Protection
In reference to the Block Diagram and Typical Application, all of the foregoing operational cases
require: R1
100 , C1 47 F
R3
1.0 k, R4 4.7 k, R5 4.7 k
The circuit will not operate during the transient conditions. By using the above component values, the
circuit will be able to sustain the following overvoltages on V
bb
without permanent damage: 1. +28 V for 5
minutes 2. -15 V for 5 minutes 3. -16 V cycled off for 1.0 minute 4. +80 V pulse decaying exponentially to
8.0 V in 400 ms repeated 3 times at 1.0 minute intervals.
5.
300 V pulse decaying exponentially to 30 V in 300 ms with a maximum energy of 1.0 Joule.
6.
100 V pulse decaying exponentially to 10 V in 2 ms.
Recommended External Component Values
Below are the recommended component values to ensure the device will operate properly, and that all
specified parameters will stay within their tolerances.
R1 should be greater than 100
; recommended value of 220 . R1 can be up to 500 , but in this
case the t
b2v
parameter could be out of it's specified value (see Electrical Characteristics and Note 1).
Also, the minimum operating voltage range should be greater than 8.0 V. The following values should be
adhered to:
10 k
R2 68 k; 1.5 k R3 47 k; R4 4.7 k; R5 4.7 k; C1 47 uF; 47 nF C2 470 nF
Application Information
The following is an example of timing calculations using the following external components values:
R2 = 22 k
, R3 = 2.2 k, C2 = 100 nF (Referring to Block Diagram and Typical Application).
Oscillator Time Base Calculation:
t
b1
duration = t
b1
x 4 x R2 x C2 = 1 x 4 x 27e3 x 100e-9 = 10.8 ms;
t
b2
duration_g (INT to Gnd) = t
b2g
x R3 x C2 = 15.5 x 2.2e3 x 100e-9 = 3.41 ms
t
b2
duration_v (INT to V
bb
) =
t
b2v x R3 x C2 = 12.1 x 2.2e3 x 100e-9 = 2.66 ms
Intermittent timing calculation:
T3 = 16 x 4 x t
b1
duration = 16 x 4 x 10.8 ms = 691 ms
T4 = 144 x 4 x t
b2
duration_g = 144 x 4 x 3.41 ms = 1.96 s (INT connected to Gnd)
T4 = 144 x 4 x t
b2
duration_v = 144 x 4 x 2.66 ms = 1.53 s (INT connected to V
bb
)
Wash wipe timing calculation:
T2 = 96 x 4 x t
b1
= 96 x 4 x 10.8 ms = 4.15 s
T1 Debounce Time Calculation (see T1 Debounce Timing)
When oscillator is oscillating at t
b1:
T1 minimum = 4 x t
b1
= 4 x 10.8 ms = 43.2 ms
T1 maximum = 2 x 4 x t
b1
= 2 x 4 x 10.8 ms = 86.4 ms
When oscillator is oscillating at
t
b2
: T1 minimum (INT connected to Gnd, t
b2g
) = 4 x t
b2
= 4 x 3.41 ms =
13.6 ms T1 maximum (INT connected to Gnd, t
b2g
) = 2 x 4 x t
b2
= 2 x 4 x 3.41 ms = 27.3 ms