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IL33197A Automotive Wash Wiper Timer

ORDERING INFORMATION

TA = -45° to 105°C (SOIC) TA = -45° to 125°C (DIP) The IL33197A is a standard wiper timer control device designed for harsh automotive ap plications. Th e d evice can p erform the intermittent, after wash, and cont inuous wi per t imer func tions. It i s desi gned to directly drive a wi per m otor rel ay. The IL33197A requi res very few external components for full system implementation. The interm ittent control pin can be swi tched t o ground or Vbat t o m eet a l arge vari ety of possible applications. The in termittent tim ing can b e fix ed o r ad justable v ia an external resistor. The IL33197A is built using bipolar technology and parametrically specified over the au tomotive am bient tem perature range and 8.0 to 16 V suppl y voltage. The IL33197A can operat e 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 Vbat
  • 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

Representative Block Diagram This device contains 390 active transistors. ELECTRICAL CHARACTERISTICS (–45°C 3 TA ≤ +125°C, 8.0 V ≤ VCC ≤ 16 V, unl ess otherwise noted. Typical values reflect approximate mean at TA = 25°C with VCC = 14 V at the time of initial device characterization.) NOTES: 1. The oscillator frequency is defined by the current flowing through the external resi stor R2. The voltage at the INT pin is (VCC/2 – Vbe) and hence the current flowing through R3 is different if R3 is connected to Vbb 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 term inated to Gnd or to Vbb. Becau se of this, the oscillator coefficient is specified with a specific value of R1 whenever INT is connected to Vbb. If R1 is changed, the coefficient will ch ange. Also, any extra current through the resistor R1 other than the current used by the device will cause tim ing deviations in t b2 timings (as in the cas e 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 tb1 duration is given by coefficient 4 x R2 x C2 (tb1 duration = tb1 x 4 x R2 x C2). 4. The tb2 duration is given by coefficient x R3 x C2 (tb2 duration = tb2 x R3 x C2).

Figure 1. Intermittent Wash Wiper Typical Application wiper motor. This application has the Intermittent and Wash Wiper functions. (T4). The intermittent wiper function can generate intermittent timing (T4) from less than 500 ms to more than 30 seconds. against overvoltage spikes produced when relay is switched off.

  • W/W not connected or connected to ground.
  • CONT not connected or connected to ground.
  • INT connected to Vbb or to ground. In this configuration, the circuit will respond to the switching of INT to either Vbb or ground after a tim e T1 (see T1 Debounce Timing). If INT is disconnected before the end of T1; no action will be taken. After a tim e T1, the output will be switched on for a duration, T3 = 16 x 4 x tb1 and then switched off for a duration, T4 = 144 x 4 x tb2. This sequence will continue to repeat so long as INT is disconnected from Vbb or ground for a tim e 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.

Conditions:

  • INT disconnected.
  • CONT disconnected or connected to ground. In this condition, the circuit will respond to the switching of W /W to Vbb after a tim e 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 tb1. Continuous Operation In this condition, the circuit responds to the switching of CONT to Vbb. If CONT is connected to Vbb, 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 o utput and does not interfere with any other timing. Therefore, the circuit will n ot 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 st ay on for a tim e 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 The criteria for an input signal to be detected is that it should be active at two successive negative internal clock edges. oscillating with a time base of tb1 and 4 x tb2 to 2 x 4 x tb2, when the oscillator is oscillating with a time base of tb2.

  1. –16 V cycled off for 1.0 minute
  2. +80 V pulse decaying exponentially to 8.0 V in 400 ms repeated 3 times at 1.0 minute intervals.
  3. ±300 V pulse decaying exponentially to 30 V in 300 ms with a maximum energy of 1.0 Joule.
  4. ±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 tole rances. R1 should be greater than 100Ω; recommended value of 220Ω. R1 can be up to 500Ω, but in this case the tb2v parameter could be out of i t’s specified value (see El ectrical Characteristics and Note 1). Al so, t he minimum operat ing vol tage range shoul d be great er t han 8.0 V. The fol lowing val ues shoul d be adhered to: 10 k≤R2 ≤68 kΩ 1.5 kΩ ≤ R3 ≤47 kΩ R4 ≥4.7 kΩ R5 ≥4.7 kΩ 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 kΩ, R3 = 2.2 kΩ, C2 = 100 nF (Referring to Block Diagram and Typical Application). Oscillator Time Base Calculation: tb1 duration = tb1 × 4 × R2 × C2 = 1 × 4 × 27e3 × 100e–9 = 10.8 ms tb2 duration_g (INT to Gnd) = tb2g × R3 × C2 = 15.5 × 2.2e3× 100e–9 = 3.41 ms tb2 duration_v (INT to Vbb) = tb2v × R3 × C2 = 12.1 × 2.2e3× 100e–9 = 2.66 ms Intermittent timing calculation: T3 = 16 × 4 × tb1 duration = 16 × 4 × 10.8 ms = 691 ms T4 = 144 × 4 × tb2 duration_g = 144 × 4 × 3.41 ms = 1.96 s (INT connected to Gnd) T4 = 144 × 4 × tb2 duration_v = 144 × 4 × 2.66 ms = 1.53 s (INT connected to Vbb) Wash wipe timing calculation: T2 = 96 × 4 × tb1 = 96 × 4 × 10.8 ms = 4.15 s T1 Debounce Time Calculation (see T1 Debounce Timing) When oscillator is oscillating at tb1: T1 minimum = 4 × tb1 = 4 × 10.8 ms = 43.2 ms T1 maximum = 2 × 4 × tb1 = 2 × 4 × 10.8 ms = 86.4 ms When oscillator is oscillating at tb2: T1 minimum (INT connected to Gnd, tb2g) = 4 × tb2 = 4 ×3.41 ms = 13.6 ms T1 maximum (INT connected to Gnd, tb2g) = 2 × 4 × tb2 = 2 × 4 × 3.41 ms = 27.3 ms

(MS – 001BA) Symbol MIN MAX A 8.51 10.16 B 6.1 7.11 C 5.33 D 0.36 0.56 F 1.14 1.78 G H J 0° 10° K 2.92 3.81 NOTES: L 7.62 8.26 1. Dimensions “A”, “B” do not include mold flash or protrusions. M 0.2 0.36 Maximum mold flash or protrusions 0.25 mm (0.010) per side. N 0.38 D SUFFIX SOIC (MS - 012AA) Symbol MIN MAX A 4.8 5 B 3.8 4 C 1.35 1.75 D 0.33 0.51 F 0.4 1.27 G H J 0° 8° NOTES: K 0.1 0.25 1. Dimensions A and B do not include mold flash or protrusion. M 0.19 0.25 1.27 5.72 Dimension, mm Dimension, mm 2.54 7.62 A BH C K C M J F M P G D R x 45 SEATING PLANE 0.25 (0.010) M T -T- L H M J A B F G D SEATING PLANE N K 0.25 (0.010) M T -T- C