IL33193
Figure 1. Normal Operation Oscillator
Timing Diagram
Figure 2. One Defective Lamp
Oscillator Timing Diagram
INTRODUCTION
The IL33193 is designed to drive the direction indicator flasher relay. It is a new
generation industry standard UAA1041 “Flasher”. It consists of the following functions:
Supply and Protections
On–Chip Relay Driver
Oscillator
Starter Functions
Lamp Fault Detector with Internal RF Filter
Standby Mode
Supply and Protection Systems
Pin 1 is connected to ground via resistor R3 which limits the current in the event of
any high voltage transients. Pin 2 (VCC) is the positive supply and may be connected
directly to the vehicle’s battery voltage.
Overvoltage and Double Battery Protection: When the applied VCC to VSS voltage
is greater than 22 V, the overvoltage detector circuit turns the relay driver off. Both the
device and the lamps are protected if two 12 V batteries are connected in series and used
to jump start the vehicle.
Load Dump Overvoltage Protection: A 29 V overvoltage detector protects the
circuits against high voltage transients due to load dumps and other low energy spikes.
The relay driver is automatically turned on whenever the VCC to VSS voltage is greater
than 34 V.
Overvoltage Protection, High Voltage Transients: The Enable and the Starter pins
are protected against positive and negative transients by internal on–chip diodes.
On–Chip Relay Driver
The device directly drives the flasher relay. The output structure is an Emitter of an
NPN transistor. It contains the free wheeling diode circuitry necessary to protect the device
whenever the relay is switched off.
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INTEGRAL [ INTEGRAL CORP. ]
