U6433B_05 ATMEL [ATMEL Corporation], U6433B_05 Datasheet - Page 4

• Manufacturer Part Number: U6433B_05
• Description: Flasher, 18-m Shunt, Frequency Doubling Disabling
• Manufacturer: ATMEL [ATMEL Corporation]

3. Functional Description
3.1
3.2
3.3
3.4
3.5
3.6
3.6.1
4
Pin 1, GND
Pin 2, Supply Voltage, V
Pin 3, Relay Control Output (Driver)
Pins 4 and 5, Oscillator
Pin 6, Supply Voltage, Sense
Pin 7, Lamp Outage Detection
U6433B
Control Signal Threshold 1 (49-mV Comparator K1)
The integrated circuit is protected against damage via resistor R
battery reversal.
An integrated protection circuit together with external resistances R
pulses in the IC.
The arrangement of the supply connections to pin 2 must be so as to ensure that, on the con-
nection printed circuit board (PCB), the resistance of V
The relay control output is a high-side driver with a low saturation voltage and is capable of driv-
ing a typical automotive relay with a minimum coil resistance of 60 .
The flashing frequency, f
page
where
C
R
In the case of a lamp outage (see pin 7) the oscillator frequency is switched to the lamp outage
frequency f
Duty cycle in normal flashing mode: 50%
Duty cycle in lamp outage mode: 40% (bright phase)
For accurate monitoring via the shunt resistor, a minimized layer resistance from point V
to pin 6 is recommended.
The detection point for lamp failure can be calculated from the control signal threshold, typically
49 mV with V
reached at a lamp load of 21W + 11.4W. The variation of the control signal threshold supply volt-
age takes into account the PTC characteristic of filament lamps.
f
1
1
1
+ 6.8 k to 510 k
------------------------------------ - Hz
R
47 µF
2):
1
C
1
2
1
S
with f
S
– Power
1.5
= 12V. With a measuring resistance of R
2
2.2
1
, is determined by the R
f
1
.
1
C
1
components as follows (see
S
3
to pin 6 is lower than that to pin 2.
= 18 m , the frequency change-over is
4
to ground (–31) in the case of
2
and R
4
limits the current
4810B–AUTO–10/05
Figure 1-1 on
S
/shunt