U643B-MFPG3Y Atmel, U643B-MFPG3Y Datasheet - Page 4

• Manufacturer Part Number: U643B-MFPG3Y
• Description: IC FLASHER 30M OHM SHUNT 8-SOIC
• Manufacturer: Atmel
• Type: Automotive, Flasherr

Specifications of U643B-MFPG3Y

• Current - Supply: 7mA
• Current - Output: 100µA
• Voltage - Supply: 9 V ~ 15 V
• Operating Temperature: -40°C ~ 95°C
• Package / Case: SO-8
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

4. Functional Description
4.1
4.2
4.3
4.4
4.5
4
Pin 1, GND
Pin 2, Supply Voltage, V
Pin 3, Relay Control Output (Driver)
Pin 4 and 5, Oscillator
Pin 6, Supply Voltage, Sense
U643B
The U643B is protected against damage in case of battery reversal via resistor R
(–31). An integrated protection circuit together with external resistances R
rent pulses in the IC.
The arrangement of the supply connections to pin 2 must be so as to ensure that on the connec-
tion printed circuit board (PCB), the resistance of V
The relay control output is a high-side driver with a low saturation voltage. It is capable of driving
a typical automotive relay with a minimum coil resistance of 60 .
The flashing frequency, f
(see
where C
In case of a lamp outage (see pin 7) the oscillator frequency is switched to the lamp outage fre-
quency 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.
f
1
------------------------------------ - Hz
R
Figure 2-1 on page
1
1
2
C
with f
1
47 µF, R
1
S
Power
1.5
2
1
2.2
= 6.8 k to 510 k
1
2):
, is determined by the R
f
1
.
1
C
S
1
to pin 6 is lower than that to pin 2.
components as given by the formula below
2
and R
4
4727B–AUTO–09/05
limits the cur-
4
to ground
S
/shunt