TEMIC U644B-FP

U644B
Flasher, 18-mW Shunt, Extremly Low Current Consumption
Description
The bipolar integrated circuit, U644B, is used in relaycontrolled automotive flashers where a high level EMC
is required. Lamp outage is indicated by frequency doubling during hazard warning as well as direction mode.
If the flasher module provides an 4-pin connector the
control pin of U644B (Pin 6) can be used to operate the
IC in an extremly low-current mode.
Features
D Frequency doubling indicates lamp outage
D Frequency independent of temperature and voltage
D Minimum lamp load for flasher operation:
1 W
D Very low susceptibility to EMI
change
D Protection according to ISO TR7637/1 level 4
D Relay driver output with high current-carrying
D Control input (Kl 15)
capacity and low saturation voltage
Ordering Information
Extended Type Number
U644B
U644B-FP
Package
DIP8
SO8
Remarks
Block Diagram
R5
15
10 kW
30
2
Measuring
comparator K 1
V S – 49 mV
C1
4
K1
R4
Shunt
20 kW
R1
20 kW
2 kW
3
49 a
Comparator K 2
Relay
20 kW
8
5
18 mW
7
K2
Pulse
generator
6
K3
49 a
Comparator K 3
49 a
3.3 kW
13 kW
20 kW
R3
30 V
1
GND
R2
220 W
GND
–31
12707
Figure 1. Application circuit as a car flasher with control input
Resistor R1, R2 and R3: 1/4 Watt
R2 for protection against continuous reversed polarity: 1 Watt
TELEFUNKEN Semiconductors
Rev. A2, 25-Feb-97
1 (6)
U644B
+V S
+49
2
Measuring
comparator K 1
V S – 49 mV
C1
4
K1
R1
R4
Shunt
20 k
18 m
20 k
7
2 k
K2
Pulse
generator
6
3
49 a
Comparator K 2
Relay
20 k
8
K3
5
49 a
Comparator K 3
49 a
3.3 k
13 k
20 k
R3
30 V
1
GND
R2
220 GND
–31
12708
Figure 2. Application circuit as a car flasher without control input
Resistor R1, R2 and R3: 1/4 Watt
R2 for protection against continuous reversed polarity: 1 Watt
Application Note
In figure 1, the control input (Pin 6) is used to enable or disable U644B. If the ignition is switched off, the current
consumption is less than 50 A.
In figure 2, Pin 6 is bridged to Pin 2, so U644B works like U6043B. Note that the resistor values of R2 and R3 are
different from the U6043B (see application circuit).
Pin Description
Pin
1
2
3
4
5
6
7
8
Symbol
GND
VS
REL
OSC
OSC
VS
LD
SI
Function
IC ground
Supply voltage VS
Relay driver
C1 Oscillator
R1 Oscillator
Supply voltage / or control input
Lamp failure detection
Start input (49a)
GND 1
8
SI
2
7
LD
REL 3
6
Vs
4
5
OSC
VS
U644B
OSC
13297
Figure 3. Pinning
2 (6)
TELEFUNKEN Semiconductors
Rev. A2, 25-Feb-97
U644B
Functional Description
Pin 1, GND
The integrated circuit is protected against damage via
resistor R2 to ground (–31) in the case of battery reversal.
An integrated protection circuit and the external
resistances R1 and R2 limit the ac-current pulse in the IC.
Pin 2, Supply voltage, VS - Power
Connected directly to battery (Kl 30).
Pin 3, Relay control output (driver)
The relay control output is a high-side driver with a low
saturation voltage and capable to drive a typical automotive relay with a minimum coil resistance of 60 W.
An integrated overvoltage detection disables the output at
VS 20 V to protect the lamps during jump start
[
Pin 4 and 5 Oscillator
Flashing frequency, f1, is determined by the R1C1
components as follows (see figure 1):
1
f1
Hz
R 1 C 1 1.5
[
C 47 mF
R + 6.8 kW to 510 kW
where
1
1
In the case of a lamp outage (see Pin 7) the oscillator
frequency is switched to the lamp outage frequency f2
with f2 2.2 f1.
[
Duty cycle in normal flashing mode: 50%
Duty cycle in lamp outage mode: 40% (bright phase)
Pin 6, Supply voltage, control input
When the IC is powered by the battery Pin 6 is the control
input to switch the IC to zero current consumption during
stand-by.
Pin 7, Lamp outage detection
The lamp current is monitored via an external shunt
resistor R4 and an internal comparator K1 with its
reference voltage of typ. 49 mV (VS = 12 V). The outage
of one lamp out of two lamps is detected according to the
following calculation:
Nominal current of 1 lamp: 21 W / (VS = 12 V):
Ilamp = 1.75 A
Nominal current of 2 lamps: 2 x 21 W / (VS = 12 V):
Ilamp = 3.5 A.
The detection threshold is recommended to be set in the
middle of the current range: Ioutage 2.7 A
Thus the shunt resistor is calculated as:
Rsh = VT (K1) / Ioutage
Rsh = 49 mV/2.7 A = 18 mW.
Comparator K1‘s reference voltage is matched to the
characteristics of filament lamps (see “control signal
threshold” in the data part).
The combination of shunt resistor and resistance of wire
harness prevents Pin 7 from a too high voltage in the case
of shortet lamps.
[
Pin 8, Start input
Start condition for flashing: the voltage at Pin 8 has to be
below K3 threshold (flasher switch closed).
Humidity and dirt may decrease the resistance between
49 a and GND. If this leakage resistance is 5 kW the IC
is still kept in its off-condition. In this case the voltage at
Pin 8 is between the thresholds of comparators K2 and
K3.
During the bright phase the voltage at pin 8 is above the
K2 threshold, during the dark phase it is below the K3
threshold.
For proper start conditions a minimum lamp wattage of
1 W is required.
u
Absolute Maximum Ratings
Reference point Pin 1
Parameters
Supply voltage
Surge forward current
Output current
Power dissipation
tP = 0.1 ms
tP = 300 ms
tP = 300 ms
Tamb = 120°C
Tamb = 105°C
Tamb = 60°C
Tamb = 60°C
TELEFUNKEN Semiconductors
Rev. A2, 25-Feb-97
Pin 2
Pin 2
Pin 2
Pin 8
Pin 3
DIP8
SO8
DIP8
SO8
Symbol
VS
IFSM
IFSM
IFSM
IO
Ptot
Ptot
Ptot
Ptot
Value
18
1.5
1.0
50
0.3
230
300
690
560
Unit
V
A
A
mA
A
mW
mW
mW
mW
3 (6)
U644B
Absolute Maximum Ratings (continued)
Parameters
Junction temperature
Ambient temperature range
DIP8
SO8
Storage temperature range
Symbol
Tj
Tamb
Tamb
Tstg
Value
150
–40 to +120
–40 to +105
–55 to +150
Unit
°C
°C
°C
°C
Symbol
RthJA
RthJA
Value
110
160
Unit
K/W
K/W
Thermal Resistance
Parameters
Junction ambient
DIP8
SO8
Electrical Characteristics
Typical values under normal operation in application circuit figure 1, VS (+49, Pin 2) = 12 V.
Reference point ground (–31), Tamb = 25°C unless otherwise specified
Parameters
Supply voltage range
Supply current
Test Conditions / Pin
Pin 2
Dark phase or
stand-by
Pin 2
Bright phase
Pin 2
IO = 300 mA
Pin 3
Supply current
Relay output,
saturation voltage
Relay output,
Pin 3
reverse current
Relay coil resistance
Relay output overvoltage
detection (relay disabled)
Start delay
(first bright phase)
Frequency determining
resistor
Frequency determining
capacitor
Frequency tolerance (normal flashing, basic frequency
f1 not including the tolerance of the external components R1 and C1)
Bright period (basic frequency f1)
Bright period (control frequency f2)
Frequency increase (lamp failure)
Control signal threshold
Vs = 18 V
Pin 7
Vs = 8 V
Pin 7
Vs = 13.5 V
Pin 7
Resistance between 49a to ground for stand-by
Lamp load
4 (6)
Symbol
VS (+49)
IS
Min.
IS
VO
Typ.
8 to 18
5
Max.
7
Unit
V
mA
6
10
1.3
mA
V
0.1
mA
IO
RL
60
19.0
W
20.2
ton
R1
6.8
C1
22.5
V
10
ms
510
kW
47
mF
∆f1
–6.5
+ 6.5
%
∆f1
∆f2
f2
VR3
VR3
VR3
RP
PL
45
35
2.1 f1
53
40.5
47.5
55
45
2.4 f1
61
46.6
54.5
5.6
%
%
Hz
mV
mV
mV
kW
W
1
57
43.6
51
2
TELEFUNKEN Semiconductors
Rev. A2, 25-Feb-97
U644B
Package Information
Package DIP8
Dimensions in mm
7.77
7.47
9.8
9.5
1.64
1.44
4.8 max
6.4 max
0.5 min
0.58
0.48
3.3
0.36 max
9.8
8.2
2.54
7.62
8
5
technical drawings
according to DIN
specifications
13021
1
4
Package SO8
Dimensions in mm
5.2
4.8
5.00
4.85
3.7
1.4
0.25
0.10
0.4
1.27
6.15
5.85
3.81
8
0.2
3.8
5
technical drawings
according to DIN
specifications
13034
8
5
TELEFUNKEN Semiconductors
Rev. A2, 25-Feb-97
5 (6)
U644B
Ozone Depleting Substances Policy Statement
It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to
1. Meet all present and future national and international statutory requirements.
2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems
with respect to their impact on the health and safety of our employees and the public, as well as their impact on
the environment.
It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as
ozone depleting substances ( ODSs).
The Montreal Protocol ( 1987) and its London Amendments ( 1990) intend to severely restrict the use of ODSs and
forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban
on these substances.
TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy of
continuous improvements to eliminate the use of ODSs listed in the following documents.
1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively
2 . Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental
Protection Agency ( EPA) in the USA
3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances ) respectively.
TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain
such substances.
We reserve the right to make changes to improve technical design and may do so without further notice.
Parameters can vary in different applications. All operating parameters must be validated for each customer
application by the customer. Should the buyer use TEMIC products for any unintended or unauthorized
application, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of,
directly or indirectly, any claim of personal damage, injury or death associated with such unintended or
unauthorized use.
TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany
Telephone: 49 ( 0 ) 7131 67 2831, Fax number: 49 ( 0 ) 7131 67 2423
6 (6)
TELEFUNKEN Semiconductors
Rev. A2, 25-Feb-97