TEA1007 Temic Semiconductors (acquired by ATMEL Corporation), TEA1007 Datasheet - Page 2

• Manufacturer Part Number: TEA1007
• Description: Simple Phase Control Circuit
• Manufacturer: Temic Semiconductors (acquired by ATMEL Corporation)

General Description
The phase-shift of the ignition point is determined in the
usual manner by comparison between a mains
synchronized ramp voltage and a predetermined required
value. The capacitor C ö
reference point Pin 8 is discharged at the zero transition
of the mains voltage via the V
switch S
is charged from the constant current source I ö , whose
value is adjusted externally with R ö at Pin 3 due to the
unavoidable tolerance of C ö
When the potential at Pin 7 reaches the nominal value
predetermined at Pin 6, the thyristor Th
functions as a comparator, ignites and sets the following
clock flip-flop. The output of the clock flip-flop releases
the output amplifier, connects a second constant current
source to the capacitor C ö
voltage switch S
voltage V
The capacitor C ö
I ö + I
V
of the output pulse t
the value V
clock flip-flop to its initial state. The output pulse is thus
terminated and the constant source I
However, the RS flip-flop holds the switch S
internal reference voltage remains connected to Th
V
voltage at Pin 6, this prevents more than one ignition
pulse from being generated in each half-cycle of the
mains voltage. This is particularly important because the
energy contents of the output pulse is of the same order
as the internal requirements of the circuit for each
half-wave.
In the following zero transition of the mains voltage, the
zero transition detector (Input Pin 5) resets the RS
flip-flop, discharges C ö
that the clock flip-flop is in the reset condition. A further
part of the basic function is the current detector with its
input at Pin 4. When controlling inductive loads, the load
current lags behind the mains voltage which means that
the circuit could generate an ignition pulse during the
period in which current is still flowing with a polarity
opposite to that of the mains voltage if the current were
not taken into account (see figure 2).
This, in turn, would lead, to so-called “gaps” in the load
current as the next ignition pulse is generated in the subse-
quent half-cycle.
TEA1007
2 (8)
Ref
Ref
. The length of this Phase 2 corresponds to the width
tp
is greater than the maximum permissible control
2
until it reaches the internal reference voltage
. After the end of the zero transition pulse, C ö
Ref1
Ref
via an RS flip-flop and the OR gate G
, thyristor Th
1
/t
to an internally generated threshold
p
is charged in this second phase by
. When the capacitor voltage reaches
/t
/t
between Pin 7 and the common
again via S
/t
1
/t
, and switches the reference
ignites again and resets the
(Phase 1).
o
detector, gate G
2
tp
, and also insures
is switched off.
1
, which also
1
so that the
2
1
1
. As
.
and
/t
V
I
V
I
I
V
O
L
G
o
M
HI
Figure 2. Functional diagram for inductive load of
Figure 3. Triac voltages + currents at resistive load
= Zero cross voltage
= Zero cross current
= Mains voltage
= Load current
= Gate current
= Triac voltage at anode HI
TELEFUNKEN Semiconductors
Rev. A1, 28-May-96
95 11360
95 11358
a
max