TEMIC TEA1007 Datasheet

Adronic Components GmbH

Simple Phase Control Circuit

Description

Integrated circuit, TEA1007, is designed as a general
phase control circuit in bipolar technology. It has an
internal supply voltage limitation. With typical 150 mA
ignition pulse, it is possible to determine the phase-shift

Features

D

Current consumption v 2.5 mA

D

Ignition pulse typ. 150 mA

D

Voltage and current synchronization

TEA1007

of the ignition point by comparing the mains sync. ramp
voltage with a preset required value. It generates a single
ignition pulse per half wave; therefore, it is suitable for
capacitive and inductive loads in low cost applications.

D

Internal supply voltage control

Package: DIP8

Block Diagram

R = series resistance

v

TELEFUNKEN Semiconductors

Rev . A1, 28-May-96

Figure 1. Block diagram with typical circuitry

1 (8)

Adronic Components GmbH

TEA1007

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
reference point Pin 8 is discharged at the zero transition
of the mains voltage via the V
switch S

. After the end of the zero transition pulse, C

2

is charged from the constant current source Iö, whose
value is adjusted externally with R
unavoidable tolerance of C

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
voltage switch S
voltage V

The capacitor C

+ Itp until it reaches the internal reference voltage

I

ö

. The length of this Phase 2 corresponds to the width

V

Ref

via an RS flip-flop and the OR gate G1.

Ref1

ö

of the output pulse t
the value V

, thyristor Th1ignites again and resets the

Ref

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

is greater than the maximum permissible control

V

Ref

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.

between Pin 7 and the common

/t

ö

detector, gate G2and

o

at Pin 3 due to the

ö

(Phase 1).

/t

ö

, which also

1

, and switches the reference

/t

ö

to an internally generated threshold

1

is charged in this second phase by

/t

. When the capacitor voltage reaches

p

is switched off.

tp

so that the

1

. As

1

ö

/t

95 11358

Figure 2. Functional diagram for inductive load of

a

max

In the following zero transition of the mains voltage, the
zero transition detector (Input Pin 5) resets the RS
flip-flop, discharges C

again via S2, and also insures

/t

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 subse­quent half-cycle.

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Figure 3. Triac voltages + currents at resistive load

V

= Zero cross voltage

o

= Zero cross current

I

O

= Mains voltage

V

M

= Load current

I

L

= Gate current

I

G

V

= Triac voltage at anode HI

HI

TELEFUNKEN Semiconductors

Rev . A1, 28-May-96

95 11360

Adronic Components GmbH

TEA1007

In indication as to whether load current is flowing or not
is provided by the triac itself. When the triac is ignited,
the voltage at electrode H

drops from the instantaneous

1

value of the mains voltage to approximately 1.5 V, the
value of the forward voltage of the triac. When the load
current drops below the hold current of the triac towards
the end of the half-cycle, V

again returns to the instan-

H1

taneous value of the mains voltage. The current detector
with its input at Pin 4 now controls this triac voltage and
blocks the pulse generator via G

and S1by increasing the

1

reference voltage as long as the triac is conducting. As, in
the case of a resistive load, the triac may be extinguished
shortly before the zero transition of the mains voltage –
when the load current drops below the hold current – the
RS flip-flop must prevent any possible second ignition
pulse from being generated.

Additional Function

An internal supply voltage control circuit insures that
output pulses can be generated only when the supply
voltage required for operation of all logic functions is
available.

Series resistance R

+

R

1max

I

= IS + IP + Ix whereas

tot

I

= Total current consumption

tot

I

= Current requirement of the lC

S

I

= A verage current requirement of the triggering pulses

P

I

= Current requirement of other peripheral components

x

can be calculated approx. as follows:

1

V

–V

0.85

Mmin

2 I

Smax

tot

Determination of Gate Series
Resistance, Firing Current and Pulse
Width

95 11359

Figure 4. Functional diagram for resistive load and

Firing current requirement depends upon the triac used
which can be regulated with series resistance as given
below:

R

Gmax

[

+

I

P

tP[

12.5 V – V

I

G

T

8ms

nF

I

t

Gmax

p

C

Gmax

– 110

W

ö

whereas:
V

=Triac’s gate voltage

G

=Triac’s gate current

I

G

=Gate current requirement – average

I

P

T =Period duration of mains frequency

=(firing) pulse width

t

p

=Ramp capacitor

a

min

C

ö

TELEFUNKEN Semiconductors

Rev . A1, 28-May-96

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