tca785_ph_ctrl
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Semiconductor Group
1
TCA 785
This phase control IC is intended to control thyristors, triacs, and transistors. The trigger pulses
can be shifted within a phase angle between 0 ˚ and 180 ˚. Typical applications include
converter circuits, AC controllers and three-phase current controllers.
This IC replaces the previous types TCA 780 and TCA 780 D.
(top view)
Pin Configuration
Phase Control IC
TCA 785
Bipolar IC
Features
●
Reliable recognition of zero passage
●
Large application scope
●
May be used as zero point switch
●
LSL compatible
●
Three-phase operation possible (3 ICs)
●
Output current 250 mA
●
Large ramp current range
●
Wide temperature range
P-DIP-16-1
Type
Ordering Code
Package
TCA 785
Q67000-A2321
P-DIP-16-1
Pin
Symbol
Function
1
GND
Ground
2
3
4
Q2
Q U
Q2
Output 2 inverted
Output U
Output 1 inverted
5
VSYNC
Synchronous voltage
6
7
I
Q Z
Inhibit
Output Z
8
V REF
Stabilized voltage
9
10
R9
C10
Ramp resistance
Ramp capacitance
11
V11
Control voltage
12
C12
Pulse extension
13
L
Long pulse
14
15
Q 1
Q 2
Output 1
Output 2
16
VS
Supply voltage
Pin Definitions and Functions
09.94
Semiconductor Group
2
TCA 785
Functional Description
The synchronization signal is obtained via a high-ohmic resistance from the line voltage
(voltage V5). A zero voltage detector evaluates the zero passages and transfers them to the
synchronization register.
This synchronization register controls a ramp generator, the capacitor C10 of which is charged
by a constant current (determined by R9). If the ramp voltage V10 exceeds the control voltage
V11 (triggering angle
ϕ), a signal is processed to the logic. Dependent on the magnitude of the
control voltage V11, the triggering angle
ϕ can be shifted within a phase angle of 0˚ to 180˚.
For every half wave, a positive pulse of approx. 30
µs duration appears at the outputs Q 1 and
Q 2. The pulse duration can be prolonged up to 180˚ via a capacitor C12. If pin 12 is connected
to ground, pulses with a duration between
ϕ and 180˚ will result.
Outputs
and
supply the inverse signals of Q 1 and Q 2.
A signal of
ϕ +180˚ which can be used for controlling an external logic,is available at pin 3.
A signal which corresponds to the NOR link of Q 1 and Q 2 is available at output Q Z (pin 7).
The inhibit input can be used to disable outputs Q1, Q2 and
,
.
Pin 13 can be used to extend the outputs
and
to full pulse length (180˚ –
ϕ).
Q 1
Q 2
Q 1
Q 2
Q 1
Q 2
Block Diagram
Semiconductor Group
3
TCA 785
Pulse Diagram
Semiconductor Group
4
TCA 785
Unit
Parameter
Symbol
min.
max.
Limit Values
Absolute Maximum Ratings
V
Supply voltage
VS
– 0.5
18
mA
Output current at pin 14, 15
IQ
– 10
400
K/W
Thermal resistance
system - air
Rth SA