IES5528 Hendon Semiconductors, IES5528 Datasheet - Page 4

• Manufacturer Part Number: IES5528
• Description: Phase Controller And Triac Triggering Ic
• Manufacturer: Hendon Semiconductors

6.5.2
The output FLY (pin 15) is an n-p-n
open-collector output. During the
flyback period of the saw-tooth pulse
the transistor is ON.
6.6
The output stage is used to provide
gate pulses of sufficient current to
drive a triac.
The output produces negative going
gate pulses with respect to Vcc /
mains neutral. This fires the triac in its
most sensitive regions, reducing the
amount of gate current needed to
latch and hence reducing the overall
power consumption.
Depending on the configuration of the
drive circuit, the output can be used to
provide single gate pulses, or a burst
of pulses. The operating mode needs
to be taken into account when
calculating power supply
requirements.
2009 Nov 02, Revision 8.1
Output Amplifier
FLY
6.6.1
The output amplifier is a non-inverting
amplifier. An external pullup resistor
connected to AMPIN (pin 9) is used to
inhibit the amplifier while pulling
AMPIN low will enable the output to
sink large currents.
6.6.2
The output TRIG (pin 10) is an n-p-n
open-collector output capable of
sinking large currents.
A gate resistor Rg should be
connected between the output TRIG
and the triac gate to limit the output
current to the minimum required by
the triac. By doing this, the total
supply current and the power
dissipation of the IC are minimised.
Output TRIG is protected with a diode
to V
of the output voltage, e.g. caused by
an inductive load.
EE
against damage by undershoot
AMPIN
TRIG
Phase Controller and Triac Triggering IC
4
6.7
The IES5528 is capable of
determining the state of the triac. The
gate sense circuit ensures that
multiple gate pulses are not
produced, reducing overall current
consumption.
6.7.1
For phase control applications, when
gate-sense is enabled (SDIS
connected to V
conducting, the gate sense circuit will
prevent any output gate pulses.
For “static switch” applications, where
zero-crossing triggering of the triac is
required, the gate-sense is disabled
by injecting current into SDIS via a
resistor connected to V
When the disable function is not being
used, SDIS should be connected to
V
left disconnected.
EE
. The SDIS pin should never be
Gate Sense
SDIS - G
Product Specification
EE
IES5528
), and the triac is
ATE SENSE DISABLE
CC
.