ST52T440F3M6 STMicroelectronics, ST52T440F3M6 Datasheet - Page 67

• Manufacturer Part Number: ST52T440F3M6
• Description: MCU 8-Bit ST52 CISC 8KB EPROM 5V 20-Pin SO
• Manufacturer: STMicroelectronics

Specifications of ST52T440F3M6

• Package: 20SO
• Family Name: ST52
• Maximum Speed: 20 MHz
• Ram Size: 256 Byte
• Program Memory Size: 8 KB
• Operating Supply Voltage: 5 V
• Data Bus Width: 8 Bit
• Program Memory Type: EPROM
• Number Of Programmable I/os: 13
• On-chip Adc: 6-chx12-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 1

In particular, the pulses are generated by using
the rising edge of the signal MAIN1 and the falling
edge of the signal MAIN2. Figure 10.6 illustrates
the generation of the Triac pulses Tp.
The first firing pulse for the Triac is generated on
the zero crossing of the power line, while the next
pulses are centered on the zero crossing. Gener-
ally, the Triac firing pulses start 1/2 Tp before the
zero crossing and the length of the pulses is Tp,
see Figure 10.6.
The length Tp of the pulses is programmable by
using a 16 bit value UTP, obtained with
REG_CONF19
REG_CONF20, UTPLSB (see Figure 10.12 and
Table 10.5):
Figure 10.5 Burst Mode Zero Crossing Circuit
Figure 10.6 Burst Mode Zero Crossing Circuit
Triac Gate
Triac Gate
Negative
Positive
Current
Current
Power
Line
(0.5)
0.5
(1)
1
0
Ig
Ig
bits,
½ Tp
Tp
UTPMSB,
II and III quadrants
I and IV quadrants
½ Tp
and
T
The value Tp is in the range [0, 3.2] ms when the
clock master is 20 MHz.
According to REG_CONF10(0) configuration reg-
ister bit, POL, the firing pulses polarity may be set;
in order to obtain positive or negative gate Triac
currents, allowing to work respectively in I and IV
quadrants, or in the II and III quadrants (see Fig-
ure 10.6).
The pulses polarity can be changed on fly with
immediate effect.
Working in the II and III quadrant the peripheral
implements the following procedure:
1) The firing pulse is set to “1" on the rising edge
Figure 10.7 Burst Mode Zero Crossing
P
Main Voltage
= T
TRIACOUT
CLKM
MAIN1
MAIN2
-0.5
-1.5
0.5
-1
0
* UTP
Tp
ST52T400/T440/E440/T441
Tp
Tp
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