ST52T440F3M6 STMicroelectronics, ST52T440F3M6 Datasheet - Page 64

• 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

ST52T400/T440/E440/T441
Burst Mode
The Burst principle is based on turning the TRIAC
device on and off for a fixed integer number of
mains voltage periods, in order to control the
power transferred to the load.
In Burst Mode the peripheral provides a signal,
with a fixed period T containing an integer number
of pulses corresponding to the main voltage zero
crossings, with a Duty Cycle that is proportional to
the number of pulses that keep the TRIAC on (Fig-
ure 10.4).
The user can define the period T by means of the
internal 16-bit prescaler, setting REG_CONF8 and
REG_CONF9 (Figure 10.2). T is proportional to
the main voltage period and is in the range [5.10,
334233.6]s if the main frequency is 50Hz.
The duty cycle is fixed at each period by an 8-bit
value loaded in the TRIAC_COUNT register (Out-
put Register 9). The duty cycle is proportional to
the value: loading 50% duty cycle is obtained,
loading 0 the output will be low (off) during all the
period, loading 255 will be high (on).
The width and the polarity of the pulses can be
programmed according to the TRIAC device and
the circuit characteristics.
In order to work in Burst mode, the pre-post zero-
crossing of main voltage must be detected by
using an external inserting circuitry connected to
the MAIN1 and MAIN2 pins (Figure 10.5).
This kind of TRIAC control is mainly used for ther-
mal regulation.
Figure 10.2 TRIAC/PWM Configuration Registers 8 and 9
64/94
Phase Angle Partialization Mode
Phase Angle Partialization method is based on
turning on the TRIAC device only for a part (Phase
Angle) of each main voltage period. When the
phase angle is large, the energy (power) supplied
to the load is low, viceversa when the phase angle
is small, the energy supplied to the load is high.
In order to work in Phase Angle Partialization
mode, the zero-crossing of main voltage must be
detected by using an external inserting circuitry
connected to the MAIN1 and MAIN2 pins or,
optionally, only on MAIN1 pin (Figure 10.10).
In this working mode, the peripheral provides eight
pulses after the time corresponding to the Phase
Angle on the TROUT pin, obtained by setting the
TRIAC_COUNT 8-bit register (Output Register 9)
and
REG_CONF9). By modifying the TRIAC_COUNT
register the Phase Angle is controlled.
10.1 TRIAC/PWM Driver Setting
The TRIAC/PWM Peripheral can be SET or
RESET through REG_CONF10(7) bit TCRST
(Table 10.3) in all three working modes.
If the TRIAC/PWM Peripheral is SET and only in
PWM mode, it is possible to START or STOP the
internal counter of the peripheral without resetting
it, through REG_CONF10(5) bit TCST (Table
10.3), in order to use the peripheral as an addi-
tional Timer. In the other modes the TCST bit
must be kept to “1”.
NOTE: if TCRST is 0 (reset status) the TROUT
pin output is in tristate.
the
Prescaler
(REG_CONF8
and