ST52T440F3M6 STMicroelectronics, ST52T440F3M6 Datasheet - Page 63

• 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

10 TRIAC/PWM DRIVER
ST52x400/440/441 offers a peripheral able to
generate a TROUT signal on PA0 pin (able to sup-
ply up to 25 mA), to drive an external device, like a
TRIAC, an IGBT or a Power MOS. A Triac/PWM
driver can perform 3 different working modes
according to REG_CONF10(3:2) bits, MODE (see
Table 10.3):
MODE = “00”:
MODE = “01":
MODE = “1x":
The Triac/PWM Driver can be initialized by using a
value fixed by a control algorithm, and stored in
the Register File. The value is loaded in the
TRIAC_COUNT register (Output Register 9) by
using the LDPR instruction and it can be read by
using the LDRI instruction addressing the Input
Register 17.
Figure 10.1 TRIAC/PWM Driver Block Diagram
MAIN1
MAIN2
PWM
Burst Mode Triac Control
Phase Angle Partialization
(Thermal Regulations)
Triac Control (Motor Control)
REG_CONF8
REG_CONF9
MCLK
EXTCLK
50/60 Hz
Tck
GENERATOR
PULSE
PRECLK
16
PRESCALER
16 bit
MCLK
÷2
Tck
0
MODE
TRIAC/PWM DRIVER
1
Figure 10.1 illustrates the internal structure of the
Triac/PWM Driver.
PWM Mode
The PWM working mode selection can be
obtained by setting REG_CONF10(3:2) bits,
MODE, at “00" value.
In this working mode, the peripheral provides a
signal with a fixed period and a variable duty cycle
on the TROUT pin.
The PWM period can be generated starting from
the internal master clock or an external clock sig-
nal applied in MAIN1 pin.
In both cases, the clock signal is divided by a 16-
bit Prescaler, managed by REG_CONF8 and
REG_CONF9 (Figure 10.2).
At each period, the duty cycle is fixed 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).
By Using a 20 Mhz clock PWM frequencies in the
range between 1.2 Hz to 78.4 Mhz may be
obtained.
PROGRAMMABLE
REG_PERIPH_9
2
COUNTER
3
CORE
4
5
START
8
6
REG_CONF10
7
RESET
ST52T400/T440/E440/T441
POL
TRIACOUT
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