STMicroelectronics STEVAL-GLA001V1 User manual

Introduction
The STEVAL-GLA001V1 evaluation board is designed to help you develop applications with insulated control of three AC loads
up to 1 kW (230 Vrms) using Triacs and AC switches instead of relays.
To control the STEVAL-GLA001V1, you can use a NUCLEO-F030R8 development board which allows three AC switch control
modes for load control: continuous or pulse gate current, a timer option, and phase control. You can use also any external
microcontroller.
Once you have installed the relevant firmware (freely available at STSW-GLA001V1) on the NUCLEO-F030R8 development
board, you can start adjusting the main parameters through a common serial interface like HyperTerminal.
The STEVAL-GLA001V1 evaluation board features a wide input voltage range, low standby power losses, IEC61000-4-4
robustness and two low voltage power supplies.
The targeted applications are residential appliances requiring insulation between microcontroller and mains voltage, such as
washing machines and dish washers, micro-wave ovens, cookers, ovens, soya-milk makers, printers, air-conditioners, fridges,
water-heaters and heaters.
Figure 1. STEVAL-GLA001V1 evaluation board (top view)
Insulated AC switch control evaluation board for home appliances
UM2304
User manual
UM2304 - Rev 3 - January 2019
For further information contact your local STMicroelectronics sales office.
www.st.com

1Evaluation board objectives
1.1 What does this demoboard aim to demonstrate?
As said in the introduction, the STEVAL-GLA001V1 evaluation board allows insulated control of AC loads using
AC switches instead of relay solutions.
The board embeds a power supply to make it independent from power side.
You just have to connect mains voltage, loads and an external microcontroller.
On the smart control side, using an STM32 Nucleo board (NUCLEO-F030R8) with the available firmware allows
to easily configure a lot of parameters for specific load control.
1.2 STEVAL-GLA001V1 evaluation board main blocks
The STEVAL-GLA001V1 evaluation board features the following main components:
•AC switches (X101, X102 and X103)
• A flyback power converter providing:
– VCC_AC: non regulated output and referenced to mains voltage (VCC_AC positive regarding
GND_AC)
◦ used to control the three AC switches
◦ maximum output current: 150 mA
– 5VDC: 5 V positive output, referenced to GND, insulated regarding mains voltage
◦ supplies the LEDs and all other electronic parts if VDD selector is set to 5V position
◦ maximum output current: 500 mA for all the secondary side (5 V, 3.3 V and VDD mixed)
– 3.3VDC: 3.3 V positive output, referenced to GND, insulated regarding mains voltage.
◦ supplies all other electronic parts if VDD selector is set to 3.3 V position.
◦ maximum output current: 500 mA for all the secondary side (5 V, 3.3 V and VDD mixed)
– VDD: used to select whether the external microcontroller is supplied with 5 V or 3.3 V (default).
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Evaluation board objectives
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Figure 2. STEVAL-GLA001V1 evaluation board synoptic
VCC_AC VCC_AC
LDO 5 V LDO 3.3 V VDD
Viper
ZVS
To customer µC board
GND_AC
5VDC
MODE
T2 T3 tp+ tp- + -
LED1 LED2 LED3
J 203
J 202
Mains in put AC switches and load connections
Power supply primary side
Auxiliary supply fo r Triac gate control
Power supply in sulated secondary sid e
5V/3.3V supply for µC and insulated gate control
ZVS circuit
( frequency detection) AC Switches gate contro l User interface
LED4
Power / Time
T1
Inpu t switch
Fuse
M OV
Inpu t ca pa cito r
Hi gh vol ta ge
ind ica tor
X102 X103X101
VDD
selector
L
N
3.3VDC
GND
To MC Connector board
ZVS
G1
G2
G3
1.3 Targeted applications
The main targeted applications are residential appliances where insulation between microcontroller and mains
voltage is required, such as:
• Washing machine, dish washer
•Micro-wave oven, cooker, oven, soya-milk maker
• Printer
• Air-conditioning, fridge
• Water-heater, heater
1.4 Main used part numbers
The main part number references used in the STEVAL-GLA001V1 evaluation board are:
•AC Switches: T1635T-8FP, ACST310-8B and ACS108-8TN
• Rectifier diodes: STPS1L60, STTH1R06 and STPS2H100
• Transil: 1.5KE220A
• Voltage regulator: LF50ABV and LF33ABV
• Flyback IC : VIPER16HD
• Voltage reference: TS431AILT
• Op-Amp: TSV631ILT
1.5 Operating range
The STEVAL-GLA001V1 evaluation board is designed to operate within the following operating conditions:
• RMS line voltage range: 90 V to 265 Vrms
• Line voltage frequency range: 50 to 60 Hz
• Ambient temperature range: 0 to 60°C
• Maximum input current: 10 Arms
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Targeted applications
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1.6 Performance
The STEVAL-GLA001V1 evaluation board performance characteristics include:
• Stand-by losses < 300 mW (@ 240 V)
•IEC 61000-4-4 (STEVAL-GLA001V1 evaluation board with NUCLEO-F030R8 development board):
– 2 kV criteria A
– 4 kV criteria B
1.7 AC switch load capability
The STEVAL-GLA001V1 evaluation board is designed to operate with the following load conditions:
Table 1. Load capability versus ambient temperature and AC switch
Ambient temperature 0 °C 25 °C 60 °C
Load 1 7.2 A = 1650 W 6.2 A = 1430 W 4.6 A = 1050 W
Load 2 1.5 A = 350 W 1.3 A = 300 W 0.9 A = 205 W
Load 3 0.9 A = 200 W 0.75 A = 170 W 0.5 A = 115 W
Total loads power 2200 W 1900 W 1370 W
All of the above values are RMS, for VMAINS = 230 VRMS and with 5% tolerance on the maximum allowed AC
switch junction temperature.
Load numbers are given with reference to the following figure.
Figure 3. Loads connection versus AC switches
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Performance
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2Getting started
2.1 Safety instructions
Caution: The high voltage levels used to operate the STEVAL-GLA001V1 evaluation board present a serious electrical
shock hazard. This evaluation board must be used in a suitable laboratory by qualified personnel who are
familiar with the installation, use and maintenance of power electrical systems.
The STEVAL-GLA001V1 evaluation board is designed for demonstration purposes only, and shall not be used
either for domestic or industrial installations.
2.2 STEVAL-GLA001V1 evaluation board insulation
The STEVAL-GLA001V1 evaluation board is composed of the following main functional blocks:
• The primary side: includes mains voltage input, AC switches, power supply input, ZVS input and referenced
to mains voltage
•The secondary side: includes all microcontroller input/output, power supply output, ZVS output, AC switch
gate control and insulated with respect to mains voltage
Caution: Use insulated measuring equipment and never create a connection between high voltage and insulated
voltage
Figure 4. High voltage and insulated voltage on STEVAL-GLA001V1 evaluation board
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Getting started
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2.3 Board connection
Figure 5. STEVAL-GLA001V1 evaluation board connections
• J100: connect mains voltage input, complying with Line and Neutral connection and operating voltage (refer
toSection 1.5 Operating range)
• J101, J102 and J103: connect directly the load between the two points, complying with the load capability
(refer to Section 1.7 AC switch load capability).(1)
• J203: connect to the NUCLEO-F030R8 via the supplied ribbon cable.
• J202: connect to external microcontroller (if you do not use the NUCLEO-F030R8) with 5 V and 3.3 V,
complying with power supply output capability (refer to Section 1.2 STEVAL-GLA001V1 evaluation board
main blocks).
• J200: supplies insulated low voltage 5 V and 3.3 V power (if required), complying with power supply output
capability (refer to Section 1.2 STEVAL-GLA001V1 evaluation board main blocks).
2.4
1. Caution: Do not connect mains voltage.
STEVAL-GLA001V1 evaluation board start-up
Follow this procedure below to start the STEVAL-GLA001V1 evaluation board.
Step 1. Ensure SW100 switch is in the OFF position.
Step 2. Set the SW200 jumper:
– to 3.3 V for NUCLEO-F030R8 development board or 3.3 V external microcontroller
– to 5 V for 5 V external microcontroller
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Board connection
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Figure 6. SW200 jumper
Step 3. Connect the ribbon cable between:
– J203 and the NUCLEO-F030R8
– J202 and a board that is not a NUCLEO-F030R8
Step 4. Connect mains voltage on J100
Step 5. Connect loads on J101 to J103
Step 6. Make sure there is no connection between high voltage and insulated voltage sections
Step 7. Ensure any measurement equipment has insulated probes
Step 8. Switch SW100 on to turn the board on
2.5 Hardware function description
2.5.1 Power supply: primary side
The power supply primary side includes the following components:
•SW100 switch to turn the STEVAL-GLA001V1 evaluation board on or off
• F100 fuse and SIOV100 varistor for board protection
• C109 capacitor for noise immunity
• D102 LED for high voltage presence indication
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Figure 7. STEVAL-GLA001V1 evaluation board power supply primary side components
High Voltage
Mains voltage
test point
SW100
Auxiliary voltage test
point
F100SIOV100
C109
D102
“Line” and “Neutral” test points are available to measure mains voltage.
An auxiliary power supply is generated to supply the AC switch gate control: it is not regulated (fluctuates from
~12 V to ~23 V), referenced with respect to "Line" potential and can supply up to 150 mA for gate control.
“VCC_AC” and “GND_AC” test points are available to measure the power supply voltage level.
2.5.2 Power supply: secondary side
The power supply secondary side is represented by all the low power output insulated from mains voltage.
The transformer output provides 5 V regulated voltage thanks to an LDO regulator. A 3.3 V regulated voltage is
generated from the 5 V voltage thanks to a second LDO regulator.
Figure 8. STEVAL-GLA001V1 evaluation board power supply secondary side components
Up to 500 mA can be sunk from the secondary side in all, as the 5 V and 3.3 V voltages are in serial.
The J200 connector can supply another board or other external electronic functions. In this case, you must ensure
that the sum of all current on the secondary side does not exceed the output current capability.
“5VDC”, “3.3V OUT” and “GND” test points are available to measure these two low voltages.
2.5.3 VDD selector
Some of the signals (push button, mode switch and ZVS) connected to the STM32 32-bit ARM Cortex MCU or
other microcontroller input are referenced to VDD to protect the voltage input capability of any microcontroller.
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Figure 9. STEVAL-GLA001V1 evaluation board VDD selector components
For a 3.3 V compatible microcontroller, VDD must be connected to 3.3 V by setting the SW200 jumper to the
bottom (D211 LED lights up); this is the default position.
For a 5 V compatible microcontroller, VDD must be connected to 5 V by setting the SW200 jumper to the top
(D212 LED lights up).
As VDD is connected to either 5 V or 3.3 V, the VDD current capability must always be taken into account in
matters concerning the power supply secondary side.
“VDD” and “GND” test points are available to measure VDD voltage level.
2.5.4 Push buttons
Push button signals are available on J202 (user board) and J203 (NUCLEO-F030R8 development board)
connectors. They are referenced regarding VDD and GND (refer to Section 2.5.3 VDD selector).
Figure 10. STEVAL-GLA001V1 evaluation board push button components
The push buttons are normally open and the signal is set to VDD. When a button is pressed, the signal is set to
GND. When the button is released, the signal returns to VDD.
“T1”, “T2”, “T3”, “TP+”, “TP-”, “Power Time +”, “Power Time -” and “GND” test points are available to measure
push button voltage level.
2.5.5 LEDs
LED signals are available on J202 (user board) and J203 (NUCLEO-F030R8 development board) connectors.The
microcontroller voltage level is not important as they use a transistor to be voltage compatible. LED1, LED2 and
LED3 are green, while the "Fault" LED4 is red.
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Hardware function description
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Figure 11. STEVAL-GLA001V1 evaluation board LED components
If the LEDx signal is set to 0 (GND), the chosen LED is OFF; if the LEDx signal is set to 5 V, 3.3 V or VDD, the
chosen LED is illuminated.
“LED1”, “LED2”, “LED3”, “LED4” and “GND” test points are available to measure led voltage level.
2.5.6 Switch mode
The mode selector switch signal is available on J202 (user board) and J203 (NUCLEO-F030R8 development
board) connectors. It is referenced with respect to VDD and GND (refer to Section 2.5.3 VDD selector).
Figure 12. STEVAL-GLA001V1 evaluation board mode components
The switch has 3 ON positions, so there is a non-zero voltage on the MODE signal in any position. The following
table shows MODE signal voltage with respect to the switch position.
Table 2. MODE signal voltage versus switch position
MODE switch position
(board silkscreen) MODE voltage MODE voltage with VDD = 3.3 V
MODE voltage with VDD = 5
V
On/Off VDD ÷ 1.62 2.04 V 3.09 V
Phase control VDD ÷ 2.62 1.26 V 1.91 V
Timer VDD ÷ 2 1.65 V 2.5 V
“MODE” and “GND” test points are available to measure switch mode voltage level.
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2.5.7 Gate control: primary side (high voltage)
The AC switch gate control primary side contains three AC switches, the gate control circuit and optional
components which can be implemented to improve AC switch performance.
Figure 13. STEVAL-GLA001V1 evaluation board AC switch gate control (primary side) components
“VCC_AC”, “GND_AC”, “OUT1”, “G1I”, “OUT2”, “G2I”, “OUT3” and “G3I” tests points are available to measure
auxiliary voltage, AC switches output and gate voltage level.
Caution: All these test points are referenced to high voltage.
See Section 12 AC switch performance improvements for more information on how to improve AC switch
performance.
2.5.8 Gate control: secondary side (insulated voltage)
The gate command signals are available on J202 (user board) and J203 (NUCLEO-F030R8 development board)
connectors. The microcontroller voltage level is not important as the optocoupler LED is voltage compatible. The
G1 signal controls X101 Triac (OUT1, T1), the G2 signal controls X102 AC switch (OUT2, T2) and the G3 signal
controls X103 AC switch (OUT3, T3).
Figure 14. STEVAL-GLA001V1 evaluation board AC switch gate control (secondary side) components
If the Gx signal is set to 0 (GND), the corresponding AC switch is turned off; if the Gx signal is set to 5 V, 3.3 V or
VDD, the corresponding AC switch is switched on.
“G1”, “G2”, “G3” and “GND” test points are available to measure gate command voltage level.
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2.5.9 ZVS
The ZVS (Zero Voltage Switching) signal is available on J202 (user board) and J203 (NUCLEO-F030R8
development board) connectors. It is referenced with respect to VDD and GND (refer to Section 2.5.3 VDD
selector).
The ZVS signal represents the mains voltage with respect to zero crossing. It allows synchronizing AC switch
control with the mains voltage frequency.
As shown on the figure below, if the mains voltage is positive (neutral with respect to line), the ZVS signal is set to
GND. If the mains voltage is negative (neutral with respect to line), the ZVS signal is set to VDD.
Figure 15. ZVS signal versus mains voltage
ZVS signal (« ZVS »
regarding « GND »)
ZVS signal (« N_ZVS »
regarding « L_ZVS »)
VMAI NS signal (« N »
regarding « L »)
Figure 16. STEVAL-GLA001V1 evaluation board ZVS components
From the primary side, “Line”, “Neutral”, “N_ZVS” and “L_ZVS” test points are available to measure ZVS voltage
level.
Caution: These test points are referenced to high voltage.
From the secondary side (low voltage and insulated), “ZVS” and “GND” test points are available to measure ZVS
voltage level.
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3Evaluation board operation with STM32 Nucleo board
3.1 Overview
As shown in Figure 17. Ways to control the STEVAL-GLA001V1 evaluation board, you can either connect the
STEVAL-GLA001V1 to your own board and microcontroller, or to the X-NUCLEO-IHM09M1 interface board for
STM32 Nucleo mounted on a NUCLEO-F030R8 development board, which is in turn connected to a PC via a
USB cable (Type A/Mini A).
Figure 17. Ways to control the STEVAL-GLA001V1 evaluation board
User microcontroller
User board
Nucleo
STEVAL-GLA001V1
board
USB
Provided ribbon cable
Ribbon cable
1st way: use Nucleo board to control the STEVAL-GLA001V1 board
2nd way: use user board with user microcontroller to control the STEVAL-GLA001V1
J202
J203
X-NUCLEO-IHM09M1
interface board
To use the STEVAL-GLA001V1 with the NUCLEO-F030R8 the latter must first be programmed with the firmware
you can download from the STSW-GLA001V1 web page (for detailed instructions, refer to the firmware user
manual).
After programming the NUCLEO-F030R8, set jumper JP5 to the E5V position.
Figure 18. Connection setup between for STEVAL-GLA001V1 evaluation board, X-NUCLEO-IHM09M1
connector expansion board and NUCLEO-F030R8 development board
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Evaluation board operation with STM32 Nucleo board
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3.2 Triac control
A Triac or AC switch can be controlled through a DC or pulse gate command. If you apply a gate current until the
Triac current exceeds IL (latching current), the Triac remains ON even if the gate current is removed. The Triac
turns OFF when the Triac current reaches zero, if the gate control is released.
Figure 19. Triac behavior according to gate control and latching current
Gate control
V
M AIN S
ITIL
IL
Triac curr ent doe sn’t reach IL
before end of gate pulse
Triac doe s n’t remain ON Triac curr ent reaches IL before
end of gat e pulse
Triac rem ai ns ON
Triac t urns-off when the Triac
current reaches zero and if no
gate pulse is app l ied
You can control a Triac gate in one of the following ways:
1. DC gate control: a continuous gate current is applied. This ensures the TRIAC turns ON, but it is energy-
consuming.
2. Pulse gate control: a pulse gate current is applied. The gate power consumption is lower but you need to
verify that IL is reached before releasing the gate current.
3.3 Operating mode
The following operating modes are available to use the loads by controlling the AC switches:
1. ON/OFF basic mode: the Triac is ON during the whole period. So the load current is a full-wave sinusoidal
current. This control mode is usually used to control fans, pumps or resistive loads. The gate signal can be
DC or pulsed.
2. ON/OFF timer mode: the Triac is ON for a defined period, so the load current is a full-wave sinusoidal
current for a chosen duration. This control mode is usually used to control fans, pumps or resistive loads,
and also for specific applications like lighting and other home control applications with timer functions.
3. Phase control mode: the Triac turns ON with a delay with respect to the ZVS. Current conduction starts at
the end of the half-cycle. The current conduction per half-cycle can then be set between 0 to half-a-cycle in
order to control the load power. This control mode is usually used to control fans, universal motor speeds or
lamp brightness. Only the pulse gate command is available.
The above loads (and corresponding AC switches) can be controlled at the same time or individually. To control
several AC switches at the same time, the control mode and parameters are common to all the AC switch
controls.
3.3.1 Mode selection
The “ON/OFF basic”, “ON/OFF timer” and “Phase control” operating modes are selectable through the three-
position “MODE” switch (SW201), see Section 2.5.6 Switch mode for more information.
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Triac control
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3.3.2 ON/OFF basic mode
Figure 20. ON/OFF control in basic mode (DC command on the left and pulse command on the right)
Triac push
button
Triac gate
command
VMAINS
IT
Current in the Triac
turns off at next
zero current
cros sing
Wait for next zero voltage crossing
tp tp
push push
Triac push
button
Triac gate
command
VMAINS
IT
Current in the Triac
turns off at next
zero current
cros sing
Wait for next zero voltage crossing
push push
This mode is selected through the MODE switch (refer to Section 3.3.1 Mode selection).
After you push the AC switch/Load button (Tx) ON, the NUCLEO-F030R8 development board waits for the next
ZVS, lights ON the corresponding LED (LEDx) and then activates the corresponding AC switch gate (Gx).
To stop the AC switch/load, push the AC switch/Load button (Tx) ON again: the gate is deactivated and the LED
is switched OFF.
By default, the gate command is a pulsed signal with a duration equal to the “tp” value. You can modify this gate
ON duration by pushing on the “TP+” button (to increase ON time) or “TP-” button (to decrease ON time). The
gate command becomes a DC signal when the “tp” value reaches the half-period.
All parameters (range, default value, unit, step, etc.) used to configure the load control for this mode are
described in Section 3.6 User interface. For more details regarding the hardware components involved in this
mode, refer to Section 2.5 Hardware function description.
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3.3.3 ON/OFF timer mode
Figure 21. ON/OFF control in timer mode (DC command on the left and pulse command on the right)
Triac push
button
Triac gate
command
VMAINS
IT
Current in the Triac
turns off at next
zero current
cros sing
Wait for next zero voltage crossing
tp tp
push
Triac push
button
Triac gate
command
VMAINS
IT
Current in the Triac
turns off at next
zero current
cros sing
Wait for next zero voltage crossing
push
OnTime OnTime
This mode is selected through the MODE switch (refer to Section 3.3.1 Mode selection). This mode operation is
similar to the ON/OFF basic mode, but a timer stops the AC switch/Load instead of pushing a button.
When you push the AC switch/Load button (Tx) ON, the NUCLEO-F030R8 development board waits for the next
ZVS, lights ON the corresponding LED (LEDx) and then activates the corresponding AC switch gate (Gx).
The AC switch/load is stopped after the timer (“OnTime” duration) has elapsed: the gate is deactivated and the
LED is switched OFF.
By default, the gate command is a pulsed signal with a duration equal to “tp” value. You can modify this gate ON
duration by pushing on the “TP+” button (to increase ON time) or “TP-” button (to decrease ON time). The gate
command becomes a DC signal when “tp” value has reached the half-period. You can also modify the timer
duration “OnTime” by pushing on the “Power Time +” button (to increase timer duration) or “Power Time -” button
(to decrease timer duration).
All parameters (range, default value, unit, step, etc.) used to configure the load control for this mode are
described in Section 3.6 User interface. For more details regarding the hardware components used for this mode,
refer to Section 2.5 Hardware function description.
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3.3.4 Phase control mode
Figure 22. Phase control (zoom on the right)
td td td
td tp
MainsPeriod/2
MainsPeriod
tp = MainsPeriod
2td
Triac push
button
Triac gate
command
VMAINS
IT
Current in the Triac
turns off at next
zero current
crossing
Wait for next zero
voltage crossing
push push
This mode is selected through the MODE switch (refer to Section 3.3.1 Mode selection).
When you push the AC switch/Load button (Tx) ON, the NUCLEO-F030R8 development board waits for the next
ZVS, lights ON the corresponding LED (LEDx) and then activates the corresponding AC switch gate (Gx).
The AC switch/load is stopped when the user pushes the AC switch/Load button (Tx) ON again: the gate is
deactivated and the LED is switched OFF.
The gate command is a pulsed signal with the time delay equal to “td” value. You can modify this time delay by
pushing on the “Power Time +” button (to decrease “td” and so increase load power) or “Power Time -” button (to
increase “td” and so decrease load power).
“td” represents the time delay before turning on the AC switch at each cycle. The “td” value is selected from a
table consisting of a configurable column number (see Figure 23. td value table details). “td” values should be
entered in ascending order (lowest index for lowest “td” value and highest index for highest “td” value).
For safety reasons, on first load control with new values, the NUCLEO-F030R8 firmware will start with the highest
“td” value (highest index), which corresponds to the minimum power.“td” is decreased (according to the table
values) when “Power Time +” is pressed and increased when “Power Time -” is pressed.
Figure 23. td value table details
Power -
+
td value
-+
Power Time - button
Power Time + button
Additionally, a soft-start and a soft-stop function are implemented in this mode to allow starting and stopping the
load gradually. The number of steps is configurable.
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Figure 24. Soft-start operation (on the left) and soft-stop operation (on the right)
Wait for next zero
voltag e cr ossing
tp_1
td_1 td_(x-1)
tp_(x-1)
td_2
tp_2 tp_1
td_1 td_(x-1)
tp_(x-1)
td_(x-2)
tp_(x-2)
Triac gate
command
VMAINS
td
tp
td
tp
All parameters (range, default value, unit, step, etc.) used to configure the load control for this mode are
described in Section 3.6 User interface. For more details regarding the hardware components used for this mode,
refer to Section 2.5 Hardware function description.
3.4 ZVS function
The ZVS (Zero Voltage Switching) function allows control of the loads in synchronization with the mains voltage,
which is especially useful for avoiding excessive dI/dt at turn ON that can damage the AC switches. The ZVS
signal versus mains voltage is shown below.
Figure 25. ZVS signal versus mains voltage (zoom on the right)
The real ZVS signal is not exactly synchronized with mains voltage due to component tolerance and delay. A
virtual delay “td_zvs” is implemented in the NUCLEO-F030R8 development board firmware to counter this
problem. You measure it with an oscilloscope and modify the value through the user interface (for more details,
refer to firmware user manual).
In case of inductive load use, you must take into account the delay due to the STEVAL-GLA001V1 evaluation
board and the phase shift due to the load. By adding these two delays, you can control the inductive load exactly
at the zero current crossing.
Figure 26. Parameters in case of inductive load (example on the right) shows an example of inductive load use:
the “Final value” entered in “td_zvs” should be the difference between the “td_zvs” delay and the inductive load
delay. For example, “td_zvs” due to the STEVAL-GLA001V1 is 1000 µs, and inductive load delay is 2500 µs: the
final value is “td_zvs” – “inductive load delay” = 1000 – 2500 = –1500 µs.
Figure 26. Parameters in case of inductive load (example on the right)
In phase control mode, the “zcs_margin” parameter lets you avoid period overlap. This parameter should be taken
into account in "td" calculation: a half-period should be equal to the sum of “tp”, “td” and “zcs_margin” as shown in
Figure 27. Parameters for phase control mode.
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Figure 27. Parameters for phase control mode
Triac gate command
VMAI NS
tp
MainsPeriod/2
td
zcs_margin
The firmware is able to manage ZVS circuit presence: according to the “zvs_hw” parameter value, some mode
operations may or may not be available. With the STEVAL-GLA001V1, the ZVS parameter is activated by default.
In case of firmware re-use with user-own design, ZVS function could be deactivated..
Table 3. Modes and gate controls available vs zvs circuit implementation lists all load modes and gate control
types available regarding ZVS circuit implementation.
Table 3. Modes and gate controls available vs zvs circuit implementation
ZVS circuit Load control Timer mode Gate control
Not available ON/OFF
No
DC
Yes
Available
ON/OFF
No
Pulse
DC
Yes
Pulse
DC
Phase control Not available Pulse
All parameters (range, default value, unit, etc.) used to configure the ZVS delay are described in Section 3.6 User
interface. For more details regarding the hardware components used for this function, refer to
Section 2.5 Hardware function description.
3.5 Fault LED
The red fault LED lights ON to indicate an error. Your can determine the fault type through the user interface (for
more details, refer to firmware user manual). For more details regarding the hardware components used for this
function, refer to Section 2.5 Hardware function description.
3.6 User interface
The user-friendly interface is designed to let you read and write parameters easily. This interface consists of many
commands (described in a menu) available through a terminal emulator such as HyperTerminal or TeraTerm. The
list of commands is shown below.
UM2304
Fault LED
UM2304 - Rev 3 page 19/46

Figure 28. User interface list of commands
The commands perform the following functions:
• read board state and configuration parameters
• set configuration parameters
•start and stop AC switches
• store configurations
• restore configuration to factory settings
Table 4. Readable parameters
Name Description Unit
Mains period Mains voltage period ms
ZVS_hw ZVS function implemented NA
Operating mode Operating mode selected (SW201
switch position) NA
td_ZVS ZVS delay µs
PBTlow Push button pressure delay ms
Tx AC switch / Load state NA
LEDx LED state NA
tp Gate control pulse time (for ON/OFF
basic and timer modes) µs
tp_step Step for increasing or decreasing tp µs
td Current gate control turn-on delay (for
phase control mode) µs
td_buffer td table NA
Index Current td table index NA
N_td td table columns number NA
td_min Minimum of td value range µs
td_max Maximum of td value range µs
Soft Start/Stop n_step Number of steps for soft-start and soft-
stop NA
UM2304
User interface
UM2304 - Rev 3 page 20/46