Features
• Fully electronic solution without the need for an inrush current limiter resistor
and bulky by-pass electromechanical relay
• DC bus disconnection at standby to reduce loss below 0.3 W
• Inrush current compliant with IEC61000-3-3
•
Operation allowed with PFC (continuous or discontinuous)
• EN 55015, IEC 61000-4-11 compliant
• Criteria A @ 2 kV IEC 61000-4-5 and @ 4 kV IEC 61000-4-4
• Insulated control of AC switches used to drive AC loads for residential
appliances
• RoHS compliant
Description
The STEVAL-IHT008V1 evaluation board limits the inrush current charging a DC bus
capacitor so that it is compliant with the IEC 61000-3-3 standard. This inrush current
is based on a soft-start procedure for the rectifier bridge achieved with a T1635T-8FP
Triac added in series with the mains line, which is controlled by the STM8S103K3
microcontroller through progressive phase-control during the startup phase.
This solution drastically reduces standby losses as the DC bus can be totally
disconnected from the AC mains when it is not required. The DC bus is easily turned
off by turning off the series Triac, without needing an additional relay to open the
circuit in standby.
Steady-state losses are also reduced because NTC resistors, traditionally used to
limit inrush current, are not required; nor are the corresponding relays to bypass
them.
This board also demonstrates that AC loads can be driven with an easy-design
isolated solution using the same power supply for the whole system and some opto-
transistors to control the ACST210-8FP, ACS108-8SN and Z0109MUF AC switches.
Product summary
STEVAL-IHT008V1
evaluation board
STEVAL-
IHT008V1
STEVAL-IHT008V1
evaluation board
firmware
STSW-IHT008
Mainstream Access
line 8-bit MCU with 8
Kbytes Flash, 16 MHz
CPU, integrated
EEPROM
STM8S103K3
16 A Snubberless
T
riac
T1635T-8FP
Overvoltage protected
AC switch
ACS108-8SN
Overvoltage protected
AC switch
ACST210-8FP
1 A Triacs Z0109MUF
Low standby loss front-end with inrush current limitation and insulated AC switch
control
STEVAL-IHT008V1
Data brief
DB2822 - Rev 2 - February 2019
For further information contact your local STMicroelectronics sales office.
www.st.com
1 Schematic diagram
Figure 2. STEVAL-IHT008V1 power and insulated control schematic
L
N
OUT1
L1
N1
OUT2
OUT3
VCC_AC
ICL_CNTRL
HVDC
HV_discharge
GND_AC
T1_CTRL
G1
G1
G2
G3
T2_CTRL
T3_CTRL
G2
Triac_ICL_G
Triac_ICL_CNTRL
G3
EC1
EC2
EC3
EC_ICL
BP_doubler
OUT4
G4
OUT5
G5
G4
T4_CTRL
EC4
G5
T5_CTRL
EC5 VCC_AC
GND_DC
GND_DC
GND_DC
GND_DC
GND_DC
GND_DC
GND_DC
GND_DC
TP5
OUT_ICL
T_ICL
T1635T-8FP
C6
56nF
D8
LED
D9 LED
D5
BZX55C15
U6
IS127
1
3
4
6
TP8
OUT3
J2
JUMPER
1 2
U2
IS127
1
3
4
6
C7
56nF
T2
ACS108-8S
1
2
3
R22
91
TP6
OUT1
U3
IS127
1
3
4
6
Q1
BUX87
R20
91
TP10
OUT5
R12
250k
TP16
G2
TP11
HVDC/2
J7
douber / rectifier mode
1
2
3
4
C1
100uF
R2
220
Q2
STQ1NK80ZR-AP
- +
U8
1000V/10A
2
4
3
1
R25
270
TP15
G1
R19
91
TP19
G5
TP4
L
R11
50k
C9
100uF
R10
250k
R38
2.7M
R9
50k
TP9
OUT4
TP7
OUT2
F1
FUSE 10A/250V
TP3
HVDC
R4
220
TP20
G_ICL
J6
JUMPER
1 2
R16
50k
T5
Z0109MUF
1
2
3
D1
BZX55C30
D4
BZX55C5V6
TP14
GND_DC
U
SIOV1
S07K300/EPC
TP1
L1
R8
2.5k 5W
TP18
G4
L1
0.012H/10A
1
2
4
3
U
SIOV2
S14K300/EPC
T1
ACST210-8
J4
JUMPER
1 2
R17
91
TP12
N
R40
4.7k
C3
1uF/450V
TP13
N1
D6 LED
U1
IS127
1
3
4
6
D10 LED
T3
ACS108-8S
1
2
3
R15
3.3k
TP2
VCC_AC
R26 270
R6
470
J1
JUMPER
1
2
Q3
2N2222
R28
36 / 2W
R18
1.5k
D2
LED
U4
IS127
1
3
4
6
R27 270
R21
91
C10
1n
J5
JUMPER
1 2
TP33
VCC_AC
R7
250k
C5
2.2nF
T4
Z0109MUF
1
2
3
U5
IS127
1
3
4
6
TP17
G3
R39
2.7M
C4
2.2nF
R1
220
R14
50k
J3
JUMPER
1 2
R23
270
D7 LED
R24
270
C8
2.2nF
R3
220
C2
2.2nF
R13
250k
R5
220
R29
2.7k
AC Power Side
Triac gate ctrl
DB2822 - Rev 2
page 2/8
STEVAL-IHT008V1
Schematic diagram