December 2010 Doc ID 15238 Rev 4 1/13
13
ACST12
Overvoltage protected AC switch
Features
■Triac with overvoltage crowbar technology
■Low IGT (<10 mA) or high immunity
(IGT<35 mA) version
■High noise immunity: static dV/dt > 2000 V/µs
Benefits
■Enables equipment to meet IEC 61000-4-5
■High off-state reliability with planar technology
■Need no external over voltage protection
■Reduces the power passive component count
■High immunity against fast transients
described in IEC 61000-4-4 standards
Applications
■AC mains static switching in appliance and
industrial control systems
■Drive of medium power AC loads such as:
– Universal motor of washing machine drum
– Compressor for fridge or air conditioner
Description
The ACST12 series belongs to the ACS™/ACST
power switch family built with A.S.D.® (application
specific discrete) technology. This high
performance device is suited to home appliances
or industrial systems and drives loads up to 12 A.
This ACST12 switch embeds a Triac structure and
a high voltage clamping device able to absorb the
inductive turn-off energy and withstand line
transients such as those described in the
IEC 61000-4-5 standard. The ACST1210-7 needs
a low gate current to be activated (IGT < 10 mA)
and still provides a high electrical noise immunity
complying with the IEC 61000-4-4 standard. The
ACST1235-7 offers an extremely high static dV/dt
immunity of 2 kV/µs minimum.
Figure 1. Functional diagram
TM: ACS is a trademark of STMicroelectronics
®: A.S.D. is a registered trademark of STMicroelectronics
Table 1. Device summary
Symbol Value Unit
IT(RMS) 12 A
VDRM/VRRM 700 V
IGT 10 or 35 mA
TO-220AB
ACST1210-7T
ACST1235-7T
COM
OUT
OUT
G
D2PAK
ACST1210-7G
ACST1235-7G
G
OUT
COM
G
COM
OUT
www.st.com
Characteristics ACST12
2/13 Doc ID 15238 Rev 4
1 Characteristics
Table 2. Absolute ratings (limiting values)
Symbol Parameter Value Unit
IT(RMS) On-state rms current full sine wave
TO-220AB
D2PA K Tc = 104 °C 12
A
D2PA K
with 1cm2 of Cu
Tamb = 47
°C 2
ITSM
Non repetitive surge peak on-state current
Tj initial = 25 °C,( full cycle sine wave)
F = 60 Hz tp = 16.7 ms 126 A
F = 50 Hz tp = 20.0 ms 120 A
I2tI
2t for fuse selection tp = 10 ms 95 A2s
dI/dt Critical rate of rise on-state current
IG = 2 x IGT, (tr ≤ 100 ns) F = 120 Hz Tj = 125 °C 100 A/µs
VPP Non repetitive line peak pulse voltage (1) Tj = 125 °C 2 kV
PG(AV) Average gate power dissipation Tj = 125 °C 0.1 W
PGM Peak gate power dissipation (tp = 20 µs) Tj = 125 °C 10 W
IGM Peak gate current (tp = 20 µs) Tj = 125 °C 1.6 A
Tstg Storage temperature range - 40 to + 150 °C
TjOperating junction temperature range - 40 to + 125 °C
Tlmaximum lead soldering temperature during 10 s (at 3 mm from plastic case) 260 °C
1. According to test described in IEC 61000-4-5 standard and Figure 19
Table 3. Electrical characteristics
Symbol Test conditions Quadrant Tj
Value Unit
ACST1210-7 ACST1235-7 Unit
IGT(1) VOUT = 12 V, RL = 33 ΩI - II - III 25 °C MAX. 10 35 mA
VGT VOUT = 12 V, RL = 33 ΩI - II - III 25 °C MAX. 1.0 V
VGD VOUT = VDRM, RL = 3.3 ΩI - II - III 125 °C MIN. 0.2 V
IH(2) IOUT = 500 mA 25 °C MAX. 30 50 mA
ILIG = 1.2 x IGT I - II - III 25 °C MAX. 50 70 mA
dV/dt(2) VOUT = 67% VDRM, gate open 125 °C MIN. 200 2000 V/µs
(dI/dt)c(2) (dV/dt)c = 15 V/µs 125 °C MIN. 5.3 A/ms
Without snubber MIN. 14
VCL ICL = 0.1 mA, tp = 1 ms 25 °C MIN. 850 V
1. Minimum IGT is guaranteed at 5% of IGT max
2. For both polarities of OUT pin referenced to COM pin
ACST12 Characteristics
Doc ID 15238 Rev 4 3/13
Table 4. Static characteristics
Symbol Test conditions Value Unit
VTM(1) IOUT = 17 A, tp = 500 µs Tj = 25 °C MAX. 1.5 V
VT0(1) Threshold voltage Tj = 125 °C MAX. 0.9 V
Rd(1) Dynamic resistance Tj = 125 °C MAX. 30 mΩ
IDRM
IRRM
VOUT = VDRM/ VRRM
Tj = 25 °C MAX. 20 µA
Tj = 125 °C 1.5 mA
1. For both polarities of OUT pin referenced to COM pin
Table 5. Thermal characteristics
Symbol Parameter Value Unit
Rth(j-c) Junction to case (AC) TO-220AB 1.5 °C/W
D2PAK ° C / W
Rth(j-a) Junction to ambient TO-220AB 60 °C/W
D2PAK with 1 cm2 of Cu 45 °C/W
Figure 2. Maximum power dissipation versus
on-state rms current (full cycle)
Figure 3. On-state rms current versus case
temperature (full cycle)
P(W)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0123456789101112
α
=180
°
I (A)
T(RMS)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
0 25 50 75 100 125
IT(RMS)(A)
TC(°C)TC(°C)
Figure 4. On-state rms current versus
ambient temperature (free air
convection full cycle)
Figure 5. Relative variation of thermal
impedance versus pulse duration
IT(RMS)(A)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0 25 50 75 100 125
TO-220AB
D2PAK
With 1cm2of cu
Tamb(°C)
K=[Zth/Rth]
1.0E-02
1.0E-01
1.0E+00
1.0E-03 1.0E-02 1.0E-01 1.0E+00 1.0E+01 1.0E+02 1.0E+03
Zth(j-a)
Zth(j-c)
tp(s)
Characteristics ACST12
4/13 Doc ID 15238 Rev 4
Figure 6. On-state characteristics
(maximum values)
Figure 7. Non repetitive surge peak on-state
current versus number of cycles
(Tj initial = 25 °C)
1
10
100
1000
012345
I
TM
(A)
Tj=25 °C
Tj=125 °C
Tjmax :
Vto = 0.90 V
Rd= 30 mΩ
VTM (V) 0
10
20
30
40
50
60
70
80
90
100
110
120
130
1 10 100 1000
I(A)
TSM
Non repetitive
Tjinitial=25 °C
One cycle
t=20ms
Repetitive
TC=104 °C Number of cycles
Figure 8. Non repetitive surge peak on-state
current for a sinusoidal pulse and
corresponding value of I2t
Figure 9. Relative variation of gate triggering
current and gate voltage versus
junction temperature (typical value)
I (A), I t (A s)
TSM
22
1
10
100
1000
10000
0.01 0.10 1.00 10.00
T
j
initial=25 °C
dI/dt limitation: 100 A/µs
I
TSM
I²t
t
P
(ms)
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-50
-25 0 25 50 75 100 125
I
GT
Q1-Q2
V
GT
Q1-Q2-Q3
I
GT
Q3
Tj(°C)
I , V [T ] / I , V [T = 25 °C]
GT GT j GT GT j
Figure 10. Relative variation of holding
current (IH) and latching current (IL)
versus junction temperature
Figure 11. Relative variation of critical rate of
decrease of main current (di/dt)c
versus (dV/dt)c
I ,I [T]/I , I [T = 25 °C]
H L j H L j
0.0
0.5
1.0
1.5
2.0
2.5
-50 -25 0 25 50 75 100 125
IH
IL
Tj(°C)
Typical values
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
0.1 1 10 100
ACST12-7Cxx
ACST12-7Sxx
(di/dt)c[(dV/dt)c] / Specified(di/dt)c
(dV/dt)c (V/µs)
ACST12 Characteristics
Doc ID 15238 Rev 4 5/13
Figure 12. Relative variation of critical rate of
decrease of main current versus
junction temperature
Figure 13. Relative variation of static dV/dt
immunity versus junction
temperature
(dI/dt)c[Tj] / (dI/dt)c[Tj=125°C]
Tj(°C)
0
1
2
3
4
5
6
7
8
9
10
11
25 50 75 100 125
dV/dt[Tj] / dV/dt[Tj=125°C]
Tj(°C)
0
1
2
3
4
5
6
7
8
9
10
11
12
25 50 75 100 125
V
D
=V
R
=469 V
Figure 14. Relative variation of maximum
clamping voltage, VCL versus
junction temperature
Figure 15. Variation of thermal resistance
junction to ambient versus copper
surface under tab
0.85
0.90
0.95
1.00
1.05
1.10
1.15
-50 -25 0 25 50 75 100 125
V [T /V [T = 25 °C]
CL J CL J
T (°C)
J
Minimum values
0
10
20
30
40
50
60
70
80
0 5 10 15 20
R (°C/W)
th(j-a)
S (cm²)
CU
D²PAK
Epoxy printed circuit board
FR4, copper thickness = 35 µm
Application information ACST12
6/13 Doc ID 15238 Rev 4
2 Application information
2.1 Typical application description
The ACST12 device has been designed to control medium power load, such as AC motors
in home appliances. Thanks to its thermal and turn off commutation performances, the
ACST12 switch is able to drive an inductive load up to 12 A with no turn off additional
snubber. It also provides high thermal performances in static and transient modes such as
the compressor inrush current or high torque operating conditions of an AC motor. Thanks
to its low gate triggering current level, the ACST1210-7 can be driven directly by a MCU
through a simple gate resistor as shown in Figure 16.
Figure 16. Compressor control – typical diagrams
Compressor
Electronic
starter
Electronic
thermostat
ACST
Rg
ACST
Power supply
AC Mains
Gate
Driver
logical circuitry
1
2
3
PTC
Compressor with integrated e-starter
Compressor
Start
switch
Run
switch
PTC
Rg
ACST
Power supply
Gate
Driver
ACST
Rg
AC Mains
Compressor with external electronic drive
ACST12 Application information
Doc ID 15238 Rev 4 7/13
Figure 17. Universal drum motor control – typical diagram
2.2 AC line transient voltage ruggedness
In comparison with standard Triacs, which are not robust against surge voltage, the ACST12
is self-protected against over-voltage, specified by the new parameter VCL. The ACST12
switch can safely withstand AC line transient voltages either by clamping the low energy
spikes, such as the inductive spikes at switch off, or by switching to the on state (for less
than 10 ms) to dissipate higher energy shocks through the load. This safety feature works
even with high turn-on current ramp-up.
The test circuit of Figure 18 represents the ACST12 application, and is used to stress the
ACST switch according to the IEC 61000-4-5 standard conditions. With the additional effect
of the load which is limiting the current, the ACST switch withstands the voltage spikes up to
2 kV on top of the peak line voltage. The protection is based on an overvoltage crowbar
technology. The ACST12 folds back safely to the on state as shown in Figure 19. The
ACST12 recovers its blocking voltage capability after the surge and the next zero crossing
current. Such a non repetitive test can be done at least 10 times on each AC line voltage
polarity.
Universal motor
Motor direction
setting
Speed motor
regulation
Rg
AC Mains
Stator
MCU
Vcc
12V
ACST
Rotor
MCU
Application information ACST12
8/13 Doc ID 15238 Rev 4
Figure 18. Overvoltage ruggedness test circuit for resistive and inductive loads for
IEC 61000-4-5 standards
Figure 19. Typical voltage and current waveforms across the ACST12
during IEC 61000-4-5 standard test
AC Mains
R
Filtering unit
Rg
Model of the load
Rgene
Surge generator
ACST12
2kV surge
L
R = , L = µH, Vsurge = 2 kV20 2Ω
I
V
0
0
Vpeak =V CL
1.2/50 µs voltage surge
8/20 µs current surge
ACST12 Ordering information scheme
Doc ID 15238 Rev 4 9/13
3 Ordering information scheme
Figure 20. Ordering information scheme
ACS T 12 10 - 7 G TR
AC switch
Topology
On-state rms current
Sensitivity
Voltage
Package
Delivery mode
T = Triac
12 = 12 A
10 = 10 mA
35 = 35 mA
7 = 700 V
G = D²PAK
T = TO-220AB
TR = Tape and reel (DPAK)
Blank = Tube (TO-220FPAB, DPAK)
Package information ACST12
10/13 Doc ID 15238 Rev 4
4 Package information
●Epoxy meets UL94, V0
●Recommended torque (TO-220AB): 0.4 to 0.6 N·m
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK® is an ST trademark.
Table 6. TO-220AB dimensions
Ref.
Dimensions
Millimeters Inches
Min. Max. Min. Max.
A 4.40 4.60 0.173 0.181
C 1.23 1.32 0.048 0.051
D 2.40 2.72 0.094 0.107
E 0.49 0.70 0.019 0.027
F 0.61 0.88 0.024 0.034
F1 1.14 1.70 0.044 0.066
F2 1.14 1.70 0.044 0.066
G 4.95 5.15 0.194 0.202
G1 2.40 2.70 0.094 0.106
H2 10 10.40 0.393 0.409
L2 16.4 typ. 0.645 typ.
L4 13 14 0.511 0.551
L5 2.65 2.95 0.104 0.116
L6 15.25 15.75 0.600 0.620
L7 6.20 6.60 0.244 0.259
L9 3.50 3.93 0.137 0.154
M 2.6 typ. 0.102 typ.
Diam. 3.75 3.85 0.147 0.151
A
C
D
L7
Dia
L5
L6
L9
L4
F
H2
G
G1
L2
F2
F1
E
M
ACST12 Package information
Doc ID 15238 Rev 4 11/13
Figure 21. Footprint (dimensions in mm)
Table 7. D2PAK dimensions
Ref.
Dimensions
Millimeters Inches
Min. Typ. Max. Min. Typ. Max.
A 4.30 4.60 0.169 0.181
A1 2.49 2.69 0.098 0.106
A2 0.03 0.23 0.001 0.009
B 0.70 0.93 0.027 0.037
B2 1.25 1.40 0.048 0.055
C 0.45 0.60 0.017 0.024
C2 1.21 1.36 0.047 0.054
D 8.95 9.35 0.352 0.368
E 10.00 10.28 0.393 0.405
G 4.88 5.28 0.192 0.208
L 15.00 15.85 0.590 0.624
L2 1.27 1.40 0.050 0.055
L3 1.40 1.75 0.055 0.069
R 0.40 0.016
V2 0° 8° 0° 8°
G
L
L3
L2
B
B2
E
2mm min.
FLAT ZONE
A
C2
D
R
A2
V2
C
A1
16.90
10.30
8.90 3.70
5.08
1.30
Ordering information ACST12
12/13 Doc ID 15238 Rev 4
5 Ordering information
6 Revision history
Table 8. Ordering information
Order code Marking Package Weight Base qty Packing mode
ACST1210-7T
ACST12107
TO-220AB 2.3 g 50 Tube
ACST1210-7G D2PAK 1.5 g 50 Tube
ACST1210-7GTR D2PAK 1.5 g 1000 Tape and reel
ACST1235-7T
ACST12357
TO-220AB 2.3 g 50 Tube
ACST1235-7G D2PAK 1.5 g 50 Tube
ACST1235-7GTR D2PAK 1.5 g 1000 Tape and reel
Table 9. Document revision history
Date Revision Changes
02-Dec-2008 1 First issue.
13-Apr-2010 2 Updated ECOPACK statement. Reformatted for consistency with
other datasheets in this product class.
01-Jul-2010 3 Updated Figure 20.
07-Dec-2010 4 Updated Table 3.
ACST12
Doc ID 15238 Rev 4 13/13
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