STMICROELECTRONICS ACST88C

ACST8-8C
®
ASD™
AC Switch Family
OVER VOLTAGE PROTECTED
AC POWER SWITCH
MAIN APPLICATIONS
AC static switching in appliance & industrial
control systems
Washing machine with bi-rotational induction
motor drive
Induction motor drive for:
- refrigerator / freezer compressor
- air conditioning compressor
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FEATURES
VDRM / VRRM = +/- 800V
Avalanche controlled device
IT(RMS) = 8A with TCASE = 90 °C
High noise immunity: static dV/dt > 750 V/µs
Gate triggering current : IGT < 30 mA
Snubberless turn off commutation:
(dI/dt)c > 4.5A/ms
TO-220FPAB package
G
OUT
COM
TO-220FPAB
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FUNCTIONAL DIAGRAM:
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OUT
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BENEFITS
Enables equipment to meet EN61000-4-5
standard
High off-state reliability with planar technology
Need no external overvoltage protection
Reduces the power component count
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G
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DESCRIPTION
The ACST8-8C belongs to the AC power switch
family built around the ASD technology. This high
performance device is adapted to home appliances
or industrial systems and drives an induction motor
up to 8A.
This ACST switch embeds a triac structure with a
high voltage clamping device to absorb the inductive
turn off energy and withstand line transients such as
those described in the IEC61000-4-5 standards.
January 2002 - Ed: 4B
COM
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ACST8-8C
ABSOLUTE RATINGS (limiting values)
Symbol
Parameter
VDRM /
VRRM
Repetitive peak off-state voltage
IT(RMS)
RMS on-state current full cycle sine wave 50 to 60 Hz
ITSM
I2t
VPP
Non repetitive line peak pulse voltage
Tstg
V
8
A
tp = 20ms
80
A
tp = 16.7ms
85
A
tp = 10ms
35
A2s
Rate period > 1mn
100
A/µs
Thermal constraint for fuse selection
Non repetitive on-state current critical rate of rise
IG = 10mA (tr < 100ns)
Unit
800
Tcase = 90°C
Non repetitive surge peak on-state current
Tj initial = 25°C, full cycle sine wave
dI/dt
Value
note 1
2
kV
Storage temperature range
- 40 to + 150
°C
Tj
Operating junction temperature range
- 40 to + 125
°C
Tl
Maximum lead soldering temperature during 10s
260
°C
Note 1: according to test described by IEC61000-4-5 standard & Figure A.
GATE CHARACTERISTICS (maximum values)
Symbol
PG (AV)
Parameter
Value
Unit
Average gate power dissipation
0.1
W
PGM
Peak gate power dissipation (tp = 20µs)
10
W
IGM
Peak gate current (tp = 20µs)
1
A
THERMAL RESISTANCE
Symbol
Value
Unit
Rth (j-a)
Junction to ambient
Parameter
60
°C/W
Rth (j-c)
Junction to case for full cycle sine wave conduction
3.5
°C/W
PARAMETER DESCRIPTION
Parameter Symbol
Parameter description
IGT
Gate triggering current
VGT
Gate triggering voltage
VGD
Non triggering voltage
IH
Holding current
IL
Latching current
VTM
On state voltage
VTO
On state characteristic threshold voltage
RD
On state characteristic dynamic resistance
IDRM / IRRM
Forward or reverse leakage current
dV/dt
Static pin OUT voltage rise
(dI/dt)c
Turn off current rate of decay
VCL
Avalanche voltage at turn off
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ACST8-8C
ELECTRICAL CHARACTERISTICS PER SWITCH
For either positive or negative polary of pin OUT voltage respect to pin COM voltage
Symbol
Test conditions
Values
Unit
IGT
VOUT = 12V (DC)
RL = 33Ω
Tj = 25°C
MAX.
30
mA
VGT
VOUT = 12V (DC)
RL = 33Ω
Tj = 25°C
MAX.
1.5
V
VGD
VOUT = VDRM
RL = 3.3kΩ
Tj =125°C
MIN.
0.2
V
IH
IOUT = 100mA Gate open
Tj = 25°C
MAX.
40
mA
IL
IG = 20mA
Tj = 25°C
MAX.
70
mA
VTM
IOUT = 11A
Tj = 25°C
MAX.
1.5
V
VTO
Tj = 125°C
MAX.
0.95
V
RD
Tj = 125°C
MAX.
50
mΩ
Tj = 25°C
MAX.
10
µA
Tj = 125°C
MAX.
1
mA
Tj = 125°C
MIN.
750
V/µs
Without snubber
Tj = 125°C
MIN.
4.5
A/ms
ICL = 1mA
Tj = 25°C
TYP.
1200
V
IDRM
IRRM
dV/dt
(dI/dt)c
VCL
tp = 380µs
VOUT = VDRM
VOUT = VRRM
VOUT = 550V
gate open
tp = 1ms
AC LINE SWITCH BASIC APPLICATION
The ACST8-8C device is especially designed to drive medium power induction motors in washing machines, refrigerators, dish washers, and tumble dryers.
Pin COM
: Common drive reference, to be connected to the power line neutral
Pin G
: Switch Gate input to be connected to the controller
Pin OUT
: Switch Output to be connected to the load
When driven from a low voltage controller, the ACST switch is triggered with a negative gate current flowing out of the gate pin G. It can be driven by the controller through a resistor as shown on the typical application diagram. In appliance systems, the ACST8-8C switch intends to drive medium power load in ON /
OFF full cycle or phase angle control mode.
Thanks to its thermal and turn-off commutation characteristics, the ACST8-8C switch is able to drive
an inductive load up to 8A without a turn-off aid snubber circuit.
In washing machine or drier appliances, the tumble rotates in both directions. When using bidirectional
phase shift induction motor, two switches are connected on each side of the phase shift capacitor: in
steady-state operation, one switch only conducts energising the coils and defining the tumble direction.
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ACST8-8C
TYPICAL APPLICATION DIAGRAM
OUT
G
COM
CONTROL
UNIT
ROBUSTNESS AGAINST FAST CAPACITOR DISCHARGE
When parasitic transients or controller mis-operation occur, the blocked switch may turn on by spurious
switch firing. Since the phase shift capacitor is charged, its energy is instantaneously dissipated through
the two ACSTs which can be destroyed. To prevent such a failure, a resistive inductive circuit R-L is added
in series with the phase shift capacitor.
The dI/dt depends on the maximal voltage Vmax of the phase shift capacitor (700V on 240V mains applications), and on the inductance L:
dI V max
=
dt
L
The total switch turn on di/dt is the sum of the di/dt created by any RC noise suppressor discharge and the
dI/dt created by the motor capacitor discharge.
Since the maximal di/dt capability at turn-on of the ACST8 is 100A/µs, the motor capacitor di/dt is assumed
to be less than 50A/µs; therefore, the inductance should be 14µH.
The resistor R limits the surge current through the ACST8 during the capacitor discharge according to the
specified curve ITSM = f (tp) as shown in Figure 6 (to be issued), and 1.2 Ω is low enough to limit the resistor
dissipation (usually less than 1 W).
Finally both the 14µH inductance and the 1.2Ω resistance provide a safety margin of two on the surge current ITSM described in Figure 6.
M
VAC
C
L
R
700V
T1
ON
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T2
Fast capacitor discharge when
one ACST switch turns on (T2)
and the motor runs (T1 ON).
ACST8-8C
AC LINE TRANSIENT VOLTAGE RUGGEDNESS
The ACST8-8C switch is able to safely withstand the AC line transient voltages either by clamping the low
energy spikes or by breaking over under high energy shocks.
The test circuit in Figure A is representative of the ACST application and is used to test the ACST switch
according to the IEC61000-4-5 standard conditions. Thanks to the load impedance, the ACST switch withstands voltage spikes up to 2 kV above the peak line voltage by breaking over safely. Such non repetitive
testing can be done 10 times on each AC line voltage polarity.
Fig. A: Overvoltage ruggedness test circuit for resistive and inductive loads
according to IEC61000-4-5 standard R = 47Ω, L = 10µH & VPP = 2kV
L
R
OUT
SURGE VOLTAGE
AC LINE & GENERATOR
VAC + V PP
G
COM
Fig. 1: Maximum power dissipation versus RMS
on-state current.
Fig. 2-1: RMS on-state current versus case
temperature.
P(W)
IT(RMS)(A)
11
9
α=180°
10
α=180°
8
9
7
8
6
7
6
5
5
4
4
3
3
180°
2
1
2
α
α
1
Tc(°C)
IT(RMS)(A)
0
0
0
1
2
3
4
5
6
7
8
0
25
50
75
100
125
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ACST8-8C
Fig. 2-2: RMS on-state current versus ambient
temperature.
Fig. 3: Relative variation of thermal impedance
versus pulse duration.
K = [Zth/Rth]
IT(RMS)(A)
1.E+00
2.5
α=180°
Printed circuit board FR4
Natural convection
Zth(j-c)
2.0
1.E-01
Zth(j-a)
1.5
1.0
1.E-02
0.5
Tamb(°C)
tp(s)
0.0
1.E-03
0
25
50
75
100
125
Fig. 4: On-state characteristics (maximum values).
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
Fig. 5: Surge peak on-state current versus number
of cycles.
Iout(A)
ITSM(A)
100
90
80
Tj=25°C
Tj=125°C
70
t=20ms
Non repetitive
Tj initial=25°C
60
50
10
40
Repetitive
Tc=90°C
30
20
Tj max. :
Vto = 0.95 V
Rd = 50 mΩ
VTM(V)
10
1
Number of cycles
0
0
1
2
3
4
5
6
Fig. 6: Non repetitive surge peak on-state current
for a sinusoidal pulse with width tp < 10ms, and
corresponding value of I2t.
1
10
100
1000
Fig. 7: Relative variation of gate trigger current,
holding current and latching current versus junction temperature (typical values).
ITSM(A), I2t(A2s)
IGT, IH, IL[Tj]/IGT, IH, IL[Tj=25°C]
3.0
1000
Tj initial=25°C
2.5
IGT & IH
dI/dt limitation:
100A/µs
2.0
ITSM
1.5
100
IL
1.0
I²t
0.5
tp(ms)
Tj(°C)
0.0
10
0.01
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0.10
1.00
10.00
-40 -30 -20 -10
0
10 20 30 40 50 60 70 80 90 100 110 120 130
ACST8-8C
Fig. 8: Relative variation of critical rate of decrease
of main current versus reapplied dV/dt (typical values).
Fig. 9: Relative variation of critical rate of decrease
of main current versus junction temperature.
(dI/dt)c[(dV/dt)c] / Specified (dI/dt)c
(dI/dt)c[Tj] / (dI/dt)c[Tj=125°C]
5
6
4
5
4
3
3
2
2
1
1
dV/dt (V/µs)
Tj(°C)
0
0
0.1
1.0
10.0
100.0
0
25
50
75
100
125
Fig. 10: Relative variation of static dV/dt versus
junction temperature
dV/dt[Tj] / dV/dt[Tj = 125°C]
3.5
Vout=550V
3.0
2.5
2.0
1.5
1.0
0.5
Tj(°C)
0.0
0
25
50
75
100
125
ORDERING INFORMATION
ACS
T
8
-
IT(RMS): 8A
AC Switch
Topology: Triac
8
C
FP
IGT
C = 30mA
VDRM: 800V
Package
FP: TO-220FPAB
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ACST8-8C
PACKAGE MECHANICAL DATA
TO-220FPAB (Plastic)
DIMENSIONS
REF.
Millimeters
Inches
A
B
D
E
F
F1
F2
G
G1
H
L2
L3
L4
L5
L6
L7
Dia.
Min.
Max.
4.4
4.6
2.5
2.7
2.5
2.75
0.45
0.70
0.75
1
1.15
1.70
1.15
1.70
4.95
5.20
2.4
2.7
10
10.4
16 Typ.
28.6
30.6
9.8
10.6
2.9
3.6
15.9
16.4
9.00
9.30
3.00
3.20
Min.
Max.
0.173
0.181
0.098
0.106
0.098
0.108
0.018
0.027
0.030
0.039
0.045
0.067
0.045
0.067
0.195
0.205
0.094
0.106
0.393
0.409
0.63 Typ.
1.126
1.205
0.386
0.417
0.114
0.142
0.626
0.646
0.354
0.366
0.118
0.126
A
B
H
Dia
L6
L2
L7
L3
L5
D
F1
L4
F2
F
E
G1
G
OTHER INFORMATION
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Ordering type
Marking
Package
Weight
Base qty
Delivery mode
ACST8-8CFP
ACST88C
TO-220FPAB
2.4 g
50
Tube
Epoxy meets UL94,V0
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of
use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to
change without notice. This publication supersedes and replaces all information previously supplied.
STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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© 2002 STMicroelectronics - Printed in Italy - All rights reserved.
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