™
CAPZero
Family
Zero
1
Loss Automatic X Capacitor Discharge IC
Product Highlights
•
•
•
•
•
•
•
•
Blocks current through X capacitor discharge resistors when
AC voltage is connected
Automatically discharges X capacitors through discharge
resistors when AC is disconnected
Simplifies EMI filter design – larger X capacitor allows smaller
inductive components with no change in consumption
Only two terminals – meets safety standards for use before or
after system input fuse
>4 mm creepage on package and PCB
Self supplied – no external bias required
High common mode surge immunity – no external ground
connection
High differential surge withstand – 1000 V internal MOSFETs
®
R1
D1
MOV
and Other
X Capacitor
EMI Filter
Components
D2
R2
PI-6599-110711
AC
CAPZero
EcoSmart – Energy Efficient
•
<5 mW consumption at 230 VAC for all X capacitor values
Applications
•
All ACDC converters with X capacitors >100 nF
•
Appliances requiring EuP Lot 6 compliance
•
Adapters requiring ultra low no-load consumption
•
All converters requiring very low standby power
Figure 1.
Typical Application – Not a Simplified Circuit.
Component Selection Table
Product
3
CAP002DG
CAP012DG
CAP003DG
CAP013DG
CAP004DG
CAP014DG
CAP005DG
CAP015DG
CAP006DG
CAP016DG
CAP007DG
CAP017DG
CAP008DG
CAP018DG
CAP009DG
CAP019DG
BV
DSS
825 V
1000 V
825 V
1000 V
825 V
1000 V
825 V
1000 V
825 V
1000 V
825 V
1000 V
825 V
1000 V
825 V
1000 V
Maximum Total
X Capacitance
≤
500 nF
750 nF
1
mF
1.5
mF
2
mF
2.5
mF
3.5
mF
5
mF
Total Series
Resistance
2
(R1 + R2)
1.5 MW
1.02 MW
780 kW
480 kW
360 kW
300 kW
200 kW
150 kW
Description
When AC voltage is applied, CAPZero blocks current flow in the
X capacitor safety discharge resistors, reducing the power loss to
less than 5 mW, or essentially zero
1
at 230 VAC. When AC
voltage is disconnected, CAPZero automatically discharges the
X capacitor by connecting the series discharge resistors. This
operation allows total flexibility in the choice of the X capacitor to
optimize differential mode EMI filtering and reduce inductor costs,
with no change in power consumption.
Designing with CAPZero is simply a matter of selecting the
appropriate CAPZero device and external resistor values in Table 1
for the X capacitor value being used. This design choice will
provide a worst case RC time constant, when the AC supply is
disconnected, of less than 1 second as required by international
safety standards.
The simplicity and ruggedness of the two terminal CAPZero IC
makes it an ideal choice in systems designed to meet EuP Lot 6
requirements.
The CAPZero family has two voltage grades: 825 V and 1000 V.
The voltage rating required depends on surge requirement and
circuit configuration of the application. See Key Applications
Considerations section for details.
Table 1. Component Selection Table.
Notes:
1. IEC 62301 clause 4.5 rounds standby power use below 5 mW to zero.
2. Values are nominal. RC time constant is <1 second with ±20% X capacitor and
±5% resistance from these nominal values.
3. Packages: D: SO-8.
www.powerint.com
November 2011
CAPZero Family
Pin Functional Description
The pin configuration of Figure 2 ensures that the width of the
SO-8 package is used to provide creepage and clearance
distance of over 4 mm.
Although electrical connections are only made to pins 2, 3, 6
and 7, it is recommended that pins 1-4 and pins 5-8 are
coupled together on the PCB – see Applications Section.
NC
D1
D1
NC
D Package (SO-8)
1
2
3
4
8
7
6
5
NC
D2
D2
NC
PI-5608-060810
Figure 2.
Pin Configuration.
2
Rev. D 11/11
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CAPZero Family
R1
D1
MOV
POS1
AC
C
EXT
X Capacitor1
CAPZero
R2
D2
X Capacitor2
MOV
POS2
Other EMI
Filter
Components
PI-6600-110711
Figure 3.
Placement Options of MOV and C
EXT
.
Key Application Considerations
Breakdown Voltage Selection
Figure 3 illustrates possible system configurations influencing
the choice of CAPZero breakdown voltage. The system
configuration variables include the placement of the system
MOV and X capacitor(s) as well as the differential surge voltage
specifications of the application.
As shown in Table 1, each device in the CAPZero family has a
825 V or 1000 V option. For applications where the system
MOV is placed in position 1 (MOV
POS1
in Figure 3), the 825 V
option will typically provide adequate voltage withstand for
surge requirements up to 3 kV or more. The 1 kV CAPZero
would be recommended for higher surge requirements or if
additional voltage margin is required.
For MOV placement that is not directly across the X Capacitor1
(for example MOV
POS2
in Figure 3) the 1000 V CAPZero devices
can be used up to a surge specification of 1.5 kV. For differential
surge voltage specifications of >1.5 kV it is recommended that
the MOV is always placed in the location shown in Figure 3 as
MOV
POS1
.
It is always recommended that the peak voltage between
terminals D1 and D2 of CAPZero is measured during surge
tests in the final system. Measurements of peak voltage across
CAPZero during surge tests should be made with oscilloscope
probes having appropriate voltage rating and using an isolated
supply to the oscilloscope to avoid ground currents influencing
measurement results. When making such measurements, it is
recommended that 50 V engineering margin is allowed below
the breakdown voltage specification (for example 950 V with the
1000 V CAPZero).
If the measured peak Drain voltage exceeds 950 V, an external
1 kV ceramic capacitor of value up to 47 pF can also be placed
between D1 and D2 terminals to attenuate the voltage applied
between the CAPZero terminals during surge. This optional
external capacitor placement is shown as C
EXT
in Figure 3. It
should be noted that use of an external capacitor in this way will
increase power consumption slightly due to the C
EXT
charge/
discharge currents flowing in R1 and R2 while AC is connected.
A C
EXT
value of 33 pF will add approximately 0.5 mW at 230 VAC,
50 Hz.
PCB Layout and External Resistor Selection
Figure 4 shows a typical PCB layout configuration for CAPZero.
The external resistors in this case are divided into two separate
surface mount resistors to distribute loss under fault conditions
– for example where a short-circuit exists between CAPZero
terminals D1 and D2. R1 and R2 values are selected according
to Table 1.
Under a fault condition where CAPZero terminals D1 and D2 are
shorted together, each resistor will dissipate a power that can
be calculated from the applied AC voltage and the R1 and R2
values. For example in an application using CAP004 or CAP014,
R1=R2=390 kW. If CAPZero is shorted out at 265 VAC R1 and
R2 will each dissipate 45 mW.
Resistors R1 and R2 should also be rated for 50% of the system
input voltage again to allow for the short-circuitry of CAPZero
D1 to D2 pins during single point fault testing.
If lower dissipation or lower voltage across each resistor is
required during fault tests, the total external resistance can be
divided into more discrete resistors, however the total resistance
must be equal to that specified in Table 1.
3
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Rev. D 11/11
CAPZero Family
Safety
CAPZero meets safety requirements even if placed before the
system input fuse. If a short-circuit is placed between D1 and
D2 terminals of CAPZero, the system is identical to existing
systems where CAPZero is not used.
X Capacitor
R1
With regard to open circuit tests, it is not possible to create a
fault condition through a single pin fault (for example lifted pin
test) since there are two pins connected to each of D1 and D2.
If several pins are lifted to create an open circuit, the condition
is identical to an open circuit X capacitor discharge resistor in
existing systems where CAPZero is not used. If redundancy
against open circuit faults is required, two CAPZero and R1 / R2
configurations can be placed in parallel.
Discharge Operation
To meet the safety regulations, when the AC supply is
disconnected, CAPZero will discharge the X capacitor to the
safety extra low voltage (SELV) levels according to the above
functional description. Although there are no specific safety
requirements below SELV, CAPZero still continues the discharge
until the X capacitor is fully discharged. As such CAPZero can
be safely used at low input voltages such as the common
industrial 18 VAC and 24 VAC supply rails while retaining X
capacitor discharge when the AC source is disconnected.
R2
≥4
mm
PI-5610-041310
Figure 4.
Typical PCB Layout.
4
Rev. D 11/11
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CAPZero Family
Absolute Maximum Ratings
4
CAP002-CAP009 ..............................825 V
CAP012-CAP019 .............................1000 V
2
DRAIN Peak Current CAP002/CAP012 .................... 0.553 mA
CAP003/CAP013 .....................0.784 mA
CAP004/CAP014 .....................1.026 mA
CAP005/CAP015 .....................1.667 mA
CAP006/CAP016 .................... 2.222 mA
CAP007/CAP017 ......................2.667 mA
CAP008/CAP018 .................... 4.000 mA
CAP009/CAP019 .................... 5.333 mA
Storage Temperature ...................................... -65 °C to 150 °C
Lead Temperature
3
..........................................................260 °C
Operating Ambient Temperature ...................... -10 °C to 105 °C
Maximum Junction Temperature ...................... -10 °C to 110 °C
DRAIN Pin Voltage
1
Notes:
1. Voltage of D1 pin relative to D2 pin in either polarity.
2. The peak DRAIN current is allowed while the DRAIN voltage
is simultaneously less than 400 V.
3. 1/16 in. from case for 5 seconds.
4. The Absolute Maximum Ratings specified may be applied
one at a time without causing permanent damage to the
product. Exposure to Absolute Maximum Rating conditions
for extended periods of time may affect product reliability.
Parameter
Control Functions
AC Removal
Detection Time
Symbol
Conditions
T
A
= -10 to 105 °C
(Unless Otherwise Specified)
Min
Typ
Max
Units
t
DETECT
Line Cycle Frequency 47-63 Hz
CAP002/012
CAP003/013
CAP004/014
0.25
0.37
0.48
0.78
1.04
1.25
1.88
2.5
22
31.4
ms
Drain Saturation
Current
A,B
I
DSAT
CAP005/015
CAP006/016
CAP007/017
CAP008/018
CAP009/019
mA
Supply Current
I
SUPPLY
T
A
= 25 °C
21.7
mA
Notes
A. Saturation current specifications ensure a natural RC discharge characteristic at all voltages up to 265 VAC pk with the external
resistor values specified in Component Selection Table 1.
B. Specifications are guaranteed by characterization and design.
5
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Rev. D 11/11
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