CLARE CPC1580PTR

CPC1580
Optically Isolated Gate Drive Circuit
Features
Description
•
•
•
•
•
•
•
The CPC1580 optical gate driver provides isolated
control of a discrete power MOSFET transistor without
the need of an external power supply. Control of the
power MOSFET transistor is accomplished by the
application of sufficient input LED current to activate
the driver circuitry.
Drives External Power MOSFET
Low LED Current (2.5mA)
Requires No External Power Supply
Load Voltages up to 65V
High Reliability
Small 8-pin Surface Mount Package
3750Vrms Input/Output Isolation
On the load side, an external storage capacitor and an
internal bootstrap diode enable the internal
photovoltaic and gate driver circuitry to provide fast
output switching characteristics by supplying the
charge necessary to satisfy the MOSFET’s bias
requirements.
Applications
•
•
•
•
•
•
Industrial Controls
Instrumentation
Medical Equipment Isolation
Electronic Switching
I/O Subsystems
Appliances
Provided in a small 8-pin package, the CPC1580
provides 3750Vrms of input-to-output isolation.
Approvals
Ordering Information
• UL recognized component: File # E76270
Part
Description
CPC1580P
8-Pin Flatpack (50/Tube)
CPC1580PTR
8-Pin Flatpack (1000/Reel)
Figure 1. CPC1580 Application Circuit Diagram
CPC1580
1
4
NC
CST
8 VCAP
7
V+
VD
NC
5
LED +
LED -
2
3
VG
6
VS
DS-CPC1580 - R00G
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CPC1580
1. Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.1 Package Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.2 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.3 Pin Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.4 ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.5 General Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.6 Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.7 Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
3
3
3
3
4
4
5
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. External Part Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.1 Storage Capacitor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2 Transistor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.1 Transistor Switching Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
6
7
7
4. CPC1580 Over-Voltage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1 Other Protection Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Application Switching Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.1 Resistive Load Losses: The Ideal Case. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.2 Inductive/Resistive Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.3 Capacitive Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5.4 dV/dt Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
9
9
9
9
6. Design Switching Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7. Manufacturing Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.1 Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.2 Washing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.3 Mechanical Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7.4 Tape and Reel Specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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CPC1580
1. Specifications
1.1 Package Pinout
1.3 Pin Description
CPC1580P Pinout
N/C
LED +
LED N/C
1
8
2
7
3
6
4
5
N/C
2
LED +
Positive input to LED
VD
3
LED -
Negative input to LED
VS
4
N/C
Not connected
5
VG
Output, MOSFET Gate Control
6
VS
MOSFET Source Voltage
7
VD
MOSFET Drain Voltage
8
VCAP
VG
Blocking Voltage (VDS)
65
VP
Reverse Input Voltage
5
V
Input Control Current
50
mA
1
A
Input Power Dissipation 1
150
mW
Output Power Dissipation 2
500
mW
Isolation Voltage (Input to Output)
3750
Vrms
Operational Temperature
-40 to +110
°C
Storage Temperature
-40 to +125
°C
Derate linearly 1.33mW/°C
2
Derate linearly 6.0mW/°C
Not connected
Storage Capacitor
1.4 ESD Rating
Units
1
Description
1
Rating
Peak (10ms)
Name
VCAP
1.2 Absolute Maximum Ratings
Parameter
Pin#
ESD Rating
(Human Body Model)
1000 V
Absolute maximum electrical ratings are at 25°C
Absolute maximum ratings are stress ratings. Stresses in
excess of these ratings can cause permanent damage to
the device. Functional operation of the device at conditions
beyond those indicated in the operational sections of this
data sheet is not implied.
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CPC1580
1.5 General Conditions
Unless otherwise specified, minimum and maximum
values are guaranteed by production testing.
provided for informational purposes only and are not
part of the manufacturing testing requirements.
Typical values are characteristic of the device at 25°C
and are the result of engineering evaluations. They are
Unless otherwise noted, all electrical specifications
are listed for TA=25°C.
1.6 Electrical Specifications
Parameter
Conditions
Symbol
Min
Typ
Max
Units
Load Side Characteristics
Gate Voltage
IF=2.5mA
8.2
IF=5mA
IF=10mA
7.5
VGS
8.7
12
9.1
V
IF=2.5mA
4.2
-40°C<TA<110°C
Capacitor Voltage
Gate Drive Capability
10V<VDS<65V
VCAP
VDS-0.8
-
VDS-0.2
IG_source
2
3.6
7
0.35
0.47
0.16
0.22
0.06
0.09
IF=0mA, VGS=4V, VCAP=4V
IG_sink
IF=0mA, VGS=2V, VCAP=2V
1
V
mA
VDS=48V, VGS=4V, CVG=4nF
IF=2.5mA
IF=5mA
TON
1
IF=10mA
Turn-Off Delay
14.4
IF=2.5mA, VGS=0V, VCAP=15V
IF=0mA, VGS=8V, VCAP=8V
Turn-On Delay
-
48
140
16
40
7
20
μs
VDS=48V, VGS=2V, CVG=4nF
IF=2.5mA
IF=5mA
150
TOFF1
40
IF=10mA
175
400
μs
600
μs
195
VDS=48V, VGS=1V, CVG=4nF
IF=2.5mA
IF=5mA
240
TOFF2
40
IF=10mA
270
290
VDS=65V
IDS
-
-
1
μA
Forward Voltage Drop
IF=5mA
VF
1
1.27
1.4
V
Input Dropout Current
VGS=1V
IF
0.2
0.7
1
mA
Reverse Bias Leakage Current
VR=5V
IR
-
-
10
μA
-
CI/O
-
3
-
pF
Off-State Leakage Current
LED Characteristics
Common Characteristics
Input to Output Capacitance
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CPC1580
1.7 Performance Data
7.5
CPC1580
Gate Source Current vs. Temperature
(IF=5mA, VCAP=15V)
VGS=2V
7.0
IG_source (mA)
6.5
VGS=4V
6.0
5.5
5.0
4.5
4.0
3.5
-40
0.30
-20
0
80
100
CPC1580
Gate Sink Current vs. Temperature
(IF=0mA, VGS=VCAP)
0.25
IG_sink (mA)
20
40
60
Temperature (ºC)
VGS=4V
0.20
0.15
VGS=2V
0.10
LED Forward Voltage Drop (V)
0.05
-40
0
20
40
60
Temperature (ºC)
80
100
CPC1580
LED Forward Voltage Drop
vs. Temperature
(IF=5mA)
1.40
1.35
1.30
1.25
1.20
1.15
1.10
1.05
1.00
-40
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-20
-20
0
20
40
60
80
Temperature (ºC)
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120
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CPC1580
2. Introduction
The CPC1580 Isolated Gate Driver uses an efficient
optocoupler design to provide remote gate drive
current to a MOSFET, while providing 3750Vrms of
isolation between the LED control current input and
the MOSFET gate drive output. To make the most
efficient use of the input control current to the
optocoupler’s LED, the CPC1580 has multiple
phototransistors in a stacked configuration. As a
result, the gate drive current to the attached MOSFET
can be switched on with just a small input control
current to the LED.
To minimize MOSFET turn-on time, the CPC1580
makes use of an external charge storage capacitor.
When control current is applied to the CPC1580 to
turn on the MOSFET, the charge held in this capacitor
is delivered to the MOSFET’s gate, which charges the
gate quickly and turns on the MOSFET. After the
capacitor charge has turned the MOSFET on and as
long as sufficient input control current is applied, the
continuing flow of phototransistor current will keep the
MOSFET turned on; in other words, there is no lower
operating frequency with the CPC1580. When the
MOSFET is turned off, the capacitor recharges,
through the internal bootstrap diode from the
MOSFET power supply, for the next turn-on cycle. In
addition, the bootstrap diode prevents the capacitor
from discharging through the MOSFET.
The CPC1580 is powered from the system bus supply
voltage of the MOSFET, which means that no
separate power supply is required. Because of this,
circuit design is greatly simplified, circuit complexity is
minimized, and added heat and cost are avoided.
By selecting a few external components, the charge
capacitor and two resistors, the designer has control
over the operating parameters of the CPC1580 circuit,
and can customize the circuit to accommodate the
requirements of a wide selection of MOSFETs.
Overvoltage protection for the CPC1580 can be
provided in a number of ways; one is discussed in the
remainder of this data sheet along with a description
of external component selection.
The equation used to calculate the value of the charge
storage capacitor is:
CST >
VLOAD - VCAP
(FARADS)
Where VCAP > 15V and QG is the total gate charge
(listed in the MOSFET data sheet).
The storage capacitor needs to deliver enough charge
to the gate without going below the 15V required for
switching the MOSFET. This means that VLOAD must
equal, at a minimum, 15.7V. The part can operate at a
lower voltage, but the MOSFETs will be turned on only
partially.
The proper selection of a capacitor is important. The
rated voltage should be at least two to three times the
VCAP . The extra margin is important because some
capacitors lose capacitance when operated at their full
rated voltages. When selecting a capacitor, be sure to
add in their tolerance because of capacitor drift. For
example:
• CST = 1μF, 20% tolerance; VCAP = 15V
• 1μF x 20% = 0.2μF
• 1μF + 0.2μF = 1.2μF
Capacitance drift can also be due to temperature and
the dielectrics used. Therefore, the required capacitor
value is 1.2μF or next higher value, and the capacitor
voltage rating must be at least 30 volts. It is
recommended to go higher in the voltage rating if
engineering restraints permit, such as 50V.
Temperature requirements for capacitors are
application-specific. The designer must know the
intended operating temperature when selecting
capacitors. The information given above should be
applied to other capacitors discussed in this data
sheet.
The CPC1580 can deliver 32nC at the rated operating
speed and will operate with much larger loads (>4μF)
with slower turn-on and turn-off times.
3. External Part Selection
3.1 Storage Capacitor Selection
The storage capacitor (CST) enables the part to turn
on quickly by holding a reservoir of charge to be
transferred to the gate of the MOSFET. The turn-off
cycle does not depend on the storage capacitor.
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Note: Care must be taken to minimize any
capacitor-to-ground leakage current path
between pins 7 and 8 (MOSFET gate current)
and between pins 5 and 6. Leakage currents will
discharge the storage capacitor and, even
though the device is already on, will become a
load to the photocurrent, which keeps the gate
voltage on. The gate voltage will be reduced if
>500nA of leakage is present, therefore the
combined impedance from pin 8 to pin 7, pin 5,
and pin 6, capacitor current, and MOSFET
current must be >20MΩ over the temperature
rating of the part.
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CPC1580
3.2 Transistor Selection
The CPC1580 charges and discharges an external
MOSFET transistor. The selection of the MOSFET is
determined by the user to meet the specific power
requirements for the load. The CPC1580 output
voltage is listed in the specifications, but as mentioned
earlier, there must be little or no gate leakage.
Another parameter that plays a significant role in the
selection of the transistor is the gate drive voltage
available from the part. The CPC1580 uses
photovoltaic cells to collect the optical energy
generated by the LED; to generate more voltage, the
photovoltaic diodes are stacked. The voltage change
of the photovoltaic stack reduces with increased
temperature. The user must select a transistor that will
maintain the load current at the maximum
temperature, given the VGS in Section 1.6, the
CPC1580 Table of Electrical Specifications.
The example circuits shown in Figure 1 and Figure 2
use “logic level” MOSFETs for each design to maintain
the load described.
by the CPC1580 unloaded discharge characteristic
and should be reviewed in light of the final application
component selections if critical.
The value for the charge time, TCHG, is due to external
component selection. The storage capacitor charge
recovery time (seconds) is computed as:
tCHG
~ - (400 + ROVP) • (CST + COVP) • ln
(
(VLOAD - VFINAL) • CST
QGATE
)
Which reduces to:
tCHG
~ - (400 + ROVP) • (CST + COVP) • 3
ROVP and COVP are optional over-voltage protection
elements that are present in the application circuit
diagram (see Figure 2).
The term inside the logarithm reflects the discharge
and recharge voltage on CST. For practical circuit
component selection, this can be simplified as
described above.
Use this information to calculate the maximum
switching frequency in Section 6 below.
3.2.1 Transistor Switching Characteristics
The primary characteristics of the application
switching are tON, tOFF, tRISE, tFALL, and the recovery
time of the storage capacitor, tCHG. These parameters
are dependent on the MOSFET selection and need to
be reviewed in light of the application requirements.
The CPC1580 turns on the MOSFET transistor to the
specified VGS after the tON delay. Similarly the tOFF
delay is the amount of time until the LED is turned off
and the capacitive load discharges to the level in the
CPC1580 specification. For MOSFETs with larger or
smaller required gate charge the tON and tOFF will be
proportionately faster and slower, but it is not a linear
relationship.
Note: The CPC1580 is ideal to use where
remote power is otherwise unavailable. If the
LED is also powered remotely, care must be
taken to ensure that parasitic transient signals
are reliably filtered from the input control signal.
Large transient currents will mutually couple
energy between cables and a simple R-C
filtering of the CPC1580 input may be sufficient
to suppress false turn-on.
To calculate the nominal rise time of the transistor's
drain voltage, VD:
tRISE,VD
~
VLOAD • CRSS
(SECONDS)
IG_SINK
To calculate the nominal fall time of the transistor's
drain voltage, VD:
tFALL,VD ~
VLOAD • CRSS
IG_SOURCE
(SECONDS)
Where CRSS is the MOSFET gate-drain capacitance
(averaged over the switching voltage range) found in
the MOSFET data sheet, IG_SINK is the gate sinking
current of the CPC1580, and IG_SOURCE is the gate
driving ability. The maximum value of tRISE is limited
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CPC1580
4. CPC1580 Over-Voltage Protection
One simple way to reduce the amount of stored
inductive energy is to increase the energy dissipated
in the switch. This can be accomplished by adding a
larger capacitor in parallel with the gate-drain
connection of the MOSFET, however care must be
taken so that the rise time and peak current do not
exceed the Safe Operating Area (SOA) rating of the
transistor.
Over-voltage protection is generally required for the
CPC1580 because of parasitic inductance in the load,
wires, board traces, and axial leads of protectors.
Purely resistive loads or loads with low voltage
switching may be able to rely on the transistor to
handle any parasitic energy and thereby not require
protection for the CPC1580. For very low inductance
loads and traces, over-voltage suppression may be
handled with a simple R-C filter consisting of ROVP
and COVP, or by use of a free-wheeling diode (see
Figure 2). For more moderate load inductance, or
remote switching of a load (i.e. through a long cable) a
voltage suppressor can be used. For heavily inductive
loads only a free-wheeling diode, DOVP, connected
across the load element is recommended, see
Figure 2.
The consequence of increasing the gate-drain
effective capacitance is reduced dV/dt tolerance.
When used in a circuit with an inductive load,
precautions must be taken to prevent damage to the
circuit from inductively generated voltage spikes. The
circuit shown in Figure 2 includes such protection
across the inductive load.
4.1 Other Protection Techniques
The energy not consumed in switching losses must be
absorbed by the over-voltage protection element. Most
protective devices are designed to withstand certain
peak power, in the case of a Transient Voltage
Suppressor (TVS); or maximum avalanche energy, in
the case of a MOSFET. Understanding the switching
losses and load dynamics is absolutely essential.
Switching loads with higher inductance characteristics
requires consideration of other circuit protection
techniques, device ratings, or protector types. Of
paramount importance is that the designer know the
characteristics of the load being switched.
Figure 2. CPC1580 Over-Voltage Protection for Inductive Loads
DOVP
CPC1580
1
4
NC
CST
8 VCAP
ROVP
7
VD
NC
ZLOAD
V+
COVP
RLED
VIN+
VIN-
5
2
VG
LED +
3
LED -
6
VS
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CPC1580
5. Application Switching Losses
5.2 Inductive/Resistive Loads
During the transition intervals, the application and load
components change energy states and, in the
process, incur switching losses. The switching losses
are manifested as heat in the application circuit and
must be addressed by the designer to ensure that no
one component exceeds its power rating. The
designer must understand the details of the load
behavior in order to adequately size and protect the
application circuit. There are three general cases to
observe: (1) purely resistive loads,
(2) inductive/resistive loads, and (3) loads with
significant capacitance. Inductors and capacitors are
energy storage elements that require special
consideration for switching.
If the load is resistive and inductive, and the
inductance doesn't saturate, the load current during
turn off, tRISE, in Amps is:
During the switching periods, energy is conserved.
Inductors turning off transfer their stored energy to
MOSFET switching losses, to the capacitance of the
load and application circuit, and to the protector.
During the turn-on interval, the inductor energy is zero,
and so the capacitive energy in the load and parasitic
elements of the switching application must be
dissipated by the MOSFET, in order for the load to
change state.
To calculate the stored inductive energy in Joules:
EL =
1
2
• L • ILOAD2
ILOAD(t) =
VLOAD
RLOAD
For purely resistive loads, the energy dissipated by
changing states occurs primarily in the MOSFET.
The equation describing MOSFET energy dissipation
during rise time, in Joules, is:
ERISE > VLOAD2 •
CRSS
IG_SINK
•
ILOAD
6
=
PLOAD
6
• tRISE
The average power of the MOSFET for any load type
in Watts is:
PAVG = ILOAD2 • RDSAT • D + fSWITCH • (ERISE + EFALL)
Where fSWITCH is the application switching frequency;
RDSAT is the MOSFET’s on-resistance; D is the
switch's operational duty cycle: D = tON/(tON+tOFF);
and EFALL is MOSFET energy dissipation during fall
time, in Joules.
IG_SINK
LLOAD • CRSS
•
( )
2
LLOAD
RLOAD
•
[
-R LOAD
RLOAD
LLOAD
LLOAD
• t
• t-1+e
]
and the MOSFET drain voltage during turn off, tRISE,
in Volts is:
VDRAIN(t) =
IG_SINK
CRSS
• t
The instantaneous power in the MOSFET will be the
product of the two equations and the energy will be the
integral of the power over time.
5.3 Capacitive Loads
The energy absorbed by the MOSFET for loads that
are more capacitive in nature occurs during the
MOSFET turn-on as opposed to the turn-off. The
energy absorbed by the MOSFET will be a function of
the load, the TVS (or other protector), and the
MOSFET drain capacitance. The MOSFET energy,
EFALL, in Joules is:
EFALL =
5.1 Resistive Load Losses: The Ideal Case
-
1
2
• (CTVS + COSS + CLOAD) • VLOAD2
COSS is the MOSFET output capacitance found in the
data sheet. As mentioned earlier, the MOSFET
switching losses occur at different times, either rising
or falling, so loads with a combination of inductance
and capacitance can also be calculated by the energy
equations described above.
5.4 dV/dt Characteristics
The application circuit shown in Figure 1 dissipates
significant energy caused by large dV/dt events. Fault
voltages across the MOSFET will turn it on for the
same reason the part turns off slowly. For dV/dt events
> IG_SINK/CRSS (from Equation 2) the application
circuit will dissipate energy proportional to the CRSS
and gFS (forward conductance) of the selected
transistor. CRSS is a function of the transistor's
on-resistance and current/power capability, so higher
load designs are more sensitive.
The CPC1580 provides an internal clamp to protect
the gate of the MOSFET from damage in such an
event. The part can withstand 100mA for short
periods, like dV/dt transients.
R00G
www.clare.com
9
CPC1580
6. Design Switching Frequency
The maximum switching frequency is the last design
value to be calculated, because the over-voltage
protection and the storage capacitor play a significant
role in determining the result. Inasmuch as those
factors are already determined, the following gives a
good approximation for the maximum switching
frequency. The maximum switching frequency is a
function of the gate charge of the MOSFET, the
storage capacitor (CST), and ROVP. The maximum
switching frequency relationship in Hz is:
FMAX <
1
-1
• (tON + tOFF + (tRISE,VD | tCHG) + tFALL,VD)
M
Where:
• M=3 (multiplication factor for temperature and process variations
• tON and tOFF are CPC1580 data sheet parameters
• tRISE, VD is the rise time of the drain voltage and tCHG
is the charge time of the storage capacitor and the
over-voltage protection circuitry as derived in
Section 3.2: choose the greater of tRISE,VD or tCHG
for the calculation
• tFALL,VD is the fall time across the transistor
There is no minimum switching frequency since the
CPC1580 uses photovoltaic diodes to keep the output
charged while LED current flows.
10
www.clare.com
R00G
CPC1580
7. Manufacturing Information
7.1 Soldering
7.2 Washing
For proper assembly, the component must be
processed in accordance with the current revision of
IPC/JEDEC standard J-STD-020. Failure to follow the
recommended guidelines may cause permanent
damage to the device resulting in impaired
performance and/or a reduced lifetime expectancy.
Clare does not recommend ultrasonic cleaning or the
use of chlorinated hydrocarbons.
7.3 Mechanical Dimensions
8 Pin Flatpack Package
2.159 TYP.
(0.085 TYP.)
2.540 ± 0.127
(0.100 ± 0.005)
6.350 ± 0.127
(0.250 ± 0.005)
9.398 ± 0.127
(0.370 ± 0.005)
7.620 ± 0.254
(0.300 ± 0.010)
Recommended PCB Land Pattern
2.286 MAX.
(0.090 MAX.)
2.54
(0.10)
0.635 ± 0.127
(0.025 ± 0.005)
0.65
(0.0255)
8.70
(0.3425)
0.203
(0.008)
8.077 ± 0.127
(0.318 ± 0.005)
1.55
(0.0610)
9.652 ± 0.381
(0.380 ± 0.015)
2.159 TYP.
(0.085 TYP.)
Dimensions
mm
(inches)
0.457 ± 0.076
(0.018 ± 0.003)
7.4 Tape and Reel Specification
Tape and Reel Packaging for 8 Pin Flatpack Package
W = 16.30 max
(0.642 max)
330.2 DIA.
(13.00 DIA.)
1
Top Cover
Tape Thickness
0.102 MAX.
(0.004 MAX.)
8
Bo = 10.30
(0.406)
Top Cover
Tape
K0 = 2.70
(0.106)
K1 = 2.00
(0.079)
Embossed Carrier
Embossment
P = 12.00
(0.472)
Ao = 10.30
(0.406)
User Direction of Feed
Dimensions
mm
(inches)
NOTE: Tape dimensions not shown comply with JEDEC Standard EIA-481-2
For additional information please visit our website at: www.clare.com
Clare, Inc. makes no representations or warranties with respect to the accuracy or completeness of the contents of this publication and reserves the right to make changes to specifications and
product descriptions at any time without notice. Neither circuit patent licenses nor indemnity are expressed or implied. Except as set forth in Clare’s Standard Terms and Conditions of Sale,
Clare, Inc. assumes no liability whatsoever, and disclaims any express or implied warranty, relating to its products including, but not limited to, the implied warranty of merchantability, fitness for
a particular purpose, or infringement of any intellectual property right.
The products described in this document are not designed, intended, authorized or warranted for use as components in systems intended for surgical implant into the body, or in other
applications intended to support or sustain life, or where malfunction of Clare’s product may result in direct physical harm, injury, or death to a person or severe property or environmental
damage. Clare, Inc. reserves the right to discontinue or make changes to its products at any time without notice.
Specification: DS-CPC1580-R00G
©Copyright 2007, Clare, Inc.
All rights reserved. Printed in USA.
8/17/07
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