cpc1590 Clare, Inc., cpc1590 Datasheet - Page 8

• Manufacturer Part Number: cpc1590
• Description: Cpc1590 Optically Isolated Gate Drive Circuit
• Manufacturer: Clare, Inc.

between 10V and 16V. The capacitor’s voltage rating
should be two to three times this range.
The designer should select the storage capacitor
based on the particular application requirements. If the
final product requires operating at a higher ambient
temperature range of -40°C to +110°C, then it is better
to select COG/NPO capacitors in order to meet
minimum capacitance requirements.
4.3 Transistor Selection
The CPC1590 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 CPC1590 output
voltage is listed in the specification, 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 CPC1590 uses
photovoltaic cells to collect the optical energy
Figure 3. Application Circuit for Using the CPC1590 as an AC Switch
6. Conclusion
See Clare’s Application Note, AN-202, for a thorough
discussion, and for examples of device usage,
component selection, and over-voltage protection
circuitry.
CPC1590
8
LED +
LED -
1
4
2
3
NC
NC
CPC1590
PRELIMINARY
generated by the internal LED; to generate more
voltage, the photovoltaic diodes are stacked. As such,
the voltage 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 V
specifications.
5. CPC1590 Used as an AC Switch
The CPC1590 can be used in other configurations.
One typical configuration is shown in
is called an AC Switch. This simply means that either
terminal can be positive or negative. This configuration
requires a second MOSFET (Q2) and two rectifying
diodes (D1 and D2).
The design considerations are identical for this
application. Diodes D1 and D2 must have voltage
ratings greater than the breakdown voltage of the
MOSFETs.
8
7
5
6
V
V
V
V
CAP
L1
G
L2
C
ST
D1
Q2
Q1
LOAD
GS
Figure
in the CPC1590
D2
+/- V
+/- V
3, which
LOAD
LOAD
R00B