HV830(2013) Ver la hoja de datos (PDF) - Supertex Inc
Número de pieza
componentes Descripción
Fabricante
HV830 Datasheet PDF : 6 Pages
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HV830
External Component Description
External
Component
Diode
Description
Fast reverse recovery diode, BAS21LT1 or equivalent.
CS
Capacitor
0.01µF to 0.1µF, 200V capacitor to GND is used to store the energy transferred from the inductor.
REL-Osc
The EL lamp frequency is controlled via an external REL resistor connected between REL-Osc and VDD
pins of the device. The lamp frequency increases as REL decreases. As the EL lamp frequency increases,
the amount of current drawn from the battery will increase and the output voltage VCS will decrease. The
color of the EL lamp is dependent upon its frequency.
A 3.3MΩ resistor would provide lamp frequency of 220 to 280Hz. Decreasing the REL-Osc by a factor of 2
will increase the lamp frequency by a factor of 2.
RSW-Osc
CSW
Capacitor
LX
Inductor
The switching frequency of the converter is controlled via an external resistor, RSW between the RSW-Osc
and VDD pins of the device. The switching frequency increases as RSW decreases. With a given inductor,
as the switching frequency increases, the amount of current drawn from the battery will decrease and the
output voltage, VCS, will also decrease.
A 1nF capacitor is recommended between the RSW-Osc pin and GND when a 0.01µF CS capacitor is
used. This capacitor is used to shunt any switching noise that may couple into the RSW-Osc pin. The CSW
capacitor may also be needed when driving large EL lamp due to increase in switching noise. A CSW larger
than 1.0nF is not recommended.
The inductor LX is used to boost the low input voltage by inductive flyback. When the internal switch is
on, the inductor is being charged. When the internal switch is off, the charge stored in the inductor will
be transferred to the high voltage capacitor CS. The energy stored in the capacitor is connected to the
internal H-bridge and therefore to the EL lamp. In general, smaller value inductors, which can handle
more current, are more suitable to drive larger size lamps. As the inductor value decreases, the switching
frequency of the inductor (controlled by RSW) should be increased to avoid saturation.
220µH Murata inductors with 5.4Ω series DC resistance is typically recommended. For inductors with the
same inductance value but with lower series DC resistance, lower RSW value is needed to prevent high
current draw and inductor saturation.
Lamp
As the EL lamp size increases, more current will be drawn from the battery to maintain high voltage across
the EL lamp. The input power, (VIN x IIN), will also increase. If the input power is greater than the power dis-
sipation of the package (400mW), an external resistor in series with one side of the lamp is recommended
to help reduce the package power dissipation.
Doc. # DSFP-HV830
E072913
Supertex inc.
5
www.supertex.com
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