OZ960 Просмотр технического описания (PDF) - O2Micro International
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OZ960 Datasheet PDF : 12 Pages
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OZ960
Intelligent CCFL Inverter Controller
FEATURES
• Supports wide-range voltage input
applications (8v to 20v)
• Built-in intelligence to manage ignition and
normal operation of CCFLs
• Reduces the number of components and
board size by 30% compared with
conventional designs
• 85% efficiency vs. typical 70% efficiency of
conventional designs
• Zero-voltage-switching full bridge topology
• Built-in internal open-lamp and over-voltage
protections
• Integrated burst mode control, and wide
dimming range (10% to 100%) with
integrated burst mode control
• Supports multiple CCFL lamps
• Simple and reliable 2-winding transformer
design
• Constant-frequency design eliminates
interference with LCDs
• Low stand-by power
ORDERING INFORMATION
OZ960S - 20-pin plastic SSOP 150mil
OZ960IS - 20-pin plastic SSOP 150mil
OZ960G - 20-pin plastic SOP 300mil
OZ960IG - 20-pin plastic SOP 300mil
OZ960D - 20-pin plastic DIP 300mil
OZ960ID - 20-pin plastic DIP 300mil
GENERAL DESCRIPTION
The OZ960 is a unique, high-efficiency, Cold
Cathode Fluorescent Lamp (CCFL) backlight
inverter controller that is designed for wide input
voltage inverter applications. Additionally, the
OZ960 performs the lamp dimming function with
an analog voltage or low frequency Pulse Width
Modulation (PWM) control.
Operating Principle:
Operating in a zero-voltage switching, full-bridge
configuration, the inverter circuit achieves a very
high efficiency power conversion. In addition, the
transformer in the OZ960 does not require any
specific gap-less arrangement. The simple, low
cost transformer provides designers a high
degree of design flexibility in specifying
transformers. Setting the switching frequency
higher than the resonant frequency of a high-
quality-factor resonant tank circuit yields a good-
quality waveform received, at the CCFL voltage
and current.
The OZ960 operates at a single, constant
frequency in a phase-shift PWM mode. Intelligent
open-lamp and over-voltage protections provide
design flexibility so various transformer
models/manufacturers may be used. The built-in
burst mode control provides a wide dimming
range and simplifies the application circuit
designs. Both operating and burst-mode
frequencies are user-programmable parameters.
The single stage design results in a low cost,
reliable transformer without expensive, less
reliable secondary fold-back treatment. The
transformer does not require a more expensive
center tapped primary.
The OZ960 is available in a 20-pin SSOP
package. It is specified over the commercial
temperature range of 0°C to +70°C, and the
industrial temperature range of -40°C to +85°C.
FUNCTIONAL BLOCK
DIAGRAM
Refer to the functional block diagram in Figure 2,
page 3, and the Pin Description Table on page 4.
A precision reference provides a reference
voltage for both internal and external uses. An
oscillator circuit generates a user-programmable
operating frequency with an external capacitor
and a timing resistor. In addition, another resistor
to program striking frequency is provided. The
drive circuit consists of four outputs. These are
designed to achieve zero-voltage switching, full-
bridge applications. An error amplifier is provided
to regulate the CCFL current. The Soft-start
circuit offers a gradual increase of the power to
the CCFL during the ignition period. The over-
voltage protection block offers a regulated
striking voltage for CCFLs. The striking time is
programmable simply through an external
component. The open-lamp protection is
integrated in the protection block. This block
intelligently differentiates the striking condition
and open-lamp condition. ENA circuitry enables
the operation of the IC through a TTL signal
interface. Wide-dimming control is achieved
through the burst-mode control block.
10/23/01
Copyright 2000 - 01 by O2Micro
OZ960-DS-1.6
All Rights Reserved
Page 1
U.S. Patent #6,259,615
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