OZ965 Datasheet, PDF (1/7 Pages) List of Unclassifed Manufacturers – High-Efficiency Inverter Controller

OZ965
High-Efficiency Inverter Controller
FEATURES
• Single-stage power conversion, requiring
only a +5 V voltage source
• Reduces the number of components and
board size by 30% compared with
conventional design
• Supports both floating and grounded
secondary designs
• 90% efficiency vs. typical 75% efficiency of
conventional designs
• Internal open-lamp and short-circuit
protections
• Wide dimming range
• Supports multiple CCFLs
• Simple and reliable 2-winding transformer
design
• Eliminates leakage current when used in a
floating secondary design
• Constant-frequency design eliminates
interference with LCDs
ORDERING INFORMATION
OZ965G - 16-pin plastic SOP
OZ965R - 16-pin plastic TSSOP
OZ965IG - 16-pin plastic SOP
OZ965IR - 16-pin plastic TSSOP
GENERAL DESCRIPTION
dimming function with an analog voltage or low
frequency Pulse Width Modulation (PWM)
control.
Operating Principle:
The CCFL tube, transformer secondary, and
capacitor form a resonant circuit. The OZ965
utilizes the low energy loss resonate mode
principle to deliver a very high efficiency inverter.
The OZ965 drives the transformer primary with a
variable pulse width voltage directly from the +5v
supply. The resultant primary drive current is
alternately reversing with zero-voltage-switching.
Because of the transformer leakage inductance
and the secondary resonant circuit, the
secondary voltage and current are approximately
sinusoidal. This sinusoid results in very little
harmonic emi/rfi emissions.
The OZ965 operates at a single, constant
frequency in a PWM mode. Typical operating
frequency ranges between 30 KHz to 200 KHz,
dependent upon the CCFL and transformer
characteristics. Intelligent open-lamp protection
provides design flexibility so various transformer
models/manufacturers may be used.
Its high driving capability allows the OZ965 to
drive high power MOSFETs.
The OZ965 is a single chip, high-efficiency, Cold
Cathode Fluorescent Lamp (CCFL) backlight
inverter controller whose primary function is to
convert +5 volt DC power to approximately 600
VAC. Additionally, the OZ965 performs the lamp
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.
Figure 1. Typical Application Circuit
J1
5V
1
2
5V ₃
ENA
DIM
4
5
100k
C2
22u
GND
GND
6
R1
C1
0.1u
R2
22
R3
150k
R4
20k
R5
15k
C3
10u
C4
0.1u
C9
0.01u
U1
1
2
3
4
REF
HCLMP
LCLMP
5
6
7
8
SCP
ADJ
FB
CMP
GND
OZ965
C8
0.1u
16
VDD
RT
CT
15
14
13
OPS
ENA
NDR
PDR
12
11
10
9
SST
C10
2.2u
R6 59.0k
470p C6
C11
0.1u
R13
510k
U2
2
8
1
7
Q1
4
6
3
5
Q2
Si4532
2
The OZ965 is available in 16-pin SOP and
TSSOP packages. 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.
2
17:2200
C5
J2
7
1
68p 3kv
2
HV
RTN
5
6
T1
C7
10u
CR3
BAV99L
R15
4.3k
R16
100k
R17
C12
1.02k
0.1u
06/20/00
Copyright 2000 by O₂Micro
OZ965-SF-3.0
All Rights Reserved
Page 1
U.S. Patent #5,619,402