鈥?/div>
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
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 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 OZ965 is available in 16-pin SOP and
TSSOP packages. It is specified over the
commercial temperature range of 0擄C to +70擄C,
and the industrial temperature range of -40擄C to
+85擄C.
ORDERING INFORMATION
OZ965G
- 16-pin plastic SOP
OZ965R
- 16-pin plastic TSSOP
OZ965
I
G
- 16-pin plastic SOP
OZ965
I
R
- 16-pin plastic TSSOP
GENERAL DESCRIPTION
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
Figure 1. Typical Application Circuit
J1
5V
5V
ENA
DIM
GND
GND
1
2
3
4
5
6
100k
R1
C2
22u
C1
0.1u
R3
150k
C3
10u
R4
20k
R5
15k
C4
0.1u
R2
22
C5
U1
1
2
3
4
5
6
7
8
C9
0.01u
C8
0.1u
REF
HCLMP
LCLMP
SCP
ADJ
FB
CMP
GND
OZ965
VDD
RT
CT
OPS
ENA
NDR
PDR
SST
16
15
14
13
12
11
10
9
C10
2.2u
R6 59.0k
U2
2
1
470p C6
4
3
Q2
Si4532
3
Q1
6
5
8
7
2
17:2200
5
T1
C7
10u
6
7
68p 3kv
1
2
J2
HV
RTN
2
C11
0.1u
R13
510k
CR3
BAV99L
R15
4.3k
R16
100k
C12
0.1u
R17
1.02k
06/20/00
餂?/div>
Copyright 2000 by O
2
Micro
OZ965-SF-3.0
All Rights Reserved
1
Page 1
U.S. Patent #5,619,402
1
2
3
4
5
6
7
