oz9938

oz9938, Układy scalone

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OZ9938
Change Summary
CHANGES
No.
Applicable Section
Description
Page(s)
Update
慞
rotection release threshold
in Timer & protection
parameter Min & Max limits
1. Electrical Characteristics
3
2. Throughout datasheet
Miscellaneous changes
---
REVISION HISTORY
Revision No.
Description of change
Release Date
0.60
Initial release
5/12/2005
0.65
1. Electrical Characteristics:
a.
Modify general test conditions in line 1;
b.
Modify Driver Frequency Striking & Normal Operation Typ limit;
c.
Modify PWM Dimming Control LCT frequency. 2. Reference Application
Circuit: Modify C14, C9 & R9 values
6/27/2005
1.0
1. Ordering Information: Add OZ9938G, IG, D & DN. 2. Recommended
Operating Range: a. Add Dimming Range; b. Fill in Thermal Impedance.
3. Electrical Characteristics: a. Update Supply Current limits; b. Update
Soft Start limits; c. Update Under Voltage Lockout limits; d. Update
Reference Voltage limits; e. Update Driver Frequency limits; f. Update
Timer & Protection limits; g. Update Drivers parameter name & limits; h.
Update PWM Dimming Control limits; i. Delete Analog Dimming Control.
4. Function Description: Update formula in NO. 4 Ignition, No. 6 Normal
Operation & No. 9 Dimming Control. 5. Package Information: Add DIP
package drawing.
9/22/2005
10/14/2005
OZ9938-DS-1.1
Page 0
Copyright
2005 by O
2
Micro
All Rights Reserved
CONFIDENTIAL
Patent#6,559,606, #6,856,519 & #6,809,938
 OZ9938
LCDM Inverter Controller
FEATURES
The control logic provides a regulated ignition
voltage and appropriate protection features for
over-voltage or over-current conditions.
Positive PWM dimming polarity
Constant operating frequency
Drives positive/negative-impedance lamps
during ignition
The OZ9938 offers a high level of integration,
while maintaining flexibility and high-efficiency
operation that reduces external component
heating, resulting in higher reliability and longer
CCFL life. The proprietary design technique
provides a simple, low-cost system solution.
High drive current for external MOSFETs
User-defined ignition time and shutdown
delay time
Multiple mode dimming control
Built-in intelligence for ignition and normal
operation of CCFLs
Built-in open-lamp protection and over-
voltage protection for backlight system
PIN DIAGRAM
Optimized soft-start function
ORDERING INFORMATION
Part
Number
Temp Range
Package
-20
o
C to 85
o
C
OZ9938G
16-pin SOIC
16-pin SOIC
Lead-Free
-20
o
C to 85
o
C
OZ9938GN
-40
o
C to 85
o
C
OZ9938IG
16-pin SOIC
16-pin SOIC
Lead-Free
-40
o
C to 85
o
C
OZ9938IGN
-20
o
C to 85
o
C
OZ9938D
16-pin DIP
16-pin DIP
Lead-Free
-20
o
C to 85
o
C
OZ9938DN
SIMPLIFIED APPLICATION
CIRCUIT
GENERAL DESCRIPTION
The OZ9938 is a high performance, cost-effective
CCFL (Cold Cathode Fluorescent Lamp)
controller designed for driving large-size Liquid
Crystal Display (LCD) applications requiring 2 to
6 CCFLs.
The controller converts unregulated DC voltages
into a nearly sinusoidal lamp voltage and current
waveforms.
The OZ9938 provides two drive signals for most
power conversion topologies while maintaining
high-efficiency operation. The PWM controller
provides a soft-start operation, current and
voltage regulation, over-voltage and over-current
protection, high drive capability and multiple
dimming functions (internal PWM or external
PWM or analog dimming functions).
10/14/2005
OZ9938-DS-1.1
Page 1
Copyright
2005 by O
2
Micro
All Rights Reserved
CONFIDENTIAL
Patent#6,559,606, #6,856,519 & #6,809,938
 OZ9938
PIN DESCRIPTION
Pin No.
Names
Description
1
DRV1
Drive output
2
VDDA
Supply voltage input
3
TIMER
Timing capacitor to set striking time and shutdown delay time
Analog dimming or Internal LPWM dimming or external PWM pulse input for
dimming function
4
DIM
5
ISEN
Current sense feedback
6
VSEN
Voltage sense feedback
7
OVPT
Over-voltage/ over-current protection threshold setting pin
8
NC
No connection
9
NC
No connection
10
ENA
ON/OFF control of IC
Timing capacitor to set internal PWM dimming frequency and also a pin for
analog dimming selection
11
LCT
12
SSTCMP
Capacitor for soft start time and loop compensation
13
CT
Timing resistor and capacitor for operation and striking frequency
14
GNDA
Ground for analog signals
15
DRV2
Drive output
16
PGND
Ground for power paths
ABSOLUTE MAXIMUM RATINGS
(1)
Input Voltage VDDA
7.0V
GNDA
+/- 0.3V
Signal Inputs
-0.3V to VDDA +0.3V
OZ9938
I
OZ9938
Operating Temp.
-20
o
C to 85
o
C
-40
o
C to 85
o
C
125
o
C
Operating Junction Temp.
-55
o
C to 150
o
C
Storage Temp.
RECOMMENDED OPERATING RANGE
VDDA - Input Voltage
4.5V to 5.5V
f
op
- Operating Frequency
20KHz to 150KHz
Analog Dimming Range
0.7V to 2.1V
Thermal Impedance
(
J-A
)
-
16-pin SOP
86
o
C/W
56
o
C/W
-
16-pin DIP
Note
(1)
: The
揂
bsolute Maximum Ratings?are those values beyond which the safety of the device cannot be guaranteed.
The device should not be operated at these limits. The
揈
lectrical Characteristics?table defines the conditions for actual
device operation. Exposure to absolute maximum rated conditions for
extended periods may affect device reliability.
CONFIDENTIAL
OZ9938-DS-1.1
Page 2
 OZ9938
ELECTRICAL CHARACTERISTICS
Parameter
Symbol
Test Conditions
Limits
Unit
VDDA=5V; Ta=25
o
C
R
CT
=39Kohm, C
CT
=470pF
R
LCT
=3.3Mohm, C
LCT
=4.7nF
Min
Typ
Max
Supply Current
Stand By
I
dds
ENA=0V
2.0
5.0
A
Capacitance at DRV1 &
DRV2=2nF
Operating
I
dd
1.5
2.0
2.5
mA
Soft Start
Current Source
ISSTCMP
1.83
2.29
2.75
A
Under Voltage Lockout
Lock out
UVLO
VDDA 5V
0V
3.2
V
Resume
UVLO
VDDA 0V
5V
4.0
V
Reference Voltage
ISEN=SSTCMP
1.12
1.18
1.23
V
ISEN reference voltage
ppm/
O
C
Temperature Coefficient
360
VSEN=SSTCMP
2.78
2.92
3.06
V
VSEN reference voltage
during striking
ppm/
O
C
Temperature Coefficient
310
Driver Frequency
62.6
65.8
69.0
KHZ
Striking
f
str
ppm/
O
C
Temperature Coefficient
290
50.0
52.0
54.0
kHz
Normal operation
F
op
ppm/
O
C
Temperature Coefficient
110
Timer and Protection
Striking current Source
ISEN =0V
2.3
2.9
3.5
uA
Open lamp and over voltage
protection current Source
SSTCMP > 3.3V or
VSEN>OVPT
8.0
10.0
12.0
uA
Protection release threshold
2.60
2.81
3.02
V
Drivers
DRV1/2 source
Ron
12
18
DRV1/2 sink
Ron
5
9
Maximum duty cycle
45
CONFIDENTIAL
OZ9938-DS-1.1
Page 3
 OZ9938
ELECTRICAL CHARACTERISTICS (Continued)
Parameter
Symbol
Test Conditions
Limits
Unit
VDDA=5V; Ta=25
o
C
R
CT
=39Kohm, C
CT
=470pF
R
LCT
=3.3Mohm, C
LCT
=4.7nF
Min
Typ
Max
PWM Dimming Control
LCT frequency
194
200
206
Hz
ENA Threshold
On
2.0
V
Off
1.0
V
CONFIDENTIAL
OZ9938-DS-1.1
Page 4
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