LXM1612-12-XX Datasheet PDF - Microsemi Corporation

LXM1612-12-XX View Datasheet(PDF) - Microsemi Corporation

Part Name

Description

Manufacturer

LXM1612-12-XX

12V Highly-Integrated, Digital Dimming CCFL Inverter Module

Microsemi Corporation

LXM1612-12-XX Datasheet PDF : 6 Pages

1 2 3 4 5 6

A MICROSEMI COMPANY

LXM1612-12-xx

12V Highly-Integrated, Digital Dimming CCFL Inverter Module

PRELIMINARY DATASHEET

Integrated brightness control circuit includes a DC voltage to In applications with no access to a vertical sync., an onboard

pulse width converter that minimizes system design work and

oscillator operates the inverter burst rate at about 250Hz. In

system noise susceptibility. This provides a familiar and

this non-synchronous mode, minor display disturbances can

convenient interface while reducing the potential for

be found under certain video conditions. This performance

externally induced noise, which can cause lamp flicker.

may be acceptable for many applications, but

RangeMAX inverter modules are designed to operate with the

burst frequency synchronized to the video frame rate. This

synchronization must be used when no disturbance can be

tolerated.

provides operation with no visible display disturbances A single input will accommodate negative and positive

caused by beat frequencies between the lamps and video

vertical sync pulses at any pulse width.

frame rates. In this synchronous mode, the inverter burst rate Separate feedback loops for lamp current and open circuit

operates at twice the video refresh rate, well beyond standard

voltage regulation insure reliable strike under all operating

50/60Hz video refresh rates where the eye can perceive

conditions, automatic over-voltage prevention with broken

pulsing light.

or failed lamps, and accurate lamp current regulation.

12V

DAC or

Pot

BRITE

V IN1

10k

LXM1612-12-xx

BRITE RTN

SLEEP VSYNC

V LO

GND

V SYN C

CCFL

TUBE

Figure 5 - Potentiometer Brightness Control

PW M Signal

from System

BRITE

P.W .

< 2ms

LXM1612-12-xx

0 < P.W. < 100% of perio d

Figure 5A - PW M Brightness Control

The brightness control may be a voltage output DAC, digital

resistor or a simple 10k potentiometer. If desired, an

additional series resistor with the 10k potentiometer can be

used to set a higher minimum brightness setting as shown in

Figure 5. A 2.5V to 5V Logic Level PWM signal from a

micro-controller may also be used as shown in Figure 5A.

If synchronization to the video frame rate is desired, connect

the vertical sync pulse from the system video controller to

the VSYNC input. If no video synchronization is desired,

connect VSYNC to ground.

If you need to turn the inverter ON/OFF remotely, connect

to 2.5V to 5V logic signal to the SLEEP input.

Connect VHI to high voltage wire from the lamp. Connect

VLO to the low voltage wire (wire with thinner insulation).

Never connect VLO to circuit ground as this will defeat lamp

current regulation. If both lamp wires have heavy high

voltage insulation, connect the longest wire to VLO. This

wire is typically white.

&' (

The LXM1612-05 output current can be adjusted by changing the

value of two resistors on the PCB. The following table shows the

approximate new output current values:

Output Current

7.0mA

6.0mA

5.8mA

5.0mA

4.0mA

3.0mA

R12

2.00K 1%

2.61K 1%

2.74K 1%

R16

Not Used

499K 1%

178K 1%

78.7K 1%

R30

R21

R20

R41

R33 R34

C21

R38

R39

R15

C11 R12 R14

C15

C16

C12

R11

C14

C13 C10

R16

R10

R13

- Component Replacement Locations

Rev. 0.3f, 2000-12-06

Microsemi

Linfinity Microelectronics Division

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 5

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