lx1695 Microsemi Corporation, lx1695 Datasheet - Page 2

• Manufacturer Part Number: lx1695
• Description: Switched Royer Ccfl Inverter Monitor Ic
• Manufacturer: Microsemi Corporation

Copyright © 2004
Rev. 1.0a, 2006-01-06
DIM_FREQ
BRITE_IN
FLT_DLY
OL_SNS
ENABLE
ROYER
Supply Voltage (V
Inputs (BRITE_IN, OLSNS, FLT_DLY, ENABLE, DIM_FREQ)................. V
Output Current (ROYER) ...........................................................................150mA
RoHS / Pb-free Peak Package Solder Reflow Temperature
(40 seconds Maximum Exposure) .....................................................................................260°C (+0, -5)
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to
Junction Temperature Calculation: T
The θ
above assume no ambient airflow.
Name
GND
VDD
DM
M
THERMAL RESISTANCE
THERMAL RESISTANCE
JA
Ground. Currents are positive into, negative out of specified terminal
TM
numbers are guidelines for the thermal performance of the device/pc-board system. All of the
Plastic 8-Pin DIP
Plastic 8-Pin SOIC
Input Voltage. The IC will be functional and in specifications when this pin is between 4.5 and 5.5V
Ground
Lamp Brightness Control. A DC input of 0 to 2V controls the duty cycle of the Royer output. Zero volts
corresponds to minimum duty cycle (3.125%), maximum input voltage must yield 100% duty cycle. BRITE_IN
has a high input impedance.
Open Lamp Sense Input. This input receives rectified and filtered voltages from each Royer transformer
secondary winding that are proportional to lamp current amplitude. These signals are diode OR’ed and
compared to 3VDC at the OL_SNS input. If an under limit condition is detected, a fault is declared and the output
is turned off. This condition is latched and can only be cleared by cycling the main power input or the ENABLE
input signal off and on.
Royer Bias Drive Output. This output signal drives external transistors that feed bias currents to one or more
oscillators to turn them on. Output drive is totem pole and must be capable of ±50mA at 0.4 and 4.0V output
when the supply voltage is 4.5 to 5.5 volts.
Fault Delay. An external resistor and capacitor at this pin program the time that open lamp fault detection is
disabled following power on or an ENABLE low to high transition. By choosing the appropriate resistor and
capacitor combination, delay time may be as high as 5 seconds
A resistor to ground determines the frequency of the dual slope ramp generator for the digital dimming PWM.
This pin may be overdriven through a resistor with totem pole output logic gates to force an external clock to over
ride the internal clock, allowing the ROYER output to be synchronized to an external frequency without using
another package pin. Input voltage levels of the external pulse are as follows:
A positive logic level enables the ROYER output pin. A low level turns it off, resets the fault latch and discharges
the FLT_DLY capacitor. Logic threshold is about 1.6V. Upon ENABLE going high (True), the fault delay
capacitor is allowed to charge, initiating the delay.
A B S O L U T E M A X I M U M R A T I N G S
DD
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
) ........................................................................................6V
High state is; 2.9 to 5.5V minus 0.4 volts noise margin for minimum of 2.5 volts.
Low state is; 0 to 0.36V plus 0.44 volts for noise margin for total of 0.8 volts.
-
-
JUNCTION
JUNCTION
T H E R M A L D A T A
J
= T
A
+ (P
F U N C T I O N A L P I N D E S C R I P T I O N
A
A
D
MBIENT
MBIENT
x θ
JA
).
, θ
, θ
Integrated Products Division
JA
JA
®
Microsemi
Switched Royer CCFL Inverter Monitor IC
Description
.
163°C/W
85°C/W
P
RODUCTION
DD
RoHS / Pb-free 100% Matte Tin Lead Finish
DIM_FREQ
BRITE_IN
DIM_FREQ
FLT_DLY
D
ENABLE
BRITE_IN
FLT_DLY
P A C K A G E P I N O U T
ENABLE
ATA
S
HEET
DM Package
(Top View)
M Package
(Top View)
1
2
3
4
1
2
3
4
8
7
6
5
DC
8
7
6
5
.
LX1695
OLSNS
GND
ROYER
VDD
OLSNS
GND
ROYER
VDD
Page 2