lx1996 Microsemi Corporation, lx1996 Datasheet - Page 2

• Manufacturer Part Number: lx1996
• Description: Multi-string Led Back-light Controller
• Manufacturer: Microsemi Corporation

Copyright © 2007
Rev. 1.0, 2007-12-14
Supply Input Voltage (VIN), EN ........................................................................ -0.3V to 30V
CS# pins .............................................................................................................. -0.3V to 28V
DSEL1, DSEL2, DI and PWM pins .................................................................. -0.3V to 6.0V
OT, DRV, SRC, OVP, PRG, CLF, CT, RT Pins .................................. -0.3V to V
CS# Current ................................................................................................................... 35mA
Operating Temperature Range ............................................................................... -40 to 85°C
Maximum Operating Junction Temperature ...................................................................150°C
Storage Temperature Range............................................................................. -65°C to 150°C
Package Peak Temp. for Solder Reflow (40 seconds maximum exposure) ....... 260°C (+0 -5)
Notes: Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground.
DSEL1
DSEL2
CS1-6
Name
VLDO
PWM
GND
PRG
CLF
EN
OT
RT
CT
DI
Currents are positive into, negative out of specified terminal.
Solder reflow to follow: IPC/JEDEC J-STD-020B 7/02 Pb-Sn Small Body Profile
TM
Pin #
to18
10
11
12
13
1
2
3
4
5
6
7
8
9
A B S O L U T E M A X I M U M R A T I N G S
Enable Input - Logic input. Pull low to put the system into sleep mode; If not used must be tied to VIN.
Internal 5V Regulator Output – Power Pin. Provides a regulated 5V for internal 5V circuits. It can also power
an external light sensor and/or SM Buss chip (limited to 1mA). Must be decoupled closely to the GND with a
ceramic capacitor typical value of 4.7μF.
Dimming Mode Select Input 1. Three level input. Refer to Table 1 in the applications section for functionality
Dimming Mode Select Input 2. – Two Level Logic Input. Refer to Table 1 in the applications section for
functionality
Dimming Input – Signal Pin. Connect a DC dimming voltage or the light sensor output to this pin.
LED Ambient Over Temperature Protection – Signal Pin – Connect to an external NTC thermistor to monitor
the LED light bar temperature. If NTC is not used, then tie this pin to the IC’s VLDO pin. The NTC needs to
be 100kΩ at 25°C and B constant of 4000. Please see the applications section for more details regarding the
OT option.
Pulse Width Modulated Dimming Signal – Signal Input. PWM input used for multi-dimming mode. With
DSEL1 pin tied low, a PWM signal input in the range of 100Hz to 25kHz provides direct digital dimming for the
LED outputs. With DSEL1 pin open and DSEL2 pin tied high, this pin is used as a sync input for
synchronizing the LX1996’s internal PWM dimming clock with an external clock signal of 400ns or greater
width.
Current source setting resistor. Must be 100KΩ between this pin and ground when Analog to Digital Dimming
or Ultrasonic Pulse Skipping modes are used. If neither mode is used, this pin may be left open or tied to
V
Internal Digital Dimming frequency setting capacitor. A capacitor between this pin and ground sets the
internal Digital Dimming frequency. The relationship between the C
F(Hz) = 5e-6/C
This pin should be left open or grounded when the internal oscillator is not used.
PLL Loop filter connection pin. A loop filter capacitor should be connected between this pin and ground when
the internal dimming is used with synchronization mode engaged. Typical capacitor values are; 0.1uF for
200Hz; 1nF for 20Khz. This pin should be left open or grounded when the synchronization option is not used.
LED current programming. Connect a resistor between this pin and ground to set the LED current. Refer to
applications section for functionality
Signal ground. Should be tied at a single common point to Power Ground (PGND pin 20).
Current Sink pins – controls individual LED string current. CS pins can be wired in parallel for higher currents.
The lowest CS voltage is kept at approx. 0.8V at 20mA.
LDO
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
.
T
(Farads)
F U N C T I O N A L P I N D E S C R I P T I O N
Analog Mixed Signal Group
Microsemi
®
Multi-string LED Back-light Controller
Description
LDO
+ 0.3V
P
RODUCTION
T
pin capacitor and internal frequency is;
RoHS / Pb-free 100% Matte Tin pin Finish
XXXX = Date code / Lot code identifier
DSEL2
DSEL1
VLDO
D
EN
OT
P A C K A G E P I N O U T
DI
ATASHEET
3
2
4
5
6
1
24
7
LQ P
(Top View)
23
8
Connect Bottom
Pad to GND
ACKAGE
LX1996
22
XXXX
9
MSC
10
21
LX1996
20
11
19
12
18
15
14
13
17
16
CS5
CS3
CS2
CS1
Page 2
CS6
CS4