LX1991 Datasheet, PDF (1/9 Pages) Microsemi Corporation – Six Output Programmable LED Current Sink

LX1991
TM
®
Six Output Programmable LED Current Sink
PRODUCTION DATA SHEET
DESCRIPTION
LED Display Driver: This six channel
current sink driver is ideal for controlling
brightness and hue of high quality
dimmable LED displays. High accuracy,
dual mode dimming, and controlled current
switching time provides consistent color
hue, at brightness ratios of up to 1000:1,
and keeps electro magnetic emissions in
check.
Its wide compliance voltage range
combined with 43 volt breakdown cap-
ability make the LX1991 ideal for
automotive in-dash displays.
Precision current control: Precision
current mirror circuitry sets all channels to
the same current with a single programming
input. Sinking current value can be pro-
grammed up to 30 mA per channel with a
single resistor or potentiometer from I_SET+ to
I_SET-. Channel to channel matching is ty-
pically within ±1 percent of channel mean
at the rated output current.
Dual Mode Dimming: Display dimming
can be achieved by controlling either
current amplitude or duty cycle, and both
methods can be employed at the same time.
1000:1 Dimming Range: The DIG_DIM
input accepts a TTL or CMOS logic signal
that controls duty cycle of the output
currents.
Independent Channels: The six channels
feature independent regulation with respect
to output voltage, so one does not affect the
others. Any one or more outputs can be left
unloaded without affecting current
regulation of the other channels. Multiple
channels can also be connected together to
sink more current in a single load.
EMI Control: Rise and fall time of sink
currents are precisely controlled by placing
a capacitor on the SLOPE_C pin. Special
control circuitry maintains symmetrical rise
and fall times, preserving the LX1991’s
ability to provide accurate output current
response to very narrow input pulses on the
DIG_DIM pin.
Power Handling: The LX1991 is
supplied in a 4x4 MLPQ package capable
of 1.5 watts dissipation. Logic Enable: A
separate input puts the LX1991 to sleep at
less than 1 uA I_DD.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
KEY FEATURES
ƒ Six precision independent
current sink channels
ƒ Simultaneous Analog and
Digital Dimming Modes
ƒ Precision programming of
current rise & fall times
ƒ 1% band gap reference
ƒ 40 volt rated output stages
ƒ 3V / 5V logic input compatible
ƒ 1.5 watt power dissipation
ƒ On-chip thermal shutdown
ƒ 16 Pin 4 x 4 MLPQ Package
BENEFITS
ƒ Consistent LED color hue
results from high current
accuracy
ƒ 1000:1 dimming ratio with
digital dimming
ƒ Lowered emissions with
current slope programming
ƒ Reduced component count
for compact designs
ƒ Drive up to 108 colored
LED’s per IC (6 x 18 @ 2.1
volts)
ƒ Drive up to 60 white or blue
LED’s per IC (6 x 10 @ 3.8
volts)
PRODUCT HIGHLIGHT
5V
PWM
SIGNAL
SLEW CONTROL
ON
OFF
1.5K
LX1991
VDD
SINK1
CSLOPE
SINK2
DIG_DIM _SINK3
LX1991
ENA
SINK4
ISET+
ISET-
SINK5
SINK6
GND
+36V
54 White LED’s
V_F ~3.7V
@20mA
Bill of Materials
1
LX1991
1
Cap
1
Resistor
54
White LEDs
57
Total Count
Copyright © 2001
Rev. 1.0, 5/18/2005
PACKAGE ORDER INFO
T_J (°C)
-40 to 85
MIN V_DD
4.5
MAX V_DD
5.5V
Plastic 4x4 MLPQ
LQ 16-PIN
RoHS Compliant / Pb-free Transition DC: 0436
LX1991ILQ
Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX1991ILQ-TR)
Microsemi
Integrated Products
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: [phone]
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