IS31LT3135V1 Datasheet, PDF (1/4 Pages) Integrated Silicon Solution, Inc – Power supply under‐voltage detection

IS31LT3135­V1, IS31LT3135­V2
Dual Ch. (Main/Sub) LED Driver Evaluation Board Guide
Description
Quick Start
The IS31LT3135 is a dual‐channel LED driver that has two
modes of operation; it can function as the main‐channel
driver or as a sub‐channel source. When operating in main
mode, the device functions as a constant current source
that outputs an adjustable current, via an external resistor,
through the main LED. The device is operable with a
dropout voltage of 0.1V while driving a 200mA current.
When operating as a sub‐channel driver, the IC grounds the
LED’s cathode. The device normally operates with a single
channel powered on, allowing for quick switching between
the main and sub channel modes. A sweeping power
supply that operates between high and low voltages,
allows for simple switching between sub/main‐channel
modes, even during conditions where the UV pin is below
the 1.17V (typical) UV threshold IS31LT3135‐V1; or 1.23V
(typical) UV threshold for IS31LT3135‐V2. The sweeping
power supply allows sub‐channel to main channel
switching during conditions where the UV pin is ≥80mV
than the UV threshold. In addition, the main channel
features short protection via switching to sub‐channel if
any abnormal behaviors occur in the main‐channel LED
circuitry.
Features
 Power supply under‐voltage detection
 Main‐channel LED short protection
 Over‐temperature protection
 Input voltage range: 2.7V to 5.5V
 Main/sub‐channel adjustable output current
 (Set via user‐configurable external resistors)
 Main‐channel dropout VDP=0.1V
 Ultra‐low quiescent current
 SOP‐8 Package, small PCB footprint size
Figure 1: Photo of IS31LT3135V1/V2 evaluation board
Recommended Equipment
 5VDC Power supply
 1W LED
 Multi‐meter
Recommended I/O Ratings
 Power supply voltage: 3.8VDC
 Output of I_MAIN: 320mA per LED
 Output of I_SUB: 20mA per LED
Note: When the power supply voltage ≥ LED voltage rating, extra voltage
is dissipated through the main‐channel, causing a drop in system
efficiency and an increase in wasted energy.
Absolute Maximum Ratings
 Input voltage ≤ 5VDC
Caution: Do not exceed the input voltage conditions listed above to
avoid risking permanent damage to the board.
Ordering Information
Part Number
Temperature Range
IC Package
IS31LT3135‐V1GRLS2‐EB
IS31LT3135‐V2GRLS2‐EB
−40°C to +85°C (Industrial Grade)
SOP‐8 (5mm x 4mm)
Table 1: Ordering Information for IS31LT3135‐V1/V2 evaluation board.
Customers with inquiries regarding pricing, delivery, part availability, and related information, can
reach ISSI Analog marketing via either of the following methods:
 Email: [e-mail] / Phone: [phone]‐6600
Integrated Silicon Solution, Inc. – http://www.issi.com
1
V2, 4/23/2012