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TLC5926 Datasheet, PDF (1/29 Pages) Texas Instruments – 16-CHANNEL CONSTANT-CURRENT LED SINK DRIVERS
TLC5926, TLC5927
www.ti.com ....................................................................................................................................................................................................... SLVS677 – JULY 2008
16-CHANNEL CONSTANT-CURRENT LED SINK DRIVERS
FEATURES
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•2 16 Constant-Current Output Channels
• Output Current Adjusted By External Resistor
• Constant Output Current Range: 5 mA to
120 mA
• Constant Output Current Invariant to Load
Voltage Change
• Open-Load, Shorted-Load and
Overtemperature Detection
• 256-Step Programmable Global Current Gain
• Excellent Output-Current Accuracy:
– Between Channels: < ±6% (Max),
10 mA to 50 mA
– Between ICs: < ±6% (Max), 10 mA to 50 mA
• 30-MHz Clock Frequency
• Schmitt-Trigger Input
• 3.3-V or 5-V Supply Voltage
• Thermal Shutdown for Overtemperature
Protection
• ESD Performance: 2-kV HBM
APPLICATIONS
• General LED Lighting Applications
• LED Display Systems
• LED Signage
• Automotive LED Lighting
• White Goods
DESCRIPTION/ORDERING INFORMATION
The TLC5926/TLC5927 is designed for LED displays and LED lighting applications with open-load, shorted-load,
and overtemperature detection, and constant-current control. The TLC5926/TLC5927 contains a 16-bit shift
register and data latches, which convert serial input data into parallel output format. At the TLC5926/TLC5927
output stage, 16 regulated-current ports provide uniform and constant current for driving LEDs within a wide
range of VF (Forward Voltage) variations. Used in systems designed for LED display applications (e.g., LED
panels), TLC5926/TLC5927 provides great flexibility and device performance. Users can adjust the output
current from 5 mA to 120 mA through an external resistor, Rext, which gives flexibility in controlling the light
intensity of LEDs. TLC5926/TLC5927 is designed for up to 17 V at the output port. The high clock frequency, 30
MHz, also satisfies the system requirements of high-volume data transmission.
The TLC5926/TLC5927 provides a Special Mode in which two functions are included, Error Detection and
Current Gain Control. In the TLC5926/TLC5927 there are two operation modes and three phases: Normal Mode
phase, Mode Switching transition phase, and Special mode phase. The signal on the multiple-function pin
OE(ED2) is monitored, and when an one-clock-wide short pulse appears on OE(ED2), TLC5926/TLC5927 enters
the Mode Switching phase. At this time, the voltage level on LE(ED1) determines the next mode into which the
TLC5926/TLC5927 switches.
In the Normal Mode phase, the serial data is transferred into TLC5926/TLC5927 via SDI, shifted in the shift
register, and transferred out via SDO. LE(ED1) can latch the serial data in the shift register to the output latch.
OE(ED2) enables the output drivers to sink current.
In the Special Mode phase, the low-voltage-level signal OE(ED2) can enable output channels and detect the
status of the output current, to tell if the driving current level is enough or not. The detected error status is loaded
into the 16-bit shift register and shifted out via SDO, along with the CLK signal. The system controller can read
the error status to determine whether or not the LEDs are properly lit. In the Special Mode phase,
TLC5926/TLC5927 also allows users to adjust the output current level by setting a runtime-programmable
Configuration Code. The code is sent into TLC5926/TLC5927 via SDI. The positive pulse of LE(ED1) latches the
code in the shift register into a built-in 8-bit configuration latch, instead of the output latch. The code affects the
voltage at R-EXT and controls the output-current regulator. The output current can be adjusted finely by a gain
ranging from 1/12 to 127/128 in 256 steps. Therefore, the current skew between ICs can be compensated within
less than 1%, and this feature is suitable for white balancing in LED color-display panels.
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated
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