TLC59116 Datasheet, PDF (11/30 Pages) Texas Instruments – 16-CHANNEL Fm+ I2C-BUS CONSTANT-CURRENT LED SINK DRIVER

TLC59116
www.ti.com .................................................................................................................................................. SLDS157A – FEBRUARY 2008 – REVISED APRIL 2008
AI[2:0] = 110 is used when the LED drivers must be globally programmed with different settings during the same
I²C bus communication, for example, global brightness or blinking change.
AI[2:0] = 111 is used when individually and global changes must be performed during the same I²C bus
communication, for example, changing color and global brightness at the same time.
Only the five least significant bits D[4:0] are affected by the AI[2:0] bits.
When the Control register is written, the register entry point determined by D[4:0] is the first register that will be
addressed (read or write operation), and can be anywhere between 0 0000 and 1 1011 (as defined in Table 2).
When AI[2] = 1, the Auto-Increment flag is set and the rollover value at which the point where the register
increment stops and goes to the next one is determined by AI[2:0]. See Table 1 for rollover values. For example,
if the Control register = 1111 0100 (F4h), then the register addressing sequence will be (in hex):
14 → ... → 1B → 00 → ... → 13 → 02 → ... → 13 → 02 → ... as long as the master keeps sending or
reading data.
Driver Output
Constant Current Output
In LED display applications, TLC59116 provides nearly no current variations from channel to channel and from
device to device. While I_OUT ≤ 52 mA, the maximum current skew between channels is less than ±6% and less
than ±8% between devices.
Adjusting Output Current
TLC59116 scales up the reference current (I_ref) set by the external resistor (R_ext) to sink the output current (I_out) at
each output port. Table 11 shows the Configuration Code and discusses bits CM, HC, and CC[5:0]. The following
formulas can be used to calculate the target output current I_OUT,target in the saturation region:
V_REXT = 1.26 V × VG
I_ref = V_REXT/R_ext, if another end of the external resistor R_ext is connected to ground
I_OUT,target = I_ref × 15 × 3^{CM – 1}
Where R_ext is the resistance of the external resistor connected to the REXT terminal, and V_REXT is the voltage of
REXT, which is controlled by the programmable voltage gain (VG), which is defined by the Configuration Code.
The Current Multiplier bit (CM) sets the ratio I_OUT,target/I_ref to 15 or 5 (sets the exponent "CM – 1" to either 0 or
–1). After power on, the default value of VG is 127/128 = 0.992, and the default value of CM is 1, so that the ratio
I_OUT,target/I_ref = 15. Based on the default VG and CM:
V_REXT = 1.26 V × 127/128 = 1.25 V
I_OUT,target = (1.25 V/R_ext) × 15
Therefore, the default current is approximately 52 mA at 360 Ω and 26 mA at 720 Ω. The default relationship
after power on between I_OUT,target and R_ext is shown in Figure 8.
140
120
100
80
40
0
0 500 1000 1500 2000 2500 3000 3500 4000
R
ext
–
W
Figure 8. I_OUT,target vs R_ext
Copyright © 2008, Texas Instruments Incorporated
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