DETAILED DESCRIPTION

SETTING FOR THE MAXIMUM OUTPUT CURRENT VALUE

R

(k

)=42.5

W

IREF

´

V

(V)

IREF

I

(mA)

OLCMax

(1)

DOT CORRECTION (DC) FUNCTION

I

=I

OUTn

DCn

63

(2)

TLC59461

Where:

• V

• R

correction is set to the maximum value of 3Fh (63d). The sink current for each output can be reduced by

lowering the respective output dot correction value.

IREF terminal to GND. A variable power supply may be connected to the IREF pin through a resistor to change

the maximum output current per output. The maximum output current is 42.5 times the current flowing out of the

IREF pin.

The TLC59461 is able to individually adjust the output current of each channel (OUT0 to OUT15). This function is

called dot correction (DC). The DC function allows the user to individually adjust the brightness and color

deviations of LEDs connected to the outputs OUT0 to OUT15. Each respective channel output current can be

into the TLC59461 via the serial interface.

The output current is calculated by Equation 2:

Where:

• I

• DCn = the programmed dot correction value of output n (DCn = 0 to 63)

When MODE is high, the input shift register works as a DC shift register. The shift registers and data latches are

each 96 bits in length, and are used to individually adjust the constant-current values for each constant-current

driver. Each channel can be adjusted from 0% to 100% of the maximum LED current with 6-bit resolution.

Figure 23 illustrates the DC serial data configuration. Figure 12 illustrates the timing chart for writing data into the

shift registers and data latches. Each channel LED current is dot-corrected by the percentage corresponding to

the data in its DC data latch. DC data present on the SIN pin are clocked into the shift register with each rising

edge of the SCLK pin. Data are shifted in MSB first. The data are latched from the shift register into the DC data

latch with a rising edge on the XLAT pin.

The BLANK signal does not need to be high to latch in new data. When XLAT goes high, the new dot-correction

data immediately become valid and change the output currents if the output is on. When the IC is powered on,

the data in the shift register and DC data latch are not set to any default values. Therefore, DC data must be

written to the DC latch before turning on the constant-current output.

14

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