Dot Correction (DC) Shift Register and Data Latch

¼

¼

¼

¼

¼

¼

DotCorrectionShiftRegister(6Bits

16Channels)

´

DotCorrectionDataLatch(6Bits

16Channels)

´

SOUT

(DCSEL=H)

DCDataforOUT15

DCDataforOUT14

DCDataforOUT1

¼

DCDataforOUT0

MSB

95

90

89

6

5

LSB

0

OUT1-Bit0

OUT0-Bit5

OUT0-Bit0

OUT15-Bit0

OUT14-Bit5

OUT15-Bit5

SIN

SCLK

(DCSEL=H)

¼

¼

¼

DCDataforOUT15

DCDataforOUT14

DCDataforOUT1

¼

DCDataforOUT0

MSB

95

90

89

6

5

LSB

0

OUT15-Bit0

OUT14-Bit5

OUT15-Bit5

XLAT

(DCSEL=H)

96Bits

ToConstantCurrentDriverBlock

OUT0-Bit0

OUT0-Bit5

OUT1-Bit0

TLC5944

The dot correction (DC) shift register and latches are each 96 bits long and are used to individually adjust the

constant current value for each constant current driver. Each channel can be adjusted from 0% to 100% of the

maximum LED current with 6-bit resolution. Table 2 describes the percentage of maximum current for each dot

correction data. Figure 29 shows the shift register and latch configuration for DC data. Figure 15 illustrates the

timing for writing data into the DC shift registers and latches. Each LED channel current is dot-corrected by the

percentage value that corresponds to the data in the respective DC data latch. DC data present on the SIN pin

are clocked, MSB first, into the DC shift register at each rising edge of the SCLK pin when DCSEL is high. Data

are latched from the shift register into the DC data latch with a rising edge on the XLAT pin when DCSEL is high.

A DCSEL level change is allowed when SCLK is low and 100 ns after the rising edge of XLAT.

When the IC is powered on, the data in the DC shift register and data latch are not set to any default value.

Therefore, dot correction data must be written to the DC latch before turning on the constant current output.

Figure 29. Dot Correction Shift Register and Latch Configuration

20

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