Ver1.0

20

LD1072

16-CH LED DRIVER WITH DOT CORRECTION AND 12-BIT PWM CONTROL

The LD1072 has a serial interface, which can be connected to microcontrollers or digital

signal processors. Only 3 pins are needed to input data into the device. The rising edge of CLK signal

shifts the data from the DIN pin to the internal register. After all data is clocked in, a high-level pulse of

ST signal latches the serial data to the internal registers. The internal registers are level-triggered

latches of ST signal. All data are clocked in with the MSB first. The length of serial data is 96 bit or 192

bit, depending on the programming mode. PWM data and dot correction data can be entered during a

PWM cycle. Although new PWM data can be clocked in during a PWM cycle, the ST signal should only

latch the PWM data at the end of the PWM cycle. Latching in new PWM data immediately overwrites

the existing PWM data. Figure 14 shows the timing chart. More than two LD1072s can be connected

in series by connecting an DO pin from one device to the DIN pin of the next device. An example of

cascading two LD1072s is shown in Figure 14. The DO pin can also be connected to the controller to

receive status information from LD1072 as shown in Figure 29.

PRINCIPLES OF OPERATION

Figure 14. Serial Data Input Timing Chart

DC Data Input Mode

PWM Data Input Mode

MOD

ST

t

h

3

t

su3

t

wh2

DIN

DC

MSB

DC

LSB

PW

M1

MSB

PWM1

LSB

PWM2

MSB

PWM2

LSB

PWM3

MSB

1st PWM Data Input Cycle

2nd PWM Data Input Cycle

1

96

h

2

t

su2

t

su1

t

h1

1

192

193

1

t

wh0

192

t

su0

t

h

0

193

1

CLK

DC

MSB

PWM1

MSB

SID

1

MSB

SID1

MSB-1

SID

1

LSB

PWM2

MSB

SID2

MSB-

1

SID

2

MSB

DO

t

wl

0

t

pd0

OEB

1st PWM Data Output Cycle

2nd PWM Data Output

Cycle

t

su5

t

wh3

t

h

4

t

su4

t

wh1

4096

PWMC

K

t

pd4

t

pd1

OUT0

(current

)

t

pd3

t

pd3

T

PWM

clk

t

wl1

t

t

t

d

T

15 x t

d

OUT1

(current

)

OUT15

(current

)

t

pd2

ERR

t

outon

SERIAL INTERFACE