TLC8044

12-BIT ANALOG-TO-DIGITAL INTERFACE FOR

CHARGE-COUPLED DEVICE IMAGE SENSORS FOR SCANNERS

SLAS128 – JUNE 1997

4

POST OFFICE BOX 655303

Terminal Functions

TERMINAL

TYPE

I/O

DESCRIPTION

NAME

NO.

TYPE

I/O

DESCRIPTION

AGND

47

Analog

I

Analog ground (0 V)

AVDD

48

Analog

Positive analog supply (5 V)

BINN

45

Analog

I

Negative blue channel input video

BINP

46

Analog

I

Positive blue channel input video

CC1,0

10, 11

Digital

O

Color code outputs. CC0 and CC1 indicate which channel the current output sample was taken

from (R = 00, G = 01, B = 10).

DAC

44

Analog

O

Buffered midpoint of ADC reference string. DAC is used internally to set DAC reference voltages.

DETOP

13

Digital

O

Threshold detector output (active high). DETOP indicates that the current output pixel has

exceeded the internally programmed threshold for that channel.

DGND

14

Digital

I

Digital ground (0 V)

DVDD1,2

60, 1

Digital

I

Positive digital supply (5 V)

GINN

49

Analog

I

Negative green channel input video

GINP

50

Analog

I

Positive green channel input video

MCLK

55

Digital

I

Master clock. MCLK is applied at either six times or twice the input pixel rate for color and

monochrome operation, respectively. MCLK is divided by two internally to define the ADC sample

rate and to provide the clock source for the DSP section.

OE

53

Digital

I

Output 3-state control. Outputs are enabled when OE = 0.

ONE

59

Digital

I

Odd not even. ONE defines the even and odd pixels when the internal pixel offset correction

registers are in use (even = 0, odd = 1).

OP15–OP0

61-68,

2-9

Digital

O

Digital 16-bit output (3-state). In 8-, 10-, and 12-bit output modes, OP15 is used to indicate that

the output pixel is negative; i.e., OP15 can be used as an under range indicator. OP15 is active

high when indicating under range.

ORNG

12

Digital

O

Over range signal (active high). In 8-, 10-, and 12-bit output modes, this signal indicates that the

current output pixel has exceeded the maximum achievable for the output word length in use.

POC11–POC0

27-38

Digital

I

Pixel offset coefficient input. The POC11–POC0 12-bit word is applied at the multiplexed pixel rate

(i.e., three samples per pixel period in color mode) to correct offset errors in a pixel-by-pixel

fashion.

PSC11–PSC0

15-26

Digital

I

Pixel shading coefficient input. The PSC11–PSC0 12-bit quantity is applied at the multiplexed

pixel rate (i.e., three samples per pixel period in color mode) to correct shading effects in a

pixel-by-pixel fashion.

RESET

39

Digital

I

Reset input (active high). RESET forces a reset of all internal registers in the TLC8044.

RINN

51

Analog

I

Negative red channel input video

RINP

52

Analog

I

Positive red channel input video

RU, RT, RB,

RL

42, 40,

41, 43

Analog

I

ADC reference terminals. The voltage applied between RT (full scale) and RB (zero level). define

the ADC reference range. RU and RL, upper and lower resistor terminals, are used to derive

optimum reference voltages from an external 5-V reference.

SCK

57

Digital

I

Serial clock. Serial interface clock signal.

SDI

58

Digital

I

Serial data in. Serial interface input data signal.

SEN

56

Digital

I

Serial enable

VSMP

54

Digital

I

Video sample synchronization pulse. VSMP applied synchronously with MCLK specifies the point

in time that the input is sampled. The timing of internal multiplexing between the R, G, and B

channels is derived from this signal.