WM8253

Production Data

w

PD, Rev 4.1, August 2011

18

REFERENCES

The ADC reference voltages are derived from an internal bandgap reference, and buffered to pins

VRT and VRB, where they must be decoupled to ground. The output buffer from the RLCDAC also

requires decoupling at pin VRLC/VBIAS when this is configured as an output.

POWER SUPPLY

The WM8253 runs from a 3.3V single supply.

POWER MANAGEMENT

Power management for the device is performed via the Control Interface. The device can be powered

on or off completely by setting the EN bit low.

All the internal registers maintain their previously programmed value in power down mode and the

Control Interface inputs remain active.

OPERATING MODES

Table 3 summarises the most commonly used modes, the clock waveforms required and the register

contents required for CDS and non-CDS operation.

MODE

DESCRIPTION

CDS

AVAILABLE

MAX

SAMPLE

RATE

TIMING

REQUIREMENTS

REGISTER

CONTENTS WITH

CDS

REGISTER

CONTENTS

WITHOUT CDS

1

Monochrome/

Colour Line-by-Line

Yes

6MSPS

MCLK max = 36MHz

MCLK:VSMP ratio is

6:1

SetReg1: 03(hex)

SetReg1: 01(hex)

2

Fast Monochrome/

Colour Line-by-Line

Yes

6MSPS

MCLK max = 18MHz

MCLK:VSMP ratio is

3:1

Identical to Mode

1 plus SetReg3:

bits 5:4 must be

set to 0(hex)

Identical to

Mode 1

3

Maximum speed

Monochrome/

Colour Line-by-Line

No

6MSPS

MCLK max = 12MHz

MCLK:VSMP ratio is

2:1

CDS not possible

SetReg1: 41(hex)

4

Slow Monochrome/

Colour Line-by-Line

Yes

4.5MSPS

MCLK max = 36MHz

MCLK:VSMP ratio is

2n:1, n

 4

Identical to

Mode 1

Identical to

Mode 1

Table 3 WM8253 Operating Modes