29

2270f

LTC2270

REGISTER A3: OUTPUT MODE REGISTER (ADDRESS 03h)

D7

D6

D5

D4

D3

D2

D1

D0

X

ILVDS2

ILVDS1

ILVDS0

TERMON

OUTOFF

OUTMODE1

OUTMODE0

Bit 7

Unused, Don’t Care Bit.

Bits 6-4

ILVDS2:ILVDS0 LVDS Output Current Bits

000 = 3.5mA LVDS Output Driver Current

001 = 4.0mA LVDS Output Driver Current

010 = 4.5mA LVDS Output Driver Current

011 = Not Used

100 = 3.0mA LVDS Output Driver Current

101 = 2.5mA LVDS Output Driver Current

110 = 2.1mA LVDS Output Driver Current

111 = 1.75mA LVDS Output Driver Current

Bit 3

TERMON

LVDS Internal Termination Bit

0 = Internal Termination Off

1 = Internal Termination On. LVDS Output Driver Current is 2× the Current Set by ILVDS2:ILVDS0

Bit 2

OUTOFF

Output Disable Bit

0 = Digital Outputs Are Enabled

1 = Digital Outputs Are Disabled and Have High Output Impedance

Note: If the Digital Outputs Are Disabled the Part Should Also Be Put in Sleep or Nap Mode (Both Channels).

Bits 1-0

OUTMODE1:OUTMODE0

Digital Output Mode Control Bits

00 = Full-Rate CMOS Output Mode

01 = Double Data Rate LVDS Output Mode

10 = Double Data Rate CMOS Output Mode

11 = Not Used

REGISTER A4: DATA FORMAT REGISTER (ADDRESS 04h)

D7

D6

D5

D4

D3

D2

D1

D0

X

X

OUTTEST2

OUTTEST1

OUTTEST0

ABP

RAND

TWOSCOMP

Bit 7-6

Unused, Don’t Care Bits.

Bits 5-3

OUTTEST2:OUTTEST0

Digital Output Test Pattern Bits

000 = Digital Output Test Patterns Off

001 = All Digital Outputs = 0

011 = All Digital Outputs = 1

101 = Checkerboard Output Pattern. OF, D15-D0 Alternate Between 1 0101 0101 0101 0101 and 0 1010 1010 1010 1010

111 = Alternating Output Pattern. OF, D15-D0 Alternate Between 0 0000 0000 0000 0000 and 1 1111 1111 1111 1111

Note: Other Bit Combinations Are not Used

Bit 2

ABP

Alternate Bit Polarity Mode Control Bit

0 = Alternate Bit Polarity Mode Off

1 = Alternate Bit Polarity Mode On. Forces the Output Format to Be Offset Binary

Bit 1

RAND

Data Output Randomizer Mode Control Bit

0 = Data Output Randomizer Mode Off

1 = Data Output Randomizer Mode On

Bit 0

TWOSCOMP

Two’s Complement Mode Control Bit

0 = Offset Binary Data Format

1 = Two’s Complement Data Format

APPLICATIONS INFORMATION