Single LNB Supply and Control Voltage Regulator

A8294

11

Allegro MicroSystems, LLC

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Table 2. Control Register Address (I1, I0) = 10

Bit

Name

Function

0

TMODE

0: Enable external tone modulation via EXTM pin

1: Enable internal clock modulation of tone, with

gating via EXTM pin

1

TGATE

Must be set to 1: Tone Ready

2

-

Not Used (0 recommended)

3

-

Not Used

4

-

Not Used

5

-

Not Used

6

I0

Address Bit: 0

7

I1

Address Bit: 1

Bit 0

TMODE Tone Mode. Selects source of tone frequency generation. When set to 0, a digital

pulse signal on the EXTM pin is used. When set to 1, a 22-kHz internal clock signal

is used. In the case where the the internal clock is used, set the EXTM pin high to

enable modulation, and set it low to disable modulation. See Tone Generation Sec-

tion for more information.

Bit 1

TGATE Tone Ready. Must be set to 1.

Bit 2

–

Not Used.

Bit 3

–

Not Used.

Bit 4

–

Not Used.

Bit 5

–

Not Used.

Bit 6

I0

Address.

Bit 7

I1

Address.