Specifications

DTT 7685x

SBU Technology – Tuners ATSC half NIM with CH 3 / 4 modulator

20 Apr 2007

Preliminary Specification Page 27 / 29

Application note:

1) All tuner supply line, CLK & DATA line decoupling Ceramic capacitor should be place near

to Tuner in PCB layout

2) The supply ripple must not more then 10mVp-p

3) Recommend CD6 setting hex “33” for digital reception

4) To ensure correct Time Constant & Filtering for analog application

5) Lug 3 and 4 (L3 & L4) are for holding the tuner module only, do not connect them to a

ground plane else it may result in immunity deterioration. Do ensure sufficient isolation of

these 2x lugs away from the ground plane to prevent stray capacitance coupling.

6) Lug 1 and 2 (L1 & L2) are for connection to a ground plane. The ground plane should be

large for lesser ground inductance hence providing better grounding for the tuner module.

8) For analog reception, set AGD bit to “1” to disable internal wideband AGC

11.8 Recommend AGC switch circuit for analogue reception only

DTT 7685X

Pin5

Conventional AGC

AGC switch control

50k

10k

+5V