Toshiba CF35E50, Technical Training Manual

Page: 53 / 139

53
1. OUTLINE
This IC enables more precise picture setting than that of former IC (TA8845N) by means of large scale employment
of IIC bus, and reduces many peripheral components by containing filters inside.
The main features (comparing TA8845) are as follows.
2. LARGE SCALE EMPLOYMENT OF BUS CONTROL OF PARAMETER FOR PICTURE
CONTROLS
(Soft method of picture making)
(Former/TA8845N) TA1222N
* Black expanding start point External constant BUS control
* DC transmission correction quantity point External constant BUS control
* Black level correction quantity External constant BUS control
* Each ABCL characteristic External constant BUS control
3. EMPLOYMENT OF CONTAINING EACH VIDEO BAND FILTER INSIDE
(Employment of automatic adjustment circuit by Fsc to absorb deviation
/ Employment of deviation aborbing method by high S/N filter and mask triming using fixed CR)
(Former/TA8845N) TA1222N
* Y-DL Apa-con DL inside Inside
* Chroma TOF/BPF External Inside
*Velocity modulation processing circuit External Inside
* Fsc trap for chroma demodulation output External Inside
4. EMPLOYMENT OF CONTAINING EACH FILTER (FOR S/H) INSIDE
(Circuit operation by extremely low current
/ Employment of leak current cancel circuit
/ Employment of detection circuit which does not suffer from influence of stray capacity)
(Former/TA8845N) TA1222N
* Chroma ACC / killer filter External Inside
* Y / color difference clamp filter External Inside
* Filter for filter automatic adjustment External Inside
* AFC 2 filter External Inside
5. LOW COST OF IC
* Involving peripheral components inside ——> Down sizing of chip ——> Newly employment (NPN Tr area
ratio to former : -25%) of miniature process (PLAS-1 S process)
* Involving peripheral components inside——>Increasing of power consumption——>2 power supply system
(5V / 9V used)
* Involving peripheral components inside ——> Reducing of number of elements ——> Employment of new
circuit
(1) Reducing of gate (change of preset method) of register for IIC decoder
(2) Reducing of DAC elements (employment of rudder type DAC + temperature compensation circuit)
(3) Deletion of chroma CW, ACC (employment of 90 degree shift phase circuit with automatic adjustment)