TDA4780 Datasheet, PDF (20/44 Pages) NXP Semiconductors – RGB video processor with automatic cut-off control and gamma adjust

Philips Semiconductors
RGB video processor with automatic
cut-off control and gamma adjust
Preliminary specification
TDA4780
SYMBOL
PARAMETER
CONDITIONS
MIN. TYP. MAX. UNIT
GAMMA ADJUST (ACTS ON INTERNAL Y SIGNAL; Y MATRIX SEE Y OUTPUT; I²C-BUS CONTROLLED POTENTIOMETER
(SUBADDRESS 0BH); RESOLUTION 6 BIT; note 3)
d_g
range of gamma
minimum (3FH)
−
0.7 −
−
maximum (00H)
−
1.0 −
−
G_max
maximum gain at minimum gamma
near nominal black
5
6
7
dB
SATURATION ADJUST (ACTS ON RGB SIGNALS; Y MATRIX SEE Y OUTPUT; I²C-BUS CONTROLLED POTENTIOMETERS
(SUBADDRESS 01H); RESOLUTION 1.5% OF MAXIMUM SATURATION)
d_s(max)
maximum saturation
I²C-bus data 3FH;
4.7 5.2 5.8 dB
measured at 100 kHz;
relative to nominal
saturation; note 4
d_s(min)
minimum saturation
I²C-bus data 00H;
−
−
measured at 100 kHz;
relative to typical value
of maximum saturation
−50 dB
CONTRAST ADJUST (ACTS ON RGB SIGNALS; I²C-BUS CONTROLLED POTENTIOMETERS (SUBADDRESS 02H); RESOLUTION
1.5% OF MAXIMUM CONTRAST)
d_c(max)
maximum contrast
I²C-bus data 3FH;
limiters inactive;
relative to nominal
contrast; note 5
−
4.5 5.5 dB
d_c(min)
minimum contrast
I²C-bus data 00H;
relative to maximum
contrast
−28 −22 −16 dB
BRIGHTNESS ADJUST (ACTS ON RGB SIGNALS; I²C-BUS CONTROLLED POTENTIOMETERS (SUBADDRESS 00H); RESOLUTION
1.5% OF RANGE; ∆ BLACK LEVEL IN PERCENT OF NOMINAL SIGNAL AMPLITUDE REFERRED TO CUT-OFF MEASURING LEVEL)
d_br(max)
d_br(nom)
d_br(min)
d_br(max)
d_br(min)
maximum brightness: ∆ black level
nominal brightness: ∆ black level
minimum brightness: ∆ black level
maximum brightness: ∆ black level
minimum brightness: ∆ black level
I²C-bus data 3FH
23 30 37 %
I²C-bus data 29H
−7 0
+7 %
I²C-bus data 00H
−58 −50 −42 %
I²C-bus data 3FH;
23 30 37 %
control bits BCOF = 1
and MOD2 = 0
I²C-bus data 00H;
−58 −50 −42 %
control bits BCOF = 1
and MOD2 = 0
BLUE STRETCH (BLUE STRETCH IS ACTIVATED BY I²C-BUS CONTROL BIT BLST = 1; see Fig.9)
G_bs
increase of small signal gain
100% of nominal signal 15 20 25 %
amplitude and at 1 MHz
1997 Feb 06
20