TDA4885 Datasheet, PDF (17/56 Pages) NXP Semiconductors – 150 MHz video controller with I2C-bus

Philips Semiconductors
150 MHz video controller with I²C-bus
Product specification
TDA4885
SYMBOL
PARAMETER
CONDITIONS
MIN. TYP. MAX. UNIT
t_d11(clamp)t
delay between clamping input
at pin 11 (trailing edge) and
end of internal output clamping
pulse
see Fig.8
−
−
60
ns
I²C-bus inputs (pins 15 and 16)
f_SCL
V_IL
V_IH
I_IL
I_IH
V_OL
I_ack
V_th(POR)(r)
V_th(POR)(f)
SCL clock frequency
LOW-level input voltage
HIGH-level input voltage
LOW-level input current
HIGH-level input current
LOW-level output voltage
V_IL = 0 V
V_IH = 5 V
during acknowledge
output current at pin 15 during V_OL = 0.4 V
acknowledge
threshold for power-on reset on rising supply voltage
falling supply voltage
threshold for power-on reset off rising supply voltage
falling supply voltage
−
−
100
kHz
0.0
−
1.5
V
3.0
−
5.0
V
−
−
−10
µA
−
−
−10
µA
0.0
−
0.4
V
3.0
−
5.0
mA
−
1.5 2.0
V
−
3.5 −
V
−
−
7.0
V
−
1.5 −
V
Notes to the characteristics
1. Definition of levels (see Figs 3 to 5):
Reference black level: this is the level to which the input level is clamped during the input clamping pulse
(V₅ > 3.5 V). It is used internally as a reference for the gain settings. It can be observed on the outputs:
a) when the input is at black and the brightness setting is nominal (subaddress 01H = 10H)
b) during output blanking/clamping (V₁₁ > 3.5 V) if control bit PEDST = 0.
Video black level: this is the black level of the actual video. On the input it is still equal to the reference black level.
On the output it may deviate from it according to the brightness setting. Contrast setting leaves the video black level
unaltered .
Pedestal black level: this is an ultra black level which deviates from reference black level by a fixed amount. It can
be observed on the output during output blanking/clamping (V₁₁ > 3.5 V) if control bit PEDST = 1.
Switch-off voltage: this is the lowest signal voltage at outputs. The signals will be switched off by discharging the
internal black level storage capacitors if the supply voltage is less than V_PSO.
Blanking level: this level equals reference black (control bit PEDST = 0) or pedestal black (control bit PEDST = 1).
2. Explanation to black level adjustment:
The actual blanking level on the output depends on the external feedback application. The loop will only function
correctly if it is within the control range of V_{30, 25, 20rbl(min)} to V_{30, 25, 20rbl(max)}. Note: changing control bit PEDST in a
given application will not affect the blanking level, but instead shifts the video (and needs re-alignment of the three
black levels).
The three reference black levels are aligned correctly when they are made equal to the ‘extended cut-off levels’ of
the three cathodes. Full raster and spot cut-off can only be achieved by enabling the pedestal blanking or by applying
a negative pulse to grid 1.
1997 Nov 25
17