SAA7182A Datasheet, PDF (41/45 Pages) NXP Semiconductors – Digital Video Encoder EURO-DENC2

Philips Semiconductors
Digital Video Encoder (EURO-DENC2)
Preliminary specification
SAA7182A; SAA7183A
Analog output voltages
The analog output voltages are dependent on the open
loop voltage of the operational amplifiers for full-scale
conversion (typical value 1.4 V), the internal series resistor
(typical value 2 Ω), the external series resistor and the
external load impedance.
The digital output signals in front of the DACs under
nominal conditions occupy different conversion ranges, as
indicated in Table 40 for a ¹⁰⁰⁄₁₀₀ colour bar signal.
Values for the external series resistors result from a 75 Ω
load (see Figs 20 and 21).
The analog inputs RI, GI, and BI are shifted first by an
offset of 0.16 V (typical value), followed by an amplification
of 1.72 (typical value). For an input voltage of 0 to 0.7 V an
open loop output voltage of 0.28 to 1.48 V is achieved,
resulting in V_o = 0.86 V (p-p) with an internal series
resistor of 2 Ω, an external series resistor of 27 Ω at a 75 Ω
load impedance.
Table 40 Digital output signals conversion range
CONVERSION RANGE (peak-to-peak
CVBS, SYNC
TIP-TO-PEAK CARRIER
(digits)
1 023
Y (VBS) SYNC TIP-TO-WHITE
(digits)
888
RGB (Y)
BLACK-TO-WHITE AT GDY = GDC = −6
(digits)
712
1996 Oct 02
41