U3661M Datasheet, PDF (1/9 Pages) TEMIC Semiconductors – Baseband Delay Line

Baseband Delay Line (64 ms)
U3661M
Application
In TV sets, the integrated baseband delay line circuit is suitable for decoders with color-difference signal outputs
Description
The integrated delay line circuit U3661M is suitable for
all chroma decoders with baseband color-difference
outputs. It is suitable for PAL-, SECAM- and
NTSC-signals as well. The U3661M contains two
separate delay lines for processing (R–Y)-output and
(B–Y)-output separately. The delay is performed by
internally switched capacitors. On-chip postfiltering
avoids the need for external filter components.
A summing circuitry combines the information of
adjacent TV-lines, thus giving an interpolated sum for the
PAL-system, storing preceeding lines for the SECAM-
system and providing a comb-filtered output for
NTSC-signals. Due to internally-generated timing,
synchronization is easily done by feeding a line-frequent
impulse (usually the SC-impulse) to the sync-input of
the IC.
Features
D One line delay time, addition of delayed and
non-delayed output signals
D Adjustment-free application, VCO without
external components
D Handles negative or positive color-difference
input signals
D Clamping of ac-coupled input signals
[±(R–Y) and ±(B–Y)]
D Line-locked by the sandcastle pulse
D No crosstalk between SECAM color
carriers (diaphoty)
D Comb filtering functions for NTSC
color-difference signals
D Correction of phase errors in the PAL system
"(B–Y)
14
"(R–Y)
16
V_{DD2 1}
GND2 3
Clamping
Clamping
Line memory
Shift register
Line memory
Bias
SC detector
5
f_SC
PLL
V_Ref
S+H
+
LPF
" ₁₂ (B–Y)
S+H
+
LPF
" _{11 (R–Y)}
V_Ref
Control
3 MHz
9 ^VDD1
Clock generator
10 ^GND1
SC pulse
Figure 1. Block diagram
94 8846
TELEFUNKEN Semiconductors
1 (9)
Rev. A1, 17-Jul-96
Preliminary Information