U3661M
Baseband Delay Line (64
m
s)
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
Line-locked by the sandcastle pulse
D
No crosstalk between SECAM color
carriers (diaphoty)
D
Adjustment-free application, VCO without
external components
D
Handles negative or positive color-difference
input signals
D
Comb filtering functions for NTSC
color-difference signals
D
Clamping of ac-coupled input signals
[±(R–Y) and
±(B–Y)]
D
Correction of phase errors in the PAL system
"
(B–Y) 14
"
(R–Y) 16
V
Ref
Clamping
Line memory
Shift register
Clamping
S+H
S+H
LPF
+
12
"
(B–Y)
"
(R–Y)
Line memory
V
Ref
+
11
LPF
Bias
f
SC
V
DD2
GND2
1
SC detector
3 MHz
Control
9
PLL
Clock generator
V
DD1
GND1
3
5
94 8846
10
SC pulse
Figure 1. Block diagram
TELEFUNKEN Semiconductors
Rev. A1, 17-Jul-96
1 (9)
Preliminary Information
TEMIC [ TEMIC SEMICONDUCTORS ]
