vp101-5bahp Zarlink Semiconductor, vp101-5bahp Datasheet - Page 7

• Manufacturer Part Number: vp101-5bahp
• Description: 30/50mhz 8-bit Cmos Video Dac
• Manufacturer: Zarlink Semiconductor

APPLICATION NOTES
RS-343A and RS-170 Video Generation
recommended that a doubly terminated 75
with an R
recommended that a singly terminated 75
with an R
a large capacitive load, there will be negligible difference in
video quality between doubly terminated 75
terminated 75 loads.t
recommended that an output buffer with unloaded gain >2 be
used to drive a doubly terminated 75 load.
COMP Resistor
may be added in series between the COMP capacitor and
COMP pin. The series resistor damps inductive ringing on
COMP, thus improving settling time.
TIMING WAVEFORMS
NOTES
1. Output delay, t
2. Settling time, t
3. Output rise/fall time, t
VP101
6
For generation of RS-343A compatible video levels it is
Similarly for generation of RS-170-compatible video, it is
If driving a large capacitive load (load RC >1/20
To optimise the settling time of the VP101, a resistor
SET
SET
resistor value of approximately 542
value of about 774 . If the VP101 is not driving
s
DLY
, measured from the 50% point of full scale transition to the output remaining within
, measured from the 50% point of the rising edge of CLOCK to the 50% point of full scale transition.
VRF
, measured between the 10% and 90% points of full scale transition.
load be used
load be used
and singly
Fig.4 Input/output timing
II
f
c
) it is
Non-Video Applications
disabling the video specific control inputs. REF WHITE
should be a logic ‘0’ while BLANC and SYNC should be a
logic ‘1’. I
three outputs will have the same full scale output current.
current (I
With the data inputs at $00, there is a DC offset current (I
defined as follows:
I
‘force to full scale’ control.
min
. The REF WHITE input may optionally be used as a
The VP101 may be used in non-video applications by
The relationship between R
Therefore the total full scale output current will be I
OUT
Note that 1 LSB
SYNC
I
out
I
min
) in this configuration is as follows:
(mA) = 7968 X
(mA) = 656 X
should be connected to V
32 X R
V
V
R
R
REF
REF
SET
V
SET
REF
SET
(V)
(V)
( )
( )
SET
1 LSB.
(V)
and full scale output
( )
255 LSBs
21 LSBs
AA
or AGND. All
OUT
min
+
)