HV57009PG SUTEX [Supertex, Inc], HV57009PG Datasheet - Page 7

• Manufacturer Part Number: HV57009PG
• Description: 64-Channel Serial To Parallel Converter With P-Channel Open Drain Controllable Output Current
• Manufacturer: SUTEX [Supertex, Inc]

Typical Current
Programming Circuits
*Required if R
Figure 8a: Negative Control
Figure 8b: Positive Control
©2001 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited.
current source.
V
V
BP
BP
V
REF
0.1µF
+IN
HV570
0.1µF
+IN
HV570
- +
- +
V
REF
-IN
EXT
R
-IN
I
R
REF
EXT
I
REF
EXT
> 10K or R
V
V
DD
390pF
DD
10K
R
390pF
10K
R
D
C
D
*
C
D
*
Logic
D
*
EXT
*
Logic
is replaced by a constant
V
V
SS
SS
To other
outputs
To other
outputs
I
HV
OUT
I
HV
OUT
OUT
OUT
7
Since I
Therefore, if I
If R
stability as shown.
This control method behaves linearly as long as the operational
amplifier is not saturated. However, it requires a negative power
source and needs to provide a current I
chip being controlled.
If HV
perfect current source, and the output current will diminish. This
effect depends on the magnitude of the output current.
Given I
R
The intersection of a set of I
in the graph shown below. The value picked for R
be in the shaded area for linear operation. This control method
has the advantage that V
current. If R
for stability as shown.
Note: Lower reference current I
∆I
EXT
CS
, on the output.
EXT
=
OUT
V
OUT
OUT
>10KΩ, add series network R
REF
I
≥ +1V, the HV
REF
8
7
6
5
4
3
2
1
0
and V
If I
= I
EXT
100
=
OUT
OUT
REF
V
> 10K, add series network R
REF
I
250
1235 Bordeaux Drive, Sunnyvale, CA 94089
= 2mA and V
= 1mA and R
REF
OUT
=
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, the R
1
500
OUT
V
R EXT = 1K
R
REF
EXT
cascode may no longer operate as a
REF
EXT
2K
2
OUT
is positive, and draws only leakage

can be calculated by using:
V REF (V)
EXT
REF
and V
REF
= 1KΩ → V
= -5V → R
5K
, results in higher distortion,
3
REF
REF
D
values can be located
and C
= I
www.supertex.com
EXT
OUT
D
4
REF
and C
= 2.5KΩ.
D
for each HV570
EXT
= -1V.
to ground for
must always
D
HV57009
5
to ground
03/12/02