HA1-5320883 Intersil Corporation, HA1-5320883 Datasheet - Page 9

• Manufacturer Part Number: HA1-5320883
• Description: High Speed Precision Sample and Hold Amplifier
• Manufacturer: Intersil Corporation

DESIGN INFORMATION
August 1999
The information contained in this section has been developed through characterization by Intersil Semiconductor and is for use as applica-
tion and design information only. No guarantee is implied.
Applying the HA-5320
The HA-5320 has the uncommitted differential inputs of an
op amp, allowing the Sample and Hold function to be
combined with many conventional op amp circuits. See the
Intersil Application Note 517 for a collection of circuit ideas.
Layout
A printed circuit board with ground plane is recommended
for best performance. Bypass capacitors (0.01 to 0.1 F,
ceramic) should be provided from each power supply termi-
nal to the Supply Ground terminal on pin 13.
The ideal ground connections are pin 6 (SIG. Ground)
directly to the system Signal Ground, and pin 13 (Supply
Ground) directly to the system Supply Common.
Hold Capacitor
The HA-5320 includes a 100pF MOS hold capacitor, suffi-
cient for most high speed applications (the Electrical Specifi-
cations section is based on this internal capacitor).
Additional capacitance may be added between pins 7 and
11. This external hold capacitance will reduce droop rate at
the expense of acquisition time, and provide other trade-offs
as shown in the Performance Curves.
If an external hold capacitor C
band- width capacitor of value 0.1C
from pin 8 to ground. Exact value and type are not critical.
The hold capacitor C
tance and low dielectric absorption, to minimize droop
Semiconductor
S/H CONTROL
S
FIGURE 1. TYPICAL HA-5320/883 CONNECTIONS; NONINVERTING UNITY GAIN MODE
EXT
H
should have high insulation resis-
V
IN
GROUND
SYSTEM
OFFSET
ADJUST
POWER
15mV
EXT
14
EXT
1
2
13
is used, then a noise
3
should be connected
10k
+
NOTE: Pin Numbers Refer to DIP Package Only.
-
4
-15V +15V
GROUND
HA-5320
SYSTEM
SIGNAL
5
9
11
6
100pF
+
-
8
0.1C
C
7-11
EXT
EXT
7
errors. Polystyrene dielectric is a good choice for operating
temperatures up to +85
offer good performance to +125
The hold capacitor terminal (pin 11) remains at virtual
ground potential. Any PC connection to this terminal should
be kept short and “guarded” by the ground plane, since
nearby signal lines or power supply voltages will introduce
errors due to drift current.
Applications
Figure 1 shows the HA-5320 connected as a unity gain non-
inverting amplifier – its most widely used configuration. As
an input device for a fast successive – approximation A/D
converter, it offers very high throughput rate for a monolithic
IC sample/hold amplifier. Also, the hold step error is adjust-
able to zero using the Offset Adjust potentiometer, to deliver
a 12-bit accurate output from the converter.
The application may call for an external hold capacitor C
as shown. As mentioned earlier, 0.1C
mended at pin 8 to reduce output noise in the Hold mode.
The HA-5320 output circuit does not include short circuit
protection, and consequently its output impedance remains
low at high frequencies. Thus, the step changes in load cur-
rent which occur during an A/D conversion are absorbed at
the S/H output with minimum voltage error. A momentary
short circuit to ground is permissible, but the output is not
designed to tolerate a short of indefinite duration.
Teflon is a registered Trademark of Dupont Corporation.
CONVERT
13
5
9
INPUT
R/C
ANALOG
COMMON
HI-574A
Sample and Hold Amplifier
HA5320
o
C. Teflon
High Speed Precision
o
Spec Number
C and above.
DIGITAL
OUTPUT
and glass dielectrics
EXT
is then recom-
511096-883
EXT