®
®
ADS-951
+25°C
ANALOG OUTPUT
Internal Reference
Voltage
Drift
External Current
DIGITAL OUTPUTS
Logic Levels
Logic "1"
Logic "0"
Logic Loading "1"
Logic Loading "0"
Output Coding
POWER REQUIREMENTS
Power Supply Ranges
+15V Supply
–15V Supply
+5V Supply
–5V Supply
Power Supply Currents
+15V Supply
–15V Supply
+5V Supply
–5V Supply
Power Dissipation
Power Supply Rejection
+14.5
–14.5
+4.75
–4.75
—
—
—
—
—
—
+15.0
–15.0
+5.0
–5.0
+29
–15
+104
–54
1.45
—
+15.5
–15.5
+5.25
–5.25
—
—
—
—
1.65
±0.05
+14.5
–14.5
+4.75
–4.75
—
—
—
—
—
—
+2.4
—
—
—
—
—
—
—
—
+0.4
–4
+4
+2.4
—
—
—
MIN.
+4.95
—
—
TYP.
+5.0
±30
1
MAX.
+5.05
—
—
MIN.
+4.95
—
—
0 to +70°C
TYP.
+5.0
±30
1
MAX.
+5.05
—
—
MIN.
+4.95
—
—
–40 to +110°C
TYP.
+5.0
±30
1
MAX.
+5.05
—
—
UNITS
Volts
ppm/°C
mA
—
—
—
+0.4
—
–4
—
+4
Complementary Offset Binary
+2.4
—
—
—
—
—
—
—
—
+0.4
–4
+4
Volts
Volts
mA
mA
+15.0
–15.0
+5.0
–5.0
+29
–15
+104
–54
1.45
—
+15.5
–15.5
+5.25
–5.25
—
—
—
—
1.65
±0.05
+14.5
–14.5
+4.75
–4.75
—
—
—
—
—
—
+15.0
–15.0
+5.0
–5.0
+29
–15
+104
–54
1.45
—
+15.5
–15.5
+5.25
–5.25
—
—
—
—
1.65
±0.05
Volts
Volts
Volts
Volts
mA
mA
mA
mA
Watts
%FSR/%V
Footnotes:
➀
All power supplies must be on before applying a start convert pulse. All supplies
and the clock (START CONVERT) must be present during warmup periods. The
device must be continuously converting during this time.
➁
Contact DATEL for other input voltage ranges.
➂
A 1MHz clock with a 500nsec positive pulse width (50% duty cycle) is used for
all production testing. Any duty cycle may be used as long as a minimum
positive pulse width of 20nsec is maintained. For applications requiring lower
sampling rates, clock frequencies lower than 1MHz may be used.
➃
Effective bits is equal to:
(SNR + Distortion) – 1.76 +
20 log
6.02
Full Scale Amplitude
Actual Input Amplitude
➄
This is the time required before the A/D output data is valid once the analog input
is back within the specified range.
TECHNICAL NOTES
1. Obtaining fully specified performance from the ADS-951
requires careful attention to pc-card layout and power
supply decoupling. The device's analog and digital ground
systems are not connected to each other internally. For
optimal performance, tie all ground pins (3, 12 and 13)
directly to a large
analog
ground plane beneath the
package.
Bypass all power supplies and the +5V REFERENCE
OUTPUT (pin 5) to ground with 10µF tantalum capacitors in
parallel with 0.1µF ceramic capacitors. Locate the bypass
capacitors as close to the unit as possible. Tie a 47µF
capacitor between COMPENSATION (pin 7) and ground.
2. The ADS-951 achieves its specified accuracies without the
need for external calibration. If required, the device's small
initial errors can be reduced to zero using the adjustment
circuitry shown in Figure 2. When using this circuitry, or any
similar offset and gain calibration hardware, make adjust-
ments following warmup. To avoid interaction, always adjust
offset before gain. Float pin 6 if not using gain adjust
circuits.
3. Applying a start convert pulse while a conversion is in
progress (EOC = logic "1") will initiate a new and probably
inaccurate conversion cycle. Data for the interrupted and
subsequent conversions will be invalid.
THERMAL REQUIREMENTS
All DATEL sampling A/D converters are fully characterized and
specified over operating temperature (case) ranges of 0 to
+70°C and –40 to +110°C. All room-temperature (T
A
= +25°C)
production testing is performed without the use of heat sinks or
forced-air cooling. Thermal impedance figures for each device
are listed in their respective specification tables.
These devices do not normally require heat sinks, however,
standard precautionary design and layout procedures should be
used to ensure devices do not overheat. The ground and power
planes beneath the package, as well as all pcb signal runs to
and from the device, should be as heavy as possible to help
conduct heat away from the package. Electrically-insulating,
thermally-conductive "pads" may be installed underneath the
package. Devices should be soldered to boards rather than
"socketed", and of course, minimal air flow over the surface can
greatly help reduce the package temperature.
3
MURATA-PS [ MURATA POWER SOLUTIONS INC. ]
