Electrical characteristics – Rainbow Electronics ADC10738 User Manual
Page 8
Electrical Characteristics
(Continued)
Note 1
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur
Note 2
Operating Ratings indicate conditions for which the device is functional but do not guarantee specific performance limits For guaranteed specifcations and
test conditions see the Electrical Characteristics The guaranteed specifications apply only for the test conditions listed Some performance characteristics may
degrade when the device is not operated under the listed test conditions
Note 3
All voltages are measured with respect to GND unless otherwise specified
Note 4
When the input voltage (V
IN
) at any pin exceeds the power supplies (V
IN
k
GND or V
IN
l
AV
a
or DV
a
) the current at that pln should be limited to 30 mA
The 120 mA maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 30 mA to four
Note 5
The maximum power dissipation must be derated at elevated temperatures and is dictated by T
Jmax
i
JA
and the ambient temperature T
A
The maximum
allowable power dissipation at any temperature is P
D
e
(T
Jmax
b
T
A
) i
JA
or the number given In the Absolute Maximum Ratings whichever is lower For this
device T
Jmax
e
150 C The typical thermal resistance (i
JA
) of these Paris when board mounted can be found in the following table
Part Number
Thermal Resistance
Package Type
ADC10731CIN
82 C W
N16E
ADC10731CIWM
90 C W
M16B
ADC10732CIN
47 C W
N20A
ADC10732CIWM
80 C W
M20B
ADC10734CIMSA
134 C W
MSA20
ADC10734CIN
47 C W
N20A
ADC10734CIWM
80 C W
M20B
ADC10738CIN
60 C W
N24A
ADC10738CIWM
75 C W
M24B
Note 6
The human body model is a 100 pF capacitor discharged through a 1 5 kX resistor into each pin The machine model is a 200 pF capacitor discharged
directly into each pin
Note 7
See AN-450 ‘‘Surface Mounting Methods and Their Effect on Product Reliability’’ or the section titied ‘‘Surtace Mount’’ found in any post 1986 National
Semiconductor Linear Data Book for other methods of soldering surtace mount devices
Note 8
Two on-ohip diodes are tied to each analog input as shown below They will forward-conduct for analog input voltages one diode drop below ground or one
diode drop greater than V
a
supply Be careful during testing at low V
a
levels (
a
4 5V) as high level analog inputs (
a
5V) can cause an input diode to conduct
especially at elevated temperatures which will cause errors In the conversion result The specification allows 50 mV forward bias of either diode this means that as
long as the analog V
IN
does not exceed the supply voltage by more than 50 mV the output code will be oorrect Exceeding this range on an unselected channel will
corrupt the reading of a selected channel If AV
a
and DV
a
are minimum (4 5 V
DC
) and full scale must be
s a
4 55 V
DC
TL H 11390 – 6
Note 9
No connection exists between AV
a
and DV
a
on the chip
To guarantee accuracy it is required that the AV
a
and DV
a
be connected together to a power supply with separate bypass filter at eacn V
a
pin
Note 10
One LSB is referenced to 10 bits of resolution
Note 11
Typicals are at T
J
e
T
A
e
25 C and represent most likely pararmetric norm
Note 12
Tested limits are guaranteed to National’s AOQL (Average Outgolng Quality Level)
Note 13
Total unadjusted error includes offset full-scale linearity multiplexer and hold step errors
Note 14
The DC common-mode error is measured in the differential multiplexer mode with the assigned positive and negative input channels shorted together
Note 15
Channel leakage current is measured after the channel selection
Note 16
All the timing specifications are tested at the TTL logic levels V
IL
e
0 8V for a falling edge and V
IH
e
2 0V for a rising TRl-STATE voltage level is forced
to 1 4V
Note 17
The voltage applied to the digital inputs will affect the current drain during power down These devices are tested with CMOS logic levels (logic Low
e
0V
and logic High
e
5V) TTL levels increase the current during power down to about 300 mA
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