ADC081S021
Single Channel, 50 to 200 ksps, 8-Bit A/D Converter
ADC081S021 Single Channel, 50 to 200 ksps, 8-Bit A/D Converter
January 2006
General Description
The ADC081S021 is a low-power, single channel CMOS
8-bit analog-to-digital converter with a high-speed serial interface. Unlike the conventional practice of specifying performance at a single sample rate only, the ADC081S021 is
fully specified over a sample rate range of 50 ksps to 200
ksps. The converter is based upon a successiveapproximation register architecture with an internal trackand-hold circuit.
The output serial data is straight binary, and is compatible
withseveralstandards,suchasSPI
MICROWIRE, and many common DSP serial interfaces.
The ADC081S021 operates with a single supply that can
range from +2.7V to +5.25V. Normal power consumption
using a +3.6V or +5.25V supply is 1.3 mW and 7.7 mW,
respectively. The power-down feature reduces the power
consumption to as low as 2.6 µW using a +5.25V supply.
The ADC081S021 is packaged in 6-lead LLP and SOT-23
packages. Operation over the industrial temperature range
of −40˚C to +85˚C is guaranteed.
™
,QSPI™,
Features
n Specified over a range of sample rates.
n 6-lead LLP and SOT-23 packages
n Variable power management
n Single power supply with 2.7V - 5.25V range
™
n SPI
/QSPI™/MICROWIRE/DSP compatible
Key Specifications
n DNL+0.04/-0.03 LSB (typ)
n INL+0.04/-0.03 LSB (typ)
n SNR49.6 dB (typ)
n Power Consumption
4SCLKDigital clock input. This clock directly controls the conversion and readout processes.
5SDATA
6CS
POWER SUPPLY
1V
2GNDThe ground return for the supply and signals.
PADGND
IN
A
Analog input. This signal can range from 0V to VA.
Digital data output. The output samples are clocked out of this pin on falling edges of
the SCLK pin.
Chip select. On the falling edge of CS, a conversion process begins.
Positive supply pin. This pin should be connected to a quiet +2.7V to +5.25V source
and bypassed to GND witha1µFcapacitor and a 0.1 µF monolithic capacitor located
within 1 cm of the power pin.
For package suffix CISD(X) only, it is recommended that the center pad should be
connected to ground.
20145407
www.national.com2
ADC081S021
Absolute Maximum Ratings (Notes 1, 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Analog Supply Voltage V
A
Voltage on Any Analog Pin to GND−0.3V to (V
Voltage on Any Digital Pin to GND−0.3V to 6.5V
Input Current at Any Pin (Note 3)
Package Input Current (Note 3)
Power Consumption at T
= 25˚CSee (Note 4)
A
ESD Susceptibility (Note 5)
Human Body Model
Machine Model
Junction Temperature+150˚C
Storage Temperature−65˚C to +150˚C
−0.3V to 6.5V
+0.3V)
A
±
10 mA
±
20 mA
3500V
300V
Operating Ratings (Notes 1, 2)
Operating Temperature Range−40˚C ≤ T
V
Supply Voltage+2.7V to +5.25V
A
Digital Input Pins Voltage Range
(regardless of supply voltage)
Analog Input Pins Voltage Range0V to V
Clock Frequency1 MHz to 4 MHz
Sample Rateup to 200 ksps
Package Thermal Resistance
Packageθ
6-lead LLP94˚C / W
6-lead SOT-23265˚C / W
Soldering process must comply with National Semiconductor’s Reflow Temperature Profile specifications. Refer to
www.national.com/packaging. (Note 6)
Throughput TimeAcquisition Time + Conversion Time20SCLK cycles
t
QUIET
t
AD
t
AJ
(Note 10)50ns (min)
Aperture Delay3ns
Aperture Jitter30ps
= 1 MHz to 4 MHz, f
SCLK
MIN
to T
= 50 ksps to 200 ksps,
SAMPLE
: all other limits TA= 25˚C.
MAX
Limits
(Note 9)
Units
50ksps (min)
200ksps (max)
40% (min)
60% (max)
ADC081S021 Timing Specifications
The following specifications apply for VA= +2.7V to 5.25V, GND = 0V, f
f
= 50 ksps to 200 ksps, Boldface limits apply for TA=T
SAMPLE
MIN
SymbolParameterConditionsTypicalLimitsUnits
t
CS
t
SU
t
EN
t
ACC
t
CL
t
CH
t
H
t
DIS
t
POWER-UP
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. For guaranteed specifications 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 2: All voltages are measured with respect to GND = 0V, unless otherwise specified.
Note 3: When the input voltage at any pin exceeds the power supply (that is, V
mA maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 10 mA to two. The Absolute
Maximum Rating specification does not apply to the V
Note 4: The absolute maximum junction temperature (T
junction-to-ambient thermal resistance (θ
for maximum power dissipation listed above will be reached only when the device is operated in a severe fault condition (e.g. when input or output pins are driven
beyond the power supply voltages, or the power supply polarity is reversed). Obviously, such conditions should always be avoided.
Note 5: Human body model is 100 pF capacitor discharged through a 1.5 kΩ resistor. Machine model is 220 pF discharged through zero ohms
Note 6: Reflow temperature profiles are different for lead-free and non-lead-free packages.
Note 7: Tested limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 8: This is the frequency range over which the electrical performance is guaranteed. The device is functional over a wider range which is specified under
Operating Ratings.
Note 9: Data sheet min/max specification limits are guaranteed by design, test, or statistical analysis.
Note 10: Minimum Quiet Time required by bus relinquish and the start of the next conversion.
Minimum CS Pulse Width10ns (min)
CS to SCLK Setup Time10ns (min)
Delay from CS Until SDATA TRI-STATE
®
Disabled (Note 11)
= +2.7V to +3.6V40ns (max)
Data Access Time after SCLK Falling Edge
(Note 12)
V
A
V
= +4.75V to +5.25V20ns (max)
A
SCLK Low Pulse Width
SCLK High Pulse Width
= +2.7V to +3.6V7ns (min)
V
SCLK to Data Valid Hold Time
SCLK Falling Edge to SDATA High
Impedance (Note 13)
A
V
= +4.75V to +5.25V5ns (min)
A
= +2.7V to +3.6V
V
A
V
= +4.75V to +5.25V
A
Power-Up Time from Full Power-Down1µs
<
GND or V
IN
pin. The current into the VApin is limited by the Analog Supply Voltage specification.
A
max) for this device is 150˚C. The maximum allowable power dissipation is dictated by TJmax, the
), and the ambient temperature (TA), and can be calculated using the formula PDMAX=(TJmax − TA)/θJA. The values
JA
J
= 1.0 MHz to 4.0 MHz, CL=25pF,
SCLK
to T
: all other limits TA= 25˚C.
MAX
20ns (max)
0.4 x
t
SCLK
0.4 x
t
SCLK
25ns (max)
6ns (min)
25ns (max)
5ns (min)
>
VA), the current at that pin should be limited to 10 mA. The 20
IN
ns (min)
ns (min)
ADC081S021
www.national.com5
ADC081S021 Timing Specifications (Continued)
Note 11: Measured with the timing test circuit shown in Figure 1 and defined as the time taken by the output signal to cross 1.0V.
Note 12: Measured with the timing test circuit shown in Figure 1 and defined as the time taken by the output signal to cross 1.0V or 2.0V.
Note 13: t
to remove the effects of charging or discharging the output capacitance. This means that t
ADC081S021
is derived from the time taken by the outputs to change by 0.5V with the timing test circuit shown in Figure 1. The measured number is then adjusted
DIS
is the true bus relinquish time, independent of the bus loading.
DIS
www.national.com6
Loading...
+ 11 hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.