Datasheet AD581 (Analog Devices) - 7

link to page 7 link to page 7
AD581
The error band which is guaranteed with the AD581 is the
12V
maximum deviation from the initial value at +25°C; this error
10.03V T U
band is of more use to a designer than one which simply guarantees
P T 11V 10.02V T U P
the maximum total change over the entire range (that is, in the
T OU 10.01V OU
latter definition, all of the changes could occur in the positive
10V 10.00V
direction). Thus, with a given grade of the AD581, the designer
20V
can easily determine the maximum total error from initial toler-
T U
ance plus temperature variation (for example, for the AD581T, the
10V P IN
initial tolerance is ±10 mV, the temperature error band is ±15 mV,
0V
7 00 4- thus the unit is guaranteed to be 10.000 V ±25 mV from −55°C 01 08
0 50 100 150 200 250
to +125°C).
SETTLING TIME (µs) OUTPUT CURRENT CHARACTERISTICS
Figure 7. Output Settling Characteristic The AD581 has the capability to either source or sink current and provide good load regulation in either direction, although
1000
it has better characteristics in the source mode (positive current
NOISE SPECTRAL DENSITY (nV/ Hz)
into the load). The circuit is protected for shorts to either positive supply or ground. The output voltage vs. output current charac-
100
teristics of the device are shown in Figure 6. Source current is displayed as negative current in the figure; sink current is positive. Note that the short-circuit current (that is, 0 V output)
TOTAL NOISE (µV rms) UP
is about 28 mA; when shorted to +15 V, the sink current goes to
TO SPECIFIED FREQUENCY 10
about 20 mA.
+V
08
S = 15V
0
14 T
4-
A = 25°C
01
1
08
12 10 100 1k 10k 100k 1M ) (V FREQUENCY (Hz) E 10 G
Figure 8. Spectral Noise Density and Total rms Noise vs. Frequency
A LT O 8 V T U 1000 6 TP U O 4 900 2
6
A)
-00
µ
14
( 1.5µA/°C 0
080
NT 800 –20 –15 –10 –5 0 5 10 15 20 RE SOURCE SINK OUTPUT CURRENT (mA) CUR Y L 700
Figure 6. Output Voltage vs. Sink and Source Current
P P U S DYNAMIC PERFORMANCE 600
Many low power instrument manufacturers have been in- 09 0 4- creasingly concerned with the turn-on characteristics of the 01
500
08 components used in their systems. Fast turn-on components often
–55 –50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100 110 120 125 TEMPERATURE (°C)
enable the end user to keep power off when not needed, and yet Figure 9. Quiescent Current vs. Temperature respond quickly when the power is turned on for operation. Figure 7 displays the turn-on characteristic of the AD581. This characteristic is generated from a cold start operation and repre- sents the true turn-on waveform after an extended period with the supplies off. The figure shows both the coarse and fine transient characteristics of the device; the total settling time to within ±10 mV is about 180 μs, and there is no long thermal tail appearing after the point. Rev. C | Page 7 of 12 Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION APPLYING THE AD581 VOLTAGE VARIATION vs. TEMPERATURE OUTPUT CURRENT CHARACTERISTICS DYNAMIC PERFORMANCE PRECISION HIGH CURRENT SUPPLY CONNECTION FOR REDUCED PRIMARY SUPPLY THE AD581 AS A CURRENT LIMITER NEGATIVE 10 V REFERENCE 10 V REFERENCE WITH MULTIPLYING CMOS DACs OR ADCs PRECISION 12-BIT DAC REFERENCE OUTLINE DIMENSIONS ORDERING GUIDE