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参数资料
| 型号： | AD9060SZ |
| 厂商： | ANALOG DEVICES INC |
| 元件分类： | ADC |
| 英文描述： | 10-Bit 75 MSPS A/D Converter |
| 中文描述： | 1-CH 10-BIT FLASH METHOD ADC, PARALLEL ACCESS, CQFP68 |
| 封装： | GULL WING, CERAMIC, LCC-68 |
| 文件页数： | 8/12页 |
| 文件大小： | 215K |
| 代理商： | AD9060SZ |
AD9060
–8–
REV. A
T he select resistors (R
S
) shown in the schematic (each pair can
be a potentiometer) are chosen to adjust the quarter-point
voltage references but are not necessary if R1–R4 match
within 0.05%.
E
S
32
38
44
50
56
62
10.0
9.0
8.0
7.0
6.0
5.0
0.4
0.8
1.0
±V
SENSE
– Volts
1.4
1.8
2.0
0.6
1.2
1.6
AD9060 SNR and ENOB vs. Reference Voltage
An alternative approach for defining the quarter-point references
of the resistor ladder to evaluate the integral linearity error of an
individual device and adjust the voltage at the quarter-points to
minimize this error. T his may improve the low frequency ac
performance of the converter.
Performance of the AD9060 has been optimized with an analog
input voltage of
±
1.75 V (as measured at
±
V
SENSE
). If the ana-
log input range is reduced below these values, relatively larger
differential nonlinearity errors may result because of comparator
mismatches. As shown in the figure below, performance of the
converter is a function of
±
V
SENSE
.
Applying a voltage greater than 4 V across the internal resistor
ladder will cause current densities to exceed rated values and
may cause permanent damage to the AD9060. T he design of
the reference circuit should limit the voltage available to the
references.
Analog Input Signal
T he signal applied to ANALOG IN drives the inputs of 512
parallel comparator cells (see Equivalent Analog Input figure).
T his connection has a typical input resistance of 7 k
and input
capacitance of 45 pF. T he input capacitance is nearly constant
over the analog input voltage range as shown in the graph, which
illustrates that characteristic.
T he analog input signal should be driven from a low distortion,
low noise amplifier. A good choice is the AD9617, a wide band-
width, monolithic operational amplifier with excellent ac and dc
performance. T he input capacitance should be isolated by a
small series resistor (24
for the AD9617) to improve the ac
performance of the amplifier (see AD9060/PCB Evaluation
Board Block Diagram).
USING T HE AD9060
Voltage References
T he AD9060 requires the user to provide two voltage references:
+V
REF
and –V
REF
. T hese two voltages are applied across an inter-
nal resistor ladder (nominally 37
) and set the analog input
voltage range of the converter. T he voltage references should be
driven from a stable, low impedance source. In addition to these
two references, three evenly spaced taps on the resistor ladder
(1/4
REF
, 1/2
REF
, 3/4
REF
) are available. Providing a reference to
these quarter points on the resistor ladder will improve the inte-
gral linearity of the converter and improve ac performance. (AC
and dc specifications are tested while driving the quarter points
at the indicated levels.) T he figure below is not intended to show
the transfer characteristic of the ADC but illustrates how the lin-
earity of the device is affected by reference voltages applied to
the ladder.
0000000000
0100000000
1000000000
1100000000
1111111111
O
V
IN
–V
SENSE
+V
SENSE
3/4
REF
1/2
REF
1/4
REF
TAPS
FLOATING
IDEAL
LINEARITY
TAPS
DRIVEN
(NOT TO SCALE)
Effect of Reference Taps on Linearity
Resistance between the reference connections and the taps of the
first and last comparators causes offset errors. T hese errors,
called “top and bottom of the ladder offsets,” can be nulled by
using the voltage sense lines, +V
SENSE
and –V
SENSE
, to adjust the
reference voltages. Current through the sense lines should be
limited to less than 100
μ
A. Excessive current drawn through the
voltage sense lines will affect the accuracy of the sense line
voltage.
T he next page shows a reference circuit that nulls out the offset
errors using two op amps, and provides appropriate voltage refer-
ences to the quarter-point taps. Feedback from the sense lines
causes the op amps to compensate for the offset errors. T he two
transistors limit the amount of current drawn directly from the
op amps; resistors at the base connections stabilize their opera-
tion. T he 10 k
resistors (R1–R4) between the voltage sense
lines form an external resistor ladder; the quarter point voltages
are taken off this external ladder and buffered by an op amp. T he
actual values of resistors R1–R4 are not critical, but they should
match well and be large enough (
≥
10 k
) to limit the amount of
current drawn from the voltage sense lines.
相关PDF资料 |
PDF描述 |
|---|---|
| AD9060TE | 10-Bit 75 MSPS A/D Converter |
| AD9060TZ | 10-Bit 75 MSPS A/D Converter |
| AD9060JE | 10-Bit 75 MSPS A/D Converter |
| AD9060JZ | 10-Bit 75 MSPS A/D Converter |
| AD9060KE | 10-Bit 75 MSPS A/D Converter |
相关代理商/技术参数 |
参数描述 |
|---|---|
| AD9060SZ/883B | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| AD9060TE | 制造商:AD 制造商全称:Analog Devices 功能描述:10-Bit 75 MSPS A/D Converter |
| AD9060TZ | 制造商:AD 制造商全称:Analog Devices 功能描述:10-Bit 75 MSPS A/D Converter |
| ad9060tz/883b | 制造商:Rochester Electronics LLC 功能描述:10 BIT ECL ADC IC 883 IC - Bulk 制造商:Analog Devices 功能描述: |
| AD-9063 | 制造商:BOTHHAND 制造商全称:Bothhand USA, LP. 功能描述:ADSL CPE SIDE SPLITTER |
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