Very Fast, Complete
10- or 12-Bit A/D Converters
a
AD578/AD579
FUNCTIONAL BLOCK DIAGRAM
FEATURES
Complete 12-Bit A/D Converter with Reference
and Clock
Fast Conversion: 3 s Max
Buried Zener Reference for Long-Term Stability and
Low Gain TC: ؎30 ppm/؇C Max (AD578)
؎40 ppm/؇C Max (AD579)
AD578/AD579
(AD578)
BIT 12
(AD578)
BIT 11
BIT 10
BIT 9
BIT 8
BIT 7
BIT 6
BIT 5
1
2
3
4
5
6
7
8
9
32
–15V
31 +15V
100⍀
20k⍀
30 ANALOG GND
20k⍀
5k⍀
29
28
ZERO ADJ
5k⍀
20V SPAN INPUT
Max Nonlinearity: <؎0.012%
27 10V SPAN INPUT
No Missing Codes over Temperature
Low Power: 555 mW (AD578); 775 mW (AD579)
Available to MIL-STD-883
Positive-True Parallel or Serial Logic Outputs
Short Cycle Capability
Precision +10 V Reference for External Applications
Adjustable Internal Clock
“Z” Models for ؎12 V Supplies
10k⍀
26
25
BIPOLAR OFFSET
GAIN (REF IN)
24 REF OUT
BIT 4
BIT 3 10
BIT 2 11
BIT 1 12
BIT 1 13
23 SERIAL OUT
22
SERIAL OUT
21 CONVERT START
20 EOC
SHORT
14
15
19 CLOCK IN
18 CLOCK OUT
17 CLOCK ADJ
CYCLE
DIGITAL
GND
SAR
CLOCK
+5V 16
COMPARATOR
GENERAL DESCRIPTION
PRODUCT HIGHLIGHTS
The AD578 and AD579 are high speed 12-bit and 10-bit succes-
sive approximation analog-to-digital converters that include an
internal clock, reference, and comparator. Their hybrid design
utilizes MSI digital and linear ICs in conjunction with a 12-bit
or 10-bit monolithic, monotonic DAC to provide superior
performance and versatility with IC size, price, and reliability.
1. Both the AD578 and AD579 are complete analog-to-digital
converters. No external components are required to perform
a conversion.
2. The fast conversion rates—3 ms for the AD578, and 1.8 ms
for the AD579—make them ideal candidates for high speed
data acquisition systems requiring high throughput.
Important performance characteristics of the AD578 include
±1/2 LSB12 linearity error maximum at +25∞C, maximum gain
tempco of ±30 ppm/∞C, and maximum conversion time of 3 ms
at a typical power dissipation of 555 mW. The 10-bit AD579
provides ±1/2 LSB10 maximum linearity error at 1.8 ms maximum,
and 775 mW typical PD.
3. The internal buried Zener reference is laser trimmed to high
initial accuracy and low TC and is available externally.
4. Precision thin-film scaling resistors on the DAC provide for
excellent thermal tracking.
5. Short cycle and external clock capabilities are provided for
applications requiring faster conversion speeds and/or lower
resolution.
Both the AD578 and AD579 include scaling resistors that provide
analog input signal ranges of ±5 V, ±10 V, and 0 V to +10 V.
Both are contained in 32-lead ceramic side-brazed DIP pack-
ages, and are available with MIL-STD-883 Class B processing.
The serial output function is no longer supported on this
product after date code 9623.
REV. B
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