1991 Burr-Brown Corporation
PDS-1109F
Printed in U.S.A. July, 1995
ADS774
FEATURES
q
REPLACES ADC574, ADC674 AND ADC774
FOR NEW DESIGNS
q
COMPLETE SAMPLING A/D WITH
REFERENCE, CLOCK AND
MICROPROCESSOR INTERFACE
q
FAST ACQUISITION AND CONVERSION:
8.5
s max OVER TEMPERATURE
q
ELIMINATES EXTERNAL SAMPLE/HOLD
IN MOST APPLICATIONS
q
GUARANTEED AC AND DC PERFOR-
MANCE
q
SINGLE +5V SUPPLY OPERATION
q
LOW POWER: 120mW max
q
PACKAGE OPTIONS: 0.6" and 0.3" DIPs,
SOIC
Microprocessor-Compatible Sampling
CMOS ANALOG-to-DIGITAL CONVERTER
Comparator
2.5V Reference
Input
CDAC
10V Range
20V Range
Bipolar Offset
+
2.5V Reference
Output
Control
Inputs
2.5V
Reference
Clock
Successive
Approximation
Register
Control Logic
Three-State Buffers
Status
Parallel
Data
Output
DESCRIPTION
The ADS774 is a 12-bit successive approximation
analog-to-digital converter using an innovative
capacitor array (CDAC) implemented in low-power
CMOS technology. This is a drop-in replacement for
ADC574, ADC674, and ADC774 models in most
applications, with internal sampling, much lower power
consumption, and the ability to operate from a single
+5V supply.
The ADS774 is complete with internal clock, micro-
processor interface, three-state outputs, and internal
scaling resistors for input ranges of 0V to +10V, 0V to
+20V,
5V, or
10V. The maximum throughput time
is 8.5
s over the full operating temperature range,
including both acquisition and conversion.
Complete user control over the internal sampling func-
tion facilitates elimination of external sample/hold
amplifiers in most existing designs.
The ADS774 requires +5V, with 15V optional. No
+15V supply is required. Available packages include
0.3" or 0.6" wide 28-pin plastic DIP and 28-pin SOICs.
International Airport Industrial Park Mailing Address: PO Box 11400, Tucson, AZ 85734 Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 Tel: (520) 746-1111 Twx: 910-952-1111
Internet: http://www.burr-brown.com/ FAXLine: (800) 548-6133 (US/Canada Only) Cable: BBRCORP Telex: 066-6491 FAX: (520) 889-1510 Immediate Product Info: (800) 548-6132
ADS774
ADS774
ADS774
ADS774
2
SPECIFICATIONS
ELECTRICAL
At T
A
= T
MIN
to T
MAX
, V
DD
= +5V, V
EE
= 15V to +5V, sampling frequency of 117kHz, f
IN
= 10kHz; unless otherwise specified.
ADS774JE, JP, JU
ADS774KE, KP, KU
PARAMETER
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
RESOLUTION
12
T
Bits
INPUTS
ANALOG
Voltage Ranges: Unipolar
0 to +10, 0 to +20
V
Bipolar
5,
10
V
Impedance: 0 to +10V,
5V
8.5
12
T
T
k
10V, 0V to +20V
35
50
T
T
k
DIGITAL (CE, CS, R/C, A
O
, 12/8)
Voltages: Logic 1
+2.0
+5.5
T
T
V
Logic 0
0.5
+0.8
T
T
V
Current
5
0.1
+5
T
T
T
A
Capacitance
5
T
pF
TRANSFER CHARACTERISTICS
DC ACCURACY
At +25
C
Linearity Error
1
1/2
LSB
Unipolar Offset Error (adjustable to zero)
2
T
LSB
Bipolar Offset Error (adjustable to zero)
10
4
LSB
Full-Scale Calibration Error
(1)
0.25
T
% of FS
(2)
(adjustable to zero)
No Missing Codes Resolution
12
12
Bits
T
MIN
to T
MAX
(3)
Linearity Error
1
1/2
LSB
Full-Scale Calibration Error
0.47
0.37
% of FS
Unipolar Offset
4
3
LSB
Bipolar Offset
12
5
LSB
No Missing Codes Resolution
12
12
Bits
AC ACCURACY
(4)
Spurious Free Dynamic Range
73
78
76
T
dB
Total Harmonic Distortion
77
72
T
75
dB
Signal-to-Noise Ratio
69
72
71
T
dB
Signal-to-(Noise + Distortion) Ratio
68
71
70
T
dB
Intermodulation Distortion
75
T
(F
IN1
= 20kHz, F
IN2
= 23kHz)
TEMPERATURE COEFFICIENTS
(5)
Unipolar Offset
1
T
ppm/
C
Bipolar Offset
2
T
ppm/
C
Full-Scale Calibration
12
T
ppm/
C
POWER SUPPLY SENSITIVITY
Change in Full-Scale Calibration
(6)
+4.75V < V
DD
< +5.25V
Max Change
1/2
T
LSB
CONVERSION TIME (Including Acquisition Time)
t
AQ
+ t
C
at 25
C:
8-Bit Cycle
5.5
5.9
T
T
s
12-Bit Cycle
7.5
8
T
T
s
12-Bit Cycle, T
MIN
to T
MAX
:
8
8.5
T
T
s
SAMPLING DYNAMICS
Sampling Rate at 25
C
125
T
kHz
T
MIN
to T
MAX
117
T
kHz
Aperture Delay, t
AP
With V
EE
= +5V
20
T
ns
With V
EE
= 0V to 15V
1.6
T
s
Aperture Uncertainty (Jitter)
With V
EE
= +5V
300
T
ps, r ms
With V
EE
= 0V to 15V
10
T
ns, r ms
Settling time to 0.01% for
1.4
T
s
Full-Scale Input Change
ADS774
3
SPECIFICATIONS
(CONT)
ELECTRICAL
At T
A
= T
MIN
to T
MAX
, V
DD
= +5V, V
EE
= 15V to +5V, sampling frequency of 117kHz, f
IN
= 10kHz; unless otherwise specified.
ADS774JE, JP, JU
ADS774KE, KP, KU
PARAMETER
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user's own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
OUTPUTS
DIGITAL (DB
11
- DB
0
, STATUS)
Output Codes: Unipolar
Unipolar Straight Binary (USB)
Bipolar
Bipolar Offset Binary (BOB)
Logic Levels: Logic 0 (I
SINK
= 1.6mA)
+0.4
T
V
Logic 1 (I
SOURCE
= 500
A)
+2.4
T
V
Leakage, Data Bits Only, High-Z State
5
0.1
+5
T
T
T
A
Capacitance
5
T
pF
INTERNAL REFERENCE VOLTAGE
Voltage
+2.4
+2.5
+2.6
T
T
T
V
Source Current Available for External Loads
0.5
T
mA
POWER SUPPLY REQUIREMENTS
Voltage: V
EE
(7)
16.5
V
DD
T
T
V
V
DD
+4.5
+5.5
T
T
V
Current: I
EE
(7)
(V
EE
= 15V)
1
T
mA
I
DD
+15
+24
T
T
mA
Power Dissipation (T
MIN
to T
MAX
)
(V
EE
= 0V to +5V)
75
120
T
T
mW
TEMPERATURE RANGE
Specification
0
+70
T
T
C
Operating:
40
+85
T
T
C
Storage Temperature Range
65
+150
T
T
C
T
Same specification as ADS774JE, JP, JU.
NOTES: (1) With fixed 50
resistor from REF OUT to REF IN. This parameter is also adjustable to zero at +25
C. (2) FS in this specification table means Full Scale
Range. That is, for a
10V input range, FS means 20V; for a 0 to +10V range, FS means 10V. (3) Maximum error at T
MIN
and T
MAX
. (4) Based on using V
EE
=
+5V, which is the Control Mode. See the section "S/H Control Mode and ADC774 Emulation Mode." (5) Using internal reference. (6) This is worst case change
in accuracy from accuracy with a +5V supply. (7) V
EE
is optional, and is only used to set the mode for the internal sample/hold. When V
EE
= 15V, I
EE
= 1mA
typ; when V
EE
= 0V, I
EE
=
5
A typ; when V
EE
= +5V, I
EE
= +167
A typ.
ADS774
4
ABSOLUTE MAXIMUM RATINGS
V
EE
to Digital Common ....................................................... +V
DD
to 16.5V
V
DD
to Digital Common .............................................................. 0V to +7V
Analog Common to Digital Common ....................................................
1V
Control Inputs (CE, CS, A
O
, 12/8, R/C)
to Digital Common .................................................. 0.5V to V
DD
+0.5V
Analog Inputs (Ref In, Bipolar Offset, 10V
IN
)
to Analog Common ......................................................................
16.5V
20V
IN
to Analog Common ..................................................................
24V
Ref Out .......................................................... Indefinite Short to Common,
Momentary Short to V
DD
Max Junction Temperature ............................................................ +165
C
Power Dissipation ........................................................................ 1000mW
Lead Temperature (soldering,10s) ................................................. +300
C
Thermal Resistance,
JA
: Plastic DIPs ........................................ 100
C/W
SOIC ................................................... 100
C/W
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degrada-
tion to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.
1
2
3
4
5
Power-Up Reset
Control
Logic
Clock
12 Bits
Succesive Approximation Register
12
Bits
Three-State Buffers and Control
Nibble A
Nibble B
Nibble C
+
CDAC
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
+5VDC Supply
(V )
DD
A
O
R/C
12/8
CE
NC*
2.5V Ref
Out
Analog
Common
2.5V Ref
In
V
EE
Bipolar
Offset
10V Range
20V Range
Digital
Common
DB0 (LSB)
DB1
DB2
DB3
DB4
DB5
DB6
DB7
DB8
DB9
DB10
DB11 (MSB)
STATUS
*Not Internally Connected
2.5V
Reference
CS
PACKAGE/ORDERING INFORMATION
TEMPERATURE
LINEARITY
PACKAGE DRAWING
PRODUCT
SINAD
(1)
RANGE
ERROR
PACKAGE
NUMBER
(2)
ADS774JE
68dB
0
C to +70
C
1LSB
28-Pin 0.3" Plastic DIP
246
ADS774KE
70dB
0
C to +70
C
1/2LSB
28-Pin 0.3" Plastic DIP
246
ADS774JP
68dB
0
C to +70
C
1LSB
28-Pin 0.6" Plastic DIP
215
ADS774KP
70dB
0
C to +70
C
1/2LSB
28-Pin 0.6" Plastic DIP
215
ADS774JU
68dB
0
C to +70
C
1LSB
28-Lead SOIC
217
ADS774KU
70dB
0
C to +70
C
1/2LSB
28-Lead SOIC
217
NOTES: (1) SINAD is Signal-to-(Noise + Distortion) expressed in dB. (2) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-
Brown IC Data Book.
CONNECTION DIAGRAM
ADS774
5
FREQUENCY SPECTRUM (1V, 20kHz Input)
Magnitude (dB)
Input Frequency (kHz)
0
60
120
0
10
100
80
40
20
20
30
40
50
55
S/(N + D) = 53.1dB
THD = 74.2dB
SNR = 53.1dB
POWER SUPPLY REJECTION
vs SUPPLY RIPPLE FREQUENCY
Power Supply Rejection Ratio (V/V in dB)
Supply Ripple Frequency (Hz)
80
40
10
10
100
1k
10M
60
20
10k
100k
1M
SIGNAL/(NOISE + DISTORTION) vs
INPUT FREQUENCY AND AMBIENT TEMPERATURE
Signal/(Noise + Distortion) (dB)
Input Frequency (kHz)
75
70
65
0.1
1
10
100
55C
+25C
+125C
TYPICAL PERFORMANCE CURVES
At T
A
= +25
C, V
DD
= V
EE
= +5V; Bipolar
10V Input Range; sampling frequency of 110kHz; unless otherwise specified. All plots use 4096 point FFTs.
FREQUENCY SPECTRUM (10V, 2kHz Input)
Magnitude (dB)
0
60
120
100
80
40
20
Input Frequency (kHz)
0
10
20
30
40
50
55
S/(N + D) = 72.6dB
THD = 93.5dB
SNR = 72.6dB
FREQUENCY SPECTRUM (10V, 20kHz Input)
Magnitude (dB)
Input Frequency (kHz)
0
60
120
0
10
100
80
40
20
20
30
40
50
55
S/(N + D) = 70.6dB
THD = 77.5dB
SNR = 71.5dB
SPURIOUS FREE DYNAMIC RANGE, SNR AND THD
vs INPUT FREQUENCY
Spurious Free Dynamic Range, SNR, THD (dB)
Input Frequency (kHz)
100
80
60
0.1
1
10
100
90
70
Spurious Free Dynamic Range
Total Harmonic Distortion (THD)
Signal-to-Noise Ratio (SNR)
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