7820 - ADC 8 Bit, 73.5 kSPS

7820
Microprocessor-compatible
8-Bit ADC
FEATURES:
DESCRIPTION:
•
•
•
•
•
•
The 7820 is a microprocessor compatible 8-bit Analog-to-Digital Converter with a 0V to +5V input supply range with a single
+5 Volt supply.
1.36 µ s Conversion Time
Built-in-Track-and-Hold Function
Single +5 Volt Supply
No External Clock Required
Tri-State Output Buffered
Total Ionization Dose:
- > 50 krads (Si), depending upon space mission.
• Excellent Single Event Effects
- SEL > 80 MeV/mg/cm2
• Package:
- 20 pin Rad-Pak DIP
The 7820 incorporates internal sample-and-hold circuitry
which eliminates the need for an external S/H for signals with
slew rates less than 100 mV/µ s.
The 7820 was designed to be easiliy interfaced with microprocessors, appearing as either a memory location or I/O port
without the need for external interfacing. All outputs are
latched and tri-state buffered.
Maxwell Technologies' patented RAD-PAK® packaging technology incorporates radiation shielding in the microcircuit package. It eliminates the need for box shielding while providing
the required radiation shielding for a lifetime in orbit or space
mission. In a GEO orbit, the RAD-PAK®package provides
greater than 50 krad (Si) radiation dose tolerance. This product is available with screening up to Class S.
09.09.03 Rev 3
(858) 503-3300 - Fax: (858) 503-3301 - www.maxwell.com
All data sheets are subject to change without notice
1
©2003 Maxwell Technologies
All rights reserved.
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Logic Diagram
7820
Microprocessor-compatible 8-Bit ADC
TABLE 1. PIN DESCRIPTION
PIN
SYMBOL
DESCRIPTION
1
VIN
Analog Input Range: VREF(-) to VREF(+).
2
DB0
Data Output. Three State Output, bit 0 (LSB)
3
DB1
Data Output. Three State Output, bit 1
4
DB2
Data Output. Three State Output, bit 2
5
DB3
Data Output. Three State Output, bit 3
6
WR/RDY
7
Mode
8
RD
READ Input. RD must be low to access data from the part.
9
INT
INTERUPT Output. INT going low indicates that the conversion is complete INT returns high on rising the edge of RD or CS.
10
GND
Ground
11
VREF-
Lower limit of reference span. Range: GND < VREF(-) < VREF(+)
12
VREF+
Upper limit of reference span. Range: GND < VREF(-) < VREF(+) < VDD
13
CS
Chip Select Input. CS, the decoded device address, must be low for RD
or WR to be recognized by the converter.
14
DB4
Data Output. Three State Output, bit 4
15
DB5
Data Output. Three State Output, bit 5
16
DB6
Data Output. Three State Output, bit 6
17
DB7
Data Output. Three State Output, bit 7 (MSB)
18
OFL
Overflow Output. If the analog input is higher than (VREF(+) - 1/2LSB),
OFL will be low at the end of conversion. It is a non three state output
which can be used to cascade 2 or more devices to increase resolution.
19
NC
No Connection.
20
VDD
Power supply voltage, +5V
WRITE control input/READY status output.
Mode Selection Input. It determines whether the device operates in the
WR-RD or RD mode. It is internally tied to GND through a 50 µ A current
source.
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TABLE 2. 7820 ABSOLUTE MAXIMUM RATINGS1
PARAMETER
MIN
MAX
UNIT
VDD to GND
-0
7.0
V
Digital Input Voltage to GND (Pins 6-80, 13)
-0.3
VDD +0.3
V
Digital Output Voltage to GND (Pins 2-5, 9, 14-18)
0.3
VDD +0.3
V
VREF (+) to GND
0
VDD +0.3
V
VREF (-) to GND
VSS -0.3
VREF (+)
V
09.09.03 Rev 3
All data sheets are subject to change without notice
2
©2003 Maxwell Technologies
All rights reserved.
7820
Microprocessor-compatible 8-Bit ADC
TABLE 2. 7820 ABSOLUTE MAXIMUM RATINGS1
PARAMETER
MIN
MAX
UNIT
VIN to GND
-0.3
VDD +0.3
V
Operating Temperature
-55
125
°C
Storage Temperature Range
-65
150
°C
Power Dissipation to 75°C
--
450
mW
Derates above +75°C
--
6
mW/°C
1. CAUTION: ESD (electrostatic discharge) sensitive device. The digital control inputs are diode protected; however, permanent damage may occur on unconnected devices subject to high energy electrostatic fields. Unused
devices must be stored in conductive foam or shunts. The protective foam should be discharged to the destination socket before devices are inserted.
PARAMETER
TEST CONDITIONS
SUBGROUPS
MIN
TYP
MAX
UNIT
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TABLE 3. 7820 DC ELECTRICAL CHARACTERISTICS
(VDD = +5V; VREF(+) = +5V; VREF(-) = GND = 0V, UNLESS OTHERWISE SPECIFIED) (RD MODE (PIN 7 = 0V))
(TA = -55 TO 125 °C UNLESS OTHERWISE SPECIFIED)
Accuracy
Resolution
--
8
--
--
Bits
Total Unadjusted Error1
--
--
--
±1.0
LSB
Minimum Resolution for which No
Missing Codes are Guaranteed
--
--
--
8
Bits
Reference Input
Input Resisitance
--
1, 2, 3
1.0
--
4.0
kΩ
VREF (+) Input Voltage Range
--
1, 2, 3
VREF(-)
--
VDD
V
VREF (-) Input Voltage Range
--
1, 2, 3
GND
--
VREF(+)
V
Input Voltage Range
--
1, 2, 3
VREF(-)
--
VREF(+)
V
Input Leakage Current
--
1, 2, 3
--
--
±3
µA
Input Capacitance2
--
1, 2, 3
--
45
--
pF
VINH
--
1, 2, 3
2.4
--
--
V
VINH
--
1, 2, 3
--
--
0.8
V
IINH(CS, RD)
--
1, 2, 3
--
--
1
µA
IINH(WR)
--
1, 2, 3
--
--
3
µA
IINL(WR)
--
1, 2, 3
--
--
-1
µA
Input Capacitance2
--
1, 2, 3
--
5
8
pF
Analog Input
Logic Inputs
CS, WR, RD
09.09.03 Rev 3
All data sheets are subject to change without notice
3
©2003 Maxwell Technologies
All rights reserved.
7820
Microprocessor-compatible 8-Bit ADC
TABLE 3. 7820 DC ELECTRICAL CHARACTERISTICS
(VDD = +5V; VREF(+) = +5V; VREF(-) = GND = 0V, UNLESS OTHERWISE SPECIFIED) (RD MODE (PIN 7 = 0V))
(TA = -55 TO 125 °C UNLESS OTHERWISE SPECIFIED)
PARAMETER
TEST CONDITIONS
SUBGROUPS
MIN
TYP
MAX
UNIT
VINH
--
1, 2, 3
3.5
--
--
V
IINH
--
1, 2, 3
--
--
200
µA
--
1, 2, 3
--
--
-1
µA
--
1, 2, 3
--
5
8
pF
VOH
ISOURCE =
360 µ A
1, 2, 3
4
--
--
V
VOL
ISINK = 1.6 mA
1, 2, 3
--
--
0.4
V
Floating State
Leakage
1, 2, 3
--
--
±3
µA
--
1, 2, 3
--
5
8
pF
VOL
ISINK = 2.6mA
1, 2, 3
--
--
0.4
V
IOUT
Floating State
Leakage
1, 2, 3
--
--
±3
V
Output Capacitance2
--
4, 5, 6
--
5
8
pF
Slew Rate, Tracking2
--
1, 2, 3
--
0.2
0.1
V/µ s
VDD
±5% for specified performance
1, 2, 3
--
--
5
V
IDD
CS = RD = OV
1, 2, 3
--
--
20
mA
--
1, 2, 3
--
40
--
mW
VDD = 5V ±5%
1, 2, 3
--
±1/16
±1/4
LSB
Mode
IINL
Input
Capacitance2
Logic Outputs
DB0-DB7, OFL, INT
IOUT(DB0-DB7)
Memory
Output Capacitance2
RDY
Power Supply
Power Dissipation
Power Supply Sensitivity
1. Total unadjusted error includes offset, full scale and linearity error.
2. Guarenteed by design.
09.09.03 Rev 3
All data sheets are subject to change without notice
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©2003 Maxwell Technologies
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7820
Microprocessor-compatible 8-Bit ADC
TABLE 4. 7820 AC ELECTRICAL CHARACTERISTICS1
(VDD = +5V; VREF(+) = +5V; VREF(-) = GND = 0V, UNLESS OTHERWISE SPECIFIED) (RD MODE (PIN 7 = 0V))
(TA = -55 TO 125 °C UNLESS OTHERWISE SPECIFIED)
PARAMETER
SYMBOL
MIN
MAX
UNIT
CS to RD/WR Setup Time
9, 10, 11
tCSS
0
--
ns
CS to RD/WR Hold Time
9, 10, 11
tCSH
0
--
ns
CS to Delay Time (Pull-up Resistor = 5kΩ
9, 10, 11
tRDY
--
100
ns
Conversion Time (RD Mode)
9, 10, 11
tCRD
--
2.5
µs
Data Access Time (RD Mode)
9, 10, 11
tACCD
--
tCRD + 50
ns
RD to INT Delay (RD Mode)
9, 10, 11
tINTH
--
225
ns
Data Hold Time
9, 10, 11
tDH
--
100
ns
Delay Time Between Conversions
9, 10, 11
tp
600
--
ns
Write Pulse Width
9, 10, 11
tWR
600
--
ns
--
50
µs
Delay Time Between WR and RD Pulses
9, 10, 11
tRD
700
--
ns
Data Access Time (WR-RD Mode)
9, 10, 11
tACC1
--
250
ns
RD to INT Delay
9, 10, 11
tR1
--
225
ns
WR to INT Delay
9, 10, 11
tINTL
--
1700
ns
Data Access Time (WR-RD Mode)
9, 10, 11
tACC2
--
110
ns
WR to INT Delay (Stand-Alone Operation)
9, 10, 11
tIHWR
--
150
ns
Data Access Time After INT (Stand-Alone Operation
9, 10, 11
tID
--
75
ns
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SUBGROUPS
1. Sample tested at 25°C to ensure compliance. Only on process design change.
09.09.03 Rev 3
All data sheets are subject to change without notice
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©2003 Maxwell Technologies
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 1. LOAD CIRCUITS FOR DATA ACCESS TIME TEST
Memory
FIGURE 2. LOAD CIRCUITS FOR DATA HOLD TIME RESET
09.09.03 Rev 3
All data sheets are subject to change without notice
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©2003 Maxwell Technologies
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 3. LOAD CIRCUIT FOR ACCESS TIME
Memory
FIGURE 4. LOAD CIRCUIT FOR OUTPUT FLOAT DELAY
09.09.03 Rev 3
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 5. ACCURACY VS. TWR
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FIGURE 6. ACCURACY VS. TRD
09.09.03 Rev 3
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©2003 Maxwell Technologies
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 7. ACCURACY VS. TSP
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FIGURE 8. ACCURACY VS. TREF [VREF = VREF(+) - VREF(-)]
09.09.03 Rev 3
All data sheets are subject to change without notice
9
©2003 Maxwell Technologies
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 9. SIGNAL-NOISE RATIO VS. INPUT FREQUENCY
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FIGURE 10. TINTL INTERNAL TIME DELAY VS. TEMPERATURE
09.09.03 Rev 3
All data sheets are subject to change without notice
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 11. OUTPUT CURRENT VS. TEMPERATURE
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FIGURE 12. OPERATING SEQUENCE (WR-RD MODE)
09.09.03 Rev 3
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 13. RD MODE
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FIGURE 14. WR-RD MODE (TRD>TINTL)
09.09.03 Rev 3
All data sheets are subject to change without notice
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 15. WR-RD MODE (TRD<TINTL)
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FIGURE 16. WR-RD MODE STAND-ALONE OPERATION (CS=RD=0)
09.09.03 Rev 3
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 17. POWER SUPPLY AS REFERENCE
FIGURE 18. INPUT NOT REFERENCED TO GND
Memory
09.09.03 Rev 3
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7820
Microprocessor-compatible 8-Bit ADC
FIGURE 19. EQUIVALENT INPUT CIRCUIT
Memory
FIGURE 20. RC NETWORK MODEL
09.09.03 Rev 3
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7820
Microprocessor-compatible 8-Bit ADC
Memory
20 PIN RAD-PAK® DUAL IN LINE PACKAGE
DIMENSION
SYMBOL
MIN
NOM
MAX
A
--
0.202
0.230
b
0.014
0.018
0.026
b2
0.045
0.050
0.065
c
0.008
0.010
0.018
D
--
1.000
1.060
E
0.220
0.295
0.310
eA
0.300 BSC
eA/2
0.150 BSC
e
0.100 BSC
L
0.135
0.145
0.155
Q
0.015
0.045
0.070
S1
0.005
0.025
--
S2
0.005
--
--
N
20
Note: All dimensions in inches
09.09.03 Rev 3
All data sheets are subject to change without notice
16
©2003 Maxwell Technologies
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Microprocessor-compatible 8-Bit ADC
7820
Important Notice:
These data sheets are created using the chip manufacturer’s published specifications. Maxwell Technologies verifies
functionality by testing key parameters either by 100% testing, sample testing or characterization.
The specifications presented within these data sheets represent the latest and most accurate information available to
date. However, these specifications are subject to change without notice and Maxwell Technologies assumes no
responsibility for the use of this information.
Maxwell Technologies’ products are not authorized for use as critical components in life support devices or systems
without express written approval from Maxwell Technologies.
Any claim against Maxwell Technologies must be made within 90 days from the date of shipment from Maxwell Technologies. Maxwell Technologies’ liability shall be limited to replacement of defective parts.
Memory
09.09.03 Rev 3
All data sheets are subject to change without notice
17
©2003 Maxwell Technologies
All rights reserved.
7820
Microprocessor-compatible 8-Bit ADC
Product Ordering Options
Model Number
7820
RP
D
X
Option Details
Feature
Monolithic
S = Maxwell Class S
B = Maxwell Class B
I = Industrial (testing @ -55°C,
+25°C, +125°C)
E = Engineering (testing @ +25°C)
Package
D = Dual In-line Package (DIP)
Radiation Feature
RP = RAD-PAK® package
Base Product
Nomenclature
Microprocessor-Compatible 8-Bit
ADC
09.09.03 Rev 3
All data sheets are subject to change without notice
Memory
Screening Flow
18
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