Datasheet 7820RPDS, 7820RPDI, 7820RPDE, 7820RPDB Datasheet (MAXWELL)

7820

Microprocessor-compatible

8-Bit ADC

FEATURES:

• 1.36 µs 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/cm

• Package:

- 20 pin Rad-Pak DIP

2

Logic Diagram

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.

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/µs.

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 R ogy 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, R krad (Si) radiation dose tolerance. This product is available with screening up to Class S.

AD-PAK® packaging technol-

AD-PAK provides greater than 100

Memory

1000564

(858) 503-3300 - Fax: (858) 503-3301 - www.maxwell.com

12.19.01 Rev2

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1

Microprocessor-compatible 8-Bit ADC

TABLE 1. PIN DESCRIPTION

PIN SYMBOL DESCRIPTION

7820

1VINAnalog Input Range: V

REF(-)

to V

REF(+)

.

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

6WR

/RDY WRITE control input/READY status output.

7 Mode 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 µA current source.

8RD

9INT

READ Input. RD must be low to access data from the part.

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 V

12 V

REF-

REF+

Lower limit of reference span. Range: GND < V

Upper limit of reference span. Range: GND < V

REF(-)

< V

REF(+)

< V

DD

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

Memory

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 (V

REF(+)

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 V

DD

Power supply voltage, +5V

TABLE 2. 7820 ABSOLUTE MAXIMUM RATINGS

1

PARAMETER MIN MAX UNIT

VDD to GND -0 7.0 V

Digital Input Voltage to GND (Pins 6-80, 13) -0.3 V

Digital Output Voltage to GND (Pins 2-5, 9, 14-18) 0.3 V

V

(+) to GND 0 VDD +0.3 V

REF

V

(-) to GND VSS -0.3 V

REF

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DD

REF

- 1/2LSB),

+0.3 V

(+) V

2

Microprocessor-compatible 8-Bit ADC

7820

TABLE 2. 7820 ABSOLUTE MAXIMUM RATINGS

1

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.

TABLE 3. 7820 DC ELECTRICAL CHARACTERISTICS

(VDD = +5V; VREF(+) = +5V; VREF(-) = GND = 0V, UNLESS OTHERWISE SPECIFIED) (RD MODE (PIN 7 = 0V))

(T

= -55 TO 125 °C UNLESS OTHERWISE SPECIFIED)

A

P

ARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Accuracy

Resolution -- 8 -- -- Bits

Total Unadjusted Error

1

-- -- -- ±1.0 LSB

Memory

Minimum Resolution for which No

-- -- -- 8 Bits

Missing Codes are Guaranteed

Reference Input

Input Resisitance -- 1.0 -- 4.0 k

V

(+) Input Voltage Range -- V

REF

V

(-) Input Voltage Range -- GND -- V

REF

(-) -- V

REF

DD

(+) V

REF

Ω

V

Analog Input

Input Voltage Range -- V

(-) -- V

REF

(+) V

REF

Input Leakage Current -- -- -- ±3 µA

Input Capacitance

2

-- -- 45 -- pF

Logic Inputs

CS

, WR, RD

V

INH

V

INH

I

(CS, RD)------1µA

INH

I

(WR)------3µA

INH

I

(WR)-------1µA

INL

Input Capacitance

2

-- 2.4 ----V

-- -- -- 0.8 V

-- -- 5 8 pF

Mode

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3

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))

(T

= -55 TO 125 °C UNLESS OTHERWISE SPECIFIED)

A

P

ARAMETER TEST CONDITIONS MIN TYP MAX UNIT

7820

V

INH

-- 3.5 ----V

--

V

INH

I

INH

I

INL

-- -- -- 1.5 V

-- -- -- 200 µA

-- -- -- -1 µA

--

Input Capacitance

2

-- -- 5 8 pF

Logic Outputs

DB0-DB7, OFL

V

OH

V

OL

I

(DB0-DB7) Floating State Leakage -- -- ±3 µA

OUT

Output Capacitance

, INT --

ISOURCE = 360 µA 4 -- -- V

ISINK = 1.6 mA -- -- 0.4 V

2

-- -- 5 8 pF

RDY

V

I

OL

OUT

ISINK = 2.6mA -- -- 0.4 V

Floating State Leakage -- -- ±3 V

Output Capacitance -- -- 5 8 pF

Slew Rate, Tracking

2

-- -- 0.2 0.1 V/µs

Power Supply

V

DD

±5% for specified perfor-

-- -- 5 V

mance

Memory

I

DD

CS = RD = OV -- -- 20 mA

Power Dissipation -- -- 40 -- mW

Power Supply Sensitivity VDD = 5V ±5% -- ±1/16 ±1/4 LSB

1. Total unadjusted error includes offset, full scale and linearity error.

2. Not tested.

1000564

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4

Microprocessor-compatible 8-Bit ADC

7820

TABLE 4. 7820 AC ELECTRICAL CHARACTERISTICS

1

(VDD = +5V; VREF(+) = +5V; VREF(-) = GND = 0V, UNLESS OTHERWISE SPECIFIED) (RD MODE (PIN 7 = 0V))

(T

= -55 TO 125 °C UNLESS OTHERWISE SPECIFIED)

A

ARAMETER SYMBOL MIN MAX UNIT

P

CS to RD/WR Setup Time t

CS

to RD/WR Hold Time t

CS

to Delay Time (Pull-up Resistor = 5kΩ t

Conversion Time (RD Mode) t

Data Access Time (RD Mode) t

RD

to INT Delay (RD Mode) t

Data Hold Time t

Delay Time Between Conversions t

Write Pulse Width t

CSS

CSH

RDY

CRD

ACCD

INTH

DH

p

WR

0--ns

-- 100 ns

-- 2.5 µs

-- t

+ 50 ns

CRD

-- 225 ns

-- 100 ns

600 -- ns

-- 50 µs

Delay Time Between WR and RD Pulses t

Data Access Time (WR-RD Mode) t

RD to INT Delay t

WR to INT Delay t

Data Access Time (WR-RD Mode) t

WR to INT Delay (Stand-Alone Operation) t

Data Access Time After INT (Stand-Alone Operation t

RD

ACC1

R1

INTL

ACC2

IHWR

ID

700 -- ns

-- 250 ns

-- 225 ns

-- 1700 ns

-- 110 ns

-- 150 ns

-- 75 ns

Memory

1. Sample tested at 25°C to ensure compliance. Only on process design change.

1000564

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5

Microprocessor-compatible 8-Bit ADC

FIGURE 1. LOAD CIRCUITS FOR DATA ACCESS TIME TEST

7820

Memory

FIGURE 2. LOAD CIRCUITS FOR DATA HOLD TIME RESET

1000564

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6

Microprocessor-compatible 8-Bit ADC

FIGURE 3. LOAD CIRCUIT FOR ACCESS TIME

7820

Memory

FIGURE 4. LOAD CIRCUIT FOR OUTPUT FLOAT DELAY

1000564

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Microprocessor-compatible 8-Bit ADC

7820

FIGURE 5. ACCURACY VS. T

WR

Memory

1000564

FIGURE 6. ACCURACY VS. T

12.19.01 Rev2

RD

All data sheets are subject to change without notice

8

Microprocessor-compatible 8-Bit ADC

7820

FIGURE 7. ACCURACY VS. T

SP

Memory

FIGURE 8. ACCURACY VS. T

REF [VREF

= V

REF

(+) - V

REF

(-)]

1000564

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9

Microprocessor-compatible 8-Bit ADC

FIGURE 9. SIGNAL-NOISE RATIO VS. INPUT FREQUENCY

7820

Memory

FIGURE 10. T

INTERNAL TIME DELAY VS. TEMPERATURE

INTL

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10

Microprocessor-compatible 8-Bit ADC

FIGURE 11. OUTPUT CURRENT VS. TEMPERATURE

7820

Memory

FIGURE 12. OPERATING SEQUENCE (WR-RD MODE)

1000564

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Microprocessor-compatible 8-Bit ADC

FIGURE 13. RD MODE

7820

Memory

FIGURE 14. WR-RD MODE (TRD>TINTL)

1000564

12.19.01 Rev2

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12

Microprocessor-compatible 8-Bit ADC

7820

FIGURE 15. WR-RD MODE (TRD<T

INTL

)

Memory

1000564

IGURE 16. WR-RD MODE STAND-ALONE OPERATION (CS=RD=0)

F

12.19.01 Rev2

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13

Microprocessor-compatible 8-Bit ADC

FIGURE 17. POWER SUPPLY AS REFERENCE

FIGURE 18. INPUT NOT REFERENCED TO GND

7820

Memory

1000564

12.19.01 Rev2

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14

Microprocessor-compatible 8-Bit ADC

FIGURE 19. EQUIVALENT INPUT CIRCUIT

7820

Memory

FIGURE 20. RC NETWORK MODEL

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15

Microprocessor-compatible 8-Bit ADC

D

7820

E

N/2

S2

A

Q

S1

e

b2

b

c

L

eA/2

eA

20 PIN RAD-PAK® DUAL IN LINE PACKAGE

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 -- --

N20

DIMENSION

Memory

1000564

D16-01

Note: All dimensions in inches

12.19.01 Rev2

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16

Microprocessor-compatible 8-Bit ADC

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.

7820

Memory

1000564

12.19.01 Rev2

All data sheets are subject to change without notice

17

Microprocessor-compatible 8-Bit ADC

)

Product Ordering Options

Model Number

7820

RP

D X

Feature

Screening Flow

Package

Option Details

Monolithic S = Maxwell Class S B = Maxwell Class B E = Engineering (testing @ +25°C I = Industrial (testing @ -55°C, +25°C, +125°C)

Memory

D = Dual In-line Package (DIP)

1000564

Radiation Feature

Base Product Nomenclature

12.19.01 Rev2

RP = R

AD-PAK® package

Microprocessor-Compatible 8-Bit ADC

All data sheets are subject to change without notice

18