Analog Devices AD7242KR, AD7242KN, AD7242JR, AD7242JN, AD7242AQ Datasheet

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a		LC2MOS Dual, Complete,
a		12-Bit/14-Bit Serial DACs

		AD7242/AD7244

FEATURES

Two 12-Bit/14-Bit DACs with Output Amplifiers AD7242: 12-Bit Resolution

AD7244: 14-Bit Resolution On-Chip Voltage Reference Fast Settling Time

AD7242: 3 ms to 61/2 LSB AD7244: 4 ms to 61/2 LSB

High Speed Serial Interface Operates from 65 V Supplies

Specified Over –408C to +858C in Plastic Packages

Low Power – 130 mW typ

GENERAL DESCRIPTION

The AD7242/AD7244 is a fast, complete, dual 12-bit/14-bit voltage output D/A converter. It consists of a 12-bit/14-bit DAC, 3 V buried Zener reference, DAC output amplifiers and high speed serial interface logic.

Interfacing to both DACs is serial, minimizing pin count and allowing a small package size. Standard control signals allow interfacing to most DSP processors and microcontrollers.

Asynchronous control of DAC updating for both DACs is made possible with a separate LDAC input for each DAC.

The AD7242/AD7244 operates from ±5 V power supplies, providing an analog output range of ±3 V. A REF OUT/REF IN function allows the DACs to be driven from the on-chip 3 V reference or from an external reference source.

The AD7242/AD7244 is fabricated in Linear Compatible CMOS (LC2MOS), an advanced mixed technology process that combines precision bipolar circuits with low power CMOS logic. Both parts are available in a 24-pin, 0.3-inch wide, plastic or hermetic dual-in-line package (DIP) and in a 28-pin, plastic small outline (SOIC) package. The AD7242 and AD7244 are available in the same pinout to allow easy upgrade from 12-bit to 14-bit performance.

REV. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

FUNCTIONAL BLOCK DIAGRAM

PRODUCT HIGHLIGHTS

1. Complete, Dual 12-Bit/14-Bit DACs

The AD7242/AD7244 provides the complete function for generating voltages to 12-bit/14-bit resolution. The part features an on-chip reference, output buffer amplifiers and two 12-bit/14-bit D/A converters.

2. High Speed Serial Interface

The AD7242/AD7244 provides a high speed, easy-to-use, serial interface allowing direct interfacing to DSP processors and microcontrollers. A separate serial port is provided for each DAC.

3. Small Package Size

The AD7242/AD7244 is available in a 24-pin DIP and a 28pin SOIC package offering considerable space saving over comparable solutions.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 617/329-4700	World Wide Web Site: http://www.analog.com
Fax: 617/326-8703	© Analog Devices, Inc., 1996

(V = +5 V 6 5% V = –5 V 6 5%, AGND = DGND = 0 V, REF INA =

AD7242/AD7244–SPECIFICATIONS DD SS V

REF INB = +3 V. VOUTA, VOUTB load to AGND: RL = 2 k , CL = 100 pF.

All Specifications TMIN to TMAX unless otherwise noted.)

AD7242

Parameter

J, A Versions1

K, B Versions1

Units

Test Conditions/Comments

DC ACCURACY

Resolution

Bits

Integral Nonlinearity

±1

±1/2

LSB max

Differential Nonlinearity

±1

LSB max

Guaranteed Monotonic

Bipolar Zero Error

±5

LSB max

Positive Full-Scale Error2

±5

LSB max

Negative Full-Scale Error2

±5

LSB max

REFERENCE OUTPUT3

REF OUT @ +25°C

2.99/3.01

V min/V max

TMIN to TMAX

2.98/3.02

V min/V max

REF OUT Tempco

ppm/°C typ

Reference Load Change

Reference Load Current Change (0 μA–500 μA)

( REF OUT vs. I)

–1

mV max

REFERENCE INPUTS

3 V ± 5%

REF INA, REF INB Input Range

2.85/3.15

V min/V max

Input Current

μA max

LOGIC INPUTS

(

LDACA,

LDACB,

TFSA,

TFSB,

TCLKA, TCLKB, DTA, DTB)

VDD = 5 V ± 5%

Input High Voltage, VINH

2.4

V min

Input Low Voltage, VINL

0.8

V max

VDD = 5 V ± 5%

Input Current, IIN

±10

μA max

VIN = 0 V to VDD

Input Capacitance, CIN4

pF max

ANALOG OUTPUTS

(VOUTA, VOUTB)

±3

Output Voltage Range

V nom

DC Output Impedance

0.1

Ω typ

Short Circuit Current

mA typ

AC CHARACTERISTICS4

Settling Time to Within ±1/2 LSB of Final Value

Voltage Output Settling Time

μs max

Positive Full-Scale Change

Typically 2 μs

Negative Full-Scale Change

μs max

Typically 2 μs

Digital-to-Analog Glitch Impulse

nV secs typ

DAC Code Change All 1s to All 0s

Digital Feedthrough

nV secs typ

Channel-to-Channel Isolation

110

dB typ

VOUT = 10 kHz Sine Wave

POWER REQUIREMENTS

±5% for Specified Performance

VDD

V nom

VSS

–5

V nom

±5% for Specified Performance

IDD

mA max

Cumulative Current from the Two VDD Pins

ISS

mA max

Cumulative Current from the Two VSS Pins

Total Power Dissipation

195

mW max

Typically 130 mW

NOTES

1Temperature ranges are as follows: J, K Versions: –40°C to +85°C; A, B Versions: –40°C to +85°C. 2Measured with respect to REF IN and includes bipolar offset error.

3For capacitive loads greater than 50 pF, a series resistor is required (see Internal Reference section). 4Sample tested @ +25°C to ensure compliance.

Specifications subject to change without notice.

AD7242 ORDERING GUIDE

	Temperature	Integral	Package
Model	Range	Nonlinearity	Option*

AD7242JN	–40°C to +85°C	±1 LSB max	N-24
AD7242KN	–40°C to +85°C	±1/2 LSB max	N-24
AD7242JR	–40°C to +85°C	±1 LSB max	R-28
AD7242KR	–40°C to +85°C	±1/2 LSB max	R-28
AD7242AQ	–40°C to +85°C	±1 LSB max	Q-24
AD7242BQ	–40°C to +85°C	±1/2 LSB max	Q-24

*N = Plastic DIP; Q = Cerdip; R = Small Outline IC (SOIC).

–2–

REV. A

AD7242/AD7244

AD7244

Parameter

J, A Versions1

S Version1

Units

Test Conditions/Comments

DC ACCURACY

Resolution

Bits

Integral Nonlinearity

±2

LSB max

Differential Nonlinearity

±1

LSB max

Guaranteed Monotonic

Bipolar Zero Error

±10

LSB max

Positive Full-Scale Error2

±10

LSB max

Negative Full-Scale Error2

±10

LSB max

REFERENCE OUTPUT3

REF OUT @ +25°C

2.99/3.01

V min/V max

TMIN to TMAX

2.98/3.02

V min/V max

REF OUT Tempco

ppm/°C typ

Reference Load Change

Reference Load Current Change (0 μA–500 μA)

( REF OUT vs. I)

–1

mV max

REFERENCE INPUTS

3 V ± 5%

REF INA, REF INB Input Range

2.85/3.15

V min/V max

Input Current

μA max

LOGIC INPUTS

(

LDACA,

LDACB,

TFSA,

TFSB,

TCLKA, TCLKB, DTA, DTB)

VDD = 5 V ± 5%

Input High Voltage, VINH

2.4

V min

Input Low Voltage, VINL

0.8

V max

VDD = 5 V ± 5%

Input Current, IIN

±10

μA max

VIN = 0 V to VDD

Input Capacitance, CIN4

pF max

ANALOG OUTPUTS

(VOUTA, VOUTB)

±3

Output Voltage Range

V nom

DC Output Impedance

0.1

Ω typ

Short Circuit Current

mA typ

AC CHARACTERISTICS4

Settling Time to Within ±1/2 LSB of Final Value

Voltage Output Settling Time

μs max

Positive Full-Scale Change

Typically 2.5 μs

Negative Full-Scale Change

μs max

Typically 2.5 μs

Digital-to-Analog Glitch Impulse

nV secs typ

DAC Code Change All 1s to All 0s

Digital Feedthrough

nV secs typ

Channel-to-Channel Isolation

110

dB typ

VOUT = 10 kHz Sine Wave

POWER REQUIREMENTS

±5% for Specified Performance

VDD

V nom

VSS

–5

V nom

±5% for Specified Performance

IDD

mA max

Cumulative Current from the Two VDD Pins

ISS

mA max

Cumulative Current from the Two VSS Pins

Total Power Dissipation

195

205

mW max

Typically 130 mW

NOTES

1Temperature ranges are as follows: J Version: 0°C to +70°C; A Version: –40°C to +85°C; S Version: –55°C to +125°C. 2Measured with respect to REF IN and includes bipolar offset error.

3For capacitive loads greater than 50 pF, a series resistor is required (see Internal Reference section). 4Sample tested @ +25°C to ensure compliance.

Specifications subject to change without notice.

AD7244 ORDERING GUIDE

	Temperature	Integral	Package
Model1	Range	Nonlinearity	Option2
AD7244JN	–40°C to +85°C	±2 LSB max	N-24
AD7244JR	–40°C to +85°C	±2 LSB max	R-28
AD7244AQ	–40°C to +85°C	±2 LSB max	Q-24
AD7244SQ3	–55°C to +125°C	±2 LSB max	Q-24

NOTES

1To order MIL-STD-883, Class B, processed parts, add /883B to part number. Contact local sales office for military data sheet and availability.

2N = Plastic DIP; Q = Cerdip; R = Small Outline IC (SOIC). 3This grade will be available to /883B processing only.

REV. A

–3–

Analog Devices AD7242KR, AD7242KN, AD7242JR, AD7242JN, AD7242AQ Datasheet

AD7242/AD7244

TIMING CHARACTERISTICS1, 2 (VDD = +5 V 6 5%, VSS = –5 V 6 5%, AGND = DGND = 0 V)

	Limit at TMIN, TMAX	Limit at TMIN, TMAX
Parameter	(J, K, A, B Versions)	(S Version)	Units	Conditions/Comments

t1	50	50	ns min			to TCLK Falling Edge
t1	50	50	ns min		TFS	to TCLK Falling Edge
t2	75	100	ns min		TCLK Falling Edge to		TFS
t33	150	200	ns min	TCLK Cycle Time
t4	30	40	ns min		Data Valid to TCLK Setup Time
t5	75	100	ns min		Data Valid to TCLK Hold Time
t6	40	40	ns min		LDAC Pulse Width

NOTES

1Timing specifications are sample tested at +25°C to ensure compliance. All input signals are specified with tr = tf = 5 ns (10% to 90% of 5 V) and timed from a voltage level of 1.6 V.

2See Figure 6.

3TCLK Mark/Space ratio is 40/60 to 60/40.

ABSOLUTE MAXIMUM RATINGS*

(TA = +25°C unless otherwise noted)

VDD to AGND . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +7 V VSS to AGND . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to –7 V AGND to DGND . . . . . . . . . . . . . . . . –0.3 V to VDD + 0.3 V VOUT to AGND . . . . . . . . . . . . . . . . . . . . . . . . . . . . VSS to VDD REF OUT to AGND . . . . . . . . . . . . . . –0.3 V to VDD + 0.3 V REF INA, REF INB to AGND . . . . . . . –0.3 V to VDD + 0.3 V Digital Inputs to DGND . . . . . . . . . . . . –0.3 V to VDD + 0.3 V Operating Temperature Range

J, K Versions

AD7244 . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C AD7242 . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C A, B Versions . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C S Version . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C

Storage Temperature Range . . . . . . . . . . . .	–65°C to +150°C
Lead Temperature (Soldering, 10 sec) . . . . .	. . . . . . . +300°C
Power Dissipation (Any Package) to +75°C .	. . . . . . 550 mW
Derates above +75°C by . . . . . . . . . . . . . . . .	. . . . . 6 mW/°C

*Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only, functional operation of the device at these or any other conditions above those listed in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD7242/AD7244 feature proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.

WARNING!

ESD SENSITIVE DEVICE

PIN CONFIGURATIONS

DIP

SOIC

–4–

REV. A

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