Analog Devices AD704TQ-883B, AD704SE-883B, AD704KN, AD704JN, AD704AR Datasheet

a	Quad Picoampere Input Current
	Bipolar Op Amp

FEATURES

High DC Precision

75 V Max Offset Voltage

1 V/ C Max Offset Voltage Drift

150 pA Max Input Bias Current

0.2 pA/ C Typical IB Drift

Low Noise

0.5 V p-p Typical Noise, 0.1 Hz to 10 Hz

Low Power

600 A Max Supply Current per Amplifier

MIL-STD-883B Processing Available

Available in Tape and Reel in Accordance

with EIA-481A Standard

Dual Version: AD706

APPLICATIONS

Industrial/Process Controls

Weigh Scales

ECG/EKG Instrumentation

Low Frequency Active Filters

AD704

			CONNECTION DIAGRAMS
14-Lead Plastic DIP (N)																					16-Lead SOIC
14-Lead CerDIP (Q) Packages																						(R) Package
OUTPUT	1					14		OUTPUT				OUTPUT						1												16	OUTPUT
			4
–IN	2	1				13		–IN							–IN			2	1							4				15	–IN
+IN
	3					12		+IN							+IN			3												14	+IN
+VS		AD704						–VS															AD704								–VS
	4					11									+VS			4												13
		(TOP VIEW)																				(TOP VIEW)
+IN								+IN
	5	2				10									+IN			5												12	+IN
–IN								–IN													2
	6		3			9									–IN			6								3				11	–IN
OUTPUT								OUTPUT
	7					8						OUTPUT						7												10	OUTPUT
																															NC
															NC			8												9
																			NC = NO CONNECT
							20-Terminal LCC
									(E) Package
						–IN1			OUT1		NC		OUT4			–IN4
						3			2		1		20		19

PRODUCT DESCRIPTION

The AD704 is a quad, low power bipolar op amp that has the low input bias current of a BiFET amplifier but which offers a significantly lower IB drift over temperature. It utilizes super-beta bipolar input transistors to achieve picoampere input bias current levels (similar to FET input amplifiers at room temperature), while its IB typically only increases by 5× at 125°C (unlike a BiFET amp, for which IB doubles every 10°C resulting in a 1000× increase at 125°C). Furthermore, the AD704 achieves 75 µV offset voltage and low noise characteristics of a precision bipolar input op amp.

Since it has only 1/20 the input bias current of an AD OP07, the AD704 does not require the commonly used “balancing” resistor. Furthermore, the current noise is 1/5 that of the AD OP07 which makes the AD704 usable with much higher source impedances. At 1/6 the supply current (per amplifier) of the AD OP07, the AD704 is better suited for today’s higher density circuit boards and battery-powered applications.

The AD704 is an excellent choice for use in low frequency active filters in 12and 14-bit data acquisition systems, in precision instrumentation, and as a high quality integrator. The AD704 is internally compensated for unity gain and is available in five performance grades. The AD704J and AD704K are rated over the commercial temperature range of 0°C to 70°C. The AD704A is rated over the industrial temperature of –40°C to +85°C. The AD704T is rated over the military temperature range of –55°C to +125°C and is available processed to MIL-STD-883B, Rev. C.

REV. C

+IN1 4				18	+IN4
NC 5		AMP 1	AMP 4	17	NC
+VS 6		AD704		16	–VS
NC	7	AMP 2	AMP 3	15	NC
+IN2	8			14 +IN3

	9		10	11	12		13
		–IN2	OUT2	NC		OUT3	–IN3	NC = NO CONNECT
	100
	10
– nA							TYPICAL JFET AMP
B
I	1
TYPICAL
	0.1
								AD704T
	0.01
	–55				+25			+125

TEMPERATURE – C

Figure 1. Input Bias Current Over Temperature

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Tel: [phone]	www.analog.com
Fax: [phone]	© Analog Devices, Inc., 2002

AD704–SPECIFICATIONS (@ TA = 25 C, VCM = 0 V, and 15 V dc, unless otherwise noted.)

		AD704J/A			AD704K			AD704T
Parameters	Conditions	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Unit
INPUT OFFSET VOLTAGE											µV
Initial Offset			50	150		30	75		30	100
Offset	TMIN–TMAX		100	250		50	150		80	150	µV
vs. Temp, Average TC	VS = ±2 to ±18 V		0.2	1.5		0.2	1.0			1.0	µV/°C
vs. Supply (PSRR)		100	132		112	132		112	132		dB
TMIN–TMAX	VS = ±2.5 to ±18 V	100	126		108	126		108	126		dB
Long-Term Stability			0.3			0.3			0.3		µV/month
INPUT BIAS CURRENT1	VCM = 0 V		100	270		80	150		80	200	pA
	VCM = ± 13.5 V			300			200			250	pA
vs. Temp, Average TC			0.3			0.2			1.0		pA/°C
TMIN–TMAX	VCM = 0 V			300			200			600	pA
	VCM = ± 13.5 V			400			300			700	pA
INPUT OFFSET CURRENT	VCM = 0 V		80	250		30	100		50	150	pA
	VCM = ± 13.5 V			300			150			200	pA
vs. Temp, Average TC			0.6			0.4			0.4		pA/°C
TMIN–TMAX	VCM = 0 V		100	300		80	200		80	400	pA
	VCM = ± 13.5 V		100	400		80	300		100	500	pA
MATCHING CHARACTERISTICS											µV
Offset Voltage				250			130			150
Input Bias Current2	TMIN–TMAX			400			200			250	µV
				500			300			400	pA
Common-Mode Rejection3	TMIN–TMAX			600			400			600	pA
		94			110			104			dB
Power Supply Rejection4	TMIN–TMAX	94			104			104			dB
		94			110			110			dB
Crosstalk5	TMIN–TMAX	94			106			106			dB
	f = 10 Hz
	RLOAD = 2 kΩ		150			150			150		dB
FREQUENCY RESPONSE
UNITY GAIN
Crossover Frequency			0.8			0.8			0.8		MHz
Slew Rate, Unity Gain	G = –1		0.15			0.15			0.15		V/µs
Slew Rate	TMIN–TMAX		0.1			0.1			0.1		V/µs
INPUT IMPEDANCE			40 2			40 2			40 2		MΩ pF
Differential
Common-Mode			300 2			300 2			300 2		GΩ pF
INPUT VOLTAGE RANGE		±13.5	±14		±13.5	±14		±13.5	±14
Common-Mode Voltage	VCM = ± 13.5 V										V
Common-Mode Rejection Ratio		100	132		114	132		110	132		dB
	TMIN–TMAX	98	128		108	128		108	128		dB
INPUT CURRENT NOISE	0.1 to 10 Hz		3			3			3		pA p-p
	f = 10 Hz		50			50			50		fA/√Hz
INPUT VOLTAGE NOISE	0.1 to 10 Hz		0.5			0.5	2.0		0.5	2.0	µV p-p
	f = 10 Hz		17			17			17		nV/√Hz
	f = 1 kHz		15	22		15	22		15	22	nV/√Hz
OPEN-LOOP GAIN	VO = ±12 V
	RLOAD = 10 kΩ	200	2000		400	2000		400	2000		V/mV
	TMIN–TMAX	150	1500		300	1500		300	1500		V/mV
	VO = ±10 V
	RLOAD = 2 kΩ	200	1000		300	1000		200	1000		V/mV
	TMIN–TMAX	150	1000		200	1000		100	1000		V/mV

–2–

REV. C

											AD704
		AD704J/A				AD704K			AD704T
Parameters	Conditions	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Unit
OUTPUT CHARACTERISTICS	RLOAD = 10 kΩ
Voltage Swing		±13	±14		± 13	±14		±13	±14
	TMIN–TMAX										V
Current	Short Circuit		±15			±15			±15		mA
CAPACITIVE LOAD
Drive Capability	Gain = 1		10,000			10,000			10,000		pF
POWER SUPPLY			±15			±15			±15
Rated Performance		±2.0		±18	±2.0		±18	±2.0		±18	V
Operating Range											V
Quiescent Current			1.5	2.4		1.5	2.4		1.5	2.4	mA
	TMIN–TMAX		1.6	2.6		1.6	2.6		1.6	2.6	mA
TRANSISTOR COUNT	# of Transistors		180			180			180

NOTES

1Bias current specifications are guaranteed maximum at either input.

2Input bias current match is the maximum difference between corresponding inputs of all four amplifiers. 3CMRR match is the difference of ∆VOS/∆VCM between any two amplifiers, expressed in dB.

4PSRR match is the difference between ∆VOS/∆VSUPPLY for any two amplifiers, expressed in dB. 5See Figure 2a for test circuit.

All min and max specifications are guaranteed.

Specifications subject to change without notice.

REV. C

–3–

AD704

ABSOLUTE MAXIMUM RATINGS1

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 18 V Internal Power Dissipation (25°C) . . . . . . . . . . . . See Note 2

Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± VS Differential Input Voltage3 . . . . . . . . . . . . . . . . . . . . . . . ± 0.7 V

Output Short-Circuit Duration (Single Input) . . . . . Indefinite Storage Temperature Range

Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C N, R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65°C to +125°C

Operating Temperature Range

AD704J/K . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C AD704A . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to +85°C AD704T . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C Lead Temperature Range (Soldering 10 seconds) . . . . . 300°C

NOTES

1Stresses 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 indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

2Specification is for device in free air: 14-Lead Plastic Package: θJA = 150°C/W 14-Lead Cerdip Package: θJA = 110°C/W 16-Lead SOIC Package: θJA = 100°C/W 20-Terminal LCC Package: θJA = 150°C/W

3The input pins of this amplifier are protected by back-to-back diodes. If the differential voltage exceeds ±0.7 volts, external series protection resistors should be added to limit the input current to less than 25 mA.

		9k
	1k	–		+VS	AD704
					PIN 4
		1/4	OUTPUT	0.1 F	1 F
	INPUT*	AD704		COM	1 F
		+	2.5k	0.1 F
	SIGNAL
				–VS	AD704
	1k				PIN 11

ALL 4 AMPLIFIERS ARE CONNECTED AS SHOWN

*THE SIGNAL INPUT (SUCH THAT THE AMPLIFIER’S OUTPUT IS AT MAX AMPLITUDE WITHOUT CLIPPING OR SLEW LIMITING) IS APPLIED TO ONE AMPLIFIER AT A TIME. THE OUTPUTS OF THE OTHER THREE AMPLIFIERS ARE THEN MEASURED FOR CROSSTALK.

Figure 2a. Crosstalk Test Circuit

	–80
					AMP4
	–100
dB			AMP2		AMP3
–
CROSSTALK
	–120
	–140
	–160
	10	100	1k	10k	100k

FREQUENCY – Hz

Figure 2b. Crosstalk vs. Frequency

ORDERING GUIDE

Model	Temperature Range	Package Description	Package Option
AD704JN	0°C to 70°C	Plastic	N-14
AD704JR	0°C to 70°C	Small Outline (SOIC)	R-16
AD704JR-/REEL	0°C to 70°C		Tape and Reel
AD704KN*	0°C to 70°C	Plastic	N-14
AD704AN*	–40°C to +85°C	Plastic	N-14
AD704AR	–40°C to +85°C	Small Outline (SOIC)	R-16
AD704AR-REEL	–40°C to +85°C		Tape and Reel
AD704SE/883B	–55°C to +125°C	Leadless Ceramic Chip Carrier	E-20A
AD704TQ/883B*	–55°C to +125°C	Cerdip	Q-14

Chips are also available.

*Not for new designs; obsolete April 2002.

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 AD704 features 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

–4–

REV. C