Analog Devices AD549SH-883B, AD549SH, AD549LH, AD549KH, AD549JH Datasheet

a		Ultralow Input Bias Current
		Operational Amplifier
		AD549*

FEATURES

Ultralow Bias Current: 60 fA max (AD549L) 250 fA max (AD549J)

Input Bias Current Guaranteed Over Common-Mode Voltage Range

Low Offset Voltage: 0.25 mV max (AD549K) 1.00 mV max (AD549J)

Low Offset Drift: 5 mV/8C max (AD549K) 20 mV/8C max (AD549J)

Low Power: 700 mA max Supply Current

Low Input Voltage Noise: 4 mV p-p 0.1 Hz to 10 Hz

MIL-STD-883B Parts Available

APPLICATIONS Electrometer Amplifiers Photodiode Preamp

pH Electrode Buffer

Vacuum lon Gage Measurement

CONNECTION DIAGRAM

GUARD PIN, CONNECTED TO CASE

		NC
	OFFSET NULL	8	V+
	1	AD549	7
	INVERTING 2		6	OUTPUT
	INPUT
	3		5
	NONINVERTING	4	OFFSET
			NULL
	INPUT	V–
	1	10kΩ	5
			4	–15V
		VOS TRIM
	NC = NO CONNECTION

PRODUCT DESCRIPTION

The AD549 is a monolithic electrometer operational amplifier with very low input bias current. Input offset voltage and input offset voltage drift are laser trimmed for precision performance. The AD549’s ultralow input current is achieved with “Topgate” JFET technology, a process development exclusive to Analog Devices. This technology allows the fabrication of extremely low input current JFETs compatible with a standard junctionisolated bipolar process. The 1015 Ω common-mode impedance, a result of the bootstrapped input stage, insures that the input current is essentially independent of common-mode voltage.

The AD549 is suited for applications requiring very low input current and low input offset voltage. It excels as a preamp for a wide variety of current output transducers such as photodiodes, photomultiplier tubes, or oxygen sensors. The AD549 can also be used as a precision integrator or low droop sample and hold. The AD549 is pin compatible with standard FET and electrometer op amps, allowing designers to upgrade the performance of present systems at little additional cost.

The AD549 is available in a TO-99 hermetic package. The case is connected to Pin 8 so that the metal case can be independently connected to a point at the same potential as the input terminals, minimizing stray leakage to the case.

*Protected by Patent No. 4,639,683.

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.

The AD549 is available in four performance grades. The J, K, and L versions are rated over the commercial temperature range 0°C to +70°C. The S grade is specified over the military temperature range of –55°C to +125°C and is available processed to MIL-STD-883B, Rev C. Extended reliability PLUS screening is also available. Plus screening includes 168-hour burn-in, as well as other environmental and physical tests derived from MIL-STD-883B, Rev C.

PRODUCT HIGHLIGHTS

1.The AD549’s input currents are specified, 100% tested and guaranteed after the device is warmed up. Input current is guaranteed over the entire common-mode input voltage range.

2.The AD549’s input offset voltage and drift are laser trimmed to 0.25 mV and 5 μV/°C (AD549K), 1 mV and 20 μV/°C (AD549J).

3.A maximum quiescent supply current of 700 μA minimizes heating effects on input current and offset voltage.

4.AC specifications include 1 MHz unity gain bandwidth and 3 V/μs slew rate. Settling time for a 10 V input step is 5 μs to 0.01%.

5.The AD549 is an improved replacement for the AD515, OPA104, and 3528.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: [phone] Fax: [phone]

AD549–SPECIFICATIONS (@ +258C and VS = +15 V dc, unless otherwise noted)

Model		AD549J			AD549K			AD549L			AD549S
	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Units
INPUT BIAS CURRENT1
Either Input, VCM = 0 V		150	250		75	100		40	60		75	100	fA
Either Input, VCM = ±10 V		150	250		75	100		40	60		75	100	fA
Either Input at TMAX,
VCM = 0 V		11			4.2			2.8			420		pA
Offset Current		50			30			20			30		fA
Offset Current at TMAX		2.2			1.3			0.85			125		pA
INPUT OFFSET VOLTAGE2
Initial Offset		0.5	1.0		0.15	0.25		0.3	0.5		0.3	0.5	mV
Offset at TMAX			1.9			0.4			0.9			2.0	mV
vs. Temperature		10	20		2	5		5	10		10	15	mV/°C
vs. Supply		32	100		10	32		10	32		10	32	mV/V
vs. Supply, TMIN to TMAX		32	100		10	32		10	32		32	50	mV/V
Long-Term Offset Stability		15			15			15			15		mV/Month
INPUT VOLTAGE NOISE
f = 0.1 Hz to 10 Hz		4			4	6		4			4		mV p-p
f = 10 Hz		90			90			90			90		nV/Ö			Hz
f = 100 Hz		60			60			60			60		nV/Ö
															Hz
f = 1 kHz		35			35			35			35		nV/Ö
															Hz
f = 10 kHz		35			35			35			35		nV/Ö
															Hz
INPUT CURRENT NOISE
f = 0.1 Hz to 10 Hz		0.7			0.5			0.36			0.5		fA rms
f = 1 kHz		0.22			0.16			0.11			0.16		fA/Ö	Hz
INPUT IMPEDANCE
Differential
VDIFF = ±1		1013i1			1013i1			1013i1			1013i1		WipF
Common Mode
VCM = ±10		1015i0.8			1015i0.8			1015i0.8			1015i0.8		WipF
OPEN-LOOP GAIN
VO @ ±10 V, RL = 10 k	300	1000		300	1000		300	1000		300	1000		V/mV
VO @ ±10 V, RL = 10 k,
TMIN to TMAX	300	800		300	800		300	800		300	800		V/mV
VO = ±10 V, RL = 2 k	100	250		100	250		100	250		100	250		V/mV
VO = ±10 V, RL = 2 k,
TMIN to TMAX	80	200		80	200		80	200		25	150		V/mV
INPUT VOLTAGE RANGE
Differential3			±20			±20			±20			±20	V
Common-Mode Voltage	–10		+10	–10		+10	–10		+10	–10		+10	V
Common-Mode Rejection Ratio
V = +10 V, –10 V	80	90		90	100		90	100		90	100		dB
TMIN to TMAX	76	80		80	90		80	90		80	90		dB
OUTPUT CHARACTERISTICS
Voltage @ RL = 10 k,
TMIN to TMAX	–12		+12	–12		+12	–12		+12	–12		+12	V
Voltage @ RL = 2 k,
TMIN to TMAX	–10		+10	–10		+10	–10		+10	–10		+10	V
Short Circuit Current	15	20	35	15	20	35	15	20	35	15	20	35	mA
TMIN to TMAX	9			9			9			6			mA
Load Capacitance Stability
G = +1		4000			4000			4000			4000		pF
FREQUENCY RESPONSE
Unity Gain, Small Signal	0.7	1.0		0.7	1.0		0.7	1.0		0.7	1.0		MHz
Full Power Response		50			50			50			50		kHz
Slew Rate	2	3		2	3		2	3		2	3		V/ms
Settling Time, 0.1%		4.5			4.5			4.5			4.5		ms
0.01%		5			5			5			5		ms
Overload Recovery,
50% Overdrive, G = –1		2			2			2			2		ms

–2–

REV. A

AD549

Model

AD549J

AD549K

AD549L

AD549S

Min

Typ

Max

Min

Typ

Max

Min

Typ

Max

Min Typ

Max

Units

POWER SUPPLY

±15

±15

±15

±15

Rated Performance

V

Operating

65

618

65

618

65

618

65

618

V

Quiescent Current

0.60

0.70

0.60

0.70

0.60

0.70

0.60

0.70

mA

TEMPERATURE RANGE

°C

Operating, Rated Performance

0

+70

0

+70

0

+70

–55

+125

Storage

–65

+150

–65

+150

–65

+150

–65

+150

°C

PACKAGE OPTION

TO-99 (H-08A)

AD549JH

AD549KH

AD549LH

AD549SH, AD549SH/883B

Chips

AD549JChips

NOTES

1Bias current specifications are guaranteed after 5 minutes of operation at TA = +25°C. Bias current increases by a factor of 2.3 for every 10°C rise in temperature. 2Input offset voltage specifications are guaranteed after 5 minutes of operation at T A = +25°C.

3Defined as max continuous voltage between the inputs such that neither input exceeds ± 10 V from ground. Specifications subject to change without notice.

All min and max specifications are guaranteed. Specifications in boldface are tested on all production units at final electrical test. Results from those tests are used to calculate outgoing quality levels.

ABSOLUTE MAXIMUM RATINGS1

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V

Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . . .500 mW Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±18 V2

Output Short Circuit Duration . . . . . . . . . . . . . . . . . Indefinite Differential Input Voltage . . . . . . . . . . . . . . . . . . +VS and –VS Storage Temperature Range (H) . . . . . . . . . .–65°C to +125°C Operating Temperature Range

AD549J (K, L) . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C AD549S . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to +125°C Lead Temperature Range (Soldering 60 sec) . . . . . . . . +300°C

NOTES

1Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and 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.

2For supply voltages less than ± 18 V, the absolute maximum input voltage is equal to the supply voltage.

METALIZATION PHOTOGRAPH

Dimensions shown in inches and (mm). Contact factory for latest dimensions.

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 AD549 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

REV. A

–3–

AD549–Typical Characteristics

	20
± V	15
						+VIN
VOLTAGEINPUT
	10					–VIN
	5
	0
			5	10		15		20
	0

SUPPLY VOLTAGE ± V

Figure 1. Input Voltage Range vs. Supply Voltage

– µA	800
CURRENT	700
QUIESCENT	600
AMPLIFIER
	500
	400
		0	5	10		15		20
			SUPPLY VOLTAGE ± V

Figure 4. Quiescent Current vs. Supply Voltage

– V/mV	3000
	1000
-LOOP GAIN
OPEN	300
	100
	–55		–25		5		35		65		95		125

TEMPERATURE – °C

Figure 7. Open-Loop Gain vs. Temperature

	20
			+25°C						+VOUT
			RL = 10k
± V
	15
SWING
									–VOUT
VOLTAGE	10
OUTPUT	5
	0
			5			10		15		20
	0

SUPPLY VOLTAGE ± V

Figure 2. Output Voltage

Swing vs. Supply Voltage

	120
– dB
RATIO	110
REJECTION	100
-MODE	90
COMMON	80
	70

–15 –10 0 +10 +15 INPUT COMMON-MODE VOLTAGE – V

Figure 5. CMRR vs. Input

Common-Mode Voltage

	30
	25
| – µV	20
	15
OS
|V
	10
	5
	0
	0		1		2		3	4		5		6		7
					WARM-UP TIME – Minutes

Figure 8. Change in Offset

Voltage vs. Warm-Up Time

p-p	30
	25
Volts
										VS = ±15 VOLTS
–	20
SWING
VOLTAGE	15
	10
OUTPUT
	5
	0
			100					1k					10k			100k
	10

LOAD RESISTANCE – Ω

Figure 3. Output Voltage

Swing vs. Load Resistance

– V/mV	3000
	1000
-LOOP GAIN
OPEN	300
	100
	0			5			10			15		20
						SUPPLY VOLTAGE ± V
	Figure 6. Open-Loop Gain vs.
	Supply Voltage
	50
– fA	45
	40
CURRENT
	35
INPUT	30
	25
	20
	–10			–5			0			5		10

COMMON-MODE VOLTAGE ± V

Figure 9. Input Bias Current vs. Common-Mode Voltage

–4–

REV. A