Analog Devices AD526 Datasheet

a		Software Programmable
		Gain Amplifier
		AD526

FEATURES

Digitally Programmable Binary Gains from 1 to 16 Two-Chip Cascade Mode Achieves Binary Gain from

1 to 256 Gain Error:

0.01% Max, Gain = 1, 2, 4 (C Grade)

0.02% Max, Gain = 8, 16 (C Grade)

0.5 ppm/8C Drift Over Temperature

Fast Settling Time

10 V Signal Change:

0.01% in 4.5 ms (Gain = 16)

Gain Change:

0.01% in 5.6 ms (Gain = 16)

Low Nonlinearity: 60.005% FSR Max (J Grade)

Excellent DC Accuracy:

Offset Voltage: 0.5 mV Max (C Grade)

Offset Voltage Drift: 3 mV/8C (C Grade)

TTL-Compatible Digital Inputs

PRODUCT DESCRIPTION

The AD526 is a single-ended, monolithic software programmable gain amplifier (SPGA) that provides gains of 1, 2, 4, 8 and 16. It is complete, including amplifier, resistor network and TTL-compatible latched inputs, and requires no external components.

Low gain error and low nonlinearity make the AD526 ideal for precision instrumentation applications requiring programmable gain. The small signal bandwidth is 350 kHz at a gain of 16. In addition, the AD526 provides excellent dc precision. The FETinput stage results in a low bias current of 50 pA. A guaranteed maximum input offset voltage of 0.5 mV max (C grade) and low gain error (0.01%, G = 1, 2, 4, C grade) are accomplished using Analog Devices’ laser trimming technology.

To provide flexibility to the system designer, the AD526 can be operated in either latched or transparent mode. The force/sense configuration preserves accuracy when the output is connected to remote or low impedance loads.

The AD526 is offered in one commercial (0°C to +70°C) grade, J, and three industrial grades, A, B and C, which are specified from –40°C to +85°C. The S grade is specified from –55°C to +125°C. The military version is available processed to MILSTD 883B, Rev C. The J grade is supplied in a 16-lead plastic DIP, and the other grades are offered in a 16-lead hermetic side-brazed ceramic DIP.

REV. D

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.

PIN CONFIGURATION

DIG GND						A1
	1				16
NULL						A0
	2				15
VIN						CS
	3				14
NULL		AD526				CLK
	4				13
ANALOG GND 2		TOP VIEW				A2
	5	(Not to Scale)			12
ANALOG GND 1						B
	6				11
–V						+V
	7				10		S
S
VOUT SENSE						VOUT FORCE
	8				9

APPLICATION HIGHLIGHTS

1.Dynamic Range Extension for ADC Systems: A single AD526 in conjunction with a 12-bit ADC can provide

96 dB of dynamic range for ADC systems.

2.Gain Ranging Preamps: The AD526 offers complete digital gain control with precise gains in binary steps from 1 to 16. Additional gains of 32, 64, 128 and 256 are possible by cascading two AD526s.

ORDERING GUIDE

	Temperature	Package	Package
Model	Range	Descriptions	Options
AD526JN	Commercial	16-Lead Plastic DIP	N-16
AD526AD	Industrial	16-Lead Cerdip	D-16
AD526BD	Industrial	16-Lead Cerdip	D-16
AD526CD	Industrial	16-Lead Cerdip	D-16
AD526SD	Military	16-Lead Cerdip	D-16
AD526SD/883B	Military	16-Lead Cerdip	D-16
5962-9089401MEA*	Military	16-Lead Cerdip	D-16

*Refer to official DESC drawing for tested specifications.

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

Tel: [phone]	World Wide Web Site: http://www.analog.com
Fax: [phone]	© Analog Devices, Inc., 1999

AD526–SPECIFICATIONS (@ VS = 615 V, RL = 2 kV and TA = +258C unless otherwise noted)

		AD526J			AD526A			AD526B/S			AD526C
Model	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Units
GAIN
Gain Range
(Digitally Programmable)	1, 2, 4, 8, 16				1, 2, 4, 8, 16			1, 2, 4, 8, 16			1, 2, 4, 8, 16
Gain Error
Gain = 1			0.05			0.02			0.01			0.01	%
Gain = 2			0.05			0.03			0.02			0.01	%
Gain = 4			0.10			0.03			0.02			0.01	%
Gain = 8			0.15			0.07			0.04			0.02	%
Gain = 16			0.15			0.07			0.04			0.02	%
Gain Error Drift
Over Temperature													ppm/°C
G = 1		0.5	2.0		0.5	2.0		0.5	2.0		0.5	2.0
G = 2		0.5	2.0		0.5	2.0		0.5	2.0		0.5	2.0	ppm/°C
G = 4		0.5	3.0		0.5	3.0		0.5	3.0		0.5	3.0	ppm/°C
G = 8		0.5	5.0		0.5	5.0		0.5	5.0		0.5	5.0	ppm/°C
G = 16		1.0	5.0		1.0	5.0		1.0	5.0		1.0	5.0	ppm/°C
Gain Error (TMIN to TMAX)						0.03			0.02			0.015
Gain = 1			0.06										%
Gain = 2			0.06			0.04			0.03			0.015	%
Gain = 4			0.12			0.04			0.03			0.015	%
Gain = 8			0.17			0.08			0.05			0.03	%
Gain = 16			0.17			0.08			0.05			0.03	%
Nonlinearity
Gain = 1			0.005			0.005			0.005			0.0035	% FSR
Gain = 2			0.001			0.001			0.001			0.001	% FSR
Gain = 4			0.001			0.001			0.001			0.001	% FSR
Gain = 8			0.001			0.001			0.001			0.001	% FSR
Gain = 16			0.001			0.001			0.001			0.001	% FSR
Nonlinearity (TMIN to TMAX)						0.01			0.01			0.007
Gain = 1			0.01										% FSR
Gain = 2			0.001			0.001			0.001			0.001	% FSR
Gain = 4			0.001			0.001			0.001			0.001	% FSR
Gain = 8			0.001			0.001			0.001			0.001	% FSR
Gain = 16			0.001			0.001			0.001			0.001	% FSR
VOLTAGE OFFSET, ALL GAINS
Input Offset Voltage		0.4	1.5		0.25	0.7		0.25	0.5		0.25	0.5	mV
Input Offset Voltage Drift Over													µV/°C
Temperature		5	20		3	10		3	10		3	10
Input Offset Voltage
TMIN to TMAX			2.0			1.0			0.8			0.8	mV
Input Offset Voltage vs. Supply
(VS ± 10%)	80			80			84			90			dB
INPUT BIAS CURRENT
Over Input Voltage Range ± 10 V		50	150		50	150		50	150		50	150	pA
ANALOG INPUT
CHARACTERISTICS
Voltage Range		±12			±12			±12			±12
(Linear Operation)	610			610			610			610			V
Capacitance		5			5			5			5		pF
RATED OUTPUT		±12			±12			±12			±12
Voltage	610			610			610			610			V
Current (VOUT = ±10 V)		±10		65	±10		65	±10		65	±10		mA
Short-Circuit Current	15	30		15	30		15	30		15	30		mA
DC Output Resistance		0.002			0.002			0.002			0.002		Ω
Load Capacitance
(For Stable Operation)		700			700			700			700		pF

–2–	REV. D

												AD526
		AD526J			AD526A			AD526B/S			AD526C
Model	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Min	Typ	Max	Units
NOISE, ALL GAINS
Voltage Noise, RTI													µV p-p
0.1 Hz to 10 Hz		3			3			3			3
Voltage Noise Density, RTI													nV√Hz
f = 10 Hz		70			70			70			70
f = 100 Hz		60			60			60			60		nV√Hz
f = 1 kHz		30			30			30			30		nV√Hz
f = 10 kHz		25			25			25			35		nV√Hz
DYNAMIC RESPONSE
–3 dB Bandwidth (Small Signal)
G = 1		4.0			4.0			4.0			4.0		MHz
G = 2		2.0			2.0			2.0			2.0		MHz
G = 4		1.5			1.5			1.5			1.5		MHz
G = 8		0.65			0.65			0.65			0.65		MHz
G = 16		0.35			0.35			0.35			0.35		MHz
Signal Settling Time to 0.01%
( VOUT = ± 10 V)													µs
G = 1		2.1	4		2.1	4		2.1	4		2.1	4
G = 2		2.5	5		2.5	5		2.5	5		2.5	5	µs
G = 4		2.7	5		2.7	5		2.7	5		2.7	5	µs
G = 8		3.6	7		3.6	7		3.6	7		3.6	7	µs
G = 16		4.1	7		4.1	7		4.1	7		4.1	7	µs
Full Power Bandwidth
G = 1, 2, 4		0.10			0.10			0.10			0.10		MHz
G = 8, 16		0.35			0.35			0.35			0.35		MHz
Slew Rate													V/µs
G = 1, 2, 4	4	6		4	6		4	6		4	6
G = 8, 16	18	24		18	24		18	24		18	24		V/µs
DIGITAL INPUTS
(TMIN to TMAX)													µA
Input Current (VH = 5 V)	60	100	140	60	100	140	60	100	140	60	100	140
Logic “1”	2		6	2		6	2		6	2		6	V
Logic “0”	0		0.8	0		0.8	0		0.8	0		0.8	V
TIMING1
(VL = 0.2 V, VH = 3.7 V)
A0, A1, A2
TC	50			50			50			50			ns
TS	30			30			30			30			ns
TH	30			30			30			30			ns
B
TC	50			50			50			50			ns
TS	40			40			40			40			ns
TH	10			10			10			30			ns
TEMPERATURE RANGE													°C
Specified Performance	0		+70	–40		+85	–40/–55		+85/+125	–40		+85
Storage	–65		+125	–65		+150	–65		+150	–65		+150	°C
POWER SUPPLY
Operating Range	64.5		616.5	64.5		616.5	64.5		616.5	64.5		616.5	V
Positive Supply Current		10	14		10	14		10	14		10	14	mA
Negative Supply Current		10	13		10	13		10	13		10	13	mA
PACKAGE OPTIONS
Plastic (N-16)	AD526JN
Ceramic DIP (D-16)				AD526AD			AD526BD AD526SD				AD526CD
								AD526SD/883B
NOTES

1Refer to Figure 25 for definitions. FSR = Full Scale Range = 20 V. RTI = Referred to Input.

Specifications subject to change without notice.

Specifications shown in boldface are tested on all production units at final electrical test. All min and max specifications are guaranteed, although only those shown in boldface are tested on all production units.

REV. D	–3–

AD526–Typical Performance Characteristics

	20						30
–6V	15					–6V
SWING			+258C			SWING		@ VS = 615V
							20
			RL = 2kV
VOLTAGE						VOLTAGE
	10
OUTPUT						OUTPUT	10
	5
	0						0
	0	5	10	15	20		100	1k	10k
		SUPPLY VOLTAGE –6V						LOAD RESISTANCE –V

Figure 1. Output Voltage Swing vs.

Figure 2. Output Voltage Swing vs.

Supply Voltage, G = 16							Load Resistance
	100nA						75
BIASINPUTCURRENT	10nA						pA			VS = 615V
							BIASINPUTCURRENT –
							50
	1nA
	100pA
							25
	10pA
	1pA	–20	20	60	100	140	0	–5	0	5	10
	–60						–10
		TEMPERATURE –8C						INPUT VOLTAGE – V

Figure 4. Input Bias Current vs.

Temperature
	25
p-p
V	20			GAIN = 8, 16
–
RESPONSE	15	GAIN = 1, 2, 4
POWER	10
FULL	5
	0	10k	100k	1M	10M
	1k
			FREQUENCY – Hz

Figure 5. Input Bias Current vs. Input

Voltage
	100				615V WITH 1V p-p
dB					SINE WAVE
	80
–
REJECTION						+SUPPLY
	60
SUPPLY	40
				–SUPPLY
POWER	20
	10	10	100	1k	10k	100k	1M
	1

FREQUENCY – Hz

Figure 7. Large Signal Frequency	Figure 8. PSRR vs. Frequency
Response

	20
– pA	15
CURRENT	10		VIN = 0
BIAS
INPUT	5
	0	5	10	15	20
	0

SUPPLY VOLTAGE –6V

Figure 3. Input Bias Current vs. Supply Voltage

	20					16
	10
							8
						4
GAIN						2
	1
							1
	10	100	1k	10k	100k	1M	10M
			FREQUENCY – Hz

Figure 6. Gain vs. Frequency

	1.0002
GAIN	1.0001
NORMALIZED	1.0000
	0.9999
	0.9998
			–20		20		60		100		140
	–60

TEMPERATURE –8C

Figure 9. Normalized Gain vs. Temperature, Gain = 1

–4–

REV. D

AD526

1000						0.006
Hz						0.004
VOLTAGENOISEINPUT– nV/					NONLINEARITY– %FSR
						0.002
100
						0.000
						–0.002
10						–0.004	–20	20	60	100	140
10	100	1k	10k	100k		–60

FREQUENCY – Hz	TEMPERATURE –8C
Figure 10. Noise Spectral Density	Figure 11. Nonlinearity vs.
	Temperature, Gain = 1

Figure 12. Wideband Output Noise, G = 16 (Amplified by 10)

Figure 13. Large Signal Pulse

Response and Settling Time,*

G = 1

Figure 16. Small Signal Pulse

Response, G = 2

Figure 14. Small Signal Pulse

Response, G = 1

Figure 17. Large Signal Pulse

Response and Settling Time,*

G = 4

Figure 15. Large Signal Pulse

Response and Settling Time,*

G = 2

Figure 18. Small Signal Pulse

Response, G = 4

*For Settling Time Traces, 0.01% = 1/2 Vertical Division

REV. D

–5–