ANALOG DEVICES AD521 Service Manual

..

www.BDTIC.com/ADI

,. ANALOG

W DEVICES

[

FEATURES
Programmable Gainsfrom 0.1 to 1000

Differential Inputs
HighCMRR: 11OdBmin
Low Drift: 2p.Vfc max (L)
Complete Input Protection, Power ON and Power OFF
Functionally Complete with the Addition of Two Resistors
Internally Compensated

Gain Bandwidth Product: 4OMHz
Output Current Limited: 25mA

Very LowNoise: 05p.V p-p, 0.1Hzto 10Hz, RTI (I G -1000
Chips are Available

Not Recommended for new Designs

PRODUCTDESCRIPTION
The AD521 is a second generation, low cost, monolithic IC

instrUmentation amplifier developed by Analog Devices.Asa
trUeinstrUmentation amplifier, the AD521 is a gain block with
differential inputs and an accurately programmable input/
output gain relationship.

The AD521 ICinstrUmentation amplifier should not be con-
fused with an operational amplifier, although severalmanu-

factUrers(including AnalogDevices)offer op amps which can

be used as building blocks in variablegain instrumentation

amplifier circuits. Op amps are general-purpose components

which, when used with precision-matched external resistors,

can perform the instrUmentation amplifier function.

An instrumentation amplifier is a precision differential volt-

agegain device optimized for operation in a real world envi-

ronment, and is intended to be used wherever acquisition of a

useful signal isdifficult. It is characterized by high input im-

pedance, balanced differential inputs, low bias currents and

high CMR.

Asa complete instrUmentation amplifier, the AD521 requires

only two resistors to set its gain to any value between 0.1 and

1000. The ratio matching of these resistors does not affect the

high CMRR(up to 120dB) or the high input impedance (3 X

109il) of the AD521. Furthermore, unlike most operational
amplifier-basedinstrUmentation amplifiers, the inputs are
protected against overvoltagesup to :1:15volts beyond the
supplies.

The AD521 IC instrumentation amplifier is availablein four

different versions of accuracy and operating temperatUrerange.
The economical "J" grade, the low drift "K" grade, and the
lower drift, higher linearity "L" grade are specified from 0 to

PrecisionInstrumentationAmplifier

PIN CONFIGURATION

+ INPUT I 1

GAI~ 12

OFFSET

TRIM 4

OFFSET

TRIM 8

OUTPUT I 7

+70°C.The "S" grade guarantees performance to specification
over the eXtended temperatUre range: -SSoCto +125°C.

PRODUCTHIGHLIGHTS

1. The ADS21 is a trUeinstrumentation amplifier in integrated
circuit form, offering the user performance comparable to
many modular instrumentation amplifiers at a fraction of

the cost.

2. The AD521 has low guaranteed input offset voltage drift

(21lVf Cfor L grade) and low noise for precision, high gain
applications.

3. The AD521 is functionally complete with the addition of

two resistors. Gain can be preset from 0.1 to more than

1000.

4. The AD521 is fully protected for input levelsup to 15V
beyond the supply voltagesand JOV differential at the

inputs.

5. Internally compensated for allgains, the AD521 also offers

the user the provision for limiting bandwidth.

6. Offset nulling can be achieved with an optional trim pot.

7. The AD521 offers superior dynamic performance with a

gain-bandwidth product of 40MHz, full peak response of

100kHz (independent of gain) and a settling time of 5p.s
to 0.1%of a 10V step.

IntegratedCircuit

AD521 I

141 ~AIN

131 ~ALE

I

I

9 ICOMPo

81 v+

a

01::\/ 1\

-~ ~-- ~_. ~

AD521-SPECIFICATIONS(typical@ Vs =:t15V, RL=2kO and TA= +25°Cunlessotherwisespecified)

www.BDTIC.com/ADI

~

GAIN

Ra..e (For Spocified Operation, Note I)

Equation
Error from Equation
Nonlin..rity (NatO 2)

I..G<IOOO

Gain Temporaturo C""fficient

OUTPUT CHARACTERISTICS

RatOd Output
Output at Maximum Oporati.. Temporaturo
Impodance

DYNAMIC RESPONSE

Small Signal Bandwidth (13dB)

G=I
G= 10
G= 100
G = 1000

Small Signal, t1.0% Flatn..s

G=I
G= 10
G= 100

G = 1000
Full Peak Response (NatO 3)
Skw RatO, I..G ..1000
Settling Time (any 10V stOp to within 10mV of Final Value)

G-I

G= 10

G. 100

Not Recommended for new Designs

G.lOOO

DifforcntiaJ Overload Recovery (130V Input to within

10mV of Final Value) (NatO 4)

G - 1000
Common Mode StOp Recovery (30V Input to within

10mV of Final Value) (NatO 5)

G =1000

VOLTAGE OFFSET (may be nulled)

Input Offset Voltage (Vas,)

vs. Temporature
vs. Supply

Output Offset Voltage (Vaso)

vs. Temporature

vs. Supply (Narc 6)

INPUT CURRENTS

Input Bias Current (either input)

vs. Temporature

vs. Supply

Input Offser Current

vs. Temporature

INPUT

Differential Input Impodance (NatO 7)
Common Mode Input Impedance (NatO 8)

Input Voltage Range for Specified Poriorrnance

(with rospect to ground)

Maximum Voltage without Damage to Unit, Power ON

or OFF Differential Mode (Note 9)

Voltage at either input (Narc 9)

Common Mode Rejection Ratio, DC to 60Hz with IH1

source unbalance

Gol

GolO

GolOO

G . 1000

NOISE

Voltage RTO (p-p)@O.IHz to 10Hz (Narc 10)

RMS RTO, 10Hz to 10kHz
Input Current, rms, 10Hz to 10kHz

REFERENCE TERMINAL

Bias Current
Input Resistance
Voltage Range
Gain to Output

POWER SUPPLY

Oporati!ll Voltage Ra..e
Quincent Supply Current

TEMPERATURE RANGE

Spooned Performance

Oporating
Storage

°Specificatiom AD521JD.

ooSpec:if'ocatioaa AD5Z1KD.
Specificatioaaoubjoct10<!wit<without DOO«.

AD521JD

I to 1000

G. Rs/RC V/V

(to.25~.004G)%

0.2% max

t(3 to.05G)f£mtC

UOV, tlOmA min
tlOV @ SmA min

0.10

>2MHz

300kHz
200kHz
40kHz

75kHz

26kHz

24kHz
6kHz

100kHz

10V/lis

711'
511S

lOlls

35l1s

SOliS

lOllS

3mV max (2mV typ)

1511VtC max (7I1VtC typ)

311V/%

4OOmV max (200mV typ)

4OOIIVtCmax (l50IlV!':C typ)

0.005VOSO/%

80nA max

InAtC max

2%IV

20nA max

250pAtC max

3 x 1O911111.8pF

6 x lO'O11113.0pF

tlOV

30V

Vs tl5V

70dB min (74dB typ)
90dB min (94dB typ)
lOOdB min (l04dB typ)
lOOdB min (lIOdB typ)

311A

IOM11
tlOV
I

t5V to U8V
SmA max

0 to +70.C

-25.C to +85.C

-65.C to +150.C

AD521KD

l.5mV max (0.5mV ryp)
511VtC max (l.5I1Vfc typ)

200mV max (30mV typ)

150llVfc max (50IlV!':C typ)

.

4OnA max

500pAfC max

.

10nA max
125pAtC max

74dB min (80dB typ)
94dB min (lOOdB typ)

1O4dB min (l14dB typ)

llOdB min (l20dB trP,)

AD5HW

0.1% max

.

l.Omv max (0.5mV typ)
2IIV/.C max

.

lOOmV max
7511VtCmax

.

AD521SD

(AD5HSDI883B)

t(l5 to.4G)f£mtc

-

-

-

-55.Cto+125.C

-55.C to +125.C

--

-

---

-- -

--------

REV.A

~