AD AD8519

a
FEATURES
Space-Saving SOT-23, ␮SOIC Packaging
Wide Bandwidth: 8 MHz @ 5 V
Low Offset Voltage: 1.2 mV Max
Rail-to-Rail Output Swing
2.7 V/␮s Slew Rate
Unity Gain Stable
Single Supply Operation: +2.7 V to +12 V
APPLICATIONS
Portable Communications
Microphone Amplifiers
Portable Phones
Sensor Interface
Active Filters
PCMCIA Cards
ASIC Input Drivers
Wearable Computers
Battery Powered Devices
Voltage Reference Buffers
Personal Digital Assistants
8 MHz Rail-to-Rail
Operational Amplifiers
AD8519/AD8529
PIN CONFIGURATIONS
8-Lead SOIC
(R Suffix)
The small SOT-23 package makes it possible to place the AD8519
next to sensors, reducing external noise pickup.
8 NC
2IN A 2
7 V+
+IN A 3
6 OUT A
5 NC
V2 4
NC = NO CONNECT
5-Lead SOT-23
(RT Suffix)
AD8519
OUT A 1
5 V+
V2 2
4 2IN A
+IN A 3
8-Lead SOIC
(R Suffix)
GENERAL DESCRIPTION
The AD8519 and AD8529 are rail-to-rail output bipolar amplifiers with a unity gain bandwidth of 8 MHz and a typical voltage
offset of less than 1 mV. The AD8519 brings precision and bandwidth to the SOT-23 package. The low supply current makes the
AD8519/AD8529 ideal for battery powered applications. The
rail-to-rail output swing of the AD8519/AD8529 is larger than
standard video op amps, making them useful in applications that
require greater dynamic range than standard video op amps. The
+2.7 V/µs slew rate makes the AD8529/AD8549 a good match
for driving ASIC inputs such as voice codecs.
AD8519
NC 1
OUT A 1
8 V1
AD8529
2IN A 2
1IN A 3
TOP VIEW
7 OUT B
6 2IN B
5 1IN B
V2 4
8-Lead ␮SOIC
(RM Suffix)
OUT A
2IN A
1IN A
V2
1
8
AD8529
4
5
V1
OUT B
2IN B
1IN B
The AD8519/AD8529 is specified over the extended industrial
(–40°C to +125°C) temperature range. The AD8519 is available in 5-lead SOT-23-5 and SO-8 surface mount packages.
The AD8529 is available in 8-lead SOIC and µSOIC packages.
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 1998
AD8519/AD8529–SPECIFICATIONS
ELECTRICAL CHARACTERISTICS (V
S
= +5.0 V, V– = 0 V, VCM = +2.5 V, TA = +25ⴗC unless otherwise noted)
Parameter
Symbol
Conditions
INPUT CHARACTERISTICS
Offset Voltage
VOS
AD8519ART (SOT-23-5)
–40°C ≤ TA ≤ +125°C
AD8519AR (SO-8), AD8529
–40°C ≤ TA ≤ +125°C
Offset Voltage
VOS
Input Bias Current
IB
Input Offset Current
IOS
Input Voltage Range
Common-Mode Rejection Ratio
VCM
CMRR
Large Signal Voltage Gain
AVO
Offset Voltage Drift
Bias Current Drift
OUTPUT CHARACTERISTICS
Output Voltage Swing High
Output Voltage Swing Low
Short Circuit Current
Maximum Output Current
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
∆VOS/∆T
∆IB/∆T
VOH
VOL
ISC
IOUT
PSRR
ISY
Min
Typ
Max
Units
600
800
600
1,100
1,300
1,000
1,100
300
400
± 50
± 100
+4
µV
µV
µV
µV
nA
nA
nA
nA
V
–40°C ≤ TA ≤ +125°C
–40°C ≤ TA ≤ +125°C
0 V ≤ VCM ≤ +4.0 V,
–40°C ≤ TA ≤ +125°C
RL = 2 kΩ, +0.5 V < VOUT < +4.5 V
RL = 10 kΩ, +0.5 V < VOUT < +4.5 V
RL = 10 kΩ, –40°C ≤ TA ≤ +125°C
0
63
50
30
100
30
100
dB
V/mV
V/mV
V/mV
µV/°C
pA/°C
2
500
IL = 250 µA
–40°C ≤ TA ≤ +125°C
IL = 5 mA
IL = 250 µA
–40°C ≤ TA ≤ +125°C
IL = 5 mA
Short to Ground, Instantaneous
+4.90
+4.80
V
V
± 70
± 25
VS = +2.7 V to +7 V,
–40°C ≤ TA ≤ +125°C
VOUT = +2.5 V
–40°C ≤ TA ≤ +125°C
110
80
600
80
200
1,200
1,400
mV
mV
mA
mA
dB
dB
µA
µA
DYNAMIC PERFORMANCE
Slew Rate
Settling Time
Gain Bandwidth Product
Phase Margin
SR
tS
GBP
φm
+1 V < VOUT < +4 V, RL = 10 kΩ
To 0.01%
2.9
1,200
8
60
V/µs
ns
MHz
Degrees
NOISE PERFORMANCE
Voltage Noise
Voltage Noise Density
Current Noise Density
en p-p
en
in
0.1 Hz to 10 Hz
f = 1 kHz
f = 1 kHz
0.5
7
0.4
µV p-p
nV/√Hz
pA/√Hz
Specifications subject to change without notice.
–2–
REV. A
AD8519/AD8529
ELECTRICAL CHARACTERISTICS (V
S
= +3.0 V, V– = 0 V, VCM = +1.5 V, TA = +25ⴗC unless otherwise noted)
Parameter
Symbol
Conditions
INPUT CHARACTERISTICS
Offset Voltage
VOS
AD8519ART (SOT-23-5)
–40°C ≤ TA ≤ +125°C
AD8519AR (SO-8), AD8529
–40°C ≤ TA ≤ +125°C
VOS
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
IB
IOS
VCM
CMRR
Large Signal Voltage Gain
AVO
OUTPUT CHARACTERISTICS
Output Voltage Swing High
Output Voltage Swing Low
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
VOH
VOL
PSRR
ISY
0 V ≤ VCM ≤ +2.0 V,
–40°C ≤ TA ≤ +125°C
RL = 2 kΩ, +0.5 V < VOUT < +2.5 V
RL = 10 kΩ
IL = 250 µA
IL = 5 mA
IL = 250 µA
IL = 5 mA
VS = +2.5 V to +7 V,
–40°C ≤ TA ≤ +125°C
VOUT = +1.5 V
–40°C ≤ TA ≤ +125°C
Min
Typ
Max
Units
700
900
700
1,200
1,400
1,100
1,200
300
± 50
+2
µV
µV
µV
µV
nA
nA
V
0
55
20
75
20
30
dB
V/mV
V/mV
+2.90
+2.80
60
80
600
100
200
V
V
mV
mV
1,100
1,300
dB
µA
µA
DYNAMIC PERFORMANCE
Slew Rate
Settling Time
Gain Bandwidth Product
Phase Margin
SR
tS
GBP
φm
RL = 10 kΩ
To 0.01%
1.5
2,000
6
55
V/µs
ns
MHz
Degrees
NOISE PERFORMANCE
Voltage Noise Density
Current Noise Density
en
in
f = 1 kHz
f = 1 kHz
10
0.4
nV/√Hz
pA/√Hz
Specifications subject to change without notice.
REV. A
–3–
AD8519/AD8529–SPECIFICATIONS
ELECTRICAL CHARACTERISTICS (V
S
= +2.7 V, V– = 0 V, VCM = +1.35 V, TA = +25ⴗC unless otherwise noted)
Parameter
Symbol
Conditions
INPUT CHARACTERISTICS
Offset Voltage
VOS
AD8519ART (SOT-23-5)
–40°C ≤ TA ≤ +125°C
AD8519AR (SO-8), AD8529
–40°C ≤ TA ≤ +125°C
VOS
Input Bias Current
Input Offset Current
Input Voltage Range
Common-Mode Rejection Ratio
IB
IOS
VCM
CMRR
Large Signal Voltage Gain
AVO
OUTPUT CHARACTERISTICS
Output Voltage Swing High
Output Voltage Swing Low
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
VOH
VOL
PSRR
ISY
0 V ≤ VCM ≤ +1.7 V,
–40°C ≤ TA ≤ +125°C
RL = 2 kΩ, +0.5 V < VOUT < +2.2 V
RL = 10 kΩ
IL = 250 µA
IL = 5 mA
IL = 250 µA
IL = 5 mA
VS = +2.5 V to +7 V,
–40°C ≤ TA ≤ +125°C
VOUT = +1.35 V
–40°C ≤ TA ≤ +125°C
Min
Typ
Max
Units
700
900
700
1,400
1,600
1,200
1,300
300
± 50
+2
µV
µV
µV
µV
nA
nA
V
0
55
20
75
20
30
dB
V/mV
V/mV
+2.60
+2.50
60
80
600
100
200
V
V
mV
mV
1,100
1,300
dB
µA
µA
DYNAMIC PERFORMANCE
Slew Rate
Settling Time
Gain Bandwidth Product
Phase Margin
SR
tS
GBP
φm
RL = 10 kΩ
To 0.01%
1.5
2,000
6
55
V/µs
ns
MHz
Degrees
NOISE PERFORMANCE
Voltage Noise Density
Current Noise Density
en
in
f = 1 kHz
f = 1 kHz
10
0.4
nV/√Hz
pA/√Hz
Specifications subject to change without notice.
–4–
REV. A
AD8519/AD8529
ELECTRICAL CHARACTERISTICS (V
S
= +5.0 V, V– = –5 V, VCM = 0 V, TA = +25ⴗC unless otherwise noted)
Parameter
Symbol
Conditions
INPUT CHARACTERISTICS
Offset Voltage
VOS
AD8519ART (SOT-23-5)
–40°C ≤ TA ≤ +125°C
AD8519AR (SO-8), AD8529
–40°C ≤ TA ≤ +125°C
VCM = 0 V
VCM = 0 V, –40°C ≤ TA ≤ +125°C
VCM = 0 V
VCM = 0 V, –40°C ≤ TA ≤ +125°C
VOS
Input Bias Current
IB
Input Offset Current
IOS
Input Voltage Range
Common-Mode Rejection Ratio
VCM
CMRR
Large Signal Voltage Gain
AVO
Offset Voltage Drift
Bias Current Drift
OUTPUT CHARACTERISTICS
Output Voltage Swing High
Output Voltage Swing Low
Short Circuit Current
Maximum Output Current
POWER SUPPLY
Power Supply Rejection Ratio
Supply Current/Amplifier
∆VOS/∆T
∆IB/∆T
VOH
VOL
ISC
IOUT
PSRR
ISY
Min
–4.9 V ≤ VCM ≤ +4.0 V,
–40°C ≤ TA ≤ +125°C
RL = 2 kΩ
RL = 10 kΩ
–40°C ≤ TA ≤ +125°C
Typ
Max
Units
600
800
600
1,100
1,300
1,000
1,100
300
400
± 50
± 100
+4
µV
µV
µV
µV
nA
nA
nA
nA
V
–5
70
50
25
100
30
200
dB
V/mV
V/mV
V/mV
µV/°C
pA/°C
2
500
IL = 250 µA
–40°C ≤ TA ≤ +125°C
IL = 5 mA
IL = 250 µA
–40°C ≤ TA ≤ +125°C
IL = 5 mA
Short to Ground, Instantaneous
VS = ± 1.5 V to ± 6 V,
–40°C ≤ TA ≤ +125°C
VOUT = 0 V
–40°C ≤ TA ≤ +125°C
+4.90
+4.80
V
V
± 70
± 25
60
100
600
–4.90
–4.80
1,200
1,400
V
V
mA
mA
dB
µA
µA
DYNAMIC PERFORMANCE
Slew Rate
Settling Time
Gain Bandwidth Product
Phase Margin
SR
tS
GBP
φm
–4 V < VOUT < +4 V, RL = 10 kΩ
To 0.01%
2.9
1,000
8
60
V/µs
ns
MHz
Degrees
NOISE PERFORMANCE
Voltage Noise Density
Current Noise Density
en
in
f = 1 kHz
f = 1 kHz
7
0.4
nV/√Hz
pA/√Hz
Specifications subject to change without notice.
REV. A
–5–
AD8519/AD8529
ABSOLUTE MAXIMUM RATINGS
1
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±6 V
Input Voltage2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 6 V
Differential Input Voltage3 . . . . . . . . . . . . . . . . . . . . . . ± 0.6 V
Internal Power Dissipation
SOT-23 (RT) . . . . . . . . . . . . . . . . . Observe Derating Curve
SOIC (R) . . . . . . . . . . . . . . . . . . . . Observe Derating Curve
µSOIC (RM) . . . . . . . . . . . . . . . . . Observe Derating Curve
Output Short-Circuit Duration . . . . . Observe Derating Curve
Storage Temperature Range
RT, S Packages . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Operating Temperature Range
AD8519, AD8529 . . . . . . . . . . . . . . . . . . –40°C to +125°C
Junction Temperature Range
RT, S Packages . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Lead Temperature Range (Soldering, 60 sec) . . . . . . . +300°C
Package Type
␪JA1
␪JC
Units
5-Lead SOT-23 (RT)
8-Lead SOIC (R)
8-Lead µSOIC (RM)
230
158
210
146
43
45
°C/W
°C/W
°C/W
NOTE
1
θ JA is specified for worst case conditions, i.e., θ JA is specified for device soldered
in circuit board for SOT-23 and SOIC packages.
ORDERING GUIDE
NOTES
1
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.
2
For supply voltages less than ±6 V the input voltage is limited to less than or equal
to the supply voltage.
3
For differential input voltages greater than ±0.6 V the input current should be limited
to less than 5 mA to prevent degradation or destruction of the input devices.
Model
Temperature
Range
Package
Description
Package
Option
AD8519ART1
AD8519AR
AD8529AR
AD8529ARM2
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
–40°C to +125°C
5-Lead SOT-23
8-Lead SOIC
8-Lead SOIC
8-Lead µSOIC
RT-5
SO-8
SO-8
RM-8
NOTES
1
Available in 3,000 piece reels only.
2
Available in 2,500 piece reels only.
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 AD8519/AD8529 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.
–6–
WARNING!
ESD SENSITIVE DEVICE
REV. A
Typical Characteristics – AD8519/AD8529
600
60
VS = +5V
SUPPLY CURRENT – mA
QUANTITY AMPLIFIERS
50
800
COUNT = 395 OP AMPS
40
30
20
SUPPLY CURRENT – mA
VS = +5V
TA = +258C
550
500
700
600
VS = +10V
500
VS = +2.7V, +3.0V
400
10
0.2
0.6
20.6
20.2
INPUT OFFSET VOLTAGE – mV
450
1
0
Figure 1. Input Offset Voltage
Distribution
240
280
2120
2160
2200
1
2
3
4
COMMON-MODE VOLTAGE – Volts
Figure 4. Input Bias Current vs.
Common-Mode Voltage
40
30
80
60
40
0
1
2
3
4
COMMON-MODE VOLTAGE – Volts
0
10
210
225
220
270
90
70
80
60
70
60
50
50
100M
30
10
100k
1M
FREQUENCY – Hz
10M
Figure 8. CMRR vs. Frequency
–7–
2PSRR
+PSRR
30
20
1k
10k
VS = +5V
TA = +258C
40
240
10k
REV. A
1M
10M
FREQUENCY – Hz
80
20
Figure 7. Closed Loop Gain vs.
Frequency
135
180
220
100M
PHASE
0
40
100k
1M
10M
FREQUENCY – Hz
90
20
90
VS = +5V
TA = +258C
100
CMRR – dB
20
45
Figure 6. Open Loop Gain, Phase vs.
Frequency
110
VS = +5V
RL = 830V
TA = +258C
CL 5pF
GAIN
230
100k
5
Figure 5. Common-Mode Rejection
vs. Common-Mode Voltage
60
VS = +5V
TA = +258C
40
100
20
5
25
50
75 100 125 150
TEMPERATURE – 8C
50
VS = +5V
PSRR – dB
0
0
Figure 3. Supply Current per
Amplifier vs. Temperature
GAIN – dB
COMMON MODE REJECTION – dB
INPUT BIAS CURRENT – nA
300
250 225
12
120
VS = +5V
TA = +258C
0
CLOSED LOOP GAIN – dB
4
6
8
10
SUPPLY VOLTAGE – Volts
Figure 2. Supply Current per
Amplifier vs. Supply Voltage
40
2240
2
0
1k
10k
100k
1M
FREQUENCY – Hz
10M
Figure 9. PSRR vs. Frequency
PHASE SHIFT – Degrees
0
21
AD8519/AD8529
4
VS = +5V
VCM = +2.5V
RL = 10kV
TA = +258C
VIN = 650mV
40
30
2OS
20
0
21
0.1%
1%
10
23
0
10
100
CAPACITANCE – pF
24
1k
Figure 10. Overshoot vs. Capacitance
Load
1.0
SETTLING TIME – ms
0
3
DISTORTION < 1%
2
1
0
10k
2.0
AVCC = 10
150
100
AVCC = 1
50
0
100k
70
60
50
40
30
20
10
10M
Figure 13. Output Impedance vs.
Frequency
VS = 62.5V
AV = 100kV
en = 0.4mV p-p
20mV
1s
Figure 16. 0.1 Hz to 10 Hz Noise
1k
100
FREQUENCY – Hz
10
10k
Figure 14. AD8519 Voltage Noise
Density
VS = +5V
TA = +258C
7
6
5
4
3
2
1
0
0
1M
FREQUENCY – Hz
10M
8
VS = +5V
TA = +258C
CURRENT NOISE DENSITY – pA/ Hz
VOLTAGE NOISE DENSITY – nV/ Hz
200
100k
1M
FREQUENCY – Hz
Figure 12. Output Swing vs.
Frequency
80
VS = +5V
TA = +258C
VS = +5V
AVCC = 1
RL = 10kV
TA = +258C
CL = 15pF
4
Figure 11. Settling Time vs. Step Size
300
OUTPUT IMPEDANCE – V
1
22
+OS
250
1%
0.1%
STEP SIZE – V
OVERSHOOT – %
50
5
VS = +5V
TA = +258C
3
MAXIMUM OUTPUT SWING – V p-p
60
1k
100
FREQUENCY – Hz
10
10k
Figure 15. AD8519 Current Noise
Density
VS = 62.5V
AVCC = 1
TA = +258C
CL = 100pF
RL = 10kV
VS = 62.5V
VIN = +6V p-p
AV = 1
1V
20ms
Figure 17. No Phase Reversal
–8–
20mV
500ns
Figure 18. Small Signal Transient
Response
REV. A
AD8519/AD8529
R4
10kV
VS = 62.5V
AVCC = 1
TA = +258C
CL = 100pF
R1
10kV
R2
10kV
NODE A
R3
4.99kV
R5
10kV
VIN
D1
1N914
D2
1N914
VOUT
U2
AD8519
U1
R6
5kV
500mV
50ms
VIRTUAL GROUND =
Figure 19. Large Signal Transient Response
VCC
2
This type of rectifier can be very precise if the following electrical parameters are adhered to: First, all passive components
should be of tight tolerance, 1% resistors and 5% capacitors.
Second, if the application circuit requires high impedance (i.e.,
direct sensor interface), then an FET amplifier is probably a
better choice than the AD8519. Third, an amp such as the
AD8519, which has a great slew rate specification, will yield the
best result, because the circuit involves switching. Switching
glitches are caused when D1 and D2 are both momentarily off.
This condition occurs every time the input signal is equal to the
virtual ground potential. When this condition occurs the U1
stage is taken out of the VOUT equation and VOUT is equal to
VIN ⴛ R5 ⴛ (R4储R1+R2+R3). Please note: node A should be
VIN inverted or virtual ground, but in this condition node A is a
simply tracking VIN. Given a sine wave input centered around
virtual ground glitches are generated at the sharp negative peaks
of the rectified sine wave. If the glitches are hard to notice on an
oscilloscope, then raise the frequency of the sine wave till they
become apparent. The size of the glitches are proportional to
the input frequency, the diode turn-on potential (+0.2 V or
+0.65 V) and the slew rate of the op amp.
The maximum power that can be safely dissipated by the AD8519/
AD8529 is limited by the associated rise in junction temperature.
The maximum safe junction temperature is +150°C for these
plastic packages. If this maximum is momentarily exceeded, proper
circuit operation will be restored as soon as the die temperature is
reduced. Operating the product in the “overheated” condition for
an extended period can result in permanent damage to the device.
Precision Full-Wave Rectifier
Slew Rate is probably the most underestimated parameter when
designing a precision rectifier. Yet without a good slew rate
large glitches will be generated during the period when both
diodes are off.
Let’s examine the operation of the basic circuit before considering slew rate further, U1 is set up to have two states of operation. D1 and D2 diodes switch the output between the two
states. State one is as an inverter with a gain of 1 and state two
is a simple unity gain buffer where the output is equal to the
value of the virtual ground. The virtual ground is the potential
present at the noninverting node of the U1. State one is active
when VIN is larger than the virtual ground. D2 is on in this
condition. If VIN drops below virtual ground, D2 turns off and
D1 turns on. This causes the output of U1 to simply buffer the
virtual ground and this configuration is state two. So, the function of U1, which results from these two states of operation, is a
half-wave inverter. The U2 function takes the inverted half-wave
at a gain of two and sums it into the original VIN wave, which
outputs a rectified full-wave.
−1
R7
3.32kV
Figure 20. Precision Full-Wave Rectifier
APPLICATIONS INFORMATION
Maximum Power Dissipation
VOUT = VIN − 2 VIN
AD8519
R6 and R7 are both necessary to limit the amount of bias current related voltage offset. Unfortunately, there is no “perfect”
value for R6 because the impedance at the inverting node is
altered as D1 and D2 switch. Therefore, there will also be some
unresolved bias current related offset. To minimize this offset,
use lower value resistors or choose an FET amplifier if the optimized offset is still intolerable.
The AD8519 offers a unique combination of speed vs. power
ratio at +2.7 V single supply, small size (SOT-23), and low
noise that make it an ideal choice for most high volume and
high precision rectifier circuits.
<0
10ⴛ Microphone Preamp, Meets PC99 Specifications
This circuit, while lacking a unique topology, is anything but
featureless when an AD8519 is used as the op amp. This preamp
gives 20 dB gain over a frequency range of 20 Hz to 20 kHz and is
fully PC99 compliant in all parameters including THD+N, dynamic range, frequency range, amplitude range, crosstalk, etc.
Not only does this preamp comply with the PC99 spec it far surpasses it. In fact, this preamp has a VOUT noise of around
100 dB, which is suitable for most professional 20-bit audio
systems. Referred to input noise is 120 dB. At 120 dB THD+N
in unity gain the AD8519 is suitable for all 24-bit professional
audio systems available today. In other words, the AD8519 will
not be the limiting performance factor in your audio system despite its small size and low cost.
REV. A
–9–
AD8519/AD8529
Slew-rate-related distortion would not be present at the lower
voltages because the AD8519 is so fast at 2.1 V/µs. A general rule
of thumb for determining the necessary slew rate for an audio
system is: Take the maximum output voltage range of the device
given the design’s power rails and divide by two. In our example in
Figure 21, the power rails are +2.7 V and the output is rail-to-rail:
enter those numbers into the equation 2.7/2 is +1.35 V, and our
minimum ideal slew rate is 1.35 V/µs.
While this data sheet gives only one audio example, many audio
circuits are enhanced with the use of the AD8519. Here are just a
few examples, Active audio filters like bass, treble and equalizers,
PWM filters at the output of audio DACs, Buffers and Summers
for mixing stations, and Gain stages for volume control.
240pF
+2.7V
Figure 22 is a schematic of a two-element varying bridge. This
configuration is commonly found in pressure and flow transducers. With two-elements varying the signal will be 2⫻ as compared to a single-element varying bridge. The advantages of this
type of bridge are gain setting range, no signal input equals 0 V
out, and single supply application. Negative characteristics are
nonlinear operation and required R matching. Given these sets
of conditions, requirements and characteristics, the AD8519 can
be successfully used in this configuration because of its rail-torail output and low offset. Perhaps the greatest benefits of the
AD8519, when used in the bridge configuration, are the advantages it can bring when placed in a remote bridge sensor. For
example: the tiny SOT-23 package will reduce the overall sensor
package, low power allows for remote powering via batteries or
solar cells, high output current drive to drive a long cable, and
+2.7 V operation for two cell operation.
30.9kV
+2.7V
1kV
C1
1mF
MIC
IN
+2.7V
1nF
NPO
AD8519
46.4kV
RF
CODEC LINE IN
OR MIC IN
3.09kV
R
R
R
R
48kV
AD8519
93.1kV
+2.7V
RF
10mF-ELECT
Figure 22. Two-Element Varying Bridge Amplifier
Figure 21. 10⫻ Microphone Preamplifier
Two-Element Varying Bridge Amplifier
There are a host of bridge configurations available to designers.
For a complete look the ubiquitous bridge, its positives and
negatives, and its many different forms, please refer to ADI’s
1992 Amplifier Applications Guide1.
1. Adolfo Garcia and James Wong, Chapter 2, 1992 Amplifier Applications Guide.
–10–
REV. A
AD8519/AD8529
* AD8519/AD8529 SPICE Macro-model
* 10/98, Ver. 1
* TAM / ADSC
*
* Copyright 1998 by Analog Devices
*
* Refer to “README.DOC” file for License State* ment. Use of this model
* indicates your acceptance of the terms and
* provisions in the License
* Statement.
*
* Node Assignments
*
noninverting input
*
|
inverting input
*
|
|
positive supply
*
|
|
|
negative supply
*
|
|
|
|
output
*
|
|
|
|
|
*
|
|
|
|
|
.SUBCKT AD8519
1
2
99 50 45
*
*INPUT STAGE
*
Q1
5 7 15 PIX
Q2
6 2 15 PIX
IOS 1 2 1.25E-9
I1 99 15 200E-6
EOS 7 1 POLY(2) (14,98) (73,98) 1E-3 1 1
RC1 5 50 2E3
RC2 6 50 2E3
C1
5 6 1.3E-12
D1 15 8 DX
V1 99 8 DC 0.9
*
* INTERNAL VOLTAGE REFERENCE
*
EREF 98 0 POLY(2) (99,0) (50,0) 0 .5 .5
ISY 99 50 300E-6
*
* CMRR=100dB, ZERO AT 1kHz
*
ECM
13 98 POLY(2) (1,98) (2,98) 0 0.5 0.5
RCM1 13 14 1E6
RCM2 14 98 10
CCM1 13 14 240E-12
*
* PSRR=100dB, ZERO AT 200Hz
*
RPS1 70 0 1E6
RPS2 71 0 1E6
CPS1 99 70 1E-5
CPS2 50 71 1E-5
EPSY 98 72 POLY(2) (70,0) (0,71) 0 1 1
RPS3 72 73 1.59E6
CPS3 72 73 500E-12
RPS4 73 98 15.9
*
* POLE AT 20MHz, ZERO AT 60MHz
*
G1 21 98 (5,6) 5.88E-6
REV. A
R1 21 98 170E3
R2 21 22 85E3
C2 22 98 40E-15
*
* GAIN STAGE
*
G2 25 98 (21,98) 37.5E-6
R5 25 98 1E7
CF 45 25 5E-12
D3 25 99 DX
D4 50 25 DX
*
* OUTPUT STAGE
*
Q3
45 41 99 POUT
Q4
45 43 50 NOUT
EB1 99 40 POLY(1) (98,25) 0.594 1
EB2 42 50 POLY(1) (25,98) 0.594 1
RB1 40 41 500
RB2 42 43 500
*
* MODELS
*
.MODEL PIX PNP (BF=500,IS=1E-14,KF=5E-6)
.MODEL POUT PNP (BF=100,IS=1E-14,BR=0.517)
.MODEL NOUT NPN (BF=100,IS=1E-14,BR=0.413)
.MODEL DX D(IS=1E-14,CJO=1E-15)
.ENDS AD8519
–11–
AD8519/AD8529
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
0.1968 (5.00)
0.1890 (4.80)
8
0.1574 (4.00)
0.1497 (3.80) 1
0.122 (3.10)
0.114 (2.90)
5
4
0.2440 (6.20)
0.2284 (5.80)
8
5
0.199 (5.05)
0.187 (4.75)
0.122 (3.10)
0.114 (2.90)
0.0688 (1.75)
0.0532 (1.35)
0.0500 0.0192 (0.49)
SEATING (1.27)
PLANE BSC 0.0138 (0.35)
1
0.0196 (0.50)
x 458
0.0099 (0.25)
4
PIN 1
0.0098 (0.25)
0.0075 (0.19)
0.0256 (0.65) BSC
88
08 0.0500 (1.27)
0.0160 (0.41)
0.120 (3.05)
0.112 (2.84)
0.120 (3.05)
0.112 (2.84)
0.043 (1.09)
0.037 (0.94)
0.006 (0.15)
0.002 (0.05)
SEATING
PLANE
0.018 (0.46)
0.008 (0.20)
0.011 (0.28)
0.003 (0.08)
33°
27°
0.028 (0.71)
0.016 (0.41)
5-Lead SOT-23
(RT-5)
0.1220 (3.100)
0.1063 (2.700)
0.0709 (1.800)
0.0590 (1.500)
3
2
1
4
5
PIN 1
0.1181 (3.000)
0.0984 (2.500)
0.0374 (0.950) REF
0.0748 (1.900)
REF
0.0512 (1.300)
0.0354 (0.900)
0.0079 (0.200)
0.0035 (0.090)
0.0571 (1.450)
0.0354 (0.900)
0.0590 (0.150)
0.0000 (0.000)
0.0197 (0.500)
0.0118 (0.300)
SEATING
PLANE
108
08
0.0236 (0.600)
0.0039 (0.100)
NOTE:
PACKAGE OUTLINE INCLUSIVE AS SOLDER PLATING.
PRINTED IN U.S.A.
PIN 1
0.0098 (0.25)
0.0040 (0.10)
C3454a–8–12/98
8-Lead ␮SOIC
(RM-8)
8-Lead Narrow Body SOIC
(SO-8)
–12–
REV. A