AD8616ARZ1 [ADI]

Precision, 20 MHz, CMOS, Rail-to-Rail Input/Output Operational Amplifiers; 精密, 20 MHz的CMOS轨到轨输入/输出运算放大器
AD8616ARZ1
型号: AD8616ARZ1
厂家: ADI    ADI
描述:

Precision, 20 MHz, CMOS, Rail-to-Rail Input/Output Operational Amplifiers
精密, 20 MHz的CMOS轨到轨输入/输出运算放大器

运算放大器
文件: 总20页 (文件大小:442K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
Precision, 20 MHz, CMOS, Rail-to-Rail  
Input/Output Operational Amplifiers  
AD8615/AD8616/AD8618  
FEATURES  
PIN CONFIGURATIONS  
Low offset voltage: 65 μV maximum  
Single-supply operation: 2.7 V to 5.0 V  
Low noise: 8 nV/√Hz  
Wide bandwidth: >20 MHz  
Slew rate: 12 V/μs  
5
V+  
OUT  
V–  
1
2
3
AD8615  
TOP VIEW  
(Not to Scale)  
4
–IN  
+IN  
High output current: 150 mA  
No phase reversal  
Figure 1. 5-Lead TSOT-23 (UJ-5)  
Low input bias current: 1 pA  
Low supply current: 2 mA  
Unity-gain stable  
OUT A  
–IN A  
+IN A  
V–  
1
2
3
4
8
7
6
5
V+  
AD8616  
OUT B  
–IN B  
+IN B  
TOP VIEW  
(Not to Scale)  
APPLICATIONS  
Figure 2. 8-Lead MSOP (RM-8)  
Barcode scanners  
Battery-powered instrumentation  
Multipole filters  
Sensors  
ASIC input or output amplifiers  
Audio  
Photodiode amplification  
OUT A  
–IN A  
+IN A  
V–  
1
2
3
4
8
7
6
5
V+  
AD8616  
OUT B  
–IN B  
+IN B  
TOP VIEW  
(Not to Scale)  
Figure 3. 8-Lead SOIC (R-8)  
OUT A  
–IN A  
+IN A  
V+  
+IN B  
–IN B  
OUT B  
1
14  
OUT D  
–IN D  
+IN D  
V–  
+IN C  
–IN C  
OUT C  
GENERAL DESCRIPTION  
AD8618  
TOP VIEW  
(Not to Scale)  
The AD8615/AD8616/AD8618 are single/dual/quad, rail-to-  
rail, input and output, single-supply amplifiers featuring very  
low offset voltage, wide signal bandwidth, and low input voltage  
and current noise. The parts use a patented trimming technique  
that achieves superior precision without laser trimming. The  
AD8615/AD8616/ AD8618 are fully specified to operate from  
2.7 V to 5 V single supplies.  
7
8
Figure 4. 14-Lead TSSOP (RU-14)  
OUT A  
–IN A  
+IN A  
V+  
1
2
3
4
5
6
7
14 OUT D  
13 –IN D  
12 +IN D  
11 V–  
AD8618  
TOP VIEW  
The combination of >20 MHz bandwidth, low offset, low noise,  
and low input bias current makes these amplifiers useful in a  
wide variety of applications. Filters, integrators, photodiode  
amplifiers, and high impedance sensors all benefit from the  
combination of performance features. AC applications benefit from  
the wide bandwidth and low distortion. The AD8615/AD8616/  
AD8618 offer the highest output drive capability of the DigiTrim®  
family, which is excellent for audio line drivers and other low  
impedance applications.  
(Not to Scale)  
+IN B  
–IN B  
OUT B  
10 +IN C  
9
8
–IN C  
OUT C  
Figure 5. 14-Lead SOIC (R-14)  
The AD8615/AD8616/AD8618 are specified over the extended  
industrial temperature range (−40°C to +125°C). The AD8615  
is available in 5-lead TSOT-23 package. The AD8616 is available  
in 8-lead MSOP and narrow SOIC surface-mount packages; the  
MSOP version is available in tape and reel only. The AD8618 is  
available in 14-lead SOIC and TSSOP packages.  
Applications for the parts include portable and low powered  
instrumentation, audio amplification for portable devices,  
portable phone headsets, bar code scanners, and multipole  
filters. The ability to swing rail-to-rail at both the input and  
output enables designers to buffer CMOS ADCs, DACs, ASICs,  
and other wide output swing devices in single-supply systems.  
Rev. E  
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 that may result from its use. Specifications subject to change without notice. No  
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.  
Trademarks and registeredtrademarks arethe property of their respective owners.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
Tel: 781.329.4700  
www.analog.com  
Fax: 781.461.3113 ©2004–2008 Analog Devices, Inc. All rights reserved.  
 
AD8615/AD8616/AD8618  
TABLE OF CONTENTS  
Features .............................................................................................. 1  
Output Phase Reversal............................................................... 11  
Driving Capacitive Loads.......................................................... 11  
Overload Recovery Time .......................................................... 12  
D/A Conversion ......................................................................... 12  
Low Noise Applications............................................................. 12  
High Speed Photodiode Preamplifier...................................... 13  
Active Filters ............................................................................... 13  
Power Dissipation....................................................................... 13  
Power Calculations for Varying or Unknown Loads............. 14  
Outline Dimensions....................................................................... 15  
Ordering Guide .......................................................................... 17  
Applications....................................................................................... 1  
General Description......................................................................... 1  
Pin Configurations ........................................................................... 1  
Revision History ............................................................................... 2  
Specifications..................................................................................... 3  
Absolute Maximum Ratings............................................................ 5  
Thermal Resistance ...................................................................... 5  
ESD Caution.................................................................................. 5  
Typical Performance Characteristics ............................................. 6  
Applications Information .............................................................. 11  
Input Overvoltage Protection ................................................... 11  
REVISION HISTORY  
9/08—Rev. D to Rev. E  
4/04—Rev. 0 to Rev. A  
Changes to General Description Section ...................................... 1  
Updated Outline Dimensions....................................................... 15  
Changes to Ordering Guide .......................................................... 17  
Added AD8618 ...................................................................Universal  
Updated Outline Dimensions....................................................... 16  
1/04—Revision 0: Initial Version  
5/08—Rev. C to Rev. D  
Changes to Layout ............................................................................ 1  
Changes to Figure 38...................................................................... 11  
Changes to Figure 44 and Figure 45............................................. 13  
Changes to Layout .......................................................................... 15  
Changes to Layout .......................................................................... 16  
6/05—Rev. B to Rev. C  
Change to Table 1 ............................................................................. 3  
Change to Table 2 ............................................................................. 4  
Change to Figure 20 ......................................................................... 8  
1/05—Rev. A to Rev. B  
Added AD8615 ...................................................................Universal  
Changes to Figure 12........................................................................ 8  
Deleted Figure 19; Renumbered Subsequently............................. 8  
Changes to Figure 20........................................................................ 9  
Changes to Figure 29...................................................................... 10  
Changes to Figure 31...................................................................... 11  
Deleted Figure 34; Renumbered Subsequently........................... 11  
Deleted Figure 35; Renumbered Subsequently........................... 35  
Rev. E | Page 2 of 20  
 
AD8615/AD8616/AD8618  
SPECIFICATIONS  
VS =5 V, VCM = VS/2, TA = 25°C, unless otherwise noted.  
Table 1.  
Parameter  
Symbol  
Conditions  
Min  
Typ  
Max  
Unit  
INPUT CHARACTERISTICS  
Offset Voltage, AD8616/AD8618  
Offset Voltage, AD8615  
VOS  
VS = 3.5 V at VCM = 0.5 V and 3.0 V  
23  
23  
80  
60  
100  
500  
800  
7
μV  
μV  
μV  
μV  
μV/°C  
μV/°C  
pA  
VCM = 0 V to 5 V  
−40°C < TA < +125°C  
−40°C < TA < +125°C  
Offset Voltage Drift, AD8616/AD8618  
Offset Voltage Drift, AD8615  
Input Bias Current  
∆VOS/∆T  
IB  
1.5  
3
0.2  
10  
1
−40°C < TA < +85°C  
−40°C < TA < +125°C  
50  
550  
0.5  
50  
250  
5
pA  
pA  
pA  
pA  
pA  
V
Input Offset Current  
IOS  
0.1  
−40°C < TA < +85°C  
−40°C < TA < +125°C  
Input Voltage Range  
0
Common-Mode Rejection Ratio  
Large Signal Voltage Gain  
Input Capacitance  
CMRR  
AVO  
CDIFF  
CCM  
VCM = 0 V to 4.5 V  
RL = 2 kΩ, VO = 0.5 V to 5 V  
80  
105  
100  
1500  
2.5  
dB  
V/mV  
pF  
6.7  
pF  
OUTPUT CHARACTERISTICS  
Output Voltage High  
VOH  
IL = 1 mA  
IL = 10 mA  
−40°C < TA < +125°C  
IL = 1 mA  
IL = 10 mA  
4.98  
4.88  
4.7  
4.99  
4.92  
V
V
V
mV  
mV  
mV  
mA  
Ω
Output Voltage Low  
VOL  
7.5  
70  
15  
100  
200  
−40°C < TA < +125°C  
Output Current  
Closed-Loop Output Impedance  
POWER SUPPLY  
IOUT  
ZOUT  
150  
3
f = 1 MHz, AV = 1  
Power Supply Rejection Ratio  
Supply Current per Amplifier  
PSRR  
ISY  
VS = 2.7 V to 5.5 V  
VO = 0 V  
−40°C < TA < +125°C  
70  
90  
1.7  
dB  
mA  
mA  
2
2.5  
DYNAMIC PERFORMANCE  
Slew Rate  
Settling Time  
Gain Bandwidth Product  
Phase Margin  
SR  
tS  
GBP  
Øm  
RL = 2 kΩ  
To 0.01%  
12  
<0.5  
24  
V/μs  
μs  
MHz  
Degrees  
63  
NOISE PERFORMANCE  
Peak-to-Peak Noise  
Voltage Noise Density  
en p-p  
en  
0.1 Hz to 10 Hz  
f = 1 kHz  
f = 10 kHz  
f = 1 kHz  
f = 10 kHz  
f = 100 kHz  
2.4  
10  
7
0.05  
−115  
−110  
μV  
nV/√Hz  
nV/√Hz  
pA/√Hz  
dB  
Current Noise Density  
Channel Separation  
in  
CS  
dB  
Rev. E | Page 3 of 20  
 
AD8615/AD8616/AD8618  
VS = 2.7 V, VCM = VS/2, TA = 25°C, unless otherwise noted.  
Table 2.  
Parameter  
Symbol  
Conditions  
Min  
Typ  
Max  
Unit  
INPUT CHARACTERISTICS  
Offset Voltage, AD8616/AD8618  
Offset Voltage, AD8615  
VOS  
VS = 3.5 V at VCM = 0.5 V and 3.0 V  
23  
23  
80  
65  
μV  
μV  
μV  
μV  
100  
500  
800  
7
10  
1
VCM = 0 V to 2.7 V  
−40°C < TA < +125°C  
−40°C < TA < +125°C  
Offset Voltage Drift, AD8616/AD8618  
Offset Voltage Drift, AD8615  
Input Bias Current  
∆VOS/∆T  
IB  
1.5  
3
0.2  
μV/°C  
μV/°C  
pA  
−40°C < TA < +85°C  
−40°C < TA < +125°C  
50  
pA  
pA  
pA  
pA  
pA  
V
550  
0.5  
50  
250  
2.7  
Input Offset Current  
IOS  
0.1  
−40°C < TA < +85°C  
−40°C < TA < +125°C  
Input Voltage Range  
0
Common-Mode Rejection Ratio  
Large Signal Voltage Gain  
Input Capacitance  
CMRR  
AVO  
CDIFF  
CCM  
VCM = 0 V to 2.7 V  
RL = 2 kΩ, VO = 0.5 V to 2.2 V  
80  
55  
100  
150  
2.5  
dB  
V/mV  
pF  
7.8  
pF  
OUTPUT CHARACTERISTICS  
Output Voltage High  
VOH  
VOL  
IL = 1 mA  
−40°C < TA < +125°C  
IL = 1 mA  
2.65  
2.6  
2.68  
11  
V
V
mV  
mV  
mA  
Ω
Output Voltage Low  
25  
30  
−40°C < TA < +125°C  
Output Current  
Closed-Loop Output Impedance  
POWER SUPPLY  
IOUT  
ZOUT  
50  
3
f = 1 MHz, AV = 1  
Power Supply Rejection Ratio  
Supply Current per Amplifier  
PSRR  
ISY  
VS = 2.7 V to 5.5 V  
VO = 0 V  
−40°C < TA < +125°C  
70  
90  
1.7  
dB  
mA  
mA  
2
2.5  
DYNAMIC PERFORMANCE  
Slew Rate  
Settling Time  
Gain Bandwidth Product  
Phase Margin  
SR  
tS  
GBP  
Øm  
RL = 2 kΩ  
To 0.01%  
12  
<0.3  
23  
V/μs  
μs  
MHz  
Degrees  
42  
NOISE PERFORMANCE  
Peak-to-Peak Noise  
Voltage Noise Density  
en p-p  
en  
0.1 Hz to 10 Hz  
f = 1 kHz  
f = 10 kHz  
f = 1 kHz  
f = 10 kHz  
f = 100 kHz  
2.1  
10  
7
0.05  
−115  
−110  
μV  
nV/√Hz  
nV/√Hz  
pA/√Hz  
dB  
Current Noise Density  
Channel Separation  
in  
CS  
dB  
Rev. E | Page 4 of 20  
AD8615/AD8616/AD8618  
ABSOLUTE MAXIMUM RATINGS  
Table 3.  
THERMAL RESISTANCE  
θJA is specified for the worst-case conditions, that is, θJA is specified  
for a device soldered in a circuit board for surface-mount packages.  
Parameter  
Rating  
Supply Voltage  
6 V  
Input Voltage  
GND to VS  
3 V  
Indefinite  
−65°C to +150°C  
−40°C to +125°C  
300°C  
Table 4.  
Package Type  
Differential Input Voltage  
Output Short-Circuit Duration to GND  
Storage Temperature Range  
Operating Temperature Range  
Lead Temperature (Soldering, 60 sec)  
Junction Temperature  
θJA  
θJC  
61  
45  
43  
36  
35  
Unit  
°C/W  
°C/W  
°C/W  
°C/W  
°C/W  
5-Lead TSOT-23 (UJ)  
8-Lead MSOP (RM)  
8-Lead SOIC (R)  
14-Lead SOIC (R)  
14-Lead TSSOP (RU)  
207  
210  
158  
120  
180  
150°C  
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 indicated in the operational  
section of this specification is not implied. Exposure to absolute  
maximum rating conditions for extended periods may affect  
device reliability.  
ESD CAUTION  
Rev. E | Page 5 of 20  
 
AD8615/AD8616/AD8618  
TYPICAL PERFORMANCE CHARACTERISTICS  
2200  
350  
300  
250  
200  
150  
100  
50  
V
= 5V  
= 25°C  
V = ±2.5V  
S
S
2000  
1800  
1600  
1400  
1200  
1000  
800  
T
A
V
= 0V TO 5V  
CM  
600  
400  
200  
0
0
–700  
–500  
–300  
–100  
100  
300  
500  
700  
0
25  
50  
75  
100  
125  
TEMPERATURE (-°C)  
OFFSET VOLTAGE (µV)  
Figure 9. Input Bias Current vs. Temperature  
Figure 6. Input Offset Voltage Distribution  
22  
20  
18  
16  
14  
12  
10  
8
1000  
100  
10  
V
T
= 5V  
= 25°C  
S
A
V
= ±2.5V  
S
T
= –40°C TO +125°C  
= 0V  
A
V
CM  
SOURCE  
SINK  
6
1
4
2
0
0.1  
0.001  
1
10  
100  
0.01  
0.1  
0
2
4
6
8
10  
12  
I
(mA)  
LOAD  
TCV (µV/°C)  
OS  
Figure 10. Output Voltage to Supply Rail vs. Load Current  
Figure 7. Offset Voltage Drift Distribution  
500  
400  
120  
100  
80  
60  
40  
20  
0
V
T
= 5V  
= 25°C  
S
A
V
= 5V  
S
300  
10mA LOAD  
200  
100  
0
–100  
–200  
–300  
–400  
–500  
1mA LOAD  
0
0.5  
1.0  
1.5  
2.0  
2.5  
3.0  
3.5  
4.0  
4.5  
5.0  
–40 –25 –10  
5
20  
35  
50  
65  
80  
95 110 125  
COMMON-MODE VOLTAGE (V)  
TEMPERATURE (°C)  
Figure 8. Input Offset Voltage vs. Common-Mode Voltage  
(200 Units, Five Wafer Lots Including Process Skews)  
Figure 11. Output Saturation Voltage vs. Temperature  
Rev. E | Page 6 of 20  
 
AD8615/AD8616/AD8618  
120  
100  
80  
60  
40  
20  
0
100  
225  
V
T
Ø
= ±2.5V  
= 25°C  
= 63°  
S
A
V
= ±2.5V  
S
80  
60  
40  
20  
0
180  
135  
90  
45  
0
m
–20  
–40  
–60  
–45  
–90  
–135  
–80  
–180  
–225  
–100  
1M  
10M  
60M  
1k  
10k  
100k  
1M  
10M  
FREQUENCY (Hz)  
FREQUENCY (Hz)  
Figure 15. CMRR vs. Frequency  
Figure 12. Open-Loop Gain and Phase vs. Frequency  
120  
100  
80  
60  
40  
20  
0
5.0  
V
= ±2.5V  
S
V
V
T
R
A
= 5.0V  
= 4.9V p-p  
= 25°C  
= 2k  
= 1  
4.5  
4.0  
3.5  
3.0  
2.5  
2.0  
1.5  
1.0  
0.5  
0
S
IN  
A
L
V
1k  
10k  
100k  
1M  
10M  
1k  
10k  
100k  
1M  
10M  
FREQUENCY (Hz)  
FREQUENCY (Hz)  
Figure 13. Closed-Loop Output Voltage Swing vs. Frequency  
Figure 16. PSRR vs. Frequency  
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
50  
45  
40  
35  
30  
25  
20  
15  
10  
5
V
= ±2.5V  
S
V = 5V  
S
R
= ∞  
L
T
A
= 25°C  
= 1  
A
V
A
= 100  
A = 1  
V
–OS  
+OS  
V
A
= 10  
V
0
1k  
10k  
100k  
1M  
10M  
100M  
10  
100  
1000  
FREQUENCY (Hz)  
CAPACITANCE (pF)  
Figure 14. Output Impedance vs. Frequency  
Figure 17. Small-Signal Overshoot vs. Load Capacitance  
Rev. E | Page 7 of 20  
AD8615/AD8616/AD8618  
2.4  
2.2  
2.0  
V
= 5V  
S
R
C
A
= 10k  
= 200pF  
= 1  
L
L
V
V
= 2.7V  
S
1.8  
1.6  
1.4  
1.2  
1.0  
0.8  
0.6  
0.4  
0.2  
0
V
= 5V  
S
–40 –25 –10  
5
20  
35  
50  
65  
80  
95 110 125  
TIME (1µs/DIV)  
TEMPERATURE (°C)  
Figure 21. Small Signal Transient Response  
Figure 18. Supply Current vs. Temperature  
2000  
1800  
1600  
1400  
1200  
1000  
800  
V
= 5V  
S
R
C
A
= 10k  
= 200pF  
= 1  
L
L
V
600  
400  
200  
0
0
0.5  
1.0  
1.5  
2.0  
2.5  
3.0  
3.5  
4.0  
4.5  
5.0  
TIME (1s/DIV)  
SUPPLY VOLTAGE (V)  
Figure 19. Supply Current per Amplifier vs. Supply Voltage  
Figure 22. Large Signal Transient Response  
0.1  
0.01  
1k  
V
V
= ±2.5V  
= ±1.35V  
V
V
A
= ±2.5V  
= 0.5V rms  
= 1  
S
S
S
IN  
V
BW = 22kHz  
= 100k  
R
L
100  
0.001  
0.0001  
10  
1
10  
100  
1k  
10k  
100k  
20  
100  
1k  
20k  
FREQUENCY (Hz)  
FREQUENCY (Hz)  
Figure 23. THD + N vs. Frequency  
Figure 20. Voltage Noise Density vs. Frequency  
Rev. E | Page 8 of 20  
AD8615/AD8616/AD8618  
500  
400  
V
V
A
= ±2.5V  
= 2V p-p  
= 10  
S
V
T
= 2.7V  
= 25°C  
S
A
IN  
V
300  
200  
100  
0
–100  
–200  
–300  
–400  
–500  
0
0.3  
0.6  
0.9  
1.2  
1.5  
1.8  
2.1  
2.4  
2.7  
TIME (200ns/DIV)  
COMMON-MODE VOLTAGE (V)  
Figure 24. Settling Time  
Figure 27. Input Offset Voltage vs. Common-Mode Voltage  
(200 Units, Five Wafer Lots Including Process Skews)  
500  
400  
V
= 2.7V  
S
V
T
= 3.5V  
= 25°C  
S
A
300  
200  
100  
0
–100  
–200  
–300  
–400  
–500  
0
0.5  
1.0  
1.5  
2.0  
2.5  
3.0  
3.5  
TIME (1s/DIV)  
COMMON-MODE VOLTAGE (V)  
Figure 25. 0.1 Hz to 10 Hz Input Voltage Noise  
Figure 28. Input Offset Voltage vs. Common-Mode Voltage  
(200 Units, Five Wafer Lots Including Process Skews)  
1000  
1400  
1200  
1000  
800  
600  
400  
200  
0
V
= 2.7V  
S
V
T
= ±1.35V  
= 25°C  
S
T
= 25°C  
A
A
V
= 0V TO 2.7V  
CM  
100  
10  
SOURCE  
SINK  
1
0.1  
0.001  
–700  
–500  
–300  
–100  
100  
300  
500  
700  
0.01  
0.1  
(mA)  
1
10  
I
LOAD  
OFFSET VOLTAGE (µV)  
Figure 29. Output Voltage to Supply Rail vs. Load Current  
Figure 26. Input Offset Voltage Distribution  
Rev. E | Page 9 of 20  
AD8615/AD8616/AD8618  
18  
50  
45  
40  
35  
30  
25  
20  
15  
10  
5
V
= 2.7V  
V
R
= ±1.35V  
= ∞  
S
S
16  
14  
12  
10  
8
L
T
A
= 25°C  
= 1  
V
@ 1mA LOAD  
A
OH  
V
V
@ 1mA LOAD  
OL  
–O  
S
+OS  
6
4
2
0
0
–40 –25 –10  
5
20  
35  
50  
65  
80  
95 110 125  
10  
100  
CAPACITANCE (pF)  
1000  
TEMPERATURE (°C)  
Figure 30. Output Saturation Voltage vs. Temperature  
Figure 33. Small Signal Overshoot vs. Load Capacitance  
100  
225  
V
= 2.7V  
= 10kΩ  
= 200pF  
= 1  
S
V
= ±1.35V  
= 25°C  
= 42°  
S
R
C
A
L
L
V
80  
60  
40  
20  
0
180  
135  
90  
T
A
Ø
m
45  
0
–20  
–40  
–60  
–45  
–90  
–135  
–80  
–180  
–225  
–100  
1M  
10M  
60M  
FREQUENCY (Hz)  
TIME (1µs/DIV)  
Figure 31. Open-Loop Gain and Phase vs. Frequency  
Figure 34. Small Signal Transient Response  
2.7  
V
= 2.7V  
= 10kΩ  
= 200pF  
= 1  
S
R
C
A
L
L
V
V
V
= 2.7V  
= 2.6V p-p  
= 25°C  
= 2k  
= 1  
S
2.4  
2.1  
1.8  
1.5  
1.2  
0.9  
0.6  
0.3  
0
IN  
T
A
R
A
L
V
1k  
10k  
100k  
1M  
10M  
TIME (1µs/DIV)  
FREQUENCY (Hz)  
Figure 32. Closed-Loop Output Voltage Swing vs. Frequency  
Figure 35. Large Signal Transient Response  
Rev. E | Page 10 of 20  
AD8615/AD8616/AD8618  
APPLICATIONS INFORMATION  
This reduces the overshoot and minimizes ringing, which in  
turn improves the frequency response of the AD8615/AD8616/  
AD8618. One simple technique for compensation is the snubber,  
which consists of a simple RC network. With this circuit in place,  
output swing is maintained and the amplifier is stable at all gains.  
INPUT OVERVOLTAGE PROTECTION  
The AD8615/AD8616/AD8618 have internal protective circuitry  
that allows voltages exceeding the supply to be applied at the input.  
It is recommended, however, not to apply voltages that exceed  
the supplies by more than 1.5 V at either input of the amplifier.  
If a higher input voltage is applied, series resistors should be  
used to limit the current flowing into the inputs.  
Figure 38 shows the implementation of the snubber, which  
reduces overshoot by more than 30% and eliminates ringing  
that can cause instability. Using the snubber does not recover  
the loss of bandwidth incurred from a heavy capacitive load.  
The input current should be limited to <5 mA. The extremely  
low input bias current allows the use of larger resistors, which  
allows the user to apply higher voltages at the inputs. The use of  
these resistors adds thermal noise, which contributes to the overall  
output voltage noise of the amplifier.  
V
A
C
= ±2.5V  
= 1  
= 500pF  
S
V
L
For example, a 10 kΩ resistor has less than 13 nV/√Hz of  
thermal noise and less than 10 nV of error voltage at room  
temperature.  
OUTPUT PHASE REVERSAL  
The AD8615/AD8616/AD8618 are immune to phase inversion,  
a phenomenon that occurs when the voltage applied at the input of  
the amplifier exceeds the maximum input common mode.  
Phase reversal can cause permanent damage to the amplifier  
and can create lock ups in systems with feedback loops.  
TIME (2µs/DIV)  
Figure 37. Driving Heavy Capacitive Loads Without Compensation  
V
V
A
R
= ±2.5V  
S
= 6V p-p  
= 1  
IN  
V
L
= 10k  
V
EE  
+
V–  
V+  
200  
V
OUT  
V
500pF  
IN  
500pF  
V
CC  
200mV  
Figure 38. Snubber Network  
V
= ±2.5V  
= 1  
= 200Ω  
= 500pF  
= 500pF  
S
A
R
C
C
V
S
S
L
TIME (2ms/DIV)  
Figure 36. No Phase Reversal  
DRIVING CAPACITIVE LOADS  
Although the AD8615/AD8616/AD8618 are capable of driving  
capacitive loads of up to 500 pF without oscillating, a large amount  
of overshoot is present when operating at frequencies above  
100 kHz. This is especially true when the amplifier is configured  
in positive unity gain (worst case). When such large capacitive  
loads are required, the use of external compensation is highly  
recommended.  
TIME (10µs/DIV)  
Figure 39. Driving Heavy Capacitive Loads Using the Snubber Network  
Rev. E | Page 11 of 20  
 
 
AD8615/AD8616/AD8618  
5V  
2.5V  
OVERLOAD RECOVERY TIME  
10µF  
+
Overload recovery time is the time it takes the output of the  
amplifier to come out of saturation and recover to its linear region.  
Overload recovery is particularly important in applications where  
small signals must be amplified in the presence of large transients.  
Figure 40 and Figure 41 show the positive and negative overload  
recovery times of the AD8616. In both cases, the time elapsed  
before the AD8616 comes out of saturation is less than 1 μs. In  
addition, the symmetry between the positive and negative recovery  
times allows excellent signal rectification without distortion to the  
output signal.  
0.1µF  
0.1µF  
SERIAL  
INTERFACE  
V
REFF  
REFS  
DD  
1/2  
AD8616  
CS  
UNIPOLAR  
OUTPUT  
DIN  
AD5542  
V
OUT  
SCLK  
LDAC  
DGND  
AGND  
Figure 42. Buffering DAC Output  
LOW NOISE APPLICATIONS  
V
R
A
= ±2.5V  
= 10k  
= 100  
S
L
Although the AD8618 typically has less than 8 nV/√Hz of voltage  
noise density at 1 kHz, it is possible to reduce it further. A simple  
method is to connect the amplifiers in parallel, as shown in  
Figure 43. The total noise at the output is divided by the square  
root of the number of amplifiers. In this case, the total noise is  
approximately 4 nV/√Hz at room temperature. The 100 Ω  
resistor limits the current and provides an effective output  
resistance of 50 Ω.  
V
+2.5V  
V
= 50mV  
IN  
0V  
0V  
3
V
IN  
R3  
V+  
V–  
1
–50mV  
R1  
2
100Ω  
10Ω  
TIME (1µs/DIV)  
R2  
Figure 40. Positive Overload Recovery  
1kΩ  
3
2
R6  
V+  
V–  
1
1
1
V
R
A
= ±2.5V  
= 10kΩ  
= 100  
= 50mV  
S
R4  
L
100Ω  
V
10Ω  
V
IN  
R5  
2.5V  
V
OUT  
0V  
0V  
1kΩ  
3
2
R9  
V+  
V–  
R7  
100Ω  
10Ω  
R8  
1kΩ  
+50mV  
3
2
R12  
V+  
V–  
R10  
TIME (1µs/DIV)  
100Ω  
10Ω  
Figure 41. Negative Overload Recovery  
R11  
D/A CONVERSION  
1kΩ  
The AD8616 can be used at the output of high resolution DACs.  
The low offset voltage, fast slew rate, and fast settling time make  
the part suitable to buffer voltage output or current output  
DACs.  
Figure 43. Noise Reduction  
Figure 42 shows an example of the AD8616 at the output of the  
AD5542. The AD8616s rail-to-rail output and low distortion  
help maintain the accuracy needed in data acquisition systems  
and automated test equipment.  
Rev. E | Page 12 of 20  
 
 
 
 
 
AD8615/AD8616/AD8618  
10  
0
HIGH SPEED PHOTODIODE PREAMPLIFIER  
The AD8615/AD8616/AD8618 are excellent choices for I-to-V  
conversions. The very low input bias, low current noise, and  
high unity-gain bandwidth of the parts make them suitable,  
especially for high speed photodiode preamplifiers.  
–10  
–20  
–30  
–40  
In high speed photodiode applications, the diode is operated in a  
photoconductive mode (reverse biased). This lowers the junction  
capacitance at the expense of an increase in the amount of dark  
current that flows out of the diode.  
The total input capacitance, C1, is the sum of the diode and op  
amp input capacitances. This creates a feedback pole that causes  
degradation of the phase margin, making the op amp unstable.  
Therefore, it is necessary to use a capacitor in the feedback to  
compensate for this pole.  
0.1  
1
10  
100  
1k  
10k  
100k  
1M  
FREQUENCY (Hz)  
Figure 46. Second-Order Butterworth, Low-Pass Filter Frequency Response  
To get the maximum signal bandwidth, select  
POWER DISSIPATION  
C1  
2πR2 fU  
Although the AD8615/AD8616/AD8618 are capable of providing  
load currents up to 150 mA, the usable output, load current,  
and drive capability are limited to the maximum power dissipation  
allowed by the device package.  
C2 =  
where fU is the unity-gain bandwidth of the amplifier.  
C2  
In any application, the absolute maximum junction temperature  
for the AD8615/AD8616/AD8618 is 150°C. This should never  
be exceeded because the device could suffer premature failure.  
Accurately measuring power dissipation of an integrated circuit  
is not always a straightforward exercise; Figure 47 is a design aid  
for setting a safe output current drive level or selecting a heat  
sink for the package options available on the AD8616.  
1.5  
R2  
–2.5V  
V–  
I
R
C
C
IN  
D
SH  
D
V+  
+
+2.5V  
–V  
BIAS  
Figure 44. High Speed Photodiode Preamplifier  
ACTIVE FILTERS  
1.0  
SOIC  
The low input bias current and high unity-gain bandwidth of  
the AD8616 make it an excellent choice for precision filter design.  
MSOP  
Figure 45 shows the implementation of a second-order, low-pass  
filter. The Butterworth response has a corner frequency of 100 kHz  
0.5  
and a phase shift of 90°. The frequency response is shown in  
Figure 46.  
2nF  
0
0
20  
40  
60  
80  
100  
120  
140  
V
EE  
TEMPERATURE (°C)  
Figure 47. Maximum Power Dissipation vs. Ambient Temperature  
V–  
V+  
1.1k  
1.1kΩ  
These thermal resistance curves were determined using the  
AD8616 thermal resistance data for each package and a  
maximum junction temperature of 150°C.  
V
IN  
1nF  
V
CC  
Figure 45. Second-Order, Low-Pass Filter  
Rev. E | Page 13 of 20  
 
 
 
 
AD8615/AD8616/AD8618  
The following formula can be used to calculate the internal  
junction temperature of the AD8615/AD8616/AD8618 for any  
application:  
Calculating Power by Measuring Ambient Temperature  
and Case Temperature  
The two equations for calculating the junction temperature are  
TJ = PDISS × θJA + TA  
TJ = TA + P θJA  
where:  
TJ = junction temperature  
where:  
TJ = junction temperature  
TA = ambient temperature  
θJA = the junction-to-ambient thermal resistance  
PDISS = power dissipation  
θJA = package thermal resistance, junction-to-case  
TA = ambient temperature of the circuit  
TJ = TC + P θJC  
To calculate the power dissipated by the AD8615/AD8616/  
AD8618, use the following:  
where:  
TC is case temperature.  
θJA and θJC are given in the data sheet.  
PDISS = ILOAD × (VS VOUT  
)
where:  
The two equations for calculating P (power) are  
TA + P θJA = TC + P θJC  
ILOAD = output load current  
VS = supply voltage  
VOUT = output voltage  
P = (TA TC)/(θJC θJA)  
Once the power is determined, it is necessary to recalculate the  
junction temperature to ensure that the temperature was not  
exceeded.  
The quantity within the parentheses is the maximum voltage  
developed across either output transistor.  
POWER CALCULATIONS FOR VARYING OR  
UNKNOWN LOADS  
The temperature should be measured directly on and near the  
package but not touching it. Measuring the package can be  
difficult. A very small bimetallic junction glued to the package  
can be used, or an infrared sensing device can be used, if the  
spot size is small enough.  
Often, calculating power dissipated by an integrated circuit to  
determine if the device is being operated in a safe range is not as  
simple as it may seem. In many cases, power cannot be directly  
measured. This may be the result of irregular output waveforms or  
varying loads. Indirect methods of measuring power are required.  
Calculating Power by Measuring Supply Current  
If the supply voltage and current are known, power can be  
calculated directly. However, the supply current can have a dc  
component with a pulse directed into a capacitive load, which  
can make the rms current very difficult to calculate. This difficulty  
can be overcome by lifting the supply pin and inserting an rms  
current meter into the circuit. For this method to work, make  
sure the current is delivered by the supply pin being measured.  
This is usually a good method in a single-supply system; however,  
if the system uses dual supplies, both supplies may need to be  
monitored.  
There are two methods to calculate power dissipated by an  
integrated circuit. The first is to measure the package temperature  
and the board temperature. The second is to directly measure  
the circuit’s supply current.  
Rev. E | Page 14 of 20  
 
AD8615/AD8616/AD8618  
OUTLINE DIMENSIONS  
2.90 BSC  
5
1
4
3
2.80 BSC  
1.60 BSC  
2
0.95 BSC  
1.90  
BSC  
*
0.90 MAX  
0.70 NOM  
*
1.00 MAX  
0.20  
0.08  
8°  
4°  
0°  
0.10 MAX  
0.50  
0.30  
0.60  
0.45  
0.30  
SEATING  
PLANE  
*
COMPLIANT TO JEDEC STANDARDS MO-193-AB WITH  
THE EXCEPTION OF PACKAGE HEIGHT AND THICKNESS.  
Figure 48. 5-Lead Thin Small Outline Transistor Package [TSOT]  
(UJ-5)  
Dimensions shown in millimeters  
3.20  
3.00  
2.80  
8
1
5
4
5.15  
4.90  
4.65  
3.20  
3.00  
2.80  
PIN 1  
0.65 BSC  
0.95  
0.85  
0.75  
1.10 MAX  
0.80  
0.60  
0.40  
8°  
0°  
0.15  
0.00  
0.38  
0.22  
0.23  
0.08  
SEATING  
PLANE  
COPLANARITY  
0.10  
COMPLIANT TO JEDEC STANDARDS MO-187-AA  
Figure 49. 8-Lead Mini Small Outline Package [MSOP]  
(RM-8)  
Dimensions shown in millimeters  
Rev. E | Page 15 of 20  
 
AD8615/AD8616/AD8618  
5.00 (0.1968)  
4.80 (0.1890)  
8
1
5
4
6.20 (0.2441)  
5.80 (0.2284)  
4.00 (0.1574)  
3.80 (0.1497)  
0.50 (0.0196)  
0.25 (0.0099)  
1.27 (0.0500)  
BSC  
45°  
1.75 (0.0688)  
1.35 (0.0532)  
0.25 (0.0098)  
0.10 (0.0040)  
8°  
0°  
0.51 (0.0201)  
0.31 (0.0122)  
COPLANARITY  
0.10  
1.27 (0.0500)  
0.40 (0.0157)  
0.25 (0.0098)  
0.17 (0.0067)  
SEATING  
PLANE  
COMPLIANT TO JEDEC STANDARDS MS-012-AA  
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 50. 8-Lead Standard Small Outline Package [SOIC_N]  
Narrow Body (R-8)  
Dimensions shown in millimeters and (inches)  
8.75 (0.3445)  
8.55 (0.3366)  
8
7
14  
1
6.20 (0.2441)  
5.80 (0.2283)  
4.00 (0.1575)  
3.80 (0.1496)  
1.27 (0.0500)  
0.50 (0.0197)  
0.25 (0.0098)  
45°  
BSC  
1.75 (0.0689)  
1.35 (0.0531)  
0.25 (0.0098)  
0.10 (0.0039)  
8°  
0°  
COPLANARITY  
0.10  
SEATING  
PLANE  
1.27 (0.0500)  
0.40 (0.0157)  
0.51 (0.0201)  
0.31 (0.0122)  
0.25 (0.0098)  
0.17 (0.0067)  
COMPLIANT TO JEDEC STANDARDS MS-012-AB  
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 51. 14-Lead Standard Small Outline Package [SOIC_N]  
Narrow Body (R-14)  
Dimensions shown in millimeters and (inches)  
5.10  
5.00  
4.90  
14  
8
7
4.50  
4.40  
4.30  
6.40  
BSC  
1
PIN 1  
0.65 BSC  
1.05  
1.00  
0.80  
1.20  
MAX  
0.20  
0.09  
0.75  
8°  
0°  
0.15  
0.05  
COPLANARITY  
0.10  
0.60  
0.45  
SEATING  
PLANE  
0.30  
0.19  
COMPLIANT TO JEDEC STANDARDS MO-153-AB-1  
Figure 52. 14-Lead Thin Shrink Small Outline Package [TSSOP]  
(RU-14)  
Dimensions shown in millimeters  
Rev. E | Page 16 of 20  
AD8615/AD8616/AD8618  
ORDERING GUIDE  
Model  
Temperature Range  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
–40°C to +125°C  
Package Description  
5-Lead TSOT-23  
5-Lead TSOT-23  
5-Lead TSOT-23  
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
8-Lead MSOP  
8-Lead SOIC_N  
8-Lead SOIC_N  
8-Lead SOIC_N  
8-Lead SOIC_N  
8-Lead SOIC_N  
8-Lead SOIC_N  
14-Lead SOIC_N  
14-Lead SOIC_N  
14-Lead SOIC_N  
14-Lead SOIC_N  
14-Lead SOIC_N  
14-Lead SOIC_N  
14-Lead TSSOP  
14-Lead TSSOP  
14-Lead TSSOP  
14-Lead TSSOP  
Package Option  
UJ-5  
UJ-5  
Branding  
BKA  
BKA  
AD8615AUJZ-R21  
AD8615AUJZ-REEL1  
AD8615AUJZ-REEL71  
AD8616ARM-R2  
AD8616ARM-REEL  
AD8616ARMZ1  
AD8616ARMZ-R21  
AD8616ARMZ-REEL1  
AD8616AR  
AD8616AR-REEL  
AD8616AR-REEL7  
AD8616ARZ1  
AD8616ARZ-REEL1  
AD8616ARZ-REEL71  
AD8618AR  
AD8618AR-REEL  
AD8618AR-REEL7  
AD8618ARZ1  
AD8618ARZ-REEL1  
AD8618ARZ-REEL71  
AD8618ARU  
AD8618ARU-REEL  
AD8618ARUZ1  
AD8618ARUZ-REEL1  
UJ-5  
BKA  
RM-8  
RM-8  
RM-8  
RM-8  
RM-8  
R-8  
R-8  
R-8  
R-8  
R-8  
BLA  
BLA  
A0K  
A0K  
A0K  
R-8  
R-14  
R-14  
R-14  
R-14  
R-14  
R-14  
RU-14  
RU-14  
RU-14  
RU-14  
1 Z = RoHS Compliant Part.  
Rev. E | Page 17 of 20  
 
 
AD8615/AD8616/AD8618  
NOTES  
Rev. E | Page 18 of 20  
AD8615/AD8616/AD8618  
NOTES  
Rev. E | Page 19 of 20  
AD8615/AD8616/AD8618  
NOTES  
©2004–2008 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D04648-0-9/08(E)  
Rev. E | Page 20 of 20  

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