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1
®
OPA689
©
1997 Burr-Brown Corporation
PDS-1409D
Printed in U.S.A. January, 2000
OPA689
®
Wideband, High Gain
VOLTAGE LIMITING AMPLIFIER
FEATURES
q
HIGH LINEARITY NEAR LIMITING
q
FAST RECOVERY FROM OVERDRIVE: 2.4ns
q
LIMITING VOLTAGE ACCURACY:
±
15mV
q
–3dB BANDWIDTH (G = +6): 280MHz
q
STABLE FOR G
≥
+4
q
SLEW RATE: 1600V/
µ
s
q
±
5V AND +5V SUPPLY OPERATION
q
LOW GAIN VERSION: OPA688
OPA689
OPA689
APPLICATIONS
q
TRANSIMPEDANCE WITH FAST
OVERDRIVE RECOVERY
q
FAST LIMITING ADC INPUT DRIVER
q
LOW PROP DELAY COMPARATOR
q
NON-LINEAR ANALOG SIGNAL
PROCESSING
q
DIFFERENCE AMPLIFIER
q
IF LIMITING AMPLIFIER
q
AM SIGNAL GENERATION
DESCRIPTION
The OPA689 is a wideband, voltage feedback op amp
that offers bipolar output voltage limiting, and is stable
for gains
≥
+4. Two buffered limiting voltages take
control of the output when it attempts to drive beyond
these limits. This new output limiting architecture holds
the limiter offset error to
±
15mV. The op amp operates
linearly to within 30mV of the limits.
The combination of narrow nonlinear range and low
limiting offset allows the limiting voltages to be set within
100mV of the desired linear output range. A fast 2.4ns
recovery from limiting ensures that overdrive signals will
be transparent to the signal channel. Implementing the
limiting function at the output, as opposed to the input,
gives the specified limiting accuracy for any gain, and
allows the OPA689 to be used in all standard op amp
applications.
Non-linear analog signal processing circuits will benefit
from the OPA689’s sharp transition from linear operation
to output limiting. The quick recovery time supports high
speed applications.
The OPA689 is available in an industry-standard pinout
in PDIP-8 and SO-8 packages. For lower gain applica-
tions requiring output limiting with fast recovery, con-
sider the OPA688.
2.5
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
–2.5
LIMITED OUTPUT RESPONSE
V
IN
V
O
Time (200ns/div)
Input and Output Voltage (V)
G = +6
V
H
= 2.0V
V
L
= –2.0V
2.10
2.05
2.00
1.95
1.90
1.85
1.80
1.75
1.70
1.65
1.60
DETAIL OF LIMITED OUTPUT VOLTAGE
Time (50ns/div)
V
O
Input and Output Voltage (V)
International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111
Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
For most current data sheet and other product
information, visit www.burr-brown.com
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2
®
OPA689
AC PERFORMANCE (see Fig. 1)
Small Signal Bandwidth
V
O
< 0.5Vp-p
G = +6
280
220
210
200
MHz
Min
B
G = +12
90
—
—
—
MHz
Typ
C
G = –6
220
—
—
—
MHz
Typ
C
Gain Bandwidth Product (G
≥
+20)
V
O
< 0.5Vp-p
720
490
460
430
MHz
Min
B
Gain Peaking
V
O
< 0.5Vp-p, G = +4
8
—
—
—
dB
Typ
C
0.1dB Gain Flatness Bandwidth
V
O
< 0.5Vp-p
110
—
—
—
MHz
Typ
C
Large Signal Bandwidth
V
O
= 2Vp-p
290
185
175
170
MHz
Min
B
Step Response
Slew Rate
2V Step
1600
1300
1250
950
V/
µ
s
Min
B
Rise/Fall Time
0.5V Step
1.2
1.8
1.9
2.4
ns
Max
B
Settling Time: 0.05%
2V Step
7
—
—
—
ns
Typ
C
Spurious Free Dynamic Range
f = 5MHz, V
O
= 2Vp-p
61
57
53
48
dB
Min
B
Differential Gain
NTSC, PAL, R
L
= 500
Ω
0.02
—
—
—
%
Typ
C
Differential Phase
NTSC, PAL, R
L
= 500
Ω
0.01
—
—
—
°
Typ
C
Input Noise Density
Voltage Noise
f
≥
1MHz
4.6
5.3
6.0
6.1
nV/
√
Hz
Max
B
Current Noise
f
≥
1MHz
2.0
2.5
2.9
3.6
pA/
√
Hz
Max
B
DC PERFORMANCE (V
CM
= 0V)
Open-Loop Voltage Gain (A
OL
)
V
O
=
±
0.5V
56
50
48
47
dB
Min
A
Input Offset Voltage
±
1
±
5
±
6
±
7
mV
Max
A
Average Drift
—
—
±
14
±
14
µ
V/
°
C
Max
B
Input Bias Current
(3)
+8
±
12
±
13
±
20
µ
A
Max
A
Average Drift
—
—
–60
–90
nA/
°
C
Max
B
Input Offset Current
±
0.3
±
2
±
3
±
4
µ
A
Max
A
Average Drift
—
—
±
10
±
10
nA/
°
C
Max
B
INPUT
Common-Mode Rejection Ratio
Input Referred, V
CM
=
±
0.5V
60
53
52
50
dB
Min
A
Common-Mode Input Range
(4)
±
3.3
±
3.2
±
3.2
±
3.1
V
Min
A
Input Impedance
Differential-Mode
0.4 || 1
—
—
—
M
Ω
|| pF
Typ
C
Common-Mode
1 || 1
—
—
—
M
Ω
|| pF
Typ
C
OUTPUT
V
H
= –V
L
= 4.3V
Output Voltage Range
R
L
≥
500
Ω
±
4.1
±
3.9
±
3.9
±
3.8
V
Min
A
Current Output, Sourcing
105
90
85
80
mA
Min
A
Sinking
–85
–70
–65
–60
mA
Min
A
Closed-Loop Output Impedance
G = +4, f < 100kHz
0.8
—
—
—
Ω
Typ
C
POWER SUPPLY
Operating Voltage, Specified
±
5
—
—
—
V
Typ
C
Maximum
—
±
6
±
6
±
6
V
Max
A
Quiescent Current, Maximum
15.8
17
19
20
mA
Max
A
Minimum
15.8
14
12.8
11
mA
Min
A
Power Supply Rejection Ratio
+V
S
= 4.5V to 5.5V
+PSR (Input Referred)
65
58
57
55
dB
Min
A
OUTPUT VOLTAGE LIMITERS
Default Limit Voltage
Limiter Pins Open
±
3.3
±
3.0
±
3.0
±
2.9
V
Min
A
Minimum Limiter Separation (V
H
– V
L
)
200
200
200
200
mV
Min
B
Maximum Limit Voltage
—
±
4.3
±
4.3
±
4.3
V
Max
B
Limiter Input Bias Current Magnitude
(5)
V
O
= 0
Maximum
54
65
68
70
µ
A
Max
A
Minimum
54
35
34
31
µ
A
Min
A
Average Drift
—
—
40
45
nA/
°
C
Max
B
Limiter Input Impedance
2 || 1
—
—
—
M
Ω
|| pF
Typ
C
Limiter Feedthrough
(6)
f = 5MHz
–60
—
—
—
dB
Typ
C
DC Performance in Limit Mode
V
IN
=
±
0.7V
Limiter Offset Voltage
(V
O
– V
H
) or (V
O
– V
L
)
±
15
±
35
±
40
±
40
mV
Max
A
Op Amp Input Bias Current Shift
(3)
3
—
—
—
µ
A
Typ
C
OPA689U, P
TYP
GUARANTEED
(1)
0
°
C to
–40
°
C to
MIN/
TEST
PARAMETER
CONDITIONS
+25
°
C
+25
°
C
+70
°
C
+85
°
C
UNITS
MAX LEVEL
(2)
SPECIFICATIONS — V
S
=
±
5V
G = +6, R
L
= 500
Ω
, R
F
= 750
Ω,
V
H
= –V
L
= 2V, (Figure 1 for AC performance only), unless otherwise noted.
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3
®
OPA689
OUTPUT VOLTAGE LIMITERS (CONT)
AC Performance in Limit Mode
Limiter Small Signal Bandwidth
V
IN
=
±
0.7V, V
O
< 0.02Vp-p
450
—
—
—
MHz
Typ
C
Limiter Slew Rate
(7)
100
—
—
—
V/
µ
s
Typ
C
Limited Step Response
Overshoot
V
IN
= 0 to
±
0.7V Step
250
—
—
—
mV
Typ
C
Recovery Time
V
IN
=
±
0.7V to 0 Step
2.4
2.8
3.0
3.2
ns
Max
B
Linearity Guardband
(8)
f = 5MHz, V
O
= 2Vp-p
30
—
—
—
mV
Typ
C
THERMAL CHARACTERISTICS
Temperature Range
Specification: P, U
–40 to +85
—
—
—
°
C
Typ
C
Thermal Resistance
P
8-Pin DIP
100
—
—
—
°
C/W
Typ
C
U
8-Pin SO-8
125
—
—
—
°
C/W
Typ
C
NOTES: (1) Junction Temperature = Ambient Temperature for low temperature limit and 25
°
C guaranteed specifications. Junction Temperature = Ambient Temperature
+ 23
°
C at high temperature limit guaranteed specifications. (2) TEST LEVELS: (A) 100% tested at 25
°
C. Over temperature limits by characterization and simulation.
(B) Limits set by characterization and simulation. (C) Typical value for information only. (3) Current is considered positive out of node. (4) CMIR tested as < 3dB
degradation from minimum CMRR at specified limits. (5) I
VH
(V
H
bias current) is positive, and I
VL
(V
L
bias current) is negative, under these conditions. See Note 3 and
Figures 1 and 7. (6) Limiter feedthrough is the ratio of the output magnitude to the sinewave added to V
H
(or V
L
) when V
IN
= 0. (7) V
H
slew rate conditions are: V
IN
= +0.7V, G = +6, V
L
= –2V, V
H
= step between 2V and 0V. V
L
slew rate conditions are similar. (8) Linearity Guardband is defined for an output sinusoid (f = 1MHz,
V
O
= 2Vpp) centered between the limiter levels (V
H
and V
L
). It is the difference between the limiter level and the peak output voltage where SFDR decreases by 3dB
(see Figure 8).
OPA689U, P
TYP
GUARANTEED
(1)
0
°
C to
–40
°
C to
MIN/
TEST
PARAMETER
CONDITIONS
+25
°
C
+25
°
C
+70
°
C
+85
°
C
UNITS
MAX LEVEL
(2)
SPECIFICATIONS — V
S
=
±
5V
(cont.)
G = +6, R
L
= 500
Ω
, R
F
= 750
Ω,
V
H
= –V
L
= 2V, (Figure 1 for AC performance only), unless otherwise noted.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
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4
®
OPA689
AC PERFORMANCE (see Fig. 2)
Small Signal Bandwidth
V
O
< 0.5Vp-p
G = +6
210
180
160
150
MHz
Min
B
G = +12
70
—
—
—
MHz
Typ
C
G = –6
180
—
—
—
MHz
Typ
C
Gain Bandwidth Product (G
≥
+20)
V
O
< 0.5Vp-p
440
330
310
300
MHz
Min
B
Gain Peaking
V
O
< 0.5Vp-p, G = +4
4
—
—
—
dB
Typ
B
0.1dB Gain Flatness Bandwidth
V
O
< 0.5Vp-p
35
—
—
—
MHz
Typ
C
Large Signal Bandwidth
V
O
= 2Vp-p
175
150
140
125
MHz
Min
B
Step Response
Slew Rate
2V Step
1600
1300
1250
950
V/
µ
s
Min
B
Rise/Fall Time
0.5V Step
1.9
2.1
2.2
2.6
ns
Max
B
Settling Time: 0.05%
2V Step
7
—
—
—
ns
Typ
C
Spurious Free Dynamic Range
f = 5MHz, V
O
= 2Vp-p
59
55
51
46
dB
Min
B
Input Noise
Voltage Noise Density
f
≥
1MHz
4.6
5.3
6.0
6.1
nV/
√
Hz
Max
B
Current Noise Density
f
≥
1MHz
2.0
2.5
2.9
3.6
pA/
√
Hz
Max
B
DC PERFORMANCE
Open-Loop Voltage Gain (A
OL
)
V
O
=
±
0.5V
56
50
48
47
dB
Min
A
Input Offset Voltage
±
1
±
5
±
6
±
8
mV
Max
A
Average Drift
—
—
±
14
±
14
µ
V/
°
C
Max
B
Input Bias Current
(3)
+8
±
12
±
13
±
20
µ
A
Max
A
Average Drift
—
—
–60
–90
nA/
°
C
Max
B
Input Offset Current
±
0.3
±
2
±
3
±
4
µ
A
Max
A
Average Drift
—
—
±
10
±
10
nA/
°
C
Max
B
INPUT
Common-Mode Rejection Ratio
Input Referred, V
CM
±
0.5V
58
51
50
48
dB
Min
A
Common-Mode Input Range
(4)
V
CM
±
0.8
V
CM
±
0.7
V
CM
±
0.7
V
CM
±
0.6
V
Min
A
Input Impedance
Differential-Mode
0.4 || 1
—
—
—
M
Ω
|| pF
Typ
C
Common-Mode
1 || 1
—
—
—
M
Ω
|| pF
Typ
C
OUTPUT
V
H
= V
CM
+ 1.8V, V
L
= V
CM
– 1.8V
Output Voltage Range
R
L
≥
500
Ω
V
CM
±
1.6
V
CM
±
1.4
V
CM
±
1.4
V
CM
±
1.3
V
Min
A
Current Output, Sourcing
70
60
55
50
mA
Min
A
Sinking
–60
–50
–45
–40
mA
Min
A
Closed-Loop Output Impedance
G = +4, f < 100kHz
0.8
—
—
—
Ω
Typ
C