TI SM73301

SM73301
SM73301 RRIO, High Output Current & Unlimited Cap Load Op Amp in SOT23-5
Literature Number: SNOSB92A
SM73301
RRIO, High Output Current & Unlimited Cap Load Op Amp
in SOT23-5
General Description
Features
The SM73301 is a Rail-to-Rail input and output Op Amp which
can operate with a wide supply voltage range. This device has
high output current drive, greater than Rail-to-Rail input common mode voltage range, unlimited capacitive load drive
capability, and provides tested and guaranteed high speed
and slew rate while requiring only 0.97mA supply current. It
is specifically designed to handle the requirements of flat panel TFT panel VCOM driver applications as well as being suitable for other low power, and medium speed applications
which require ease of use and enhanced performance over
existing devices.
Greater than Rail-to-Rail input common mode voltage range
with 50dB of Common Mode Rejection, allows high side and
low side sensing, among many applications, without having
any concerns over exceeding the range and no compromise
in accuracy. Exceptionally wide operating supply voltage
range of 2.5V to 30V alleviates any concerns over functionality under extreme conditions and offers flexibility of use in
multitude of applications. In addition, most device parameters
are insensitive to power supply variations; this design enhancement is yet another step in simplifying its usage. The
output stage has low distortion (0.05% THD+N) and can supply a respectable amount of current (15mA) with minimal
headroom from either rail (300mV).
The SM73301 is offered in the space saving SOT23-5 package.
(VS = 5V, TA = 25°C, Typical values unless specified).
21MHz
■ GBWP
2.5V to 30V
■ Wide supply voltage range
12V/µs
■ Slew rate
0.97 mA
■ Supply current
Unlimited
■ Cap load limit
+53mA/−75mA
■ Output short circuit current
400ns (500pF, 100mVPP step)
■ ±5% Settling time
0.3V beyond rails
■ Input common mode voltage
15nV/
■ Input voltage noise
1pA/
■ Input current noise
< 0.05%
■ THD+N
Output Response with Heavy
Capacitive Load
Connection Diagram
Applications
■
■
■
■
TFT-LCD flat panel VCOM driver
A/D converter buffer
High side/low side sensing
Headphone amplifier
SOT23-5
30157662
Top View
30157637
Ordering Information
Package
Ordering Info
Pkg Marking
SM73301MFE
5-Pin SOT-23
R134
SM73301MF
SM73301MFX
© 2011 National Semiconductor Corporation
Supplied As
NSC Drawing
250 Units Tape and Reel
1K Units Tape and Reel
MF05A
3K Units Tape and Reel
301576
www.national.com
SM73301 RRIO, High Output Current & Unlimited Cap Load Op Amp in SOT23-5
July 5, 2011
SM73301
Junction Temperature (Note 4)
Soldering Information:
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
ESD Tolerance
Human Body Model
Machine Model
VIN Differential
Output Short Circuit Duration
Supply Voltage (V+ - V−)
Voltage at Input/Output pins
Storage Temperature Range
+150°C
Infrared or Convection (20 sec.)
Wave Soldering (10 sec.)
235°C
260°C
Operating Ratings
2KV (Note 2)
200V(Note 9)
+/−10V
(Note 3, Note 11)
32V
V+ +0.8V, V− −0.1V
−65°C to +150°C
Supply Voltage (V+ - V−)
Temperature Range(Note 4)
2.5V to 30V
−40°C to +85°C
Package Thermal Resistance, θJA,(Note 4)
SOT23-5
325°C/W
2.7V Electrical Characteristics (Note 13)
Unless otherwise specified, all limits guaranteed for TA = 25°C, V+ = 2.7V, V− = 0V, VCM = 0.5V, VO = V+/2, and
RL > 1MΩ to V−. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Condition
Typ
(Note 5)
Limit
(Note 6)
Units
VOS
Input Offset Voltage
VCM = 0.5V & VCM = 2.2V
+/−0.7
+/−5
+/−7
mV
max
TC VOS
Input Offset Average Drift
VCM = 0.5V & VCM = 2.2V
(Note 12)
+/−2
–
µV/C
IB
Input Bias Current
VCM = 0.5V
(Note 7)
−1.20
−2.00
−2.70
VCM = 2.2V
(Note 7)
+0.49
+1.00
+1.60
IOS
Input Offset Current
VCM = 0.5V & VCM = 2.2V
20
250
400
CMRR
Common Mode Rejection Ratio
VCM stepped from 0V to 1.0V
100
76
60
VCM stepped from 1.7V to 2.7V
100
VCM stepped from 0V to 2.7V
70
58
50
µA
max
nA
max
dB
min
+PSRR
Positive Power Supply Rejection
Ratio
V+ = 2.7V to 5V
104
78
74
dB
min
CMVR
Input Common-Mode Voltage
Range
CMRR > 50dB
−0.3
−0.1
0.0
V
max
3.0
2.8
2.7
V
min
VO = 0.5 to 2.2V,
RL = 10K to V−
78
70
67
dB
min
VO = 0.5 to 2.2V,
RL = 2K to V−
73
67
63
dB
min
RL = 10K to V−
2.59
2.49
2.46
RL = 2K to V−
2.53
2.45
2.41
Output Swing
Low
RL = 10K to V−
90
100
120
mV
max
Output Short Circuit Current
Sourcing to V−
VID = 200mV (Note 10)
48
30
20
mA
min
Sinking to V+
VID = −200mV (Note 10)
65
50
30
mA
min
AVOL
VO
ISC
Large Signal Voltage Gain
Output Swing
High
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2
V
min
Parameter
Condition
Typ
(Note 5)
Limit
(Note 6)
Units
0.95
1.20
1.50
mA
max
IS
Supply Current
No load, VCM = 0.5V
SR
Slew Rate (Note 8)
AV = +1,VI = 2VPP
9
–
V/µs
fu
Unity Gain-Frequency
VI = 10mV, RL = 2KΩ to V+/2
10
–
MHz
GBWP
Gain Bandwidth Product
f = 50KHz
21
15.5
14
MHz
min
Phim
Phase Margin
VI = 10mV
50
–
Deg
en
Input-Referred Voltage Noise
f = 2KHz, RS = 50Ω
15
–
in
Input-Referred Current Noise
f = 2KHz
fMAX
Full Power Bandwidth
1
ZL = (20pF || 10KΩ) to
V+/2
nV/
pA/
–
1
MHz
5V Electrical Characteristics (Note 13)
Unless otherwise specified, all limited guaranteed for TA = 25°C, V+ = 5V, V− = 0V, VCM = 1V, VO = V+/2, and
RL > 1MΩ to V−. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Condition
Typ
(Note 5)
Limit
(Note 6)
Units
VOS
Input Offset Voltage
VCM = 1V & VCM = 4.5V
+/−0.7
+/−5
+/− 7
mV
max
TC VOS
Input Offset Average Drift
VCM = 1V & VCM = 4.5V
(Note 12)
+/−2
–
µV/°C
IB
Input Bias Current
VCM = 1V
(Note 7)
−1.18
−2.00
−2.70
VCM = 4.5V
(Note 7)
+0.49
+1.00
+1.60
IOS
Input Offset Current
VCM = 1V & VCM = 4.5V
20
250
400
CMRR
Common Mode Rejection Ratio
VCM stepped from 0V to 3.3V
110
84
72
VCM stepped from 4V to 5V
100
–
VCM stepped from 0V to 5V
80
64
61
µA
max
nA
max
dB
min
+PSRR
Positive Power Supply Rejection Ratio
V+ = 2.7V to 5V, VCM = 0.5V
104
78
74
dB
min
CMVR
Input Common-Mode Voltage Range
CMRR > 50dB
−0.3
−0.1
0.0
V
max
5.3
5.1
5.0
V
min
VO = 0.5 to 4.5V,
RL = 10K to V−
84
74
70
VO = 0.5 to 4.5V,
RL = 2K to V−
80
70
66
RL = 10K to V−
4.87
4.75
4.72
RL = 2K to V−
4.81
4.70
4.66
RL = 10K to V−
86
125
135
AVOL
VO
Large Signal Voltage Gain
Output Swing
High
Output Swing
Low
3
dB
min
V
min
mV
max
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SM73301
Symbol
SM73301
Symbol
ISC
Typ
(Note 5)
Limit
(Note 6)
Sourcing to V−
VID = 200mV (Note 10)
53
35
20
Sinking to V+
VID = −200mV (Note 10)
75
60
50
Parameter
Output Short Circuit Current
Condition
Units
mA
min
IS
Supply Current
No load, VCM = 1V
0.97
1.25
1.75
mA
max
SR
Slew Rate (Note 8)
AV = +1, VI = 5VPP
12
10
7
V/µs
min
fu
Unity Gain Frequency
VI = 10mV,
10.5
–
MHz
RL = 2KΩ to V+/2
GBWP
Gain-Bandwidth Product
f = 50KHz
21
16
15
MHz
min
Phim
Phase Margin
VI = 10mV
53
–
Deg
en
Input-Referred Voltage Noise
f = 2KHz, RS = 50Ω
15
–
nV/
in
Input-Referred Current Noise
f = 2KHz
1
–
pA/
fMAX
Full Power Bandwidth
ZL = (20pF || 10kΩ) to
V+/2
900
–
KHz
tS
Settling Time (±5%)
100mVPP Step, 500pF load
400
–
ns
THD+N
Total Harmonic Distortion + Noise
0.05
–
%
Typ
(Note 5)
Limit
(Note 6)
Units
V+/2
RL = 1KΩ to
f = 10KHz to AV= +2, 4VPP swing
±15V Electrical Characteristics
(Note 13)
Unless otherwise specified, all limited guaranteed for TA = 25°C, V+ = 15V, V− = −15V, VCM = 0V, VO = 0V, and
RL > 1MΩ to 0V. Boldface limits apply at the temperature extremes.
Symbol
Parameter
Condition
VOS
Input Offset Voltage
VCM = −14.5V & VCM = 14.5V
+/−0.7
+/−7
+/− 9
mV
max
TC VOS
Input Offset Average Drift
VCM = −14.5V & VCM = 14.5V
(Note 12)
+/−2
–
µV/°C
IB
Input Bias Current
VCM = −14.5V
(Note 7)
−1.05
−2.00
−2.80
VCM = 14.5V
(Note 7)
+0.49
+1.00
+1.50
µA
max
IOS
Input Offset Current
VCM = −14.5V & VCM = 14.5V
30
275
550
CMRR
Common Mode Rejection Ratio
VCM stepped from −15V to 13V
100
84
80
VCM stepped from 14V to 15V
100
–
VCM stepped from −15V to 15V
88
74
72
V+ = 12V to 15V
100
70
66
dB
min
100
70
66
dB
min
−15.3
−15.1
−15.0
V
max
15.3
15.1
15.0
V
min
+PSRR
Positive Power Supply Rejection Ratio
−PSRR
Negative Power Supply Rejection Ratio V− = −12V to −15V
CMVR
Input Common-Mode Voltage Range
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CMRR > 50dB
4
nA
max
dB
min
AVOL
Typ
(Note 5)
Limit
(Note 6)
85
78
74
79
72
66
RL = 10KΩ
14.83
14.65
14.61
RL = 2KΩ
14.73
14.60
14.55
RL = 10KΩ
−14.91
−14.75
−14.65
RL = 2KΩ
−14.83
−14.65
−14.60
Sourcing to ground
VID = 200mV (Note 10)
60
40
25
Sinking to ground
VID = 200mV (Note 10)
100
70
60
Parameter
Large Signal Voltage Gain
Condition
VO = 0V to ±13V,
RL = 10KΩ
VO = 0V to ±13V,
RL = 2KΩ
VO
Output Swing
High
Output Swing
Low
ISC
Output Short Circuit Current
Units
dB
min
V
min
V
max
mA
min
IS
Supply Current
No load, VCM = 0V
1.30
1.50
1.90
mA
max
SR
Slew Rate
(Note 8)
AV = +1, VI = 24VPP
15
10
8
V/µs
min
fu
Unity Gain Frequency
VI = 10mV, RL = 2KΩ
14
–
MHz
GBWP
Gain-Bandwidth Product
f = 50KHz
24
18
16
MHz
min
Phim
Phase Margin
VI = 10mV
58
–
Deg
en
Input-Referred Voltage Noise
f = 2KHz, RS = 50Ω
15
–
nV/
in
Input-Referred Current Noise
f = 2KHz
1
–
pA/
fMAX
Full Power Bandwidth
ZL = 20pF || 10KΩ
160
–
ts
Settling Time (±1%, AV = +1)
Positive Step, 5VPP
320
–
Negative Step, 5VPP
600
–
RL = 1KΩ, f = 10KHz,
AV = +2, 28VPP swing
0.01
–
THD+N
Total Harmonic Distortion +Noise
KHz
ns
%
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Rating indicate conditions for which the device is
intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics.
Note 2: Human Body Model is 1.5kΩ in series with 100pF.
Note 3: Applies to both single-supply and split-supply operation. Continuous short circuit operation at elevated ambient temperature can result in exceeding the
maximum allowed junction temperature of 150°C.
Note 4: The maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any ambient temperature is
PD = (TJ(MAX) - TA)/ θJA. All numbers apply for packages soldered directly onto a PC board.
Note 5: Typical Values represent the most likely parametric norm.
Note 6: All limits are guaranteed by testing or statistical analysis.
Note 7: Positive current corresponds to current flowing into the device.
Note 8: Slew rate is the slower of the rising and falling slew rates. Connected as a Voltage Follower.
Note 9: Machine Model, 0Ω is series with 200pF.
Note 10: Short circuit test is a momentary test. See Note 11.
Note 11: Output short circuit duration is infinite for VS ≤ 6V at room temperature and below. For VS > 6V, allowable short circuit duration is 1.5ms.
Note 12: Offset voltage average drift determined by dividing the change in VOS at temperature extremes into the total temperature change.
Note 13: Electrical Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating
of the device such that TJ = TA. No guarantee of parametric performance is indicated in the electrical tables under conditions of internal self heating where TJ >
TA.
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SM73301
Symbol
SM73301
Typical Performance Characteristics
TA = 25°C, Unless Otherwise Noted
VOS vs. VCM for 3 Representative Units
VOS vs. VCM for 3 Representative Units
30157630
30157629
VOS vs. VCM for 3 Representative Units
VOS vs. VS for 3 Representative Units
30157631
30157634
VOS vs. VS for 3 Representative Units
VOS vs. VS for 3 Representative Units
30157633
30157635
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SM73301
IB vs. VCM
IB vs. VS
30157624
30157636
IS vs. VCM
IS vs. VCM
30157627
30157628
IS vs. VCM
IS vs. VS (PNP side)
30157668
30157625
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SM73301
IS vs. VS (NPN side)
Gain/Phase vs. Frequency
30157626
30157618
Unity Gain Frequency vs. VS
Phase Margin vs. VS
30157607
30157608
Unity Gain Freq. and Phase Margin vs. VS
Unity Gain Frequency vs. Load
30157604
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30157605
8
SM73301
Phase Margin vs. Load
Unity Gain Freq. and Phase Margin vs. CL
30157609
30157606
CMRR vs. Frequency
+PSRR vs. Frequency
30157614
30157616
−PSRR vs. Frequency
Output Voltage vs. Output Sourcing Current
30157617
30157646
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SM73301
Output Voltage vs. Output Sourcing Current
Output Voltage vs. Output Sinking Current
30157644
30157645
Max Output Swing vs. Load
Max Output Swing vs. Frequency
30157611
30157610
% Overshoot vs. Cap Load
±5% Settling Time vs. Cap Load
30157648
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30157647
10
SM73301
+SR vs. Cap Load
−SR vs. Cap Load
30157651
30157652
+SR vs. Cap Load
−SR vs. Cap Load
30157649
30157650
Settling Time vs. Error Voltage
Settling Time vs. Error Voltage
30157642
30157643
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SM73301
Input Noise Voltage/Current vs. Frequency
Input Noise Voltage for Various VCM
30157615
30157613
Input Noise Current for Various VCM
Input Noise Voltage vs. VCM
30157655
30157612
Input Noise Current vs. VCM
THD+N vs. Frequency
30157623
30157654
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SM73301
THD+N vs. Frequency
THD+N vs. Frequency
30157622
30157621
THD+N vs. Amplitude
THD+N vs. Amplitude
30157619
30157620
Small Signal Step Response
Large Signal Step Response
30157638
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30157640
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SM73301
Application Hints
BLOCK DIAGRAM AND OPERATIONAL DESCRIPTION
A) Input Stage
30157667
FIGURE 1. Simplified Schematic Diagram
As can be seen from the simplified schematic in Figure 1, the
input stage consists of two distinct differential pairs (Q1-Q2
and Q3-Q4) in order to accommodate the full Rail-to-Rail input
common mode voltage range. The voltage drop across R5,
R6, R7, and R8 is kept to less than 200mV in order to allow
the input to exceed the supply rails. Q13 acts as a switch to
steer current away from Q3-Q4 and into Q1-Q2, as the input
increases beyond 1.4V of V+. This in turn shifts the signal path
from the bottom stage differential pair to the top one and
causes a subsequent increase in the supply current.
In transitioning from one stage to another, certain input stage
parameters (VOS, Ib, IOS, en, and in) are determined based on
which differential pair is "on" at the time. Input Bias current,
IB, will change in value and polarity as the input crosses the
transition region. In addition, parameters such as PSRR and
CMRR which involve the input offset voltage will also be effected by changes in VCM across the differential pair transition
region.
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The input stage is protected with the combination of R9-R10
and D1, D2, D3, and D4 against differential input over-voltages. This fault condition could otherwise harm the differential
pairs or cause offset voltage shift in case of prolonged over
voltage. As shown in Figure 2, if this voltage reaches approximately ±1.4V at 25°C, the diodes turn on and current flow is
limited by the internal series resistors (R9 and R10). The Absolute Maximum Rating of ±10V differential on VIN still needs
to be observed. With temperature variation, the point were the
diodes turn on will change at the rate of 5mV/°C.
14
30157666
FIGURE 2. Input Stage Current vs. Differential Input
Voltage
B) Output Stage
The output stage Figure 1 is comprised of complementary
NPN and PNP common-emitter stages to permit voltage
swing to within a VCE(SAT) of either supply rail. Q9 supplies the
sourcing and Q10 supplies the sinking current load. Output
current limiting is achieved by limiting the VCE of Q9 and Q10;
using this approach to current limiting, alleviates the draw
back to the conventional scheme which requires one VBE reduction in output swing.
The frequency compensation circuit includes Miller capacitors
from collector to base of each output transistor (see Figure
1, Ccomp9 and Ccomp10). At light capacitive loads, the high frequency gain of the output transistors is high, and the Miller
effect increases the effective value of the capacitors thereby
stabilizing the Op Amp. Large capacitive loads greatly decrease the high frequency gain of the output transistors thus
lowering the effective internal Miller capacitance - the internal
pole frequency increases at the same time a low frequency
pole is created at the Op Amp output due to the large load
capacitor. In this fashion, the internal dominant pole compensation, which works by reducing the loop gain to less than 0dB
when the phase shift around the feedback loop is more than
180°, varies with the amount of capacitive load and becomes
less dominant when the load capacitor has increased enough.
Hence the Op Amp is very stable even at high values of load
capacitance resulting in the uncharacteristic feature of stability under all capacitive loads.
30157657
FIGURE 3. Output Short Circuit Sourcing Current vs.
Input Overdrive
DRIVING CAPACITIVE LOADS
The SM73301 is specifically designed to drive unlimited capacitive loads without oscillations (See Settling Time and
Percent Overshoot vs. Cap Load plots in the typical performance characteristics section). In addition, the output current
handling capability of the device allows for good slewing characteristics even with large capacitive loads (see Slew Rate
vs. Cap Load plots). The combination of these features is ideal for applications such as TFT flat panel buffers, A/D converter input amplifiers, etc.
However, as in most Op Amps, addition of a series isolation
resistor between the Op Amp and the capacitive load improves the settling and overshoot performance.
Output current drive is an important parameter when driving
capacitive loads. This parameter will determine how fast the
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SM73301
output voltage can change. Referring to the Slew Rate vs.
Cap Load Plots (typical performance characteristics section),
two distinct regions can be identified. Below about 10,000pF,
the output Slew Rate is solely determined by the Op Amp's
compensation capacitor value and available current into that
capacitor. Beyond 10nF, the Slew Rate is determined by the
Op Amp's available output current. Note that because of the
lower output sourcing current compared to the sinking one,
the Slew Rate limit under heavy capacitive loading is determined by the positive transitions. An estimate of positive and
negative slew rates for loads larger than 100nF can be made
by dividing the short circuit current value by the capacitor.
For the SM73301, the available output current increases with
the input overdrive. Referring to Figure 3 and Figure 4, Output
Short Circuit Current vs. Input Overdrive, it can be seen that
both sourcing and sinking short circuit current increase as input overdrive increases. In a closed loop amplifier configuration, during transient conditions while the fed back output has
not quite caught up with the input, there will be an overdrive
imposed on the input allowing more output current than would
normally be available under steady state condition. Because
of this feature, the Op Amp's output stage quiescent current
can be kept to a minimum, thereby reducing power consumption, while enabling the device to deliver large output current
when the need arises (such as during transients).
SM73301
Output Voltage vs. Output Current plot (Typical Performance
Characteristics section) can be used to predict the output
swing. Figure 6 and Figure 7 show this performance along
with several load lines corresponding to loads tied between
the output and ground. In each cases, the intersection of the
device plot at the appropriate temperature with the load line
would be the typical output swing possible for that load. For
example, a 1KΩ load can accommodate an output swing to
within 250mV of V− and to 330mV of V+ (VS = ±15V) corresponding to a typical 29.3VPP unclipped swing.
30157656
FIGURE 4. Output Short Circuit Sinking Current vs. Input
Overdrive
Figure 5 shows the output voltage, output current, and the
resulting input overdrive with the device set for AV = +1 and
the input tied to a 1VPP step function driving a 47nF capacitor.
As can be seen, during the output transition, the input overdrive reaches 1V peak and is more than enough to cause the
output current to increase to its maximum value (see Figure
3 and Figure 4 plots). Note that because of the larger output
sinking current compared to the sourcing one, the output negative transition is faster than the positive one.
30157660
FIGURE 6. Output Sourcing Characteristics with Load
Lines
30157639
FIGURE 5. Buffer Amplifier scope photo
ESTIMATING THE OUTPUT VOLTAGE SWING
It is important to keep in mind that the steady state output
current will be less than the current available when there is
an input overdrive present. For steady state conditions, the
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30157659
FIGURE 7. Output Sinking Characteristics with Load
Lines
16
SM73301
TFT APPLICATIONS
Figure 8 below, shows a typical application where the
SM73301 is used as a buffer amplifier for the VCOM signal
employed in a TFT LCD flat panel:
30157661
FIGURE 8. VCOM Driver Application Schematic
Figure 9 shows the time domain response of the amplifier
when used as a VCOM buffer/driver with VREF at ground. In this
application, the Op Amp loop will try and maintain its output
voltage based on the voltage on its non-inverting input
(VREF) despite the current injected into the TFT simulated
load. As long as this load current is within the range tolerable
by the SM73301 (45mA sourcing and 65mA sinking for ±5V
supplies), the output will settle to its final value within less than
2µs.
average value (due to a DC load current) and an AC component. DC load current would flow if there is an output voltage
offset, or the output AC average current is non-zero, or if the
Op Amp operates in a single supply application where the
output is maintained somewhere in the range of linear operation. Therefore:
PTOTAL = PQ + PDC + PAC
PQ = IS · VS
Op Amp Quiescent Power
Dissipation
DC Load Power
PDC = IO · (VR - VO)
PAC = See Table 1 below
AC Load Power
where:
IS: Supply Current
VS: Total Supply Voltage (V+ - V−)
IO: Average load current
VO: Average Output Voltage
VR: V+ for sourcing and V− for sinking current
Table 1 below shows the maximum AC component of the load
power dissipated by the Op Amp for standard Sinusoidal, Triangular, and Square Waveforms:
TABLE 1. Normalized AC Power Dissipated in the Output
Stage for Standard Waveforms
PAC (W.Ω/V2)
30157665
FIGURE 9. VCOM driver performance scope photo
OUTPUT SHORT CIRCUIT CURRENT AND DISSIPATION
ISSUES
The SM73301 output stage is designed for maximum output
current capability. Even though momentary output shorts to
ground and either supply can be tolerated at all operating
voltages, longer lasting short conditions can cause the junction temperature to rise beyond the absolute maximum rating
of the device, especially at higher supply voltage conditions.
Below supply voltage of 6V, output short circuit condition can
be tolerated indefinitely.
With the Op Amp tied to a load, the device power dissipation
consists of the quiescent power due to the supply current flow
into the device, in addition to power dissipation due to the load
current. The load portion of the power itself could include an
Sinusoidal
Triangular
Square
50.7 x 10−3
46.9 x 10−3
62.5 x 10−3
The table entries are normalized to VS2/ RL. To figure out the
AC load current component of power dissipation, simply multiply the table entry corresponding to the output waveform by
the factor VS2/ RL. For example, with ±15V supplies, a 600Ω
load, and triangular waveform power dissipation in the output
stage is calculated as:
PAC= (46.9 x 10−3) · [302/600]= 70.4mW
Other Application Hints
The use of supply decoupling is mandatory in most applications. As with most relatively high speed/high output current
Op Amps, best results are achieved when each supply line is
decoupled with two capacitors; a small value ceramic capac17
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SM73301
itor (∼0.01µF) placed very close to the supply lead in addition
to a large value Tantalum or Aluminum (> 4.7µF). The large
capacitor can be shared by more than one device if necessary. The small ceramic capacitor maintains low supply
impedance at high frequencies while the large capacitor will
act as the charge "bucket" for fast load current spikes at the
Op Amp output. The combination of these capacitors will provide supply decoupling and will help keep the Op Amp oscillation free under any load.
•
•
•
•
•
SM73301 ADVANTAGES
Compared to other Rail-to-Rail Input/Output devices, the
SM73301 offers several advantages such as:
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18
Improved cross over distortion.
Nearly constant supply current throughout the output
voltage swing range and close to either rail.
Consistent stability performance for all input/output
voltage and current conditions.
Nearly constant Unity gain frequency (fu) and Phase
Margin (Phim) for all operating supplies and load
conditions.
No output phase reversal under input overload condition.
SM73301
Physical Dimensions inches (millimeters) unless otherwise noted
5-Pin SOT23-5
NS Package Number MF05A
19
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SM73301 RRIO, High Output Current & Unlimited Cap Load Op Amp in SOT23-5
Notes
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