TSH310
400µA High-Speed Operational Amplifier
Pin Connections (top view)
■ OptimWattTM device featuring ultra-low
consumption, 2mW, and low quiescent
current, 400µA
■ Bandwidth: 120MHz (Gain=2)
■ Slew rate: 115V/µs
■ Specified on 1kΩ
■ Input noise: 7.5nV/√Hz
■ Tested on 5V power supply
OUT 1
5 +VCC
-VCC 2
+-
)
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The TSH310 is a single operator available in SO8
and the tiny SOT23-5 plastic package, saving
board space as well as providing excellent
thermal performances.
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Applications
■
■
■
■
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+IN 3
4 -IN
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SOT23-5
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8 NC
NC 1
-IN 2
_
7 +VCC
+IN 3
+
6 OUT
5 NC
-VCC 4
SO8
Battery-powered and high-speed systems
Communication & video test equipment
Portable medical instrumentation
ADC drivers
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Description
The TSH310 is a very low-power, high-speed
operational amplifier. A bandwidth of 120MHz is
achieved while drawing only 400µA of quiescent
current. This low-power characteristic is
particularly suitable for high-speed, batterypowered
equipment
requiring
dynamic
performance.
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Order Codes
Part Number
TSH310ILT
TSH310ID
TSH310IDT
Temperature Range
Package
Conditioning
Marking
-40°C to +85°C
SOT23-5
SO-8
SO-8
Tape&Reel
Tube
Tape&Reel
K304
TSH310I
TSH310I
Note: OptimWattTM is an STMIcroelectronics registered trademark that applies to products with specific features that
optimize energy efficiency.
December 2004
Revision 2
1/19
TSH310
Absolute Maximum Ratings
1 Absolute Maximum Ratings
Table 1: Key parameters and their absolute maximum ratings
Symbol
VCC
Vid
Vin
Parameter
Supply Voltage 1
Differential Input
Voltage2
Range3
Value
Unit
6
V
+/-0.5
V
Input Voltage
Operating Free Air Temperature Range
+/-2.5
V
Toper
-40 to +85
°C
Tstg
Storage Temperature
-65 to +150
°C
150
°C
Tj
Rthja
Rthjc
Pmax
Maximum Junction Temperature
Thermal Resistance Junction to Ambient
SOT23-5
SO8
Thermal Resistance Junction to Case
SOT23-5
SO8
250
150
80
28
Maximum Power Dissipation4 (@Ta=25°C) for Tj=150°C
SOT23-5
SO8
HBM: Human Body Model 5 (pins 1, 4, 5, 6, 7 and 8)
HBM: Human Body Model (pins 2 and 3)
ESD
MM: Machine Model 6 (pins 1, 4, 5, 6, 7 and 8)
MM: Machine Model (pins 2 and 3)
CDM: Charged Device Model (pins 1, 4, 5, 6, 7 and 8)
CDM: Charged Device Model (pins 2 and 3)
Latch-up Immunity
)
(s
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°C/W
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mW
2
kV
0.5
kV
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°C/W
500
830
200
V
60
1.5
1.5
200
V
kV
kV
mA
1) All voltages values are measured with respect to the ground pin.
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2) Differential voltage are non-inverting input terminal with respect to the inverting input terminal.
3) The magnitude of input and output voltage must never exceed VCC +0.3V.
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4) Short-circuits can cause excessive heating. Destructive dissipation can result from short circuit on amplifiers.
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5) Human body model, 100pF discharged through a 1.5kΩ resistor into pMin of device.
6) This is a minimum Value. Machine model ESD, a 200pF cap is charged to the specified voltage, then discharged directly into the IC with
no external series resistor (internal resistor < 5Ω), into pin to pin of device.
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Table 2: Operating conditions
Symbol
Parameter
VCC
Supply Voltage 1
Vicm
Common Mode Input Voltage
1) Tested in full production at 5V (±2.5V) supply voltage.
2/19
Value
Unit
4.5 to 5.5
V
-Vcc+1.5V, +Vcc-1.5V
V
Electrical Characteristics
TSH310
2 Electrical Characteristics
Table 3: Electrical characteristics for VCC = ±2.5Volts, Tamb = 25°C (unless otherwise specified)
Symbol
Parameter
Test Condition
Min.
Typ.
Max.
6.5
Unit
DC performance
Vio
Input Offset Voltage
Offset Voltage between both inputs
Tamb
1.7
Tmin. < Tamb < Tmax.
2.1
∆Vio
Vio drift vs. Temperature
Tmin. < Tamb < Tmax.
4
Iib+
Non Inverting Input Bias Current
Tamb
DC current necessary to bias the input +
Tmin. < Tamb < Tmax.
3.1
Iib-
Inverting Input Bias Current
Tamb
DC current necessary to bias the input Tmin. < Tamb < Tmax.
0.1
CMR
SVR
Common Mode Rejection Ratio
∆Vic = ±1V
20 log (∆Vic/∆Vio )
Tmin. < Tamb < Tmax.
Supply Voltage Rejection Ratio
∆Vcc= 3.5V to 5V
20 log (∆Vcc/∆Vio)
Tmin. < Tamb < Tmax.
Power Supply Rejection Ratio
AV = +1, ∆Vcc=±100mV
at 1kHz
20 log (∆Vcc/∆Vout)
PSR
Positive Supply Current
DC consumption with no input signal
ICC
No load
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Dynamic performance and output characteristics
Bw
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-3dB Bandwidth
Frequency where the gain is 3dB below
the DC gain AV
Note: Gain Bandwidth Product criterion is
not applicable for Current-FeedbackAmplifiers
Small Signal Vout=20mVp-p
RL = 1kΩ
AV = +1, Rfb = 3kΩ
AV = +2, Rfb = 3kΩ
AV = +10, Rfb = 510Ω
VOH
VOL
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SR
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RL = 1kΩ,Vout = ±1V
-82
-79
-50
0.6
µA
dB
dB
dB
46
400
530
µA
1.45
MΩ
1.36
MΩ
230
120
26
MHz
Tmin. < Tamb < Tmax.
80
Gain Flatness @ 0.1dB
Small Signal Vout=20mVp-p
Band of frequency where the gain varia- AV = +2, RL = 1kΩ
tion does not exceed 0.1dB
Slew Rate
Maximum output speed of sweep in
large signal
Vout = 2Vp-p, AV = +2,
RL = 1kΩ
High Level Output Voltage
RL = 1kΩ
Low Level Output Voltage
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-65
µA
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5
-61
-59
Transimpedance
Output Voltage/Input Current Gain in
open loop of a CFA.
For a VFA, the analog of this feature is
the Open Loop Gain (AVD)
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12
0.3
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ROL
µV/°C
3.5
-57
Tmin. < Tamb < Tmax.
mV
25
75
115
V/µs
1.55
1.65
V
Tmin. < Tamb < Tmax.
1.58
RL = 1kΩ
-1.66
Tmin. < Tamb < Tmax.
-1.60
-1.55
V
3/19
TSH310
Electrical Characteristics
Table 3: Electrical characteristics for VCC = ±2.5Volts, Tamb = 25°C (unless otherwise specified)
Symbol
Iout
Parameter
Test Condition
Isink
Short-circuit Output current coming in
the op-amp.
See fig-8 for more details
Output to GND
Isource
Output current coming out from the opamp.
See fig-11 for more details
Output to GND
Min.
Typ.
70
110
Tmin. < Tamb < Tmax.
Max.
Unit
100
60
mA
Tmin. < Tamb < Tmax.
100
85
Noise and distortion
eN
iN
SFDR
Equivalent Input Noise Voltage
see application note on page 13
F = 100kHz
Equivalent Input Noise Current (+)
see application note on page 13
F = 100kHz
Equivalent Input Noise Current (-)
see application note on page 13
F = 100kHz
Spurious Free Dynamic Range
The highest harmonic of the output
spectrum when injecting a filtered sine
wave
Vout = 2Vp-p, AV = +2,
RL = 1kΩ
F = 1MHz
F = 10MHz
VCC
(V)
Gain
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+2
Pr
-2
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4/19
+1
-1
pA/√Hz
pA/√Hz
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let
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b
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-87
-55
dBc
dBc
0.1dB Bw
(MHz)
26
4
510
23
4
3k
120
6
1.5k
80
10
3k
210
5
1.3k
120
60
510
-10
13
-3dB Bw
(MHz)
)
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+10
±2.5
Rfb
(Ω)
nV/√Hz
6
Table 4: Closed-loop gain and feedback components
)
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7.5
Electrical Characteristics
TSH310
Figure 1: Frequency Response, positive Gain
24
22
20
24
22
20
Gain=+10
12
10
8
Gain=+4
Gain=-4
Gain=+2
12
10
8
Gain=-2
6
4
2
0
-2
-4
-6
-8
6
4
2
0
-2
Gain=+1
-4
-6
-8
Small Signal
Vcc=5V
Load=1kΩ
-10
1M
Gain=-10
18
16
14
Gain (dB)
18
16
14
Gain (dB)
Figure 4: Frequency response, negative gain
10M
Gain=-1
-10
1M
100M
10M
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6,2
6,1
6,0
12,0
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Gain Flatness (dB)
Gain Flatness (dB)
5,9
11,9
)-
11,8
s
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c
11,7
11,6
11,5
1M
Frequency (Hz)
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Pr
10M
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5,8
5,7
5,6
5,5
5,4
5,3
5,2
5,1
Gain=+2
Small Signal
Vcc=5V
Load=1k Ω
5,0
1M
100M
Figure 3: Frequency response vs. capa-load
10
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Figure 5: Gain flatness, gain=+2
12,1
Gain=+4
Small Signal
Vcc=5V
Load=1k Ω
100M
Frequency (Hz)
Frequency (Hz)
Figure 2: Gain Flatness, gain=+4
)
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Small Signal
Vcc=5V
Load=1kΩ
10M
100M
Frequency (Hz)
Figure 6: Step response vs. capa-load
3
C-Load=10pF
R-iso=0
8
6
Gain (dB)
C-Load=1pF
R-iso=0
2
0
-2
-4
Vout
+
R-iso
-
3k
-6
-8
-10
1M
C-Load=22pF
R-iso=47ohms
Vin
3k
Output step (Volt)
2
4
C-Load=1pF, 10pF and 22pF
1
Vin
-
3k
0
1k
Vout
+
3k
C-Load
1k
C-Load
Gain=+2, Vcc=5V,
Small Signal
Gain=+2, Vcc=5V,
Small Signal
10M
Frequency (Hz)
100M
-1
0,0
5,0n
10,0n
15,0n
20,0n
25,0n
30,0n
Time (ns)
5/19
TSH310
Electrical Characteristics
Figure 7: Slew rate
Figure 10: Quiescent current vs. Vcc
2,0
400
1,5
200
Icc (micro-A)
Output Response (V)
Icc(+)
1,0
0
Gain=+2
Vcc=5V
Inputs to ground, no load
-200
0,5
Gain=+2
Vcc=5V
Load=1kΩ
0,0
-10ns
-5ns
0s
5ns
10ns
15ns
1,25
20ns
1,50
1,75
Figure 8: Isink
+2.5V
VOL
without load
-25
Isink
_
V
Isink (mA)
100
RG
Amplifier in open
loop without load
Isource (mA)
- 2.5V
)-
75
s
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25
0
-2,0
-1,5
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-1,0
-0,5
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-75
+2.5V
VOH
+1V
-100
RG
-125
-150
0,0
V
0,5
Amplifier in open
loop without load
1,0
1,5
2,0
Figure 12: Input voltage noise vs. frequency
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10,0
Gain=32dB
Rg=12ohms
Rfb=510ohms
non-inverting input in short-circuit
Vcc=5V
9,5
3,5
9,0
en (nV/VHz)
Max. Output Amplitude (Vp-p)
Isource
_
V (V)
3,0
8,5
8,0
2,5
Gain=+2
Vcc=5V
Load=1k Ω
2,0
10
100
1k
Load (ohms)
6/19
without load
+
- 2.5V
0,0
Figure 9: Output amplitude vs. load
4,0
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-50
V (V)
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2,50
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0
150
+
2,25
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Figure 11: Isource
-1V
2,00
+/-Vcc (V)
Time (ns)
125
)
s
(
ct
Icc(-)
-400
10k
100k
7,5
7,0
100
1k
10k
100k
Frequency (Hz)
1M
10M
100M
Electrical Characteristics
TSH310
Figure 13: Distortion vs. output amplitude
Figure 16: CMR vs. temperature
66
-20
-25
-30
64
-40
HD2
CMR (dB)
HD2 & HD3 (dBc)
-35
-45
-50
-55
62
60
-60
Gain=+2
Vcc=5V
F=10MHz
Load=1k Ω
-65
HD3
-70
-75
58
56
-80
0
1
2
3
-40
4
-20
0
Figure 14: Output amplitude vs. frequency
4
SVR (dB)
3
)-
s
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2
du
1M
o
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10M
120
80
100
120
100
120
u
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80
75
Gain=+1
Vcc=5V
Load=100Ω
70
100M
-40
-20
0
20
40
60
Temperature (°C)
Figure 15: Bandwidth vs. temperature
Figure 18: Slew-Rate vs. temperature
s
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200
100
s
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Frequency (Hz)
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ol
80
t
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85
0
100k
60
r
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90
Gain=+2
Vcc=5V
Load=1k Ω
40
Figure 17: SVR vs. temperature
5
1
20
Temperature (°C)
Output Amplitude (Vp-p)
Vout max. (Vp-p)
)
s
(
ct
Gain=+1
Vcc=5V
Load=100Ω
140
190
neg. SR
130
180
SR (V/micro-s)
170
Bw (MHz)
160
150
140
130
120
pos. SR
110
100
120
110
100
Gain=+1
Vcc=5V
Load=100Ω
90
90
Gain=+1
Vcc=5V
Load=100Ω
80
-40
-20
0
20
40
60
Temperature (°C)
80
100
120
-40
-20
0
20
40
60
80
Temperature (°C)
7/19
TSH310
Electrical Characteristics
Figure 19: ROL vs. temperature
Figure 22: VOH & VOL vs. temperature
1,60
2
1,55
VOH & OL (V)
1,45
ROL (MΩ)
VOH
1
1,50
1,40
1,35
0
-1
VOL
-2
1,30
1,25
-4
-40
1,20
-40
-20
0
20
40
60
80
100
120
-20
0
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ICC (micro A)
IBIAS (µA)
)-
s
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c
-1
Gain=+1
Vcc=5V
Load=100Ω
-3
-20
0
20
e
t
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ol
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Pr
40
60
Temperature (°C)
80
100
0
-200
Icc(-)
-400
-600
-800
Gain=+1
Vcc=5V
no Load
in(+) and in(-) to GND
-1000
-40
120
-20
0
20
40
60
80
100
120
80
100
120
Temperature (°C)
Figure 21: Vio vs. temperature
Figure 24: Iout vs. temperature
s
b
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2,0
s
b
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200
Ib(-)
-40
u
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80
Icc(+)
Ib(+)
1
-2
60
r
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400
0
40
Figure 23: Icc vs. temperature
3
2
20
Temperature (°C)
Temperature (°C)
Figure 20: I-bias vs. temperature
)
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Gain=+1
Vcc=5V
Load=100Ω
-3
Open Loop
Vcc=5V
200
150
1,8
100
Isource
1,6
1,4
Iout (mA)
VIO (mV)
50
1,2
0
-50
Isink
-100
1,0
-150
0,8
0,6
-200
Open Loop
Vcc=5V
Load=100Ω
-250
Output: short-circuit
Gain=+1
Vcc=5V
-300
-40
-20
0
20
40
60
Temperature (°C)
8/19
80
100
120
-40
-20
0
20
40
60
Temperature (°C)
Evaluation Boards
TSH310
3 Evaluation Boards
An evaluation board kit optimized for high-speed operational amplifiers is available (order code:
KITHSEVAL/STDL). The kit includes the following evaluation boards, as well as a CD-ROM containing
datasheets, articles, application notes and a user manual:
l SOT23_SINGLE_HF BOARD: Board for the evaluation of a single high-speed op-amp in SOT23-5
package.
l SO8_SINGLE_HF: Board for the evaluation of a single high-speed op-amp in SO8 package.
l SO8_DUAL_HF: Board for the evaluation of a dual high-speed op-amp in SO8 package.
l SO8_S_MULTI: Board for the evaluation of a single high-speed op-amp in SO8 package in inverting
)
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and non-inverting configuration, dual and single supply.
l SO14_TRIPLE: Board for the evaluation of a triple high-speed op-amp in SO14 package with video
application considerations.
u
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Board material:
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l 2 layers
ε
l FR4 ( r=4.6)
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l epoxy 1.6mm
l copper thickness: 35µm
Figure 25: Evaluation kit for high-speed op-amps
)
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9/19
TSH310
Power Supply Considerations
4 Power Supply Considerations
Correct power supply bypassing is very important for optimizing performance in high-frequency ranges.
Bypass capacitors should be placed as close as possible to the IC pins to improve high-frequency
bypassing. A capacitor greater than 1µF is necessary to minimize the distortion. For better quality
bypassing, a capacitor of 10nF can be added using the same implementation conditions. Bypass
capacitors must be incorporated for both the negative and the positive supply.
For example: on the SO8_SINGLE_HF board, these capacitors are C6, C7, C8, C9.
Figure 26: Circuit for power supply bypassing
+VCC
)
s
(
ct
10microF
+
u
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10nF
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+
-
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10nF
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10microF
+
)
(s
-VCC
t
c
u
Single power supply
In the event that a single supply system is used, new biasing is necessary to assume a positive output
dynamic range between 0V and +VCC supply rails. Considering the values of VOH and V OL, the amplifier
will provide an output dynamic from +0.9V to +4.1V on 1kΩ load.
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The amplifier must be biased with a mid-supply (nominally +VCC/2), in order to maintain the DC
component of the signal at this value. Several options are possible to provide this bias supply, such as a
virtual ground using an operational amplifier or a two-resistance divider (which is the cheapest solution).
A high resistance value is required to limit the current consumption. On the other hand, the current must
be high enough to bias the non-inverting input of the amplifier. If we consider this bias current (55µA
max.) as the 1% of the current through the resistance divider to keep a stable mid-supply, two resistances
of 470Ω can be used.
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The input provides a high pass filter with a break frequency below 10Hz which is necessary to remove the
original 0 volt DC component of the input signal, and to fix it at +VCC/2.
Figure 27 illustrates a 5V single power supply configuration for the SO8_SINGLE evaluation board (see
Evaluation Boards on page 9).
10/19
Power Supply Considerations
TSH310
A capacitor CG is added in the gain network to ensure a unity gain in low frequency to keep the right DC
component at the ouput. CG contributes to a high-pass filter with Rfb//RG and its value is calculated with a
consideration of the cut-off frequency of this low-pass filter.
Figure 27: Circuit for +5V single supply
+5V
10µF
+
IN
+5V
Rin
1kΩ
OUT
R1
470Ω
1kΩ
RG
+ 1µF
10nF
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+ CG
)
(s
u
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Rfb
R2
470Ω
)
s
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_
s
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11/19
TSH310
Noise Measurements
5 Noise Measurements
The noise model is shown in Figure 28, where:
l eN: input voltage noise of the amplifier
l iNn: negative input current noise of the amplifier
l iNp: positive input current noise of the amplifier
Figure 28: Noise model
)
s
(
ct
+
iN+
R3
output
HP3577
Input noise:
8nV/√Hz
_
N3
iN-
R1
N1
The thermal noise of a resistance R is:
)
(s
t
c
u
d
o
r
where ∆F is the specified bandwidth.
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R2
N2
u
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P
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eN
s
b
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4kTR ∆ F
P
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On a 1Hz bandwidth the thermal noise is reduced to
let
o
s
b
4kTR
where k is the Boltzmann's constant, equal to 1,374.10-23J/°K. T is the temperature (°K).
The output noise eNo is calculated using the Superposition Theorem. However eNo is not the simple sum
of all noise sources, but rather the square root of the sum of the square of each noise source, as shown
in Equation 1:
O
eNo =
eNo
12/19
2
2
2
2
2
2
2
V 1 + V2 + V3 + V4 + V5 + V6
2
2
2
2
2
2
2
= eN × g + iNn × R 2 + iNp × R 3 × g
2
------+R
R1
2
22
× 4 kTR 1 + 4 kTR 2 + 1 + R
------- × 4 kTR 3
R1
Equation 1
Equation 2
Noise Measurements
TSH310
The input noise of the instrumentation must be extracted from the measured noise value. The real output
noise value of the driver is:
2
2
( Measured ) – ( instrumentation )
eNo =
Equation 3
The input noise is called the Equivalent Input Noise as it is not directly measured but is evaluated from the
measurement of the output divided by the closed loop gain (eNo/g).
After simplification of the fourth and the fifth term of Equation 2 we obtain:
eNo
2
2
2
2
2
2
2
2
= eN × g + iNn × R 2 + iNp × R 3 × g
2
+ g × 4 k TR 2 + 1 + R
------R1
2
× 4 kTR 3
)
s
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Equation 4
u
d
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Measurement of the input voltage noise eN
If we assume a short-circuit on the non-inverting input (R3=0), from Equation 4 we can derive:
eNo =
2
2
2
2
eN × g + iNn × R 2 + g × 4 kTR 2
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Equation 5
In order to easily extract the value of eN, the resistance R2 will be chosen to be as low as possible. In the
other hand, the gain must be large enough:
s
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R3=0, gain: g=100
)
(s
Measurement of the negative input current noise iNn
To measure the negative input current noise iNn, we set R3=0 and use Equation 5. This time the gain
must be lower in order to decrease the thermal noise contribution:
od
t
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u
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R3=0, gain: g=10
Measurement of the positive input current noise iNp
To extract iNp from Equation 3, a resistance R3 is connected to the non-inverting input. The value of R3
must be chosen in order to keep its thermal noise contribution as low as possible against the iNp
contribution:
t
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bs
R3=100Ω, gain: g=10
O
13/19
TSH310
Intermodulation Distortion Product
6 Intermodulation Distortion Product
The non-ideal output of the amplifier can be described by the following series:
2
n
Vout = C + C V + C V in + … C V in
0
1 in
2
n
due to non-linearity in the input-output amplitude transfer, where the input is Vin=Asinωt, C0 is the DC
component, C1(Vin) is the fundamental and Cn is the amplitude of the harmonics of the output signal Vout.
A one-frequency (one-tone) input signal contributes to harmonic distortion. A two-tone input signal
contributes to harmonic distortion and to the intermodulation product.
The study of the intermodulation and distortion for a two-tone input signal is the first step in characterizing
the driving capability of multi-tone input signals.
)
s
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ct
In this case:
V
in
u
d
o
= A sin ω t + A sin ω t
1
2
r
P
e
then:
V
= C + C ( A sin ω t + A sin ω t ) + C ( A sin ω t + A sin ω t )
1
2
1
2
2
out
0
1
2
… + C n ( A sin ω 1 t + A sin ω 2 t )
n
t
e
l
o
From this expression, we can extract the distortion terms, and the intermodulation terms form a single
sine wave: second-order intermodulation terms IM2 by the frequencies (ω1-ω2) and (ω1+ω2) with an
amplitude of C2A2 and third-order intermodulation terms IM3 by the frequencies (2ω1-ω2), (2ω1+ω2), (−
ω1+2ω2) and (ω1+2ω2) with an amplitude of (3/4)C3A3.
)
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The measurement of the intermodulation product of the driver is achieved by using the driver as a mixer
by a summing amplifier configuration (see Figure 29). In this way, the non-linearity problem of an external
mixing device is avoided.
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r
Figure 29: Inverting summing amplifier (using evaluation board SO8_S_MULTI)
P
e
t
e
l
o
bs
Vin1
R1
Vin2
R2
Rfb
_
O
Vout
+
R
14/19
1kΩ
The Bias of an Inverting Amplifier
TSH310
7 The Bias of an Inverting Amplifier
A resistance is necessary to achieve a good input biasing, such as resistance R shown in Figure 30.
The magnitude of this resistance is calculated by assuming the negative and positive input bias current.
The aim is to compensate for the offset bias current, which could affect the input offset voltage and the
output DC component. Assuming Ib-, Ib+, Rin, Rfb and a zero volt output, the resistance R will be:
R in × R fb
R = ---------------------R in + R fb
)
s
(
ct
Figure 30: Compensation of the input bias current
u
d
o
Rfb
Ib-
Rin
r
P
e
Vcc+
_
Output
+
Vcc-
Ib+
R
)
(s
t
e
l
o
Load
s
b
O
t
c
u
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s
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15/19
TSH310
Active Filtering
8 Active Filtering
Figure 31: Low-pass active filtering, Sallen-Key
C1
R2
R1
+
IN
OUT
C2
_
1kΩ
)
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Rfb
RG
u
d
o
From the resistors Rfb and RG we can directly calculate the gain of the filter in a classical non-inverting
amplification configuration:
A
R
fb
g = 1 + ---------V =
R
g
We assume the following expression as the response of the system:
T
t
e
l
o
s
b
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Vout
g
jω
= ------------------- = --------------------------------------------jω
Vin
2
jω
j ω (j ω )
1 + 2 ζ ------- + -------------ωc
2
ω
c
)
(s
r
P
e
t
c
u
The cut-off frequency is not gain-dependent and so becomes:
od
r
P
e
ω
1
c = ------------------------------------R1 R2C1C2
The damping factor is calculated by the following expression:
t
e
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o
s
b
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1
ζ = --- ω ( C R + C R + C R – C R g )
1 2
2 1
1 1
2 c 1 1
The higher the gain, the more sensitive the damping factor is. When the gain is higher than 1, it is
preferable to use some very stable resistor and capacitor values. In the case of R1=R2=R:
R
fb
2C2 – C ---------1R
g
ζ = -----------------------------------2 C C
1 2
Due to a limited selection of values of capacitors in comparison with resistors, we can fix C1=C2=C, so
that:
R
fb
2R2 – R ---------1R
g
ζ = -----------------------------------2 R R
1 2
16/19
Package Mechanical Data
TSH310
9 Package Mechanical Data
SOT23-5L MECHANICAL DATA
mm.
mils
DIM.
MIN.
TYP
MAX.
MIN.
TYP.
MAX.
A
0.90
1.45
35.4
57.1
A1
0.00
0.15
0.0
5.9
A2
0.90
1.30
35.4
51.2
b
0.35
0.50
13.7
19.7
C
0.09
0.20
3.5
D
2.80
3.00
110.2
E
2.60
3.00
102.3
E1
1.50
1.75
59.0
e
0 .95
e1
1.9
L
)-
0.35
0.55
u
d
o
7.8
r
P
e
t
e
l
o
s
b
O
13.7
)
s
(
ct
118.1
118.1
68.8
37.4
74.8
21.6
s
(
t
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P
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t
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s
b
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17/19
TSH310
Package Mechanical Data
SO-8 MECHANICAL DATA
mm.
DIM.
MIN.
inch
TYP
MAX.
MIN.
TYP.
MAX.
A
1.35
1.75
0.053
0.069
A1
0.10
0.25
0.04
0.010
A2
1.10
1.65
0.043
0.065
B
0.33
0.51
0.013
0.020
C
0.19
0.25
0.007
0.010
D
4.80
5.00
0.189
0.197
E
3.80
4.00
0.150
e
0.050
H
5.80
6.20
0.228
0.244
h
0.25
0.50
0.010
0.020
L
0.40
1.27
k
0.050
let
0.1
o
s
b
u
d
o
r
P
e
0.016
8˚ (max.)
ddd
0.04
O
)
s
(
t
c
u
d
o
r
P
e
t
e
l
o
s
b
O
18/19
)
s
(
ct
0.157
1.27
0016023/C
Revision History
TSH310
10 Revision History
Date
Revision
Description of Changes
01 Oct 2004
1
First release corresponding to Preliminary Data version of datasheet.
December 2004
2
Release of mature product datasheet.
)
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)
(s
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Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences
of use of such information nor for any infringement 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 STMicroelectronics. Specifications mentioned in this publication are subject
to change without notice. This publication supersedes and replaces all information previously supplied. STMicroelectronics products are not
authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
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All other names are the property of their respective owners
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19/19
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