Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a "controlled document". Current revisions, if any, to these
specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.
2002 Elantec Semiconductor, Inc.
E
L
2125C
Features
Voltage noise of only 0.83nV/
Hz
Current noise of only 2.4pA/
Hz
200V offset voltage
175MHz -3dB BW for A
V
=10
Low supply current - 10mA
SOT23 package available
2.5V to 15V operation
Applications
Ultrasound input amplifiers
Wideband instrumentation
Communication equipment
AGC & PLL active filters
Wideband sensors
Ordering Information
Part No
Package
Tape & Reel
Outline #
EL2125CW-T7
5-Pin SOT23
7"
MDP0038
EL2125CW-T13
5-Pin SOT23
13"
MDP0038
EL2125CS
8-Pin SO
-
MDP0027
EL2125CS-T7
8-Pin SO
7"
MDP0027
EL2125CS-T13
8-Pin SO
13"
MDP0027
General Description
The EL2125C is an ultra-low noise, wideband amplifier that runs on
half the supply current of competitive parts. It is intended for use in
systems such as ultrasound imaging where a very small signal needs to
be amplified by a large amount without adding significant noise. Its
low power dissipation enables it to be packaged in the tiny SOT23
package, which further helps systems where many input channels cre-
ate both space and power dissipation problems.
The EL2125C is stable for gains of 10 and greater and uses traditional
voltage feedback. This allows the use of reactive elements in the feed-
back loop, a common requirement for many filter topologies. It
operates from 2.5V to 15V supplies and is available in the 5-pin
SOT23 and 8-pin SO packages.
The EL2125C is fabricated in Elantec's proprietary complementary
bipolar process, and is specified for operation from -45C to +85C.
Connection Diagrams
1
2
3
4
8
7
6
5
EL2125CS
(8-Pin SO)
1
2
3
5
4
EL2125CW
(5-Pin SOT23)
-
+
-
+
VS+
IN-
IN+
VS-
OUT
NC
IN-
IN+
VS-
NC
VS+
OUT
NC
EL2125C
Ultra-Low Noise, Low Power, Wideband Amplifier
Mar
c
h 20,
2002
2
EL2125C
Ultra-Low Noise, Low Power, Wideband Amplifier
E
L
21
25C
Absolute Maximum Ratings
(T
A
= 25C)
V
S
+ to V
S
-
33V
Continuous Output Current
40mA
Any Input
V
S
- - 0.3V to V
S
+ + 0.3V
Power Dissipation
See Curves
Operating Temperature
-45C to +85C
Storage Temperature
-60C to +150C
Maximum Die Junction Temperature
+150C
Important Note:
All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the
specified temperature and are pulsed tests, therefore: T
J
= T
C
= T
A
Electrical Characteristics
V
S
= 5V, T
A
= 25C, R
F
= 180
, R
G
= 20
, R
L
= 500
unless otherwise specified.
Parameter
Description
Conditions
Min
Typ
Max
Unit
DC Performance
V
OS
Input Offset Voltage (SO8)
0.2
2
mV
Input Offset Voltage (SOT23-5)
3
mV
T
CVOS
Offset Voltage Temperature Coefficient
1.8
V/C
I
B
Input Bias Current
-30
-22
A
I
OS
Input Bias Current Offset
0.4
2
A
T
CIB
Input Bias Current Temperature Coefficient
0.09
A/C
C
IN
Input Capacitance
2.2
pF
A
VOL
Open Loop Gain
80
87
dB
PSRR
Power Supply Rejection Ratio
[1]
80
97
dB
CMRR
Common Mode Rejection Ratio
at CMIR
80
106
dB
CMIR
Common Mode Input Range
-4.6
3.8
V
V
OUTH
Output Voltage Swing High
No load, R
F
= 1k
3.5
3.65
V
V
OUTL
Output Voltage Swing Low
No load, R
F
= 1k
-3.87
-3.7
V
V
OUTH2
Output Voltage Swing High
R
L
= 100
3
3.3
V
V
OUTL2
Output Voltage Swing Low
R
L
= 100
-3.5
-3
V
I
OUT
Output Short Circuit Current
[2]
80
100
mA
I
S
Supply Current
10.1
11
mA
AC Performance - R
G
= 20
, C
L
= 5pF
BW
-3dB Bandwidth
175
MHz
BW 0.1dB
0.1dB Bandwidth
34
MHz
BW 1dB
1dB Bandwidth
150
MHz
Peaking
Peaking
0.4
dB
SR
Slew Rate
V
OUT
= 2V
PP
, measured at 20% to 80%
150
185
V/ s
OS
Overshoot, 4Vpk-pk Output Square Wave
Positive
0.6
%
Negative
2.7
%
t
S
Settling Time to 0.1% of 1V Pulse
42
ns
V
N
Voltage Noise Spectral Density
0.83
nV/
Hz
I
N
Current Noise Spectral Density
2.4
pA/
Hz
HD2
2nd Harmonic Distortion
[3]
-74
dBc
HD3
3rd Harmonic Distortion
[4]
-91
dBc
1. Measured by moving the supplies from 4V to 6V
2. Pulse test only
3. Frequency = 1MHz, V
OUT
= 2Vpk-pk, into 500
and 5pF load
3
EL2125C
Ultra-Low Noise, Low Power, Wideband Amplifier
E
L
2125C
Electrical Characteristics
V
S
= 15V, T
A
= 25C, R
F
= 180
, R
G
= 20
, R
L
= 500
unless otherwise specified.
Parameter
Description
Conditions
Min
Typ
Max
Unit
DC Performance
V
OS
Input Offset Voltage (SO8)
0.6
3
mV
Input Offset Voltage (SOT23-5)
3
mV
T
CVOS
Offset Voltage Temperature Coefficient
4.9
V/C
I
B
Input Bias Current
-30
-24
A
I
OS
Input Bias Current Offset
0.4
2
A
T
CIB
Input Bias Current Temperature Coefficient
0.08
A/C
C
IN
Input Capacitance
2.2
pF
A
VOL
Open Loop Gain
80
87
dB
PSRR
Power Supply Rejection Ratio
[1]
80
97
dB
CMRR
Common Mode Rejection Ratio
at CMIR
75
105
dB
CMIR
Common Mode Input Range
-14.6
13.8
V
V
OUTH
Output Voltage Swing High
No load, R
F
= 1k
13.35
13.5
V
V
OUTL
Output Voltage Swing Low
No load, R
F
= 1k
-13.6
-13
V
V
OUTH2
Output Voltage Swing High
R
L
= 100
11
11.6
V
V
OUTL2
Output Voltage Swing Low
R
L
= 100
-10.4
-9.8
V
I
OUT
Output Short Circuit Current
[2]
120
250
mA
I
S
Supply Current
10.8
12
mA
AC Performance - R
G
= 20
, C
L
= 5pF
BW
-3dB Bandwidth
220
MHz
BW 0.1dB
0.1dB Bandwidth
23
MHz
BW 1dB
1dB Bandwidth
63
MHz
Peaking
Peaking
2.5
dB
SR
Slew Rate
V
OUT
= 2V
PP
, measured at 20% to 80%
180
225
V/s
OS
Overshoot, 4Vpk-pk Output Square Wave
0.6
%
t
S
Settling Time to 0.1% of 1V Pulse
38
ns
V
N
Voltage Noise Spectral Density
0.95
nV/
Hz
I
N
Current Noise Spectral Density
2.1
pA/
Hz
HD2
2nd Harmonic Distortion
[3]
-73
dBc
HD3
3rd Harmonic Distortion
[4]
-96
dBc
1. Measured by moving the supplies from 13.5V to 16.5V
2. Pulse test only
3. Frequency = 1MHz, V
OUT
= 2Vpk-pk, into 500
and 5pF load
4
EL2125C
Ultra-Low Noise, Low Power, Wideband Amplifier
E
L
21
25C
Typical Performance Curves
Non-Inverting Frequency Response for Various R
F
5
-5
1M
10M
100M
Frequency (Hz)
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Inverting Frequency Response for Various R
F
6
2
-2
-6
-10
-14
1M
10M
100M
300M
Frequency (Hz)
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Inverting Frequency Response for Various R
F
6
2
-2
-6
-10
-14
1M
10M
100M
300M
Frequency (Hz)
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Non-Inverting Frequency Response for Various R
F
5
0
-5
1M
10M
100M
Frequency (Hz)
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
0
R
F
=1k
R
F
=499
R
F
=180
R
F
=100
R
F
=1k
R
F
=180
R
F
=700
R
F
=100
R
F
=499
V
S
=5V
A
V
=-10
R
L
=560
C
L
=5pF
R
F
=1k
R
F
=350
R
F
=200
R
F
=97.6
R
F
=499
R
F
=1k
R
F
=350
R
F
=200
R
F
=499
R
F
=97.6
V
S
=5V
A
V
=10
R
L
=500
C
L
=5pF
V
S
=15V
A
V
=10
R
L
=500
C
L
=5pF
-5
0
5
1M
10M
100M
200M
Frequency (Hz)
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Non-Inverting Frequency Response vs Gain
V
S
=5V
R
L
=500
C
L
=5pF
R
G
=20
-5
0
5
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Non-Inverting Frequency Response for Various Gain
V
S
=15V
R
L
=500
C
L
=5pF
R
F
=700
1M
10M
100M
200M
Frequency (Hz)
200M
300M
A
V
=50
A
V
=20
A
V
=10
A
V
=50
A
V
=20
A
V
=10
V
S
=15V
A
V
=-10
R
L
=500
C
L
=5pF
5
EL2125C
Ultra-Low Noise, Low Power, Wideband Amplifier
E
L
2125C
Typical Performance Curves
6
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Inverting Frequency Response vs Gain
2
-2
-6
-10
-14
0
6
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Inverting Frequency Response vs Gain
1M
10M
100M
300M
Frequency (Hz)
-14
A
V
=-10
A
V
=-50
A
V
=-20
1M
10M
100M
300M
Frequency (Hz)
A
V
=-50
A
V
=-20
A
V
=-10
V
S
=15V
R
L
=500
C
L
=5pF
R
G
=50
-5
5
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Non-Inverting Frequency Response for Various Output
Signal Levels
0
-14
6
N
o
r
m
al
i
z
ed
G
a
i
n
(
d
B
)
Inverting Frequency Response for Various Output Signal
Levels
0
1M
10M
100M 200M
Frequency (Hz)
V
S
=5V
A
V
=10
R
F
=180
R
L
= 500
C
L
=5pF
2V
PP
4V
PP
30mV
PP
500mV
PP
1V
PP
1M
10M
100M
300M
Frequency (Hz)
V
S
=5V
A
V
=-10
R
F
=350
R
L
= 500
C
L
=5pF
2.5V
PP
500mV
PP
3.3V
PP
250mV
PP
3mV
PP
5
No
rm
a
l
i
z
e
d
G
a
i
n
(d
B
)
Non-Inverting Frequency Response for Various C
L
3
1
-1
-3
0
5
No
rm
a
l
i
z
e
d
G
a
i
n
(d
B
)
Non-Inverting Frequency Response for Various C
L
-5
1M
10M
100M
200M
Frequency (Hz)
V
S
=5V
A
V
=10
R
F
=180
R
L
=500
-5
1M
10M
100M
200M
Frequency (Hz)
V
S
=5V
A
V
=10
R
F
=700
R
L
=500
1V
PP
C
L
=28.5pF
C
L
=16pF
C
L
=5pF
C
L
=1pF
C
L
=17pF
C
L
=11pF
C
L
=1.2pF
C
L
=5pF
V
S
=5V
R
L
=500
C
L
=5pF
R
G
=35
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