www.fairchildsemi.com
KM4111/KM4121
0.2mA, Low Cost, +2.7V & +5V, 35MHz Rail-to-Rail Amplifiers
Features
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General Description
The KM4111 (single) and KM4121 (single with disable)
are ultra-low power, low cost, voltage feedback
amplifiers. These amplifiers use only 208µA of supply
current and are designed to operate on +2.7V, +5V,
or ±2.5V supplies. The input voltage range extends
300mV below the negative rail and 1.2V below the
positive rail.
The KM4111 offers high bipolar performance at a
low CMOS price. The KM4111 offers superior dynamic
performance with a 35MHz small signal bandwidth
and 27V/µs slew rate. The combination of lowpower,
high bandwidth, and rail-to-rail performance make
the KM4111 well suited for battery-powered commu-
nication/computing systems.
208µA supply current
35MHz bandwidth
Power down to I
s
= 35µA (KM4121)
Fully specified at +2.7V and +5V supplies
Output voltage range: 0.08V to 4.88V; V
s
= +5
Input voltage range: -0.3V to +3.8V; V
s
= +5
27V/µs slew rate
±8.5mA linear output current
±13mA short circuit output current
21nV/√Hz input voltage noise
Directly replaces MAX4281
Small package options (SOT23-5 and SOT23-6)
Applications
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Normalized Magnitude (2dB/div)
0.1
Portable/battery-powered applications
A/D buffer
Active filters
Signal conditioning
Portable test instruments
Non-Inverting Freq. Response V
s
= +5V
G=
2
KM4111/KM4121 Packages
SOT23-5 (KM4111)
Out
-V
s
+In
1
2
+
5
+V
s
-
1
10
100
Frequency (MHz)
3
4
-In
SOT23-6 (KM4121)
Out
-V
s
+In
1
2
+
6
5
4
+V
s
DIS
-In
-
3
REV. 1B June 2001
DATA SHEET
KM4111/KM4121
KM4111/KM4121 Electrical Characteristics
(V
s
= +2.7V, G = 2, R
L
= 2kΩ to V
s
/2, R
f
= 2.5kΩ; unless noted)
PARAMETERS
Case Temperature
Frequency Domain Response
-3dB bandwidth
full power bandwidth
gain bandwidth product
Time Domain Response
rise and fall time
settling time to 0.1%
overshoot
slew rate
Distortion and Noise Response
2nd harmonic distortion
3rd harmonic distortion
THD
input voltage noise
DC Performance
input offset voltage
average drift
input bias current
average drift
input offset current
power supply rejection ratio
open loop gain
quiescent current
Disable Characteristics
turn on time
turn off time
off isolation
quiescent current
Input Characteristics
input resistance
input capacitance
input common mode voltage range
common mode rejection ratio
Output Characteristics
output voltage swing
linear output current
short circuit output current
power supply operating range
G = +1, Vo = 0.05V
pp
G = +2, Vo < 0.2V
pp
G = -1, Vo = 2V
pp
0.2V step
1V step
2V step, G = -1
2V step, G = -1
1V
pp
, 100kHz
1V
pp
, 100kHz
1V
pp
, 100kHz
>10kHz
CONDITIONS
TYP
+25°C
28
15
7
16
16
140
1
20
85
63
62
23
0.8
11
0.37
1
8
60
65
185
1
3.5
74
13
>10
1.4
-0.3 to 1.5
92
0.06 to 2.62
0.08 to 2.6
±8
±12.5
2.7
±5
1.3
130
56
56
245
MIN & MAX
+25°C
MHz
MHz
MHz
MHz
ns
ns
%
V/µs
dBc
dBc
dB
nV/√Hz
mV
µV/°C
µA
nA/°C
nA
dB
dB
µA
µs
µs
dB
µA
MΩ
pF
V
dB
V
V
mA
mA
V
2
2
2
2
2
2
1
UNITS
NOTES
DC
1MHz
DC, V
cm
= 0V to V
s
- 1.5
R
L
= 10kΩ to V
s
/2
R
L
= 2kΩ to V
s
/2
65
2
0.2 to 2.4
2.5 to 5.5
2
Min/max ratings are based on product characterization and simulation. Individual parameters are tested as noted. Outgoing quality levels
are determined from tested parameters.
NOTES:
1) For G = +1, Rf = 0.
2) 100% tested at +25°C.
Absolute Maximum Ratings
supply voltage
0 to +6V
maximum junction temperature
+175°C
storage temperature range
-65°C to +150°C
lead temperature (10 sec)
+260°C
operating temperature range (recommended) -40°C to +85°C
input voltage range
+V
s
+0.5V; -V
s
-0.5V
internal power dissipation
see power derating curves
Package Thermal Resistance
Package
5 lead SOT23
6 lead SOT23
θ
JA
256°C/W
230°C/W
2
REV. 1B June 2001
KM4111/KM4121
DATA SHEET
KM4111/KM4121 Electrical Characteristics
(V
s
= +5V, G = 2, R
L
= 2kΩ to V
s
/2, R
f
= 2.5kΩ; unless noted)
PARAMETERS
Case Temperature
Frequency Domain Response
-3dB bandwidth
full power bandwidth
gain bandwidth product
Time Domain Response
rise and fall time
settling time to 0.1%
overshoot
slew rate
Distortion and Noise Response
2nd harmonic distortion
3rd harmonic distortion
THD
input voltage noise
DC Performance
input offset voltage
average drift
input bias current
average drift
input offset current
power supply rejection ratio
open loop gain
quiescent current
Disable Characteristics
turn on time
turn off time
off isolation
quiescent current
Input Characteristics
input resistance
input capacitance
input common mode voltage range
common mode rejection ratio
Output Characteristics
output voltage swing
linear output current
short circuit output current
power supply operating range
G = +1, Vo = 0.05V
pp
G = +2, Vo < 0.2V
pp
G = -1, Vo = 2V
pp
0.2V step
2V step
2V step, G = -1
2V step, G = -1
2V
pp
, 100kHz
2V
pp
, 100kHz
2V
pp
, 100kHz
>10kHz
CONDITIONS
TYP
+25°C
35
18
8
20
13
140
1
27
78
66
65
21
-1.5
20
0.37
1
7
60
62
208
0.7
4.5
72
35
>10
1.2
-0.3 to 3.8
95
0.08 to 4.88
0.1 to 4.8
±8.5
±13
5
±5
1.3
130
56
56
260
MIN & MAX
+25°C
MHz
MHz
MHz
MHz
ns
ns
%
V/µs
dBc
dBc
dB
nV/√Hz
mV
µV/°C
µA
nA/°C
nA
dB
dB
µA
µs
µs
dB
µA
MΩ
pF
V
dB
V
V
mA
mA
V
2
2
2
2
2
2
1
UNITS
NOTES
DC
1MHz
DC, V
cm
= 0V to V
s
- 1.5
R
L
= 10kΩ to V
s
/2
R
L
= 2kΩ to V
s
/2
65
2
0.2 to 4.7
2.5 to 5.5
2
Min/max ratings are based on product characterization and simulation. Individual parameters are tested as noted. Outgoing quality levels
are determined from tested parameters.
NOTES:
1) For G = +1, Rf = 0.
2) 100% tested at +25°C.
REV. 1B June 2001
3
DATA SHEET
KM4111/KM4121
KM4111/KM4121 Performance Characteristics
(V
s
= +5V, G = 2, R
L
= 2kΩ to V
s
/2, R
f
= 2.5kΩ; unless noted)
Non-Inverting Frequency Response V
s
= +5V
Normalized Magnitude (2dB/div)
Normalized Magnitude (1dB/div)
G=
2
G=1
R
f
= 0
Inverting Frequency Response V
s
= +5V
G = -1
G = -2
G = 10
G = -10
G = -5
G=5
0.1
1
10
100
0.1
1
10
100
Frequency (MHz)
Non-Inverting Freq. Response V
s
= +2.7V
Normalized Magnitude (2dB/div)
G=
2
G=1
R
f
= 0
Frequency (MHz)
Inverting Frequency Response V
s
= +2.7V
Normalized Magnitude (1dB/div)
G = -1
G = -2
G = -10
G = 10
G = -5
G=5
0.1
1
10
100
0.1
1
10
100
Frequency (MHz)
Large Signal Frequency Response
100
|Gain|
Frequency (MHz)
Open Loop Gain & Phase vs. Frequency
40
Open Loop
Phase
(deg)
V
o
=
1V
pp
Open Loop Gain (dB)
Magnitude (1dB/div)
80
60
40
20
0
Phase
0
-40
-80
-120
-160
-200
10
100
1k
10k
100k
1M
10M
V
o
= 2V
pp
-20
0.1
1
10
100
Frequency (MHz)
Input Voltage Noise
100
-40
V
o
= 2V
pp
Frequency (Hz)
2nd & 3rd Harmonic Distortion; V
s
= +5V
Voltage Noise (nV/√Hz)
80
-50
Distortion (dBc)
3rd
-60
-70
-80
-90
2nd
60
40
20
0
100
1k
10k
100k
1M
-100
10
100
1000
Frequency (Hz)
Frequency (kHz)
4
REV. 1B June 2001
KM4111/KM4121
DATA SHEET
KM4111/KM4121 Performance Characteristics
(V
s
= +5V, G = 2, R
L
= 2kΩ to V
s
/2, R
f
= 2.5kΩ; unless noted)
2nd & 3rd Harmonic Distortion; V
s
= +2.7V
-40
V
o
= 1V
pp
PSRR
10
0
-50
Distortion (dBc)
3rd
-10
PSRR (dB)
2nd
-60
-70
-80
-90
-20
-30
-40
-50
-60
-70
-100
10
100
1000
100
1k
10k
100k
1M
10M
Frequency (kHz)
CMRR
-20
-30
-40
4.85
4.80
Frequency (Hz)
Output Swing vs. R
L
-50
-60
-70
-80
-90
-100
10
100
1k
10k
100k
1M
10M
Output Swing (V
pp
)
CMRR (dB)
4.75
4.70
4.65
4.60
4.55
1
10
100
Frequency (Hz)
Small Signal Pulse Response V
s
= +5V
Output Voltage (0.05V/div)
Output Voltage (0.5V/div)
R
L
(kΩ)
Large Signal Pulse Response V
s
= +5V
Time (1µs/div)
Time (1µs/div)
Enable Disable Response V
s
= +5V
Output Voltage (0.1V/div)
5V
Disable Pulse
0V
Time (1µs/div)
REV. 1B June 2001
5
