ML2111CCP [MICRO-LINEAR]
Universal Dual High Frequency Filter; 通用双高频滤波器
| 型号： | ML2111CCP |
| 厂家： | 
MICRO LINEAR CORPORATION |
| 描述： | Universal Dual High Frequency Filter |
| 文件： | 总26页 (文件大小：439K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
May 1997
ML2111*
Universal Dual High Frequency Filter
GENERAL DESCRIPTION
FEATURES
The ML2111 consists of two independent switched
capacitor filters that operate at up to 150kHz and perform
second order filter functions such as lowpass, bandpass,
highpass, notch and allpass. All filter configurations,
including Butterworth, Bessel, Cauer, and Chebyshev can
be formed.
■ Specified for operation up to 150kHz
■ Center frequency x Q product £ 5MHz
■ Separate highpass, notch, allpass, bandpass, and
lowpass outputs
The center frequency of these filters is tuned by an
external clock or the external clock and resistor ratio.
■ Center frequency accuracy of ±0.4% or ±0.8% max.
■ Q accuracy of ±4% or ±8% max.
The ML2111 frequency range is specified up to 150kHz
with ±5.0V ±10% power supplies. Using a single 5.0V
±10% power supply the frequency range is up to 100kHz.
These filters are ideal where center frequency accuracy
and high Qs are needed.
■ Clock inputs are TTL or CMOS compatible
■ Single 5V (±2.25V) or ±5V supply operation
The ML2111 is a pin compatible superior replacement for
MF10, LMF100, and LTC1060 filters.
* Some Packages Are End Of Life and Obsolete
BLOCK DIAGRAM
7
8
3
5
2
1
S1
V
BP
A
LP
V
N/AP/HP
A
A+
A
D+
A
-
INV
A
-
4
+
Σ
∫
∫
+
-
S2
A
AGND
15
10
CLK
A
LEVEL NON-OVERLAP
SHIFT
CLOCK
S
A/B
50/100HOLD
LEVEL SHIFT
6
12
9
CONTROL
CLK
B
LEVEL NON-OVERLAP
11
SHIFT
CLOCK
S2
S1
B
-
-
+
INV
B
Σ
∫
∫
+
17
-
N/AP/HP
BP
LP
B
V
V
D-
B
B
B
A-
19
20
18
16
14
13
1
ML2111
PIN CONFIGURATION
ML2111
20-Pin PDIP (P20)
20-Pin SOIC (S20)
LP
BP
1
2
3
4
5
6
7
8
9
20 LP
B
A
A
19 BP
B
N/AP/HP
INV
18 N/AP/HP
B
A
17 INV
A
B
S1
16 S1
B
A
S
15 AGND
A/B
V
14
13
V
V
A+
D+
A-
V
D-
LSh
12 50/100/HOLD
11 CLK
CLK 10
A
B
TOP VIEW
PIN DESCRIPTION
PIN NAME
FUNCTION
PIN NAME
FUNCTION
1
2
3
LP
Lowpass output for biquad A.
11
12
CLK
Clock input for biquad B.
A
B
BP
Bandpass output for biquad A.
50/100/HOLDInput pin to control the clock-to-
center-frequency ratio of 50:1 or
100:1, or to stop the clock to hold the
last sample of the bandpass or lowpass
outputs.
A
N/AP/HP
Notch/allpass/highpass output for
biquad A.
A
4
5
INV
Inverting input of the summing op amp
for biquad A.
A
13
14
15
16
V
V
Negative digital supply.
Negative analog supply.
Analog ground.
D-
S1
Auxiliary signal input pin used in
modes 1a, 1d, 4, 5, and 6b.
A
A-
AGND
S1
6
7
8
9
S
Controls S2 input function.
Positive analog supply.
Positive digital supply.
A/B
Auxiliary signal input pin used in
modes 1a, 1d, 4, 5, and 6b.
B
V
V
A+
17
18
INV
Inverting input of the summing op amp
for biquad B.
D+
B
LSh
Reference point for clock input levels.
Logic threshold typically 1.4V above
LSh voltage.
N/AP/HP
Notch/allpass/highpass output for
biquad B.
B
10
CLK
Clock input for biquad A.
19
20
BP
Bandpass output for biquad B.
Lowpass output for biquad B.
A
B
LP
B
2
ML2111
ABSOLUTE MAXIMUM RATINGS
Absolute maximum ratings are those values beyond which
the device could be permanently damaged. Absolute
maximum ratings are stress ratings only and functional
device operation is not implied.
Lead Temperature (Soldering, 10 sec) ..................... 300ºC
Thermal Resistance (q )
JA
20-Pin PDIP ...................................................... 67ºC/W
20-Pin SOIC ..................................................... 95ºC/W
Supply Voltage
OPERATING CONDITIONS
|V |, |V | - |V |, |V | ...................................... 13V
A+
D+
D+
A-
D-
V
, V to LSh ..................................................... 13V
A+
Inputs ......................|V , V | +0.3V to |V , V | -0.3V
Temperature Range
A+ D+
A- D-
Outputs ...................|V , V | +0.3V to |V , V | -0.3V
|V | to |V | ........................................................±0.3V
ML2111CCX .............................................. 0ºC to 70ºC
ML2111CIP ............................................. -40ºC to 85ºC
Supply Range ........................................ ±2.25V to ±6.0V
A+ D+
A- D-
A+
D+
Junction Temperature .............................................. 150ºC
Storage Temperature Range ...................... –65ºC to 150ºC
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, V = V = 5V ± 10%, V = V = -5V ± 10%, C = 25pF, V = 1.41V (1.000V ),
RMS
A+
D+
A-
D-
L
IN
PK
Clock Duty Cycle = 50%, T = Operating Temperature Range (Note 1)
A
SYMBOL
FILTER
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
f0(MAX) Maximum Center Frequency (Note 2)
VIN=1VPK (0.707VRMS
Figure 15 (Mode 1),
Q £ 50, Q Accuracy £ ± 25%
100
150
kHz
kHz
)
Figure 15 (Mode 1),
Q £ 20, Q Accuracy £ ± 15%
f0(MIN)
Minimum Center Frequency (Note 2)
VIN=1VPK (0.707VRMS
Figure 15 (Mode 1),
Q £ 50, Q Accuracy £ ± 30%
25
25
Hz
)
Figure 15 (Mode 1),
Hz
Q £ 20, Q Accuracy £ ± 15%
f0 Temperature Coefficient
Clock to Center Frequency Ratio
Q = 10, Figure 15 (Mode 1)
fCLK < 5MHz
-10
ppm/ºC
50:1, fCLK = 5MHz
100:1, fCLK = 5MHz
BSuffix
C Suffix
BSuffix
C Suffix
49.65
49.45
99.6
99.2
2.5
49.85
49.85
100.0
100.0
50.05
50.25
100.4
100.8
7500
20
fCLK
Clock Frequency
Clock Feedthrough
Q Accuracy
Q £ 20, Q Accuracy £ ±15%
fCLK £ 5MHz
kHz
mV(P-P)
%
10
fCLK = 5MHz, Q = 10,
BSuffix
±3
50:1, Figure 15 (Mode 1) C Suffix
±5
%
fCLK = 5MHz, Q = 10,
BSuffix
±4
%
100:1, Figure 15 (Mode 1) C Suffix
fCLK < 5MHz, Q = 10
±8
%
Q Temperature Coefficient
DCOffset
20
7
ppm/ºC
mV
VOS2,3
50:1, fCLK = 5MHz
SA/B = High or Low
100:1, fCLK = 5MHz
SA/B =High or Low
BSuffix
C Suffix
BSuffix
C Suffix
40
60
7
mV
14
14
60
mV
100
mV
3
ML2111
ELECTRICAL CHARACTERISTICS (Continued)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
FILTER (Continued)
Gain Accuracy, DC Lowpass
R1,R3 = 20kW, R2 = 2kW,
0.01
2
%
100:1, f0 = 50kHz, Q = 10
Gain Accuracy, Bandpass at f0
R1,R3 = 20kW, R2 = 2kW, BSuffix
1
1
4
6
2
%
%
%
100:1, f0 = 50kHz, Q = 10 C Suffix
Gain Accuracy, DC Notch Output
R1,R3 = 20kW, R2 = 2kW,
0.02
100:1, f0 = 50kHz, Q = 10
Noise (Note 3)
Bandpass
Lowpass
Notch
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
103
121
120
150
115
135
262
333
268
342
64
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
dB
Figure 15 (Mode 1),
Q = 1, R1 = R2 = R3 = 2kW
Noise (Note 3)
Bandpass,
R1 = 20kW
Lowpass,
R1 = 2kW
Notch,
Figure 15 (Mode 1),
Q = 10, R3 = 20kW, R2 = 2kW
R1 = 2kW
72
Crosstalk
fCLK = 5MHz, f0= 100kHz
-50
FILTER, VA+ = VD+ = 2.25V, VA- = VD- = -2.25V, VIN = 0.707 x VPK (0.5 x VRMS
)
f0(MAX) Maximum Center Frequency Figure 15 (Mode 1),
75
kHz
kHz
Hz
Q £ 50, Q Accuracy £ ± 30%
Figure 15 (Mode 1),
Q £ 20, Q Accuracy £ ± 15%
100
f0(MIN)
Minimum Center Frequency
Figure 15 (Mode 1),
25
25
Q £ 50, Q Accuracy £ ± 30%
Figure 15 (Mode 1),
Hz
Q £ 20, Q Accuracy £ ± 15%
Clock to Center Frequency Ratio
Q = 10, Figure 15 (Mode 1)
50:1, fCLK = 2.5MHz
100:1, fCLK = 2.5MHz
BSuffix
49.65
49.45
99.60
99.20
2.5
49.85
49.85
100.0
100.0
50.05
50.25
100.4
100.8
5000
±4
C Suffix
BSuffix
C Suffix
fCLK
Clock Frequency
Q Accuracy
Q £ 20, Q Accuracy £ ±15%
kHz
%
fCLK = 2.5MHz, Q = 10,
BSuffix
50:1, Figure 15 (Mode 1) C Suffix
±8
%
fCLK = 2.5MHz, Q = 10,
BSuffix
±3
±6
%
100:1, Figure 15 (Mode 1) C Suffix
%
4
ML2111
ELECTRICAL CHARACTERISTICS (Continued)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
FILTER, VA+ = VD+ = 2.25V, VA- = VD- = -2.25V, VIN = 0.707 x VPK (0.5 x VRMS) (Continued)
Noise (Note 3)
Bandpass
Lowpass
Notch
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
100kHz, 50:1
50kHz, 100:1
105
123
122
152
117
138
265
335
270
245
65
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
µVRMS
Figure 15 (Mode 1),
Q = 1, R1 = R2 = R3 = 2kW
Noise (Note 3)
Bandpass,
R1 = 20kW
Lowpass,
R1 = 2kW
Notch,
Figure 15 (Mode 1), Q = 10,
R3 = 20kW, R2 = 2kW
R1 = 2kW
73
OPERATIONAL AMPLIFIERS
VOS1
AVOL
DC Offset Voltage
2
15
1.2
0.6
mV
dB
DC Open Loop Gain
RL = 1kW
95
2.4
2.0
0.5
50
25
Gain Bandwidth Product
SlewRate
MHz
V/µs
V
Output Voltage Swing (Clipping Level)
Output Short Circuit Current
RL = 2kW, |V| from VA+ or VA-
Source
Sink
mA
mA
CLOCK
SUPPLY
VCLK Input Low Voltage
VCLK Input High Voltage
CLKA, CLKB Pulse Width
CLKA, CLKB Pulse Width
V
V
3.0
100
66
|VD+| - |VD-| ³ 4.5V
|VD+| - |VD-| ³ .90V
ns
ns
(IA+)+(ID+) Supply Current, (VA+) + (VD+
(IA-)+(ID-) Supply Current, (VA-) + (VD-
ILSh Supply Current, LSh
)
fCLK = 5MHz
fCLK = 5MHz
fCLK = 5MHz
13
12
22
21
1
mA
mA
mA
)
0.5
Note 1: Limits are guaranteed by 100% testing, sampling, or correlation with worst case test conditions.
Note 2: The center frequency is defined as the peak of the bandpass output.
Note 3: The noise is meassured with an HP8903A audio analyzer with a bandwidth of 700kHz, which is 7.5 times the f0 at 50:1 and 15 times the f0 at 100:1.
5
ML2111
TYPICAL PERFORMANCE CURVES
0.4
5
4
Q = 50
0.0
–0.4
–0.8
–1.2
–1.6
–2.0
–2.4
–2.8
Q = 20
3
Mode 1
Q = 10
IN = 0.707VRMS
V
2
TA = 85ºC
Q = 10
1
0
Mode 1
T
A = 25ºC
Q = 5
–1
–2
–3
V
IN = 0.707VRMS
TA = 25ºC
0
2
4
6
8
10
0
2
4
6
8
10
f
(MHz)
f
(MHz)
CLK
CLK
Figure 1A. f /f vs. f
(50:1, V = ±5V)
CLK
0
CLK
S
0.4
0.0
0.5
0.0
Q = 50
Q = 20
–0.4
–0.8
–1.2
–1.6
–2.0
–2.4
–2.8
–3.2
TA = 25ºC
–0.5
–1.0
Q = 10
Mode 1
Q = 10
TA = 85ºC
Mode 1
A = 25ºC
IN = 0.707VRMS
T
VIN = 0.707VRMS
V
Q = 5
–1.5
–2.0
0
2
4
6
8
10
0
2
4
6
8
10
f
(MHz)
f
(MHz)
CLK
CLK
Figure 1B. f /f vs. f
(100:1, V = ±5V)
CLK
0
CLK
S
16
10
8
14
12
10
8
Q = 10
TA = 85ºC
Mode 1
6
T
A = 25ºC
V
IN = 0.5VRMS
Mode 1
Q = 10
IN = 0.5VRMS
4
2
V
6
Q = 20
4
TA = 25ºC
2
Q = 50
0
Q = 5
0
–2
–2
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
f
(MHz)
f
(MHz)
CLK
CLK
Figure 1C. f /f vs. f
(50:1, V = ±2.5V)
S
CLK
0
CLK
6
ML2111
TYPICAL PERFORMANCE CURVES (Continued)
5
12
10
8
4
3
Mode 1
T
A = 25ºC
V
IN = 0.5VRMS
Mode 1
Q = 10
VIN = 0.5VRMS
2
6
TA = 85ºC
Q = 50
Q = 10
1
4
Q = 20
0
2
–1
–2
0
Q = 5
7
TA = 25ºC
–2
0
1
2
3
4
5
6
8
9
0
1
2
3
4
5
6
7
8
9
f
(MHz)
f
(MHz)
CLK
CLK
Figure 1D. f /f vs. f
(100:1, V = ±2.5V)
CLK
0
CLK
S
0.08
0.06
0.04
0.03
Mode 1
Q = 10
f0 = 50kHz
CLK = 5MHz
Mode 1
Q = 10
f0 = 100kHz
CLK = 5MHz
f
f
0.04
V
IN = 0.707VRMS
V
IN = 0.707VRMS
0.02
0.02
0.00
0.01
0
–0.02
–0.04
–0.06
–0.01
–40
–20
0
20
40
60
80
100
–40
–20
0
20
40
60
80
100
Temperature (ºC)
Temperature (ºC)
Figure 2A. f /f Deviation vs. Temperature
Figure 2B. f /f Deviation vs. Temperature
CLK 0
CLK
0
(50:1, V = ±5V)
(100:1, V = ±5V)
S
S
0.10
0.08
0.06
0.04
Mode 1
0.06
Q = 10
f0 = 50kHz
CLK = 2.5MHz
0.02
f
0.04
V
IN = 0.5VRMS
0.02
0.00
0.00
Mode 1
Q = 10
fo = 25kHz
CLK = 2.5MHz
IN = 0.5VRMS
–0.02
–0.04
–0.06
–0.02
–0.04
–0.06
f
V
–40
–20
0
20
40
60
80
100
–40
–20
0
20
40
60
80
100
Temperature (ºC)
Temperature (ºC)
Figure 2C. f /f Deviation vs. Temperature
Figure 2D. f /f Deviation vs. Temperature
CLK 0
CLK
0
(50:1, V = ±2.5V)
(100:1, V = ±2.5V)
S
S
7
ML2111
TYPICAL PERFORMANCE CURVES (Continued)
20
20
16
12
8
16
12
8
Mode 1
T
A = 25ºC
TA = 25ºC
V
IN = 0.707VRMS
Mode 1
Q = 10
IN = 0.707VRMS
Q = 10
V
Q = 5
4
4
0
Q = 20
TA = 85ºC
0
Q = 50
–4
–8
–4
0
2
4
6
8
10
0
2
4
6
8
10
f
(MHz)
f
(MHz)
CLK
CLK
Figure 2E. Q Error vs. f
(50:1, V = ±5V)
CLK
S
20
15
10
5
20
Mode 1
Mode 1
Q = 10
T
A = 25ºC
16
12
8
V
IN = 0.707VRMS
Q = 10
V
IN = 0.707VRMS
TA = 85ºC
Q = 5
0
4
Q = 20
Q = 50
–5
–10
–15
0
TA = 25ºC
8
–4
0
2
4
6
8
10
0
2
4
6
10
f
(MHz)
f
(MHz)
CLK
CLK
Figure 2F. Q Error vs. f
(100:1, V = ±5V)
CLK
S
10
5
8
Q = 10
Mode 1
4
0
Q = 10
IN = 0.5VRMS
TA = 25ºC
V
0
Q = 5
Q = 20
–5
TA = 85ºC
Q = 50
–10
–15
–20
–4
–8
Mode 1
T
A = 25ºC
V
IN = 0.5VRMS
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
f
(MHz)
f
(MHz)
CLK
CLK
Figure 2G. Q Error vs. f
(50:1, V = ±2.5V)
S
CLK
8
ML2111
TYPICAL PERFORMANCE CURVES (Continued)
16
16
12
8
12
Mode 1
T
A = 25ºC
8
4
Mode 1
Q = 10
IN = 0.5VRMS
V
IN = 0.5VRMS
TA = 85ºC
V
Q = 10
Q = 5
4
0
0
TA = 25ºC
–4
–8
–12
Q = 20
–4
–8
–12
Q = 50
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
f
(MHz)
f
(MHz)
CLK
CLK
Figure 2H. Q Error vs. f
(100:1, V = ±2.5V)
CLK
S
0.6
0.4
0.4
0.2
0.2
0.0
0.0
–0.2
–0.4
–0.6
–0.8
–1.0
–0.2
–0.4
–0.6
–0.8
Mode 1
Q = 10
f0 = 50kHz
CLK = 5MHz
IN = 0.707VRMS
Mode 1
Q = 10
f0 = 100kHz
CLK = 5MHz
IN = 0.707VRMS
f
f
V
V
–40
–20
0
20
40
60
80
100
–40
–20
0
20
40
60
80
100
Temperature (ºC)
Temperature (ºC)
Figure 3A. Q Deviation vs. Temperature
(50:1, V = ±5V)
Figure 3B. Q Deviation vs. Temperature
(100:1, V = ±5V)
S
S
0.2
0.2
Mode 1
Q = 10
f0 = 25kHz
fCLK = 2.5MHz
V
IN = 0.5VRMS
0.0
0.0
Mode 1
Q = 10
f0 = 50kHz
CLK = 2.5MHz
IN = 0.5VRMS
–0.2
–0.4
–0.2
–0.4
f
V
–40
–20
0
20
40
60
80
100
–40
–20
0
20
40
60
80
100
Temperature (ºC)
Temperature (ºC)
Figure 3C. Q Deviation vs. Temperature
(50:1, V = ±2.5V)
Figure 3D. Q Deviation vs. Temperature
(100:1, V = ±2.5V)
S
S
9
ML2111
TYPICAL PERFORMANCE CURVES (Continued)
4
0.05
Mode 1
T
A = 25ºC
CLK = 5MHz
IN = 1VRMS
Mode 1
f
T
A = 25ºC
V
50:1 or 100:1
f
V
CLK = 5MHz
IN = 1VRMS
0
–4
–8
0.0
100:1
50:1
–0.05
0.1
1
10
Ideal Q (R3/R2)
100
0.1
1
10
Ideal Q (R3/R2)
100
Figure 4A. f /f Deviation vs. Q (V = ±5V)
Figure 4A. f /f
Deviation vs. Q (V = ±5V)
CLK
0
S
CLK NOTCH S
4
0
2
0
–4
–2
–4
–6
–8
–8
Mode 1
Mode 1
T
A = 25ºC
f0 = 50kHz
CLK = 5MHz
VS = ±5V
T
A = 25ºC
–12
f0 = 100kHz
CLK = 5MHz
VS = ±5V
f
f
–16
0.1
1
10
Ideal Q (R3/R2)
100
0.1
1
10
Ideal Q (R3/R2)
100
Figure 5A. Q Deviation vs. Q (50:1, V = ±5V)
Figure 5B. Q Deviation vs. Q (100:1, V = ±5V)
S
S
70
70
VOUT = 2V
VOUT = 1.41V
VOUT = 0.5V
VOUT = 3V
VOUT = 2V
60
50
40
30
20
10
0
60
50
40
30
20
10
0
VOUT = 4V
VOUT = 1.41V
VOUT = 3V
VOUT = 0.5V
Mode 1
Q = 1
f0 = 50kHz
CLK = 5MHz
VS = ±5V
Mode 1
Q = 1
f0 = 100kHz
CLK = 5MHz
VS = ±5V
f
f
VOUT = 4V
T
A = 25ºC
RL = 2kΩ
Low Pass Output
T
A = 25ºC
RL = 2kΩ
Low Pass Output
0
10
20
30
40
50
0
20
40
60
80
100
fIN (kHz)
fIN (kHz)
Figure 6A. Distortion vs. f (50:1, V = ±5V)
Figure 6B. Distortion vs. f (100:1, V = ±5V)
IN S
IN
S
10
ML2111
TYPICAL PERFORMANCE CURVES (Continued)
2500
2000
1500
1000
500
250
Mode 1
50:1
R1 = R3 = 20kΩ,
R2 = 2kΩ
BANDPASS OUTPUT
VS = ±5V
Mode 1
50:1
R1 = R2 = R3 = 2kΩ
BANDPASS OUTPUT
VS = ±5V
200
150
100
50
f0 = 100kHz
CLK = 5MHz
f0 = 100kHz
CLK = 5MHz
f
f
0
0
0
100
200
300
400
500
0
100
200
300
400
500
Frequency (kHz)
Frequency (kHz)
Figure 7A. Noise Spectrum Density (Q = 1)
Figure 7B. Noise Spectrum Density (Q = 10)
100
0.8
0.4
80
100:1
0.0
100:1
60
50:1
50:1
–0.4
40
–0.8
Mode 1
Mode 1
T
A = 25ºC
Q = 10
T
A = 25ºC
Q = 10
20
0
–1.2
–1.6
VS = ±5V
IN = 0.707VRMS
VS = ±5V
IN = 0.707VRMS
V
V
0
2
4
6
8
10
0
2
4
6
8
10
f
(MHz)
f
(MHz)
CLK
CLK
Figure 8. f /f
vs. f
Figure 9. Notch Depth vs. f
CLK NOTCH
CLK
CLK
15
14
13
12
11
10
16
14
12
10
8
Q = 10
A = 25ºC
T
Mode 1
VS = ±5V
CLK = 5MHz
50:1
fCLK = 10MHz
L
Sh = VSS
50:1
f
fCLK = 5MHz
fCLK = 3MHz
fCLK = 250kHz
2
3
4
5
6
–40
–20
20
60
100
0
40
80
Supply Voltage (±V)
Temperature (ºC)
Figure 11. Supply Current vs. Temperature
Figure 10. Supply Current vs. Supply Voltage
11
ML2111
FUNCTIONAL DESCRIPTION
POWER SUPPLIES
f /f RATIO
CLK 0
The analog (V ) and digital (V ) supply pins, in most
The ML2111 is a sampled data filter and approximates
continuous time filters. The filter deviates from its ideal
A+
D+
cases, are tied together and bypassed to AGND with
100nF and 10nF disk ceramic capacitors. The supply pins
can be bypassed separately if a high level of digital noise
exists. These pins are internally connected by the IC
substrate and should be biased from the same DC source.
The ML2111 operates from either a single supply from 4V
to 12V, or with dual supplies at ±2V to ±6V.
continuous filter model when the (f /f ) ratio decreases
CLK 0
and when the Qs are low.
f ´ Q PRODUCT RATIO
0
The f ´ Q product of the ML2111 depends on the clock
0
frequency and the mode of operation. The f ´ Q product
0
CLOCK INPUT PINS AND LEVEL SHIFT
is mainly limited by the desired f and Q accuracy for
0
clock frequencies below 1MHz in mode 1 and its
derivatives. If the clock to center frequency ratio is
With dual supplies equal to or higher than ±4.0V, the LSh
pin can be connected to the same potential as either the
lowered below 50:1, the f ´ Q product can be further
0
AGND or the V - pin. With single supply operation the
increased for the same clock frequency and for the same
Q value.
A
negative supply pins and LSh pin should be tied to the
system ground. The AGND pin should be biased half way
between V and V . Under these conditions the clock
Mode 3, (Figure 23) and the modes of operation where R4
is finite, are "slower" than the basic mode 1. The resistor
R4 places the input op amp inside the resonant loop. The
finite GBW of this op amp creates an additional phase
shift and enhances the Q value at high clock frequencies.
A+
A-
levels are TTL or CMOS compatible. Both input clock
pins share the same level shift pin.
50/100/HOLD
Tying the 50/100/HOLD pin to the V and V pins
OUTPUTNOISE
A+
D+
makes the filter operate in the 50:1 mode. Tying the pin
half way between V and V makes the filter operate in
The wideband RMS noise on the outputs of the ML2111 is
nearly independent of the clock frequency, provided that
the clock itself does not become part of the noise. Noise
at the BP and LP outputs increases for high values of Q.
A+
A-
the 100:1 mode. The input range for 50/100/HOLD is
either 2.5V ±0.5V with a total power supply range of 5V,
or 5V ±0.5V with a total power supply range of 10V.
When 50/100/HOLD is tied to the negative power supply
input, the filter operation is stopped and the bandpass and
lowpass outputs act as a sample/hold circuit which holds
the last sample.
FILTER FUNCTION DEFINITIONS
Each filter of the ML2111, along with external resistors
and a clock, approximates second order filter functions.
These are tabulated below in the frequency domain.
S1 & S1
A
B
These voltage signal input pins should be driven by a
source impedance of less than 5kW. The S and S pins
can be used to feedforward the input signal for allpass
filter configurations (see modes 4 & 5) or to alter the
clock-to-center-frequency ratio (f /f ) of the filter (see
modes 1b, 1c, 2a, & 2b). When these pins are not used
they should be tied to the AGND pin.
1. Bandpass function: available at the bandpass output
1A
1B
pins (BP , BP ), Figure 12.
A
B
s w0
CLK 0
Q
G(s) = HOBP
s w
ꢀ ꢃ
0
(1)
s2 +
+ w
0
2
ꢂ ꢅ
ꢁ
Q
ꢄ
S
A/B
where:
When S
is high, the S2 negative input of the voltage
A/B
summing device is tied to the lowpass output. When the
H
= Gain at w = w
OBP 0
S
pin is connected to the negative supply, the S2 input
A/B
switches to ground.
f = w /2p. The center frequency of the complex pole
0 0
pair is f . It is measured as the peak frequency of the
0
AGND
bandpass output.
AGND is connected to the system ground for dual supply
operation. When operating with a single positive supply
the analog ground pin should be biased half way between
Q = the Quality factor of the complex pole pair. It is
the ratio of f to the -3dB bandwidth of the 2nd order
0
bandpass function. The Q is always measured at the
filter BP output.
V
and V , and bypassed with a 100nF capacitor. The
A+
A-
positive inputs of the internal op amps and the reference
point of the internal switches are connected to the AGND
pin.
12
ML2111
FILTER FUNCTION DEFINITIONS (Continued)
2. Lowpass function: available at the LP output pins,
BANDPASS OUTPUT
Figure 13.
2
w0
G(s) = HOLP
s w
ꢀ ꢃ
0
s2 +
+ w
0
2
(2)
HOBP
ꢂ ꢅ
ꢁ
Q
ꢄ
0.707 HOBP
where:
H
= DC gain of the LP output
OLP
3. Highpass function: available only in mode 3 at
fL
f0
fH
N/AP/HP and N/AP/HP , Figure 14.
A
B
s2
f (LOG SCALE)
G(s) = HOHP
s w
ꢀ ꢃ
0
s2 +
+ w
0
2
(3)
f0
ꢂ ꢅ
Q =
;f0 = fL fH
ꢁ
Q
ꢄ
fH - fL
H
= Gain of the HP output for f ® f /2.
OHP
CLK
2
ꢀ
ꢃ
ꢀ ꢃ
1
ꢂ -1
+ 1ꢅ
fL = f0
fH = f0
+
ꢂ2Qꢅ
ꢂ ꢁ ꢄ ꢅ
ꢁ2Q
ꢄ
2
ꢀ
ꢃ
ꢀ ꢃ
1
ꢂ
1
+ 1ꢅ
+
ꢂ2Qꢅ
ꢂ ꢁ ꢄ ꢅ
ꢁ2Q
ꢄ
Figure 12.
LOWPASS OUTPUT
HIGHPASS OUTPUT
HOP
HOLP
0.707 HOLP
HOP
HOHP
0.707 HOHP
fP
fC
f (LOG SCALE)
fC
fP
2
ꢀ ꢃ ꢀ ꢃ
1
1
f (LOG SCALE)
1
fC = f0 1-
+
1-
+ 1
ꢂ ꢅ ꢂ ꢅ
ꢆ
!
"
2
ꢁ
2Q2 ꢄ ꢁ 2Q2
ꢄ
ꢀ ꢃ ꢀ ꢃ
1
1
#
#
fC = f0
1-
+
1-
+ 1
ꢂ ꢅ ꢂ ꢅ
ꢁ
2Q2 ꢄ ꢁ 2Q2
ꢄ
#
$
1
2Q2
fP = f0 1-
1
ꢆ
!
"
1
fP = f0 1-
#
2Q2
#
$
1
HOP = HOLP
1
HOP = HOHP
1
Q
1
4Q2
1-
1
1
1-
4Q2
Q
Figure 13.
Figure 14.
13
ML2111
FILTER FUNCTION DEFINITIONS
OPERATION MODES
4. Notch function: available at N/AP/HP and N/AP/HP
There are three basic modes of operation — Modes 1, 2,
and 3 , each of which has derivatives; and four secondary
modes of operation — Modes 4, 5, 6, and 7, each of
which also has derivatives.
A
B
for several modes of operation.
s2 + w
2
4
9
n
G(s) = HON2
s w
ꢀ ꢃ
0
2
(4)
s2 +
+ w
ꢂ ꢅ
0
In Figure 15, the input amplifier is outside the resonant
loop. Because of this, mode 1 and its derivatives (modes
1a, 1b, 1c, and 1d) are faster than modes 2 and 3.
ꢁ
Q
ꢄ
H
H
= Gain of the notch output for f ® f /2.
ON2
ON1
CLK
= Gain of the HP output for f ® 0
Mode 1 provides a clock tunable notch. It is a practical
configuration for second order clock tunable bandpass/
notch filters. In mode 1, a band pass output with a very
high Q, together with unity gain can be obtained with the
dynamics of the remaining notch and lowpass outputs.
f = w /2p. The frequency of the notch occurrence is
n
n
f .
n
5. Allpass function: available at N/AP/HP and N/AP/
A
HP for modes 4 and 4a.
Mode 1a (Figure 16) represents the simplest hookup of the
ML2111. It is useful when voltage gain at the bandpass
output is required. However, the bandpass voltage gain is
equal to the value of Q, and second order, clock tunable,
BP resonator can be achieved with only 2 resistors. The
filter center frequency directly depends on the external
clock frequency. Mode 1a is not practical for high order
filters as it requires several clock frequencies to tune the
overall filter response.
B
s w0
Q
s w0
Q
s2 -
s2 +
+ w0
+ w0
2
2
G(s) = HOAP
(5)
H
= Gain of the allpass output for 0 < f < f /2
CLK
OAP
For allpass functions, the center frequency and the Q of
the numerator complex zero pair is the same as the
denominator. Under these conditions the magnitude
response is a straight line. In mode 5, the center
Modes 1b and 1c, Figures 17 and 18, are similar. They
both produce a notch with a frequency which is always
equal to the filter center frequency. The notch and the
center frequency can be adjusted with an external resistor
ratio.
frequency f of the numerator complex zero pair is
Z
different than f . For high numerator Q's, the
0
magnitude response will have a notch at f .
Z
½ ML2111
½ ML2111
R3
R2
VIN
R3
N
BP
2 (19)
S1A
LP
R2
BP2
BP1
S1A
LP
5 (16)
1 (20)
3 (18)
5 (16)
2 (19)
1 (20)
3 (18)
R1
VIN
+
4 (17)
Σ
+
+
4 (17)
Σ
+
SA/B
15
6
SA/B
V+
15
6
V+
fCLK
fCLK
R2
R1
R3
R1
R3
R2
R3
R2
f0 =
;fn = f0 ;HOLP = -
;HOBP = -
;
f0 =
;Q =
;HOBP1 = -
;
100(50)
100(50)
HOBP2 = 1(non - inverting);HOLP = -1
R2
R1
R3
R2
HON1 = -
;Q =
Figure 15. Mode 1: 2nd Order Filter Providing Notch,
Bandpass, Lowpass
Figure 16. Mode 1a: 2nd Order Filter Providing
Bandpass, Lowpass
14
ML2111
MODE
BP , BP
N/AP/HP ,N/AP/HP
f
C
f
Z
A
B
A
B
fCLK
100(50) R3
fCLK
100(50) R3
fCLK
100(50) R3
R2
6a
LP
LP
LP
HP
LP
R2
6b
7
fCLK
100(50) R3
R2
R2
AP
Table 1. First Order Functions.
MODE
LP , LP
BP , BP
N/AP/HP
f
0
f
N
A
B
A
B
A&B
fCLK
1
LP
LP
LP
BP
BP
BP
Notch
BP
f
0
100(50)
fCLK
1a
1b
100(50)
fCLK
fCLK
R6
R5 + R6
R6
R5 + R6
1+
1+
Notch
100(50)
100(50)
fCLK
fCLK
R6
R5 + R6
R6
R5 + R6
1c
1d
2
LP
LP
LP
BP
BP
BP
Notch
100(50)
100(50)
fCLK
100(50)
fCLK
fCLK
R2
R4
1+
Notch
Notch
Notch
HP
100(50)
100(50)
fCLK
fCLK
R2
R6
R6
R5 + R6
1+
+
1+
2a
2b
3
LP
LP
LP
BP
BP
BP
100(50)
R4 R5 + R6
100(50)
fCLK
fCLK
R2
R6
R6
R5 + R6
+
100(50)
R4 R5 + R6
100(50)
fCLK
R2
R4
100(50)
Rh
Rl
fCLK
fCLK
R2
R4
3a
LP
BP
Notch
100(50)
100(50)
fCLK
4
LP
LP
BP
BP
AP
AP
100(50)
fCLK
R2
R4
4a
100(50)
fCLK
fCLK
R2
R4
R2
R4
1+
1-
5
LP
BP
CZ
100(50)
100(50)
Table 2. Second Order Functions
15
ML2111
R5
R6
fCLK
R6
R5 + R6
R3
R2
f0 =
Q =
1+
;fn = f0
100(50)
N
BP
S1A
5 (16)
LP
2 (19)
1 (20)
3 (18)
R3
R2
R6
R5 + R6
1+
;R5 < 5kW
R1
VIN
+
4 (17)
Σ
fCLK
2 ꢄ
R2
R1
ꢀf ꢃ = -
+
HON1 f 0 = H
1 6
ON2ꢂ
ꢅ
ꢁ
R3
R1
-R2 / R1
SA/B
6
HOBP = -
;HOLP
=
15
1+ R6 /
0
R5 + R6
5
V+
Figure 17. Mode 1b: 2nd Order Filter Providing Notch, Bandpass, Lowpass
R5
R6
fCLK
R6
R5 + R6
R3
R2
f0 =
Q =
;fn = f0
100(50)
N
BP
S1A
5 (16)
LP
2 (19)
1 (20)
3 (18)
R3
R2
R6
R5 + R6
;
R1
VIN
+
4 (17)
Σ
fCLK
2 ꢄ
R2
R1
ꢀf ꢃ = -
+
HON1 f 0 = H
;
1 6
ON2ꢂ
ꢅ
ꢁ
R3
R1
-R2 / R1
SA/B
6
HOBP = -
;HOLP
=
;R5 < 5kW
15
R6 / R5 + R6
0
5
V-
Figure 18. Mode 1c: 2nd Order Filter Providing Notch, Bandpass, Lowpass
R3B
R3A
R2
N
BP
S1A
5 (16)
LP
2 (19)
1 (20)
3 (18)
fCLK
R3A
R3B
R2
R1
R1
f0 =
;Q = 1+
;VN -
;HOBP = -
Q;
VIN
100(50)
+
4 (17)
Σ
+
R2
R1
R2
HOLP = -
V
IN
R1
SA/B
6
15
V+
Figure 19. Mode 1d: 2nd Order Filter Providing Bandpass and Lowpass for Qs Greater Than or Equal To 1.
16
ML2111
R4
R3
R2
fCLK
fCLK
R2
R4
f0 =
Q =
1+
;fn =
;
100(50)
100(50)
N
BP
S1A
LP
5 (16)
2 (19)
1 (20)
3 (18)
R3
R2
R2
R4
1+-0RR22//RR14
1+
;HOLP =
5 ;
R1
VIN
+
4 (17)
Σ
-R3
R1
1+-0RR22//RR14
+
HOBP
=
;HON1 f 0 =
5 ;
1 6
fCLK
2 ꢄ
-R2
R1
SA/B
ꢀf ꢃ =
HON2
15
ꢂ
ꢅ
6
ꢁ
V+
Figure 20. Mode 2: 2nd Order Filter Providing Notch, Bandpass, Lowpass
R4
fCLK
R2
R6
R3
R1
f0 =
fn =
Q =
1+
+
;HOBP = -
;
R5
R6
100(50)
R4 R5 + R6
R3
R2
fCLK
fCLK
R6
R2
R1
ꢀf ꢃ = -
1+
;HON2
R5 + R6
;
ꢂ
ꢅ
2
ꢁ
ꢄ
100(50)
N
BP
S1A
5 (16)
LP
2 (19)
1 (20)
3 (18)
R3
R2
R2
R6
;
R1
1+
+
VIN
R4 R5 + R6
+
4 (17)
Σ
+
%
(
;
R1 1+ 0R12+/ RR46 /
5
0
R5 + R6
+ R6 / R5 + R6
5
R2
HON1 f 0 = -
1 6
&
)
'
*
SA/B
15
6
0
R2 / R4-R+2R/ 6R1/ 0R5 + R6
5
5
HOLP
=
1+
V+
Figure 21. Mode 2a: 2nd Order Filter Providing Notch, Bandpass, Lowpass
R4
fCLK
R2
R6
f0 =
fn =
+
;
R5
R6
100(50)
R4 R5 + R6
R3
R2
fCLK
R6
R5 + R6
R3
R2
R2
R6
;Q =
+
;
100(50)
R4 R5 + R6
N
BP
S1A
5 (16)
LP
2 (19)
1 (20)
3 (18)
%
(
R6 / R5 + R6
0 5
R2
HON1 f 0 = -
;
1 6
R1
&
)
R1 R2 / R4 + R6 / R5 + R6
0 5
VIN
'
*
+
4 (17)
Σ
+
fCLK
2 ꢄ
R2
R1
R3
R1
ꢀf ꢃ = -
HON2
;HOBP = -
;
ꢂ
ꢅ
ꢁ
SA/B
15
-R2 / R1
R2 / R4 + R6 / R5 + R6
6
HOLP
=
0 5 0 5
V-
Figure 22. Mode 2b: 2nd Order Filter Providing Notch, Bandpass, Lowpass
17
ML2111
OPERATION MODES (Continued)
The clock to center frequency ratio range is:
Modes 2, 2a, and 2b (Figures 20, 21, and 22) have notch
outputs whose frequency, f , can be tuned independently
n
fCLK
500
1
100 50
or
from the center frequency, f . However, for all cases f <
0
n
(mode 1c)
(6)
(7)
f . These modes are useful when cascading second order
f0
1
1
0
functions to create an overall elliptic highpass, bandpass
or notch response. The input amplifier and its feedback
resistors R2 and R4 are now part of the resonant loop.
Because of this, mode 2 and its derivatives are slower
than mode 1 and its derivatives.
fCLK
100 50
or
100 50
or
(mode 1b)
1
1
f0
2
2
The input impedance of the S1 pin is clock dependent,
and in general R5 should not be larger than 5kW for f
<
CLK
2.5MHz and 2kW for f
> 2.5MHz. Mode 1c can be
In Mode 3 (Figure 23) a single resistor ratio, R2/R4, can
CLK
used to increase the clock-to-center-frequency ratio
tune the center frequency below or above the f /100 (or
CLK
beyond 100:1. The limit for the (f /f ) ratio is 500:1 for
f
/50) ratio. Mode 3 is a state variable configuration
CLK
CLK 0
this mode. The filter will exhibit large output offsets with
larger ratios. Mode 1d (Figure 19) is the fastest mode of
operation: center frequencies beyond 20kHz can easily
be achieved at a 50:1 ratio.
since it provides a highpass, bandpass, lowpass output
through progressive integration. Notches are acquired by
summing the highpass and lowpass outputs (mode 3a,
Figure 24). The notch frequency can be tuned below or
R4
R3
R2
HP
BP
S1A
LP
5 (16)
2 (19)
1 (20)
3 (18)
fCLK
R2
R4
R3
R2
R2
R4
f0 =
;Q =
;
100(50)
R1
VIN
+
4 (17)
Σ
R2
R1
R4
R1
R3
R1
+
HOHP = -
;HOLP = -
;HOBP = -
SA/B
15
6
V-
Figure 23. Mode 3: 2nd Order Filter Providing Highpass, Bandpass, Lowpass — ½ ML2111
R2 R3
R4 R2
Q =
R4
Rh
fCLK
fCLK
R2
R4
f0 =
;fn =
;
100(50)
100(50)
Rl
R3
R2
R2
R1
R3
R1
R4
R1
HOHP = -
;HOBP = -
;HOLP = -
;
HP
BP
S1A
LP
5 (16)
2 (19)
1 (20)
3 (18)
R
ꢀ
Rg
R1
ꢃ;
HOHP
g
HON f = f = Q
HOLP
-
VIN
1 6
0
ꢂR
ꢅ
Rh
+
ꢁ
ꢄ
l
4 (17)
Rg
Σ
+
External
Op Amp
Rg
fCLK
2 ꢄ
R2
ꢀf ꢃ =
HON2
;
Rl
ꢂ
ꢅ
ꢁ
Rh R1
SA/B
NOTCH
15
Rh
6
+
Rg
Rl
R4
HON1 f 0 =
1 6
R1
V-
Figure 24. Mode 3a: 2nd Order Filter Providing Highpass, Bandpass, Lowpass, Notch — ½ ML2111
18
ML2111
OPERATION MODES (Continued)
above the center frequency through the resistor ratio R /
l
frequency. Mode 4a (Figure 26) gives a non-inverting
h
R . Because of this, modes 3 and 3a are the most versatile
output, but requires an external op amp. Mode 5 is
recommended if this response is unacceptable. Mode 5
(Figure 27) gives a flatter response than mode 4 if R1 = R2
= 0.02 ´ R4.
and useful modes for cascading second order sections to
obtain high order elliptic filters. For very selective
bandpass/bandreject filters the mode 3a approach , as in
Figure 24, yields better dynamic range since the external
op amp helps to optimize the dynamics of the output
nodes of the ML2111.
Modes 6 and 7 are used to construct 1st order filters.
Mode 6a (Figure 28) gives a lowpass and a highpass
single pole response. Mode 6b (Figure 29) gives an
inverting and non-inverting lowpass single pole filter
response. Mode 7 (Figure 30) gives an allpass and lowpass
single pole response.
Modes 4 and 5 are useful for constructing allpass res-
ponse filters. Mode 4, Figure 25, gives an allpass
response, but due to the sampled nature of the filter, a
slight 0.5 dB peaking can occur around the center
R3
R2
AP
BP
S1A
LP
5 (16)
2 (19)
1 (20)
3 (18)
R1 = R2
VIN
+
4 (17)
Σ
+
SA/B
15
6
V+
fCLK
R3
R3
R2
R2
R1
2ꢀ ꢃ
ꢂ ꢅ
ꢁR2ꢄ
fo
H
;
2
Q
H
OAP
;
;
;
HOLP
OBP
100 50
0 5
Figure 25. Mode 4: 2nd Order Filter Providing Allpass, Bandpass, Lowpass — ½ ML2111
R4
R3
fCLK
R2
R4
R3
R2
R2
R4
f0 =
;Q =
;
R2
100(50)
HP
BP
S1A
LP
5 (16)
2 (19)
1 (20)
3 (18)
R5
2R
R2
R1
R1
HOAP
=
;HOHP = -
;
VIN
+
4 (17)
Σ
+
R4
R1
HOLP = -
HOBP = -
;
R5
R3
R1
SA/B
External
Op Amp
15
6
R
+
2R
V-
Figure 26. Mode 4a: 2nd Order Filter Providing Highpass, Bandpass, Lowpass, Allpass — ½ ML2111
19
ML2111
R3
R2
R4
R3
R2
HP
LP
S1A
5 (16)
2 (19)
1 (20)
3 (18)
R1
CZ
BP
S1A
LP
VIN
5 (16)
2 (19)
1 (20)
3 (18)
+
4 (17)
Σ
+
R1
VIN
+
4 (17)
Σ
+
SA/B
15
6
SA/B
V+
V-
15
6
fCLK
fCLK
R2
R4
R1
R4
fCLK
100(50) R3
R2
R3
R1
R2
R1
f0 =
1+
1+
;fZ =
1-
;
fC =
;HOLP = -
;HOHP = -
100(50)
100(50)
R3
Q =
R2
R3
R1
R1
Figure 28. Mode 6a: 1st Order Filter Providing
Highpass, Lowpass — ½ ML2111
;QZ
=
1-
;
R2
R4
R4
0
R4 / R1
5
- 1
R3
R2
R2
R1
ꢀ1+ ꢃ;H
f 0 = 0R4 / R2 + 1
5
HOBP
=
;
OZ 1 6
ꢂ ꢅ
ꢁ ꢄ
11++0RR22//RR41
0 5
fCLK
2 ꢄ
R2
R1
ꢀf ꢃ =
HOZ
;HOLP =
ꢂ
ꢅ
ꢁ
5
Figure 27. Mode 5: 2nd Order Filter Providing
Numerator Complex Zeroes, Bandpass, Lowpass — ½
ML2111
VIN
R3
R3
R2
LP1
LP2
S1A
R2 = R1
AP
LP
S1A
5 (16)
2 (19)
1 (20)
3 (18)
5 (16)
2 (19)
1 (20)
3 (18)
R1 = R2
VIN
+
4 (17)
Σ
+
4 (17)
Σ
+
+
SA/B
6
SA/B
15
15
6
V-
V-
fCLK
R2
R2
R3
fP = fZ =
;HOLP = 2 -
100(50) R3
fCLK
100(50) R3
R2
R3
R2
fC =
;HOLP1 = 1;HOLP2 = -
fCLK
2
0 f
|GAIN AT OUTPUT| = 1 FOR
Figure 29. Mode 6b: 1st Order Filter Providing Lowpass
— ½ ML2111
Figure 30. Mode 7: 1st Order Filter Providing Allpass,
Lowpass — ½ ML2111
20
ML2111
1
2
20
19
18
17
16
15
14
13
12
11
VOUT
LPA
LPB
BPB
R31
R21
R32
R22
0
–10
–20
–30
–40
–50
–60
–70
–80
BPA
HPA
INVA
S1A
3
101,777Hz
–3.058dB
HPB
4
INVB
S1B
5
VIN
1Vp-p
6
5V
SA/B
VA+
VD+
LSh
AGND
VA-
Q1 = 0.541
Q2 = 1.302
7
8
-5V
5V
VD-
9
50/100
CLKB
10
CLKA
10k
100k
1M
Clock 5MHz
FREQUENCY (Hz)
1% RESISTOR VALUES
R22 = 1996Ω
R32 = 2604Ω
R21 = 3746Ω
R31 = 2003Ω
Figure 31. 4th Order, 100kHz Lowpass Butterworth Filter Obtained by Cascading Two Sections in Mode 1a.
VOUT
1
2
20
19
18
17
16
15
14
13
12
11
R12
R32
LPA
LPB
BPB
R31
R21
0
–10
–20
–30
–40
–50
–60
–70
–80
BPA
HPA
INVA
S1A
R22
3
HPB
VIN
2.82Vp-p
(1VRMS
R11
4
149,871Hz
–0.31dB
INVB
S1B
)
5
Q1 = Q2 = 10
6
5V
SA/B
VA+
VD+
LSh
AGND
VA-
7
8
-5V
5V
VD-
9
50/100
CLKB
10
CLKA
10k
100k
1M
Clock 7.5MHz
FREQUENCY (Hz)
RESISTOR VALUES
R12 = 20kΩ
R22 = 2kΩ
R32 = 20kΩ
R11 = 20kΩ
R21 = 2kΩ
R31 = 20kΩ
Figure 32. Cascasding 2 Sections Connected in Mode 1, each with Q = 10, to obtain a Bandpass Filter with Q = 15.5,
and f = 150kHz (f = 7.5MHz).
0
CLK
21
ML2111
R12
1
2
20
19
18
17
16
15
14
13
12
11
10
0
VOUT
LPA
LPB
BPB
BPA
HPA
INVA
S1A
R21
R11
R22
3
166,224Hz
–3.121dB
HPB
–10
–20
–30
–40
3–50
–60
–70
4
INVB
S1B
5
6
VIN
5V
SA/B
VA+
VD+
LSh
AGND
VA-
1Vp-p
7
8
-5V
5V
VD-
9
50/100
CLKB
10
CLKA
10k
100k
1M
FREQUENCY (Hz)
Clock 7.51MHz
RESISTOR VALUES
R11 = R21 = R12 = R22 = 2.0kΩ
Figure 33. Cascading Two Sections in Mode 1d, Each with Q =1, (Independent of Resistor Ratios) to Create a Sharper 4th
Order Lowpass Filter.
R23
VIN
2.82Vp-p
VOUT
R22
1
2
20
19
18
17
16
15
14
13
12
11
0
–5
LPA
LPB
BPB
BPA
HPA
INVA
S1A
R31
R24
R21
3
–10
–15
–20
–25
–30
–35
–40
–45
–50
HPB
4
INVB
S1B
R32
5
6
SA/B
VA+
VD+
LSh
AGND
VA-
R34
7
8
5V
-5V
5V
VD-
129,070Hz
9
50/100
CLKB
10
CLKA
130
FREQUENCY (kHz)
127
133
Clock 6.5MHz
1% RESISTOR VALUES
R21 = R22 = R23 = R24 = 2kΩ
R32 = 4.9kΩ
R34 = 100Ω
R31 = 80kΩ
Figure 34. Notch Filter with Q = 50 and f = 130kHz. This Circuit Uses Side A in Mode 1d and the Side B Op Amp to
0
Create a Notch Whose Depth is Controlled by R31. The Notch is Created by Subtracting the Bandpass from V . The
IN
Bandpass of Side A is Subtracted Using the Op Amp of Side B.
22
ML2111
OPERATION MODES (Continued)
OFFSETS
Mode 1a is a good choice when Butterworth filters are
Switched capacitor integrators generally exhibit higher
input offsets than discrete RC integrators.
desired since they have poles in a circle with the same f .
0
Figure 31 shows an example of a 4th order, 100kHz
lowpass Butterworth filter clocked at 5MHz.
These offsets are mainly the charge injection of the
CMOS switchers into the integrating capacitors. The
internal op amp offsets also add to the overall offset
budget.Figure 35 shows half of the ML2111 filter with its
A monotonic passband response with a smooth transition
band results, showing the circuit's low sensitivity, even
though 1% resistors are used which results in an
approximate value of Q.
equivalent input offsets V , V
, & V
.
OS1
OS2
OS3
The DC offset at the filter bandpass output is always equal
to V . The DC offsets at the remaining two outputs
(Notch and LP) depend on the mode of operation and
external resistor ratios. Table 3 illustrates this.
Figure 32 gives an example of a 4th order bandpass filter
implemented by cascading 2 sections, each with a Q of
OS3
10. This figure shows the amplitude response when f
=
CLK
7.5MHz, resulting in a center frequency of 150kHz and a
Q of 15.5.
It is important to know the value of the DC output offsets,
especially when the filter handles input signals with large
dynamic range. As a rule of thumb, the output DC offsets
increase when:
Figure 33 uses mode 1d of a 4th order flter where each
section has a Q of 1, independent of resistor ratios. In this
mode, the input amplifier is outside the damping (Q)
loop. Therefore, its finite bandwidth does not degrade the
response at high frequency. This allows the amplifier to be
used as an anti-aliasing and continuous smoothing fliter
by placing a capacitor across R2.
1. The Qs decrease
2. The ratio (f /f ) increases beyond 100:1. This is done
CLK o
by decreasing either the (R2/R4) or the R6/(R5 + R6)
resistor ratios.
(16)
(18)
(19)
(20)
1
5
2
3
VOS1
4
VOS2
+
VOS3
+
+
(17)
Σ
+
+
+
+
15
Figure 35. Equivalent Input Offsets of ½ of an ML2111 Filter.
23
ML2111
MODE
VOSN
VOSBP
VOSLP
N/AP/HPA, N/AP/HPB
BPA, BPB
LPA, LPB
1, 4
1a
VOS1 [(1/Q) + 1 + ||HOLP||] – VOS3/Q
VOS1 [1 + (1/Q)] – VOS3/Q
VOS3
VOS3
VOS3
VOSN – VOS2
VOSN – VOS2
1b
VOS1 [(1/Q)] + 1 + R2/R1] – VOS3/Q
~(VOSN – VOS2) (1 + R5/R6)
6 R5 + R6
R5 + 2R6
1c
VOS1 [(1/Q)] + 1 + R2/R1] – VOS3/Q
VOS1 [1 + R2/R1]
VOS3
VOS3
VOS3
~ V
- VOS2
1
OSN
1d
VOSN – VOS2 – VOS3/Q
2, 5
[VOS1 (1 + R2/R1 + R2/R3 + R2/R4) – VOS3(R2/R3)] ´
[R4/(R2 + R4)] + VOS2[R2/(R2 + R4)]
VOSN – VOS2
2a
2b
[VOS1 (1 + R2/R1 + R2/R3 + R2/R4) – VOS3(R2/R3)] ´
ꢆ
!
" + V ꢆ
"
;k =
R4 1+ k
1 6
R2
R6
R5 + R6
#
#
OS2
$ !
VOS3
~ VOSN - VOS2
1
6 R5+ R6
R5+ 2R6
R2+ R4 1+ k
R2+ R4 1+ k
1 6
1 6
#
#
$
[ꢀVOS1 (1 + R2/R1 + R2/R3 + R2/R4) – VOS3(R2/R3)] ´
"
ꢀ
!
"
;k =
R 4 k
1 6
R2
R2 + R 4 k
R6
R5 + R6
R5
ꢀ1+ ꢃ
+ V
#
#
O S2
~ VOSN - VOS2
1
VOS3
6
ꢂ ꢅ
R2 + R 4 k
1 6
1 6
#
$
#
ꢁ ꢄ
R6
!
$
R4 R4 R4
R1 R2 R3
R4
R4
ꢀ1
"
ꢁ ꢄ
ꢁ ꢄ
3, 4a
VOS2
VOS3
VOS1
VOS2
VOS3
ꢃ ꢆ
ꢂR2ꢅ
ꢃ ꢆ
ꢂR3ꢅ
#
!
$
Table 3.
24
ML2111
PHYSICAL DIMENSIONS inches (millimeters)
Package: P20
20-Pin PDIP
1.010 - 1.035
(25.65 - 26.29)
20
0.240 - 0.260 0.295 - 0.325
(6.09 - 6.61) (7.49 - 8.26)
PIN 1 ID
1
0.060 MIN
(1.52 MIN)
(4 PLACES)
0.055 - 0.065
(1.40 - 1.65)
0.100 BSC
(2.54 BSC)
0.015 MIN
(0.38 MIN)
0.170 MAX
(4.32 MAX)
SEATING PLANE
0.008 - 0.012
(0.20 - 0.31)
0.016 - 0.022
(0.40 - 0.56)
0º - 15º
0.125 MIN
(3.18 MIN)
Package: S20
20-Pin SOIC
0.498 - 0.512
(12.65 - 13.00)
20
0.291 - 0.301 0.398 - 0.412
(7.39 - 7.65) (10.11 - 10.47)
PIN 1 ID
1
0.024 - 0.034
(0.61 - 0.86)
(4 PLACES)
0.050 BSC
(1.27 BSC)
0.095 - 0.107
(2.41 - 2.72)
0º - 8º
0.012 - 0.020
(0.30 - 0.51)
0.022 - 0.042
(0.56 - 1.07)
0.007 - 0.015
(0.18 - 0.38)
0.090 - 0.094
(2.28 - 2.39)
0.005 - 0.013
(0.13 - 0.33)
SEATING PLANE
25
ML2111
ORDERING INFORMATION
PART NUMBER
ML2111CCP (EOL)
ML2111CCS
TEMPERATURE RANGE
0°C to 70°C
PACKAGE
20-Pin PDIP (P20)
20-Pin SOIC (S20)
20-Pin PDIP (P20)
0°C to 70°C
ML2111CIP (OBS)
-40°C to 85°C
Micro Linear Corporation
2092 Concourse Drive
San Jose, CA 95131
Tel: (408) 433-5200
Fax: (408) 432-0295
© Micro Linear 1999.
is a registered trademark of Micro Linear Corporation. All other
trademarks are the property of their respective owners.
Products described herein may be covered by one or more of the following U.S. patents: 4,897,611; 4,964,026;
5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761;
5,592,128; 5,594,376; 5,652,479; 5,661,427; 5,663,874; 5,672,959; 5,689,167; 5,714,897; 5,717,798; 5,742,151;
5,747,977; 5,754,012; 5,757,174; 5,767,653; 5,777,514; 5,793,168; 5,798,635; 5,804,950; 5,808,455; 5,811,999;
5,818,207; 5,818,669; 5,825,165; 5,825,223; 5,838,723; 5.844,378; 5,844,941. Japan: 2,598,946; 2,619,299;
2,704,176; 2,821,714. Other patents are pending.
Micro Linear makes no representations or warranties with respect to the accuracy, utility, or completeness of
the contents of this publication and reserves the right to makes changes to specifications and product
descriptions at any time without notice. No license, express or implied, by estoppel or otherwise, to any patents
or other intellectual property rights is granted by this document. The circuits contained in this document are
offered as possible applications only. Particular uses or applications may invalidate some of the specifications
and/or product descriptions contained herein. The customer is urged to perform its own engineering review
before deciding on a particular application. Micro Linear assumes no liability whatsoever, and disclaims any
express or implied warranty, relating to sale and/or use of Micro Linear products including liability or warranties
relating to merchantability, fitness for a particular purpose, or infringement of any intellectual property right.
Micro Linear products are not designed for use in medical, life saving, or life sustaining applications.
DS2111-01
26
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