LTC1164-6
Low Power 8th Order
Pin Selectable Elliptic or
Linear Phase Lowpass Filter
FEATURES
s
s
s
s
s
s
DESCRIPTIO
s
s
s
8th Order Pin Selectable Elliptic or Bessel Filter in a
14-Pin Package
4mA Supply Current with
±5V
Supplies
64dB Attenuation at 1.44 f
CUTOFF
(Elliptic Response)
f
CUTOFF
up to 30kHz (50:1 f
CLK
to f
CUTOFF
Ratio)
110µV
RMS
Wideband Noise with
±5V
Supplies
Operates at Single 5V Supply with 1V
RMS
Input Range
Operates up to
±8V
Supplies
TTL/CMOS Compatible Clock Input
No External Components
The LTC1164-6 is a monolithic 8th order elliptic lowpass
filter featuring clock-tunable cutoff frequency and low
power supply current. Low power operation is achieved
without compromising noise or distortion performance.
At
±5V
supplies the LTC1164-6 uses only 4mA supply
current while keeping wideband noise below 110µV
RMS
.
With a single 5V supply, the LTC1164-6 can provide up to
10kHz cutoff frequency and 80dB signal-to-noise ratio
while consuming only 2.5mA.
The LTC1164-6 provides an elliptic lowpass rolloff with
stopband attenuation of 64dB at 1.44 f
CUTOFF
and an f
CLK
-
to-f
CUTOFF
ratio of 100:1 (pin 10 to V
–
). For a ratio of 100:1,
f
CUTOFF
can be clock-tuned up to 10kHz. For a f
CLK
-to-
f
CUTOFF
ratio of 50:1 (pin 10 to V
+
), the LTC1164-6
provides an elliptic lowpass filter with f
CUTOFF
frequencies
up to 20kHz. When pin 10 is connected to ground, the
LTC1164-6 approximates an 8th order linear phase re-
sponse with 65dB attenuation at 4.5 f
– 3dB
and f
CLK
/ f
– 3dB
ratio of 160:1. The LTC1164-6 is pin compatible with the
LTC1064-1.
APPLICATI
s
s
s
S
Anti-Aliasing Filters
Battery-Operated Instruments
Telecommunication Filters
TYPICAL APPLICATI
10kHz Anti-Aliasing Elliptic Filter
NC
V
IN
1
2
3
8V
4
5
6
7
LTC1164-6
14
13
12
11
10
9
8
1164-6 TA01
0
NC
–8V
CLK = 1MHz
–8V
V
OUT
GAIN (dB)
–10
–20
–30
–40
–50
–60
–70
WIDEBAND NOISE = 115µV
RMS
NOTE: THE CONNECTION FROM PIN 7 TO PIN 14 SHOULD BE MADE
UNDER THE PACKAGE. THE POWER SUPPLIES SHOULD BE BYPASSED
BY A 0.1µF CAPACITOR AS CLOSE TO THE PACKAGE AS POSSIBLE.
–80
1
10
FREQUENCY (kHz)
100
1164-6 TA02
U
Frequency Response
UO
UO
1
LTC1164-6
ABSOLUTE
AXI U
RATI GS
(Note 1)
Operating Temperature Range
LTC1164-6C ...................................... – 40°C to 85°C
LTC1164-6M ................................... – 55°C to 125°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
Total Supply Voltage (V
+
to V
–
) ............................. 16V
Input Voltage (Note 2) ......... (V
+
+ 0.3V) to (V
–
– 0.3V)
Output Short-Circuit Duration ......................... Indefinite
Power Dissipation............................................. 400mW
Burn-In Voltage ...................................................... 16V
PACKAGE/ORDER I FOR ATIO
TOP VIEW
NC
V
IN
GND
V
+
GND
LP6
CONNECT 1
1
2
3
4
5
6
7
14 CONNECT 2
13 NC
12
V
–
ORDER PART
NUMBER
LTC1164-6CN
LTC1164-6CJ
LTC1164-6MJ
11 CLK
10 ELL/BESS
9
8
V
OUT
NC
J PACKAGE
14-LEAD CERAMIC DIP
N PACKAGE
14-LEAD PLASTIC DIP
T
JMAX
= 150°C,
θ
JA
= 65°C/W (J)
T
JMAX
= 110°C,
θ
JA
= 65°C/W (N)
ELECTRICAL CHARACTERISTICS
PARAMETER
Passband Gain 0.1Hz to 0.25 f
CUTOFF
(Note 4)
Passband Ripple with V
S
= Single 5V
Gain at 0.50 f
CUTOFF
(Note 3)
Gain at 0.90 f
CUTOFF
(Note 3)
Gain at 0.95 f
CUTOFF
(Note 3)
Gain at f
CUTOFF
(Note 3)
Gain at 1.44 f
CUTOFF
(Note 3)
Gain at 2.0 f
CUTOFF
(Note 3)
Gain with f
CLK
= 20kHz
Gain with V
S
=
±2.375V
Input Frequency Range (Tables 3, 4)
Maximum f
CLK
(Table 3)
V
S
=
±7.5V,
R
L
= 10k, T
A
= 25°C, f
CLK
= 400kHz, TTL or CMOS level (maximum clock rise or fall time
≤
1µs) and all gain
measurements are referenced to passband gain, unless otherwise specified. (f
CLK
/f
CUTOFF
) = 4kHz at 100:1 and 8kHz at 50:1.
CONDITIONS
f
IN
= 1kHz, (f
CLK
/ f
C
) = 100:1
1Hz to 0.8 f
C
(Table 2)
f
IN
= 2kHz, (f
CLK
/ f
C
) = 100:1
f
IN
= 3.6kHz, (f
CLK
/ f
C
) = 100:1
f
IN
= 3.8kHz, (f
CLK
/ f
C
) = 100:1
f
IN
= 4kHz, (f
CLK
/ f
C
) = 100:1
f
IN
= 8kHz, (f
CLK
/ f
C
) = 50:1
f
IN
= 5.76kHz, (f
CLK
/ f
C
) = 100:1
f
IN
= 8kHz, (f
CLK
/ f
C
) = 100:1
f
IN
= 200Hz, (f
CLK
/ f
C
) = 100:1
f
IN
= 400kHz, f
IN
= 2kHz, (f
CLK
/ f
C
) = 100:1
f
IN
= 400kHz, f
IN
= 4kHz, (f
CLK
/ f
C
) = 100:1
(f
CLK
/ f
C
) = 100:1
(f
CLK
/ f
C
) = 50:1
V
S
≥ ±7.5V
V
S
≤ ±5V
V
S
= Single 5V, AGND = 2V
q
q
q
q
q
q
q
q
2
U
U
W
W W
U
W
TOP VIEW
NC 1
V
IN
2
GND 3
V
+
4
GND 5
NC 6
LP6 7
CONNECT 1 8
16 CONNECT 2
15 NC
14 V
–
13 NC
12 CLK
11 ELL/BESS
10 NC
9
S PACKAGE
16-LEAD PLASTIC SOL
T
JMAX
= 110°C,
θ
JA
= 85°C/W
ORDER PART
NUMBER
LTC1164-6CS
V
OUT
MIN
– 0.50
– 0.45
– 0.75
–1.40
– 3.50
– 3.00
–69
– 69
– 3.50
– 0.50
– 3.30
TYP
– 0.15
0.1 to – 0.3
– 0.10
– 0.30
– 0.70
– 2.70
– 2.10
– 64
– 64
– 2.70
– 0.10
– 2.50
0 – <f
CLK
/2
0 – <f
CLK
1.5
1.0
1.0
MAX
0.25
0.10
0.10
– 0.40
– 2.30
– 1.50
– 58
– 58
– 2.30
0.30
– 2.00
UNITS
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
kHz
kHz
MHz
MHz
MHz
LTC1164-6
V
S
=
±7.5V,
R
L
= 10k, T
A
= 25°C, f
CLK
= 400kHz, TTL or CMOS level (maximum clock rise or fall time
≤
1µs) and all gain
measurements are referenced to passband gain, unless otherwise specified. (f
CLK
/ f
CUTOFF
) = 4kHz at 100:1 and 8kHz at 50:1.
PARAMETER
Clock Feedthrough
CONDITIONS
Input at GND, f = f
CLK
, Square Wave
V
S
=
±7.5V,
(f
CLK
/ f
C
) = 100:1
V
S
=
±5V,
(f
CLK
/ f
C
) = 50:1
Input at GND, 1Hz
≤
f < f
CLK
V
S
=
±7.5V
V
S
=
±2.5V
V
S
=
±2.375V
V
S
=
±5V
V
S
=
±7.5V
V
S
=
±5V,
(f
CLK
/ f
C
) = 100:1
V
S
=
±5V,
(f
CLK
/ f
C
) = 100:1
V
S
=
±2.375V,
T
A
> 25°C
V
S
=
±5V,
T
A
> 25°C
q
q
q
q
ELECTRICAL CHARACTERISTICS
MIN
TYP
500
200
115
±
5%
100
±
5%
40
±1.50
±4.10
±5.90
±100
±100
2.5
4.5
7.0
MAX
UNITS
µV
RMS
µV
RMS
µV
RMS
µV
RMS
kΩ
V
V
V
mV
µV/°C
mA
mA
mA
mA
mA
mA
V
Wideband Noise
Input Impedance
Output DC Voltage Swing
30
±1.25
±3.70
±5.40
70
Output DC Offset
Output DC Offset TempCo
Power Supply Current
±160
4.0
4.5
7.0
8.0
11.0
12.5
±8
q
V
S
=
±7.5V,
T
A
> 25°C
q
Power Supply Range
The
q
denotes specifications which apply over the full operating
temperature range.
Note 1:
Absolute Maximum Ratings are those values beyond which life of
the device may be impaired.
Note 2:
Connecting any pin to voltages greater than V
+
or less than V
–
±2.375
may cause latch-up. It is recommended that no sources operating from
external supplies be applied prior to power-up of the LTC1164-6.
Note 3:
All gains are measured relative to passband gain.
Note 4:
The cutoff frequency of the filter is abbreviated as f
CUTOFF
or f
C
.
TYPICAL PERFOR A CE CHARACTERISTICS
Stopband Gain vs Frequency
(Elliptic Response)
10
0
–10
–20
GAIN (dB)
GAIN (dB)
–30
–40
–50
–60
–70
–80
–90
2
4
6
8 10 12 14 16 18 20 22
FREQUENCY (kHz)
1164-6 G01
U W
Stopband Gain vs Frequency
(Elliptic Response)
10
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
2
4
6
8 10 12 14 16 18 20 22
FREQUENCY (kHz)
1164-6 G02
V
S
= ±5V
f
CLK
= 500kHz
f
C
= 5kHz
(f
CLK
/f
C
) = 100:1
(PIN 10 AT V
–
)
T
A
= 25°C
V
S
= ±5V
f
CLK
= 250kHz
(f
CLK
/f
C
) = 50:1
(PIN 10 AT V
+
)
T
A
= 25°C
WITH EXTERNAL
SINGLE POLE LOW-
PASS RC FILTER
(f
– 3dB
= 10kHz)
3
LTC1164-6
TYPICAL PERFOR A CE CHARACTERISTICS
Stopband Gain vs Frequency
(Linear Phase Response)
10
0
–10
–20
GAIN (dB)
GAIN (dB)
–30
–40
–50
–60
–70
–80
–90
2
6
10 14 18 22 26 30 34 38 42
FREQUENCY (kHz)
1164-6 G03
Passband Gain vs Frequency
3
0.8
0.4
0
–0.4
GAIN (dB)
–0.8
–1.2
–1.6
–2.0
–2.4
–2.8
0.4
V
S
= ±5V
f
CLK
= 500kHz
f
C
= 5kHz
(f
CLK
/f
C
) = 100:1
(PIN 10 AT V
–
)
T
A
= 25°C
(10 REPRESENTA-
TIVE UNITS)
1.0
2.2
2.8
1.6
FREQUENCY (kHz)
3.4
4.0
GAIN (dB)
–2
–3
–4
–5
–6
–7
1
V
S
= ±5V
f
CLK
= 800kHz
f
C
= 5kHz
(f
CLK
/f
C
) = 160:1
(PIN 10 AT GND)
T
A
= 25°C
GAIN
GAIN (dB)
Passband vs Frequency and f
CLK
2.0
1.5
1.0
0.5
V
S
= ±5V
(f
CLK
/f
C
) = 100:1
(PIN 10 AT V
–
)
T
A
= 25°C
A. f
CLK
= 400kHz
f
CUTOFF
= 4kHz
B. f
CLK
= 600kHz
f
CUTOFF
= 6kHz
C. f
CLK
= 800kHz
f
CUTOFF
= 8kHz
D. f
CLK
= 1MHz
f
CUTOFF
= 10kHz
3
2
1
0
–1
GAIN (dB)
GAIN (dB)
0
– 0.5
–1.0
–1.5
–2.0
–2.5
– 3.0
1
A
B
C
D
5
INPUT FREQUENCY (kHz)
4
U W
1164-6 G05
1164-6
G06
Passband Gain and Phase
vs Frequency
A.RESPONSE WITHOUT
EXTERNAL RC FILTER
B.RESPONSE WITH AN
EXTERNAL SINGLE
POLE LOWPASS RC
FILTER (f
– 3dB
AT 10kHz)
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
V
S
= ±5V
f
CLK
= 500kHz
f
C
= 5kHz
(f
CLK
/f
C
) = 100:1
(PIN 10 AT V
–
)
T
A
= 25°C
1
4
2
3
FREQUENCY (kHz)
5
1164-6 G04
0
–45
–90
–135
PHASE (DEG)
V
S
= ±5V
f
CLK
= 800kHz
f
C
= 5kHz
(f
CLK
/f
C
) = 160:1
(PIN 10 AT GND)
T
A
= 25°C
–180
–225
–270
–315
–360
–405
–450
A
B
–2.5
–3.0
Passband Gain and Phase vs
Frequency (Linear Phase Response)
0
–30
–60
PHASE
–90
Maximum Passband over
Temperature
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
–1.2
–1.4
–1.6
1
V
S
= ±5V
f
CLK
= 1MHz
f
C
= 10kHz
(f
CLK
/f
C
) = 100:1
(PIN 10 AT V
–
)
5
FREQUENCY (kHz)
10
1164-6 G07
A
B
C
A.T
A
= 125°C
B.T
A
= 85°C
D.T
A
= –40°C
2
1
0
–1
PHASE (DEG)
–120
–150
–180
–210
–240
–270
–300
4
2
3
FREQUENCY (kHz)
5
1164-6 G11
Passband Gain and Phase vs
Frequency and f
CLK
0
–45
A
B
PHASE
A
B
V
S
= ±5V
f
CLK
= 250kHz
f
C
= 5kHz
(f
CLK
/f
C
) = 50:1
(PIN 10 AT V
–
)
T
A
= 25°C
1
2
3
4
FREQUENCY (kHz)
5
1164-6 G08
–90
–135
–180
–225
–270
–315
–360
–405
–450
–495
–540
–2
–3
–4
–5
–6
–7
–8
–9
A.RESPONSE WITHOUT
EXTERNAL SINGLE
POLE RC FILTER
B.RESPONSE WITH AN
EXTERNAL SINGLE
POLE LOWPASS RC
FILTER (f
– 3dB
AT 10kHz)
PHASE (DEG)
10
LTC1164-6
TYPICAL PERFOR A CE CHARACTERISTICS
Passband vs Frequency and f
CLK
2.0
1.5
1.0
0.5
A. f
CLK
= 250kHz
f
CUTOFF
= 5kHz
B. f
CLK
= 500kHz
f
CUTOFF
= 10kHz
C. f
CLK
= 1MHz
f
CUTOFF
= 20kHz
2.0
1.5
1.0
0.5
T
A
= 70°C
T
A
= –40°C
V
S
= SINGLE 5V
(f
CLK
/f
C
) = 50:1
GND = 2V WITH
EXTERNAL RC
LOWPASS FILTER
(f
– 3dB
= 40kHz)
2
4
6
8 10 12 14 16 18 20 22
FREQUENCY (kHz)
1164-6 G10
GAIN (dB)
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
1
V
S
= ±8V
(f
CLK
/f
C
) = 50:1
(PIN 10 AT V
+
)
T
A
= 25°C
GAIN (dB)
30
1164-6 G09
0
A
B
C
10
FREQUENCY (kHz)
Group Delay vs Frequency
(Linear Phase Response)
250
f
CLK
= 800kHz
(f
CLK
/f
C
) = 160:1
f
C
= 5kHz
700
600
200
GROUP DELAY (µs)
GROUP DELAY (µs)
150
B
400
300
200
100
V
S
= ±5V
f
C
= 5kHz
T
A
= 25°C
1
2
4
3
FREQUENCY (kHz)
5
1164-6 G12
THD + NOISE (dB)
100
50
0
1
2
3
4 5 6 7 8
FREQUENCY (kHz)
9
10 11
1164-6 G22
THD + Noise vs Frequency
(Elliptic Response)
– 40
–45
– 50
V
S
= ±5V, V
IN
= 1V
RMS
,
f
CLK
= 500kHz, f
C
= 10kHz,
(f
CLK
/f
C
) = 50:1,
T
A
= 25°C,
WITH EXTERNAL RC LOWPASS
FILTER (f
– 3dB
= 20kHz)
(5 REPRESENTATIVE UNITS)
– 40
–45
– 50
THD + NOISE (dB)
–55
–60
–65
–70
–75
–80
–85
1
5
FREQUENCY (kHz)
10
1164-6 G14
THD + NOISE (dB)
THD + NOISE (dB)
–55
–60
–65
–70
–75
–80
–85
–90
U W
Maximum Passband over
Temperature
0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
Group Delay vs Frequency
(Elliptic Response)
– 40
A.f
CLK
= 250kHz, (f
CLK
/f
C
) = 50:1
WITH EXTERNAL RC LOWPASS
FILTER (f
C
= 10kHz)
B.f
CLK
= 500kHz
(f
CLK
/f
C
) = 100:1
THD + Noise vs Frequency
(Elliptic Response)
–45
A
– 50
–55
–60
–65
–70
–75
–80
–85
–90
1
500
V
S
= ±5V, V
IN
= 1V
RMS
(20k RESISTOR PIN 14 TO V
–
)
f
CLK
= 500kHz, f
C
= 5kHz
(f
CLK
/f
C
) = 100:1,
T
A
= 25°C
(5 REPRESENTATIVE UNITS)
0
2
3
FREQUENCY (kHz)
4
1164-6 G13
5
THD + Noise vs Frequency
(Elliptic Response)
–40
V
S
= SINGLE 5V, V
IN
= 0.7V
RMS
f
CLK
= 500kHz, f
C
= 5kHz,
(f
CLK
/f
C
) = 100:1,
T
A
= 25°C
(5 REPRESENTATIVE UNITS)
THD + Noise vs Frequency
(Linear Phase Response)
–45
–50
–55
–60
–65
–70
–75
–80
–85
–90
V
S
= ±5V
V
IN
= 1V
RMS
f
CLK
= 800kHz
f
C
= 5kHz
(f
CLK
/f
C
) = 160:1
T
A
= 25°C
–90
0.5
1
FREQUENCY (kHz)
5
1164-6 G16
1
2
3
FREQUENCY (kHz)
4
1164-6 G23
5
5