filter for communications receivers and transmitters. The
selectivity of the LTC6603, combined with its linear phase,
phase matching and dynamic range, make it suitable for
filtering in many communications systems. With 1.5°
phase matching between channels, the LTC6603 can be
used in applications requiring pairs of matched filters,
such as transceiver I and Q channels. Furthermore, the
differential inputs and outputs provide a simple interface
for most communications systems.
The sampled data filter does not require an external clock
yet its cutoff frequency can be set with a single external
resistor with an accuracy of 3.5% or better. The external
resistor programs an internal oscillator whose frequency
is divided prior to being applied to the filter networks.
This allows up to three cutoff frequencies that can be
obtained for each external resistor value, allowing the
cutoff frequency to be programmed over a range of more
than six octaves. Alternatively, the cutoff frequency can
be set with an external clock. The filter gain can also be
programmed to 1, 2, 4 or 16.
The LTC6603 features a low power shutdown mode that
can be programmed through the serial interface and is
available in a 24-pin 4mm
×
4mm QFN package.
Guaranteed Phase and Gain Matching Specs
Programmable BW Up to 2.5MHz
Programmable Gain (0dB/6dB/12dB/24dB)
9th Order Linear Phase Response
Differential, Rail-to-Rail Inputs and Outputs
Low Noise: –145dBm/Hz (Input Referred)
Low Distortion: –75dBc at 200kHz
Simple Pin Programming or SPI Interface
Set the Max Speed/Power with an External R
Operates from 2.7V to 3.6V
Input Range from 0V to 5.5V
4mm
×
4mm QFN Package
APPLICATIONS
n
n
n
n
Small/Low Cost Basestations:
IDEN, PHS, TD-SCDMA, CDMA2000, WCDMA,
UMTS
Low Cost Repeaters, Radio Links, and Modems
802.11x Receivers
JTRS
L,
LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
2.5MHz I and Q Lowpass Filter and Dual ADC
5V
3V
49.9Ω 100nH*
0.1μF
0.1μF
I OUTPUT
V+
IN
I
IN
Q
IN
0.1μF
+INA
–INA
+INB
–INB
R
BIAS
V
OCM
0.1μF
CAP
GAIN1
GAIN0
GND
GND
BASEBAND
GAIN CONTROL
CLKCNTL
SDO
SDI
LPFO
LPF1
6603 TA01a
LTC2297
Phase Matching
180pF
10pF
14-BIT
ADC
180pF
10pF
60
50
40
V
S
= 3V, BW = 156.25kHz
f = 125kHz, T
A
= 25°C
1000 UNITS
V+
A
V+
D
49.9Ω 100nH*
+OUTA
–OUTA
+OUTB
LTC6603 –OUTB
CLKIO
49.9Ω 100nH*
180pF
Q OUTPUT
10pF
14-BIT
ADC
180pF
10pF
V
CM
2.2μF
UNITS (%)
30
20
10
0
–2.5 –2 –1.5 –1 –0.5 0 0.5 1
MISMATCH (DEG)
30.9k
SER
49.9Ω 100nH*
3V
1.5
2
2.5
6603 TA01b
3V
*COILCRAFT 0603HP
6603f
1
LTC6603
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
GAIN0(D0)
+OUTA
18 –OUTA
17
SER
25
16 V+
D
15 CLKIO
14 GND
13 +OUTB
7
+INB
8
–INB
9 10 11 12
LPFO(SCLK)
–OUTB
SDI
SDO
GAIN1
+INA
–INA
V+
IN
to GND ................................................................6V
V+
A
, V+
D
to GND .........................................................4V
V+
A
to V+
D
.............................................. –0.3V to +0.3V
Filter Inputs to GND ....................... –0.3V to V+
IN
+ 0.3V
Pins 3, 4 to GND ............................. –0.3V to V+
A
+ 0.3V
Pins 5, 6, 9-11,
15, 17, 21, 22 to GND ................. –0.3V to V+
D
+ 0.3V
Maximum Input Current .......................................±10mA
Output Short Circuit Duration........................... Indefinite
Operating Temperature Range (Note 2)
LTC6603CUF .......................................–40°C TO 85°C
LTC6603IUF ........................................–40°C TO 85°C
Specified Temperature Range (Note 3)
LTC6603CUF ...........................................0°C TO 70°C
LTC6603IUF ........................................–40°C TO 85°C
Storage Temperature Range................... –65°C to 150°C
24 23 22 21 20 19
V+
IN
1
V+
A
2
V
OCM
3
R
BIAS
4
CLKCNTL 5
LPF1(CS) 6
UF PACKAGE
24-LEAD (4mm
×
4mm) PLASTIC QFN
T
JMAX
= 150°C,
θ
JA
= 37°C/W,
θ
JC
= 4.3°C/W
EXPOSED PAD (PIN 25) IS GND. MUST BE SOLDERED TO THE PCB.
ORDER INFORMATION
LEAD FREE FINISH
LTC6603CUF#PBF
LTC6603IUF#PBF
TAPE AND REEL
LTC6603CUF#TRPBF
LTC6603IUF#TRPBF
PART MARKING*
6603
6603
PACKAGE DESCRIPTION
SPECIFIED TEMPERATURE RANGE
24-Lead (4mm
×
4mm) Plastic QFN 0°C to 70°C
24-Lead (4mm
×
4mm) Plastic QFN –40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V+
A
= V+
D
= V+
IN
= 3V, V
ICM
= V
OCM
= 1.5V, Gain = 0dB, lowpass cutoff =
2.5MHz, internal clocking with R
BIAS
= 30.9k unless otherwise noted.
PARAMETER
Filter Gain Either
Channel
CONDITIONS
External Clock = 80MHz, Filter Cutoff (f
C
)= 156.25kHz, V
IN
= 3.6V
P-P,
Pin 3 Open
DC Gain, Gain Set = 0dB
f
IN
= 62.5kHz (0.4 • f
C
), Relative to DC Gain
f
IN
= 125kHz (0.8 • f
C
), Relative to DC Gain
f
IN
= 156.25kHz (f
C
), Relative to DC Gain
f
IN
= 234.375kHz (1.5 • f
C
), Relative to DC Gain
External Clock = 80MHz, Filter Cutoff (f
C
)= 156.25kHz, V
IN
= 3.6V
P-P,
Pin 3 Open
DC Gain, Gain Set = 0dB
f
IN
= 62.5kHz (0.4 • f
C
)
f
IN
= 125kHz (0.8 • f
C
)
f
IN
= 156.25kHz (f
C
)
MIN
TYP
MAX
UNITS
ELECTRICAL CHARACTERISTICS
l
l
l
l
l
l
l
l
l
0.25
–0.5
0.4
–0.6
CAP
0.4
–0.3
0.6
–0.4
–32
±0.03
±0.03
±0.03
±0.03
0.55
–0.1
0.8
–0.2
–29.5
±0.1
±0.1
±0.1
±0.15
dB
dB
dB
dB
dB
dB
dB
dB
dB
Matching of Filter
Gain
6603f
2
LTC6603
ELECTRICAL CHARACTERISTICS
PARAMETER
Filter Phase Either
Channel
CONDITIONS
External Clock = 80MHz, Filter Cutoff (f
C
)= 156.25kHz, V
IN
= 3.6V
P-P,
Pin 3 Open
f
IN
= 62.5kHz (0.4 • f
C
)
f
IN
= 125kHz (0.8 • f
C
)
f
IN
= 156.25kHz (f
C
)
External Clock = 80MHz, Filter Cutoff (f
C
)= 156.25kHz, V
IN
= 3.6V
P-P,
Pin 3 Open
f
IN
= 62.5kHz (0.4 • f
C
)
f
IN
= 125kHz (0.8 • f
C
)
f
IN
= 156.25kHz (f
C
)
External Clock = 80MHz, Filter Cutoff (f
C
)= 2.5MHz, V
IN
= 3.6V
P-P,
Pin 3 Open
DC Gain, Gain Set = 0dB
f
IN
= 1MHz (0.4 • f
C
), Relative to DC Gain
f
IN
= 2MHz (0.8 • f
C
), Relative to DC Gain
f
IN
= 2.5MHz (f
C
), Relative to DC Gain
f
IN
= 4MHz (1.5 • f
C
), Relative to DC Gain
External Clock = 80MHz, Filter Cutoff (f
C
)= 2.5MHz, V
IN
= 3.6V
P-P,
Pin 3 Open
f
IN
= 2MHz (0.8 • f
C
)
f
IN
= 2.5MHz (f
C
)
External Clock = 80MHz, Filter Cutoff (f
C
)= 2.5MHz, V
IN
= 3.6V
P-P,
Pin 3 Open
f
IN
= 1MHz (0.4 • f
C
)
f
IN
= 2MHz (0.8 • f
C
)
f
IN
= 2.5MHz (f
C
)
External Clock = 80MHz, Filter Cutoff (f
C
)= 2.5MHz, V
IN
= 3.6V
P-P,
Pin 3 Open
f
IN
= 1MHz (0.4 • f
C
)
f
IN
= 2MHz (0.8 • f
C
)
f
IN
= 2.5MHz (f
C
)
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V+
A
= V+
D
= V+
IN
= 3V, V
ICM
= V
OCM
= 1.5V, Gain = 0dB, lowpass cutoff =
2.5MHz, internal clocking with R
BIAS
= 30.9k unless otherwise noted.
MIN
158
–44
–152
TYP
161
–39
–146
±0.2
±0.4
±0.5
0
–2
–0.7
–1.1
0.5
–0.8
0.4
0.1
–43
±0.05
±0.2
150
–45
–152
155
–39
–141
MAX
163
–36
–142
±1.5
±3
±4
1.2
–0.1
1.5
1
–32.6
±0.2
±0.4
159
–28
–126
±2.5
±4
±4
±3
±3
±3.5
0
5.6
11.2
22.5
0.5
6
11.8
23.2
±0.1
±0.05
±0.05
±0.1
–124
–129
–135
–145
–53
–59
–65
–76
–75
1.6
5
1.2
6.6
12.5
24
±0.2
±0.1
±0.15
±0.2
UNITS
deg
deg
deg
deg
deg
deg
dB
dB
dB
dB
dB
dB
dB
deg
deg
deg
deg
deg
deg
%
%
%
dB
dB
dB
dB
dB
dB
dB
dB
dBm/Hz
dBm/Hz
dBm/Hz
dBm/Hz
dBm
dBm
dBm
dBm
dB
kΩ
kΩ
6603f
Matching of Filter
Phase
Filter Gain Either
Channel
Matching of Filter
Gain
Filter Phase
Either Channel
Matching of Filter
Phase
Filter Cutoff Accuracy CLKCNTL = 3V (Note 4)
when Self Clocked
R
BIAS
= 200k
R
BIAS
= 54.9k
R
BIAS
= 30.9k
DC Gain
Filter Cutoff (f
C
) = 2.5MHz, 0.6V to 2.4V Each Output, Pin 3 Open
Gain Setting = 0dB
Gain Setting = 6dB
Gain Setting = 12dB
Gain Setting = 24dB
Filter Cutoff (f
C
) = 2.5MHz, 0.6V to 2.4V Each Output, Pin 3 Open
Gain Setting = 0dB
Gain Setting = 6dB
Gain Setting = 12dB
Gain Setting = 24dB
Voltage Noise Referred to the Input
Gain = 0dB
Gain = 6dB
Gain = 12dB
Gain = 24dB
Noise Bandwidth = 5MHz, Referred to the Input
Gain = 0dB
Gain = 6dB
Gain = 12dB
Gain = 24dB
V
IN
= 2V
P-P
, f
IN
= 200kHz, Gain Setting = 24dB
Gain = 24dB, R
BIAS
= 30.9k, Filter Cutoff (f
C
) = 2.5MHz
Differential
Common Mode
DC Gain Matching
Noise At 200kHz
Integrated Noise
THD
Input Impedance
3
LTC6603
ELECTRICAL CHARACTERISTICS
PARAMETER
V
OS
Differential
CONDITIONS
Input Referred Differential Offset Voltage at Either Output
Lowest Cutoff Frequency, Gain Setting = 24dB
Highest Cutoff Frequency, Gain Setting = 24dB
Lowest Cutoff Frequency, Gain Setting = 0dB
Highest Cutoff Frequency, Gain Setting = 0dB
f
C
= 625kHz
Common Mode Input from 0 to 3V, V+
IN
= 3V
Common Mode Input from 0 to 5V, V+
IN
= 5V
V+
A
= V+
D
= 3V, Pin 3 Open
V+
A
= V+
D
= 3V, Pin 3 Open
Common Mode Offset Voltage, V
OCM
= 1.5V, Supplies = 3V
V
OSCM
= V
OUT-CM
– V
OCM
Source 1mA, Relative to V+
A
Sink 1mA, Relative to GND
Sourcing
Sinking
Internal Clock (R
BIAS
= 30.9k); Sum of the Currents into V+
D
, V+
A
, and V+
IN
All
Supplies Set to 3V
f
C
= 156.25kHz
f
C
= 625kHz
f
C
= 2.5MHz
Sum of the Currents into V+
D
, V+
A
, and V+
IN
; All Supplies Set to 3V
Shutdown Via Serial Interface
V+
D
, V+
A
Relative to GND
V+
IN
Relative to GND
V+
D
= V+
A
= V+
IN
, All from 2.7V to 3.6V
V+
D
= V+
A
= 3V, V+
IN
from 4.5V to 5.5V
l
l
l
l
l
l
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V+
A
= V+
D
= V+
IN
= 3V, V
ICM
= V
OCM
= 1.5V, Gain = 0dB, lowpass cutoff =
2.5MHz, internal clocking with R
BIAS
= 30.9k unless otherwise noted.
MIN
TYP
MAX
±8
±14
±40
±60
60
60
1.3
2.5
90
90
1.45
3.4
100
200
150
7
11
25
30
1.5
4.5
185
500
400
UNITS
mV
mV
mV
mV
dB
dB
V
kΩ
mV
mV
mV
mA
mA
CMRR Differential
V
OCM
Pin Voltage
V
OCM
Pin Input
Impedance
V
OSCM
Output Swing
Short-Circuit Current
Supply Current
l
l
l
l
l
l
l
l
l
l
88
121
162
170
2.7
2.7
40
65
30.9
54.9
1.17
40
50
85
96
130
175
235
3.6
5.5
mA
mA
mA
μA
V
V
dB
dB
Supply Current,
Shutdown Mode
Supply Voltage
PSRR
R
BIAS
Resistor Range CLKCNTL = 3V
Clock Frequency Error < ±3.5%
Clock Frequency Error < ±3%
R
BIAS
Pin Voltage
30.9k < R
BIAS
< 200k
Clock Frequency Drift R
BIAS
= 30.9k
CLKCNTL Pin Open
Over Temperature
Clock Frequency Drift V+
A
, V+
D
from 2.7V to 3.6V, R
BIAS
= 30.9k
Over Supply
CLKCNTL Pin Open
Output Clock Duty
Cycle
R
BIAS
= 30.9k
54.9
200
kΩ
kΩ
V
ppm/ºC
l
l
l
l
0.2
45
V+
D
– 0.3
50
0.5
55
%/V
%
V
CLKIO Pin High Level CLKCNTL = 0V (Note 5)
Input Voltage
CLKIO Pin Low Level
Input Voltage
CLKIO Pin Input
Current
CLKCNTL = 0V (Note 5)
CLKCNTL = 0V
CLKIO = 0V (Note 6)
CLKIO = V+
D
0.3
V
l
l
–1
10
2.95
2.9
μA
μA
V
V
CLKIO Pin High Level V+
A
= V+
D
= 3V, CLKCNTL = 3V
Output Voltage
I
OH
= –1mA
I
OH
= –4mA
6603f
4
LTC6603
ELECTRICAL CHARACTERISTICS
PARAMETER
CLKIO Pin Low Level
Output Voltage
CLKIO Pin Rise Time
CLKIO Pin Fall Time
SER
High Level
Input Voltage
SER
Low Level
Input Voltage
SER
Input Current
CLKCNTL High Level
Input Voltage
CLKCNTL Low Level
Input Voltage
CLKCNTL Input
Current
CONDITIONS
V+
A
= V+
D
= 3V, CLKCNTL = 3V
I
OL
= 1mA
I
OL
= 4mA
V+
A
= V+
D
= CLKCNTL = 3V, C
LOAD
= 5pF
V+
A
= V+
D
= CLKCNTL = 3V, C
LOAD
= 5pF
Pin 17
Pin 17
Pin 17 = 0V (Note 6)
Pin 17 = V+
D
Pin 5
Pin 5
CLKCNTL = 0V (Note 6)
CLKCNTL = V+
D
l
l
l
l
l
l
l
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V+
A
= V+
D
= V+
IN
= 3V, V
ICM
= V
OCM
= 1.5V, Gain = 0dB, lowpass cutoff =
2.5MHz, internal clocking with R
BIAS
= 30.9k unless otherwise noted.
MIN
TYP
0.05
0.1
0.3
0.3
V+
D
– 0.3
0.3
–10
2
V+
D
– 0.5
0.5
–25
–15
15
MAX
UNITS
V
V
ns
ns
V
V
μA
μA
V
V
μA
μA
25
Pin Programmable Control Mode Specifications. Specifications apply to pins 6, 9, 21 and 22 in pin programmable control mode.
SYMBOL
V+
D
= 2.7V to 3.6V
V
IH
V
IL
I
IN
Digital Input High Voltage
Digital Input Low Voltage
Digital Input Current
Pins 6, 9, 21, 22
Pins 6, 9, 21, 22
Pins 6, 9, 21, 22 (Note 6)
l
l
l
PARAMETER
CONDITIONS
MIN
2
TYP
MAX
UNITS
V
0.8
–1
1
V
μA
Serial Port DC and Timing Specifications. Specifications apply to pins 6, 9-11, and 21 in serial programming mode.