LTC2265-12/
LTC2264-12/LTC2263-12
1
22654312fb
TYPICAL APPLICATION
DESCRIPTION
12-Bit, 65Msps/40Msps/
25Msps Low Power Dual ADCs
The LTC
®
2265-12/LTC2264-12/LTC2263-12 are 2-channel,
simultaneous sampling 12-bit A/D converters designed for
digitizing high frequency, wide dynamic range signals. They
are perfect for demanding communications applications
with AC performance that includes 71dB SNR and 90dB
spurious free dynamic range (SFDR). Ultralow jitter of
0.15psRMS allows undersampling of IF frequencies with
excellent noise performance.
DC specs include ±0.3LSB INL (typ), ±0.1LSB DNL (typ)
and no missing codes over temperature. The transition
noise is a low 0.3LSBRMS.
The digital outputs are serial LVDS to minimize the num-
ber of data lines. Each channel outputs two bits at a time
(2-lane mode) or one bit at a time (1-lane mode). The LVDS
drivers have optional internal termination and adjustable
output levels to ensure clean signal integrity.
The ENC+ and ENC inputs may be driven differentially
or single-ended with a sine wave, PECL, LVDS, TTL, or
CMOS inputs. An internal clock duty cycle stabilizer
allows high performance at full speed for a wide range of
clock duty cycles.
LTC2265-12, 65Msps,
2-Tone FFT, fIN = 70MHz and 75MHz
FEATURES
APPLICATIONS
n 2-Channel Simultaneous Sampling ADC
n 71dB SNR
n 90dB SFDR
n Low Power: 167mW/112mW/94mW Total
n 83mW/56mW/47mW per Channel
n Single 1.8V Supply
n Serial LVDS Outputs: 1 or 2 Bits per Channel
n Selectable Input Ranges: 1VP-P to 2VP-P
n 800MHz Full Power Bandwidth S/H
n Shutdown and Nap Modes
n Serial SPI Port for Configuration
n Pin Compatible 14-Bit and 12-Bit Versions
n 40-Pin (6mm × 6mm) QFN Package
n Communications
n Cellular Base Stations
n Software Defined Radios
n Portable Medical Imaging
n Multichannel Data Acquisition
n Nondestructive Testing
CH.1
ANALOG
INPUT
CH.2
ANALOG
INPUT
ENCODE
INPUT
226512 TA01
GND OGND
+
S/H
+
S/H
12-BIT
ADC CORE
12-BIT
ADC CORE
PLL
DATA
SERIALIZER
SERIALIZED
LVDS
OUTPUTS
1.8V 1.8V
VDD OVDD
OUT1A
OUT1B
OUT2A
OUT2B
DATA
CLOCK
OUT
FRAME
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20 30
226512 TA02
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
2
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
PIN CONFIGURATIONABSOLUTE MAXIMUM RATINGS
Supply Voltages
VDD, OVDD ................................................0.3V to 2V
Analog Input Voltage (AIN+, AIN, PAR/SER,
SENSE) (Note 3) .......................... 0.3V to (VDD + 0.2V)
Digital Input Voltage (ENC+, ENC, CS,
SDI, SCK) (Note 4) ....................................0.3V to 3.9V
SDO (Note 4) ............................................0.3V to 3.9V
Digital Output Voltage ................0.3V to (OVDD + 0.3V)
Operating Temperature Range
LTC2265C, 2264C, 2263C ........................ 0°C to 70°C
LTC2265I, 2264I, 2263I .......................40°C to 85°C
Storage Temperature Range ...................65°C to 150°C
(Notes 1 and 2)
3940 38 37 36 35 34 33 32 31
11 20
12 13 14 15
TOP VIEW
41
GND
UJ PACKAGE
40-LEAD (6mm × 6mm) PLASTIC QFN
16 17 18 19
22
23
24
25
26
27
28
29
9
8
7
6
5
4
3
2
AIN1+
AIN1
VCM1
REFH
REFH
REFL
REFL
VCM2
AIN2+
AIN2
OUT1B+
OUT1B
DCO+
DCO
OVDD
OGND
FR+
FR
OUT2A+
OUT2A
VDD
VDD
SENSE
GND
VREF
PAR/SER
SDO
GND
OUT1A+
OUT1A
VDD
VDD
ENC+
ENC
CS
SCK
SDI
GND
OUT2B
OUT2B+
21
30
10
1
TJMAX = 150°C, θJA = 32°C/W
EXPOSED PAD (PIN 41) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC2265CUJ-12#PBF LTC2265CUJ-12#TRPBF LTC2265UJ-12 40-Lead (6mm × 6mm) Plastic QFN 0°C to 70°C
LTC2265IUJ-12#PBF LTC2265IUJ-12#TRPBF LTC2265UJ-12 40-Lead (6mm × 6mm) Plastic QFN 40°C to 85°C
LTC2264CUJ-12#PBF LTC2264CUJ-12#TRPBF LTC2264UJ-12 40-Lead (6mm × 6mm) Plastic QFN 0°C to 70°C
LTC2264IUJ-12#PBF LTC2264IUJ-12#TRPBF LTC2264UJ-12 40-Lead (6mm × 6mm) Plastic QFN 40°C to 85°C
LTC2263CUJ-12#PBF LTC2263CUJ-12#TRPBF LTC2263UJ-12 40-Lead (6mm × 6mm) Plastic QFN 0°C to 70°C
LTC2263IUJ-12#PBF LTC2263IUJ-12#TRPBF LTC2263UJ-12 40-Lead (6mm × 6mm) 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.
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/
LTC2265-12/
LTC2264-12/LTC2263-12
3
22654312fb
CONVERTER CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 5)
PARAMETER CONDITIONS
LTC2265-12 LTC2264-12 LTC2263-12
UNITSMIN TYP MAX MIN TYP MAX MIN TYP MAX
Resolution (No Missing Codes) l12 12 12 Bits
Integral Linearity Error Differential Analog Input (Note 6) l–1 ±0.3 1 –1 ±0.3 1 –1 ±0.3 1 LSB
Differential Linearity Error Differential Analog Input l0.5 ±0.1 0.5 0.4 ±0.1 0.4 0.5 ±0.1 0.5 LSB
Offset Error (Note 7) l12 ±3 12 12 ±3 12 –12 ±3 12 mV
Gain Error Internal Reference
External Reference
l
–2.4
–0.8
–0.8
0.6
–2.4
–0.8
–0.8
0.6
–2.4
–0.8
–0.8
0.6
%FS
%FS
Offset Drift ±20 ±20 ±20 µV/°C
Full-Scale Drift Internal Reference
External Reference
±30
±10
±30
±10
±30
±10
ppm/°C
ppm/°C
Gain Matching External Reference ±0.2 ±0.2 ±0.2 %FS
Offset Matching ±3 ±3 ±3 mV
Transition Noise External Reference 0.32 0.32 0.32 LSBRMS
ANALOG INPUT
The l denotes the specifications which apply over the full operating temperature range, otherwise
specifications are at TA = 25°C. (Note 5)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Analog Input Range (AIN+ – AIN) 1.7V < VDD < 1.9V l1 to 2 VP-P
VIN(CM) Analog Input Common Mode (AIN+ + AIN)/2 Differential Analog Input (Note 8) lVCM – 100mV VCM VCM + 100mV V
VSENSE External Voltage Reference Applied to SENSE External Reference Mode l0.625 1.250 1.300 V
IINCM Analog Input Common Mode Current Per Pin, 65Msps
Per Pin, 40Msps
Per Pin, 25Msps
81
50
31
µA
µA
µA
IIN1 Analog Input Leakage Current (No Encode) 0 < AIN+, AIN < VDD l–1 1 µA
IIN2 PAR/SER Input Leakage Current 0 < PAR/SER < VDD l–3 3 µA
IIN3 SENSE Input Leakage Current 0.625 < SENSE < 1.3V l–6 6 µA
tAP Sample-and-Hold Acquisition Delay Time 0 ns
tJITTER Sample-and-Hold Acquisition Delay Jitter 0.15 psRMS
CMRR Analog Input Common Mode Rejection Ratio 80 dB
BW-3B Full-Power Bandwidth Figure 6 Test Circuit 800 MHz
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LTC2265-12/
LTC2264-12/LTC2263-12
DYNAMIC ACCURACY
The l denotes the specifications which apply over the full operating temperature range,
otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Note 5)
SYMBOL PARAMETER CONDITIONS
LTC2265-12 LTC2264-12 LTC2263-12
UNITSMIN TYP MAX MIN TYP MAX MIN TYP MAX
SNR Signal-to-Noise Ratio 5MHz Input
30MHz Input
70MHz Input
140MHz Input
l
69.9
71
71
70.9
70.6
69.7
70.9
70.8
70.8
70.5
69.4
70.5
70.5
70.5
70.2
dBFS
dBFS
dBFS
dBFS
SFDR Spurious Free Dynamic Range
2nd or 3rd Harmonic
5MHz Input
30MHz Input
70MHz Input
140MHz Input
l
77
90
90
89
84
79
90
90
89
84
79
90
90
89
84
dBFS
dBFS
dBFS
dBFS
Spurious Free Dynamic Range
4th Harmonic or Higher
5MHz Input
30MHz Input
70MHz Input
140MHz Input
l
84
90
90
90
90
85
90
90
90
90
84
90
90
90
90
dBFS
dBFS
dBFS
dBFS
S/(N+D) Signal-to-Noise Plus
Distortion Ratio
5MHz Input
30MHz Input
70MHz Input
140MHz Input
l
69.6
70.9
70.9
70.7
70.3
69.6
70.8
70.7
70.6
70.2
69.2
70.5
70.4
70.3
69.9
dBFS
dBFS
dBFS
dBFS
Crosstalk 10MHz Input –105 –105 –105 dBc
INTERNAL REFERENCE CHARACTERISTICS
The l denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at TA = 25°C. AIN = –1dBFS. (Note 5)
PARAMETER CONDITIONS MIN TYP MAX UNITS
VCM Output Voltage IOUT = 0 0.5 • VDD – 25mV 0.5 • VDD 0.5 • VDD + 25mV V
VCM Output Temperature Drift ±25 ppm/°C
VCM Output Resistance 600µA < IOUT < 1mA 4 Ω
VREF Output Voltage IOUT = 0 1.225 1.250 1.275 V
VREF Output Temperature Drift ±25 ppm/°C
VREF Output Resistance 400µA < IOUT < 1mA 7 Ω
VREF Line Regulation 1.7V < VDD < 1.9V 0.6 mV/V
LTC2265-12/
LTC2264-12/LTC2263-12
5
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DIGITAL INPUTS AND OUTPUTS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 5)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
ENCODE INPUTS (ENC+, ENC)
Differential Encode Mode (ENC Not Tied to GND)
VID Differential Input Voltage (Note 8) l0.2 V
VICM Common Mode Input Voltage Internally Set
Externally Set (Note 8)
l
1.1
1.2
1.6
V
V
VIN Input Voltage Range ENC+, ENC to GND l0.2 3.6 V
RIN Input Resistance (See Figure 10) 10
CIN Input Capacitance 3.5 pF
Single-Ended Encode Mode (ENC Tied to GND)
VIH High Level Input Voltage VDD = 1.8V l1.2 V
VIL Low Level Input Voltage VDD = 1.8V l0.6 V
VIN Input Voltage Range ENC+ to GND l0 3.6 V
RIN Input Resistance (See Figure 11) 30
CIN Input Capacitance 3.5 pF
DIGITAL INPUTS (CS, SDI, SCK in Serial or Parallel Programming Mode. SDO in Parallel Programming Mode)
VIH High Level Input Voltage VDD = 1.8V l1.3 V
VIL Low Level Input Voltage VDD = 1.8V l0.6 V
IIN Input Current VIN = 0V to 3.6V l–10 10 µA
CIN Input Capacitance 3 pF
SDO OUTPUT (Serial Programming Mode. Open-Drain Output. Requires 2kΩ Pull-Up Resistor if SDO Is Used)
ROL Logic Low Output Resistance to GND VDD = 1.8V, SDO = 0V 200 Ω
IOH Logic High Output Leakage Current SDO = 0V to 3.6V l–10 10 µA
COUT Output Capacitance 3 pF
DIGITAL DATA OUTPUTS
VOD Differential Output Voltage 100Ω Differential Load, 3.5mA Mode
100Ω Differential Load, 1.75mA Mode
l
l
247
125
350
175
454
250
mV
mV
VOS Common Mode Output Voltage 100Ω Differential Load, 3.5mA Mode
100Ω Differential Load, 1.75mA Mode
l
l
1.125
1.125
1.250
1.250
1.375
1.375
V
V
RTERM On-Chip Termination Resistance Termination Enabled, OVDD = 1.8V 100 Ω
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LTC2265-12/
LTC2264-12/LTC2263-12
POWER REQUIREMENTS
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. (Note 9)
SYMBOL PARAMETER CONDITIONS
LTC2265-12 LTC2264-12 LTC2263-12
UNITSMIN TYP MAX MIN TYP MAX MIN TYP MAX
VDD Analog Supply Voltage (Note 10) l1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V
OVDD Output Supply Voltage (Note 10) l1.7 1.8 1.9 1.7 1.8 1.9 1.7 1.8 1.9 V
IVDD Analog Supply Current Sine Wave Input l82 98 52 63 42 50 mA
IOVDD Digital Supply Current 1-Lane Mode, 1.75mA Mode
1-Lane Mode, 3.5mA Mode
2-Lane Mode, 1.75mA Mode
2-Lane Mode, 3.5mA Mode
l
l
11
20
15
28
18
31
10
19
15
28
18
31
10
18
14
27
17
31
mA
mA
mA
mA
PDISS Power Dissipation 1-Lane Mode, 1.75mA Mode
1-Lane Mode, 3.5mA Mode
2-Lane Mode, 1.75mA Mode
2-Lane Mode, 3.5mA Mode
l
l
167
184
175
198
209
232
112
128
121
144
146
169
94
108
101
124
121
146
mW
mW
mW
mW
PSLEEP Sleep Mode Power 1 1 1 mW
PNAP Nap Mode Power 60 60 60 mW
PDIFFCLK Power Increase with Differential Encode Mode Enabled
(No Increase for Sleep Mode)
20 20 20 mW
TIMING CHARACTERISTICS
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. (Note 5)
SYMBOL PARAMETER CONDITIONS
LTC2265-12 LTC2264-12 LTC2263-12
UNITSMIN TYP MAX MIN TYP MAX MIN TYP MAX
fSSampling Frequency (Notes 10, 11) l5 65 5 40 5 25 MHz
tENCL ENC Low Time (Note 8) Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On
l
l
7.3
2
7.69
7.69
100
100
11.88
2
12.5
12.5
100
100
19
2
20
20
100
100
ns
ns
tENCH ENC High Time (Note 8) Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On
l
l
7.3
2
7.69
7.69
100
100
11.88
2
12.5
12.5
100
100
19
2
20
20
100
100
ns
ns
tAP Sample-and-Hold
Acquisition Delay Time
0 0 0 ns
LTC2265-12/
LTC2264-12/LTC2263-12
7
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TIMING CHARACTERISTICS
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at TA = 25°C. (Note 5)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Digital Data Outputs (RTERM = 100Ω Differential, CL = 2pF to GND on Each Output)
tSER Serial Data Bit Period Two Lanes, 16-Bit Serialization
Two Lanes, 14-Bit Serialization
Two Lanes, 12-Bit Serialization
One Lane, 16-Bit Serialization
One Lane, 14-Bit Serialization
One Lane, 12-Bit Serialization
1 / (8 • fS)
1 / (7 • fS)
1 / (6 • fS)
1 / (16 • fS)
1 / (14 • fS)
1 / (12 • fS)
s
tFRAME FR to DCO Delay (Note 8) l0.35 • tSER 0.5 • tSER 0.65 • tSER s
tDATA DATA to DCO Delay (Note 8) l0.35 • tSER 0.5 • tSER 0.65 • tSER s
tPD Propagation Delay (Note 8) l0.7n + 2 • tSER 1.1n + 2 • tSER 1.5n + 2 • tSER s
tROutput Rise Time Data, DCO, FR, 20% to 80% 0.17 ns
tFOutput Fall Time Data, DCO, FR, FR, 20% to 80% 0.17 ns
DCO Cycle-to-Cycle Jitter tSER = 1ns 60 psP-P
Pipeline Latency 6 Cycles
SPI Port Timing (Note 8)
tSCK SCK Period Write Mode
Readback Mode, CSDO = 20pF, RPULLUP = 2k
l
l
40
250
ns
ns
tSCS to SCK Set-Up Time l5 ns
tHSCK to CS Set-Up Time l5 ns
tDS SDI Set-Up Time l5 ns
tDH SDI Hold Time l5 ns
tDO SCK Falling to SDO Valid Readback Mode, CSDO = 20pF, RPULLUP = 2k l125 ns
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: All voltage values are with respect to GND with GND and OGND
shorted (unless otherwise noted).
Note 3: When these pin voltages are taken below GND or above VDD, they
will be clamped by internal diodes. This product can handle input currents
of greater than 100mA below GND or above VDD without latchup.
Note 4: When these pin voltages are taken below GND they will be
clamped by internal diodes. When these pin voltages are taken above VDD
they will not be clamped by internal diodes. This product can handle input
currents of greater than 100mA below GND without latchup.
Note 5: V
DD
= OV
DD
= 1.8V, f
SAMPLE
= 65MHz (LTC2265), 40MHz
(LTC2264), or 25MHz (LTC2263), 2-lane output mode, differential ENC+/
ENC = 2V
P-P
sine wave, input range = 2V
P-P
with differential drive, unless
otherwise noted.
Note 6: Integral nonlinearity is defined as the deviation of a code from a
best fit straight line to the transfer curve. The deviation is measured from
the center of the quantization band.
Note 7: Offset error is the offset voltage measured from –0.5 LSB when
the output code flickers between 0000 0000 0000 and 1111 1111 1111 in
2’s complement output mode.
Note 8: Guaranteed by design, not subject to test.
Note 9: V
DD
= OV
DD
= 1.8V, f
SAMPLE
= 65MHz (LTC2265), 40MHz
(LTC2264), or 25MHz (LTC2263), 2-lane output mode, ENC+ = single-
ended 1.8V square wave, ENC = 0V, input range = 2V
P-P
with differential
drive, unless otherwise noted. The supply current and power dissipation
specifications are totals for the entire chip, not per channel.
Note 10: Recommended operating conditions.
Note 11: The maximum sampling frequency depends on the speed grade
of the part and also which serialization mode is used. The maximum serial
data rate is 1000Mbps, so tSER must be greater than or equal to 1ns.
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22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
TIMING DIAGRAMS
2-Lane Output Mode, 16-Bit Serialization
226512 TD01
tAP N + 1
N
ANALOG
INPUT
ENC
DCO
FR
ENC+
DCO+
FR+
OUT#A+
SAMPLE N-6 SAMPLE N-5
OUT#A
OUT#B+
OUT#B
SAMPLE N-4
tFRAME
tDATA tSER
tSER
tPD
D3 D1 DX* 0 D11 D9 D7 D5 D3 D1 0 D11 D9 D7
D2 D0 DY*
DX*
DY*0 D10 D8 D6 D4 D2 D0 0 D10 D8 D6
tENCH tENCL
tSER
*DX AND DY ARE EXTRA NON-DATA BITS FOR COMPLETE SOFTWARE COMPATIBILITY WITH THE 14-BIT
VERSIONS OF THESE A/Ds. DURING NORMAL NON-OVERRANGED OPERATION DX AND DY ARE SET TO
LOGIC 0. SEE THE DATA FORMAT SECTION FOR MORE DETAILS.
226512 TD02
tAP
N + 2
N + 1
N
ANALOG
INPUT
ENC
DCO
FR
ENC+
DCO+
FR+
OUT#A+
NOTE THAT IN THIS MODE, FR+/FR HAS TWO TIMES THE PERIOD OF ENC+/ENC
SAMPLE N-6 SAMPLE N-5
OUT#A
OUT#B+
OUT#B
SAMPLE N-3SAMPLE N-4
tFRAME
tDATA tSER
tSER
tPD
D5 D3 D1 DX* D11 D9 D7 D5 D3 D1 DX* D11 D9 D7 D5 D3 D1 DX* D11 D9 D7
D4 D2 D0 DY* D10 D8 D6 D4 D2 D0 DY* D10 D8 D6 D4 D2 D0 DY* D10 D8 D6
tENCH tENCL
tSER
*DX AND DY ARE EXTRA NON-DATA BITS FOR COMPLETE SOFTWARE COMPATIBILITY WITH THE 14-BIT
VERSIONS OF THESE A/Ds. DURING NORMAL NON-OVERRANGED OPERATION DX AND DY ARE SET TO
LOGIC 0. SEE THE DATA FORMAT SECTION FOR MORE DETAILS.
2-Lane Output Mode, 14-Bit Serialization
LTC2265-12/
LTC2264-12/LTC2263-12
9
22654312fb
TIMING DIAGRAMS
2-Lane Output Mode, 12-Bit Serialization
226512 TD03
tAP N + 1
N
ANALOG
INPUT
ENC
DCO
FR+
ENC+
DCO+
FR
OUT#A+
SAMPLE N-6 SAMPLE N-5
OUT#A
OUT#B+
OUT#B
SAMPLE N-4
tFRAME
tDATA tSER
tSER
tPD
D7 D5 D3 D1 D11 D9 D7 D5 D3 D1 D11 D9 D7
D6 D4 D2 D0 D10 D8 D6 D4 D2 D0 D10 D8 D6
tENCH tENCL
tSER
226512 TD04
tAP N + 1
N
ANALOG
INPUT
ENC
DCO
FR
ENC+
DCO+
FR+
OUT#A+
OUT#B+, OUT#B ARE DISABLED
SAMPLE N-6 SAMPLE N-5 SAMPLE N-4
OUT#A
tFRAME tDATA tSER
tSER
tPD
DX* DY* 0 0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 DX*DY* 0 0 D11 D10 D9 D8
tENCH tENCL
tSER
*DX AND DY ARE EXTRA NON-DATA BITS FOR COMPLETE SOFTWARE COMPATIBILITY WITH THE 14-BIT
VERSIONS OF THESE A/Ds. DURING NORMAL NON-OVERRANGED OPERATION DX AND DY ARE SET TO
LOGIC 0. SEE THE DATA FORMAT SECTION FOR MORE DETAILS.
1-Lane Output Mode, 16-Bit Serialization
10
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
TIMING DIAGRAMS
1-Lane Output Mode, 14-Bit Serialization
1-Lane Output Mode, 12-Bit Serialization
226512 TD05
tAP N + 1
N
ANALOG
INPUT
ENC
DCO
FR
ENC+
DCO+
FR+
OUT#A+
OUT#B+, OUT#B ARE DISABLED
SAMPLE N-6 SAMPLE N-5 SAMPLE N-4
OUT#A
tFRAME tDATA tSER
tSER
tPD
D1 D0 DX* DY* DY*DX*D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D11 D10 D9 D8
tENCH tENCL
tSER
*DX AND DY ARE EXTRA NON-DATA BITS FOR COMPLETE SOFTWARE COMPATIBILITY WITH THE 14-BIT
VERSIONS OF THESE A/Ds. DURING NORMAL NON-OVERRANGED OPERATION DX AND DY ARE SET TO
LOGIC 0. SEE THE DATA FORMAT SECTION FOR MORE DETAILS.
226512 TD06
tAP
N + 1
N
ANALOG
INPUT
ENC
DCO
FR
ENC+
DCO+
FR+
OUTA+
OUTB+, OUTB ARE DISABLED
SAMPLE N-6 SAMPLE N-5 SAMPLE N-4
OUTA
tFRAME tDATA tSER
tSER
tPD
D3 D2 D1 D0 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 D11 D10 D9
tENCH tENCL
tSER
LTC2265-12/
LTC2264-12/LTC2263-12
11
22654312fb
SPI Port Timing (Readback Mode)
SPI Port Timing (Write Mode)
A6
tStDS
A5 A4 A3 A2 A1 A0 XX
D7 D6 D5 D4 D3 D2 D1 D0
XX XX XX XX XX XX XX
CS
SCK
SDI R/W
SDO HIGH IMPEDANCE
tDH
tDO
tSCK tH
A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
226512 TD07
CS
SCK
SDI R/W
SDO HIGH IMPEDANCE
TIMING DIAGRAMS
12
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
TYPICAL PERFORMANCE CHARACTERISTICS
LTC2265-12: Integral
Nonlinearity (INL)
LTC2265-12: Differential
Nonlinearity (DNL)
LTC2265-12: 8k Point FFT, fIN = 5MHz
–1dBFS, 65Msps
OUTPUT CODE
0
–1.0
–0.4
–0.6
–0.8
INL ERROR (LSB)
–0.2
0
0.2
0.8
0.4
0.6
1.0
1024 2048 3072 4096
226512 G01
OUTPUT CODE
0
–1.0
–0.4
–0.2
–0.6
–0.8
DNL ERROR (LSB)
0
0.4
0.2
0.6
0.8
1.0
1024 2048 3072 4096
226512 G02
FREQUENCY (MHz)
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
226512 G03
0 10 20 30
LTC2265-12: 8k Point FFT,
fIN = 30MHz, –1dBFS, 65Msps
LTC2265-12: 8k Point FFT,
fIN = 70MHz, –1dBFS, 65Msps
LTC2265-12: 8k Point FFT,
fIN = 140MHz, –1dBFS, 65Msps
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
226512 G04
10 20 30
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20 30
226512 G05
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20 30
226512 G06
LTC2265-12: 8k Point 2-Tone FFT,
fIN = 68MHz, 69MHz, –1dBFS,
65Msps
LTC2265-12: Shorted Input
Histogram
LTC2265-12: SNR vs Input
Frequency, –1dBFS, 2V Range,
65Msps
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20 30
226512 G07
OUTPUT CODE
2049
2000
0
10000
8000
6000
4000
COUNT
12000
16000
14000
18000
2051 20522050 2053
226512 G08
INPUT FREQUENCY (MHz)
0
72
71
70
69
68
67
66
SNR (dBFS)
50 100 150 200 250 300 350
226512 G09
LTC2265-12/
LTC2264-12/LTC2263-12
13
22654312fb
IOVDD vs Sample Rate, 5MHz Sine
Wave Input, –1dBFS
LTC2265-12: SNR vs SENSE,
fIN = 5MHz, –1dBFS
LTC2264-12: Integral Nonlinearity
(INL)
OUTPUT CODE
0
–1.0
–0.4
–0.2
–0.6
–0.8
DNL ERROR (LSB)
0
0.4
0.2
0.6
0.8
1.0
1024 2048 3072 4096
226512 G17
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20
226512 G18
SENSE PIN (V)
0.6
71
68
69
70
67
66
72
SNR (dBFS)
0.7 0.8 0.9 1.1 1.2 1.31
226512 G15
OUTPUT CODE
0
–1.0
–0.4
–0.6
–0.8
INL ERROR (LSB)
–0.2
0
0.2
0.4
0.6
0.8
1.0
1024 2048 3072 4096
226512 G16
LTC2264-12: Differential
Nonlinearity (DNL)
LTC2264-12: 8k Point FFT, fIN =
5MHz, –1dBFS, 40Msps
TYPICAL PERFORMANCE CHARACTERISTICS
LTC2265-12: SFDR vs Input Level,
fIN = 70MHz, 2V Range, 65Msps
LTC2265-12: IVDD vs Sample Rate,
5MHz Sine Wave Input, –1dBFS
LTC2265-12: SFDR vs Input
Frequency, –1dBFS, 2V Range,
65Msps
INPUT FREQUENCY (MHz)
0
90
85
80
75
70
65
95
SFDR (dBFS)
50 100 150 200 250 300 350
226512 G10
INPUT LEVEL (dBFS)
–80
60
50
40
30
20
10
0
80
70
SFDR (dBc AND dBFS)
90
100
110
–70 –60 –50 –40 –30 –20 –10 0
226512 G11
dBFS
dBc
INPUT LEVEL(dBFS)
–60
50
40
30
20
10
0
80
60
70
SNR (dBc AND dBFS)
–50 –40 –30 –20 –10 0
226512 G12
dBc
dBFS
SAMPLE RATE (Msps)
90
85
80
75
70
65
60
IVDD (mA)
0 10 20 30 40 50 60
226512 G13
SAMPLE RATE (Msps)
30
20
10
0
IOVDD (mA)
0 10 20 30 40 50 60
226512 G14
1-LANE, 1.75mA
2-LANE, 3.5mA
2-LANE, 1.75mA
1-LANE, 3.5mA
LTC2265-12: SNR vs Input Level,
fIN = 70MHz, 2V Range, 65Msps
14
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
TYPICAL PERFORMANCE CHARACTERISTICS
LTC2264-12: 8k Point FFT,
fIN = 69MHz, –1dBFS, 40Msps
LTC2264-12: 8k Point FFT,
fIN = 139MHz, –1dBFS, 40Msps
LTC2264-12: 8k Point 2-Tone FFT,
fIN = 68MHz, 69MHz, –1dBFS,
40Msps
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20
226512 G20
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20
226512 G21
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20
226512 G22
LTC2264-12: Shorted Input
Histogram
LTC2264-12: SNR vs Input
Frequency, –1dBFS, 2V Range,
40Msps
LTC2264-12: SFDR vs Input
Frequency, –1dBFS, 2V Range,
40Msps
OUTPUT CODE
2049
2000
0
6000
4000
COUNT
8000
16000
14000
12000
10000
18000
2051 20522050 2053
226512 G23
INPUT FREQUENCY (MHz)
0
72
71
70
69
68
67
66
SNR (dBFS)
50 100 150 200 250 300 350
226512 G24
INPUT FREQUENCY (MHz)
0
90
85
80
75
70
65
95
SFDR (dBFS)
50 100 150 200 250 300 350
226512 G25
LTC2264-12: IVDD vs Sample Rate,
5MHz Sine Wave Input, –1dBFS
LTC2264-12: SFDR vs Input Level,
fIN = 70MHz, 2V Range, 40Msps
INPUT LEVEL (dBFS)
–80
60
50
40
30
20
10
0
80
70
SFDR (dBc AND dBFS)
90
100
110
–70 –60 –50 –40 –30 –20 –10 0
226512 G26
dBFS
dBc
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10 20
226512 G19
LTC2264-12: 8k Point FFT,
fIN = 29MHz, –1dBFS, 40Msps
SAMPLE RATE (Msps)
60
55
50
45
40
IVDD (mA)
0 10 20 30 40
226512 G27
LTC2265-12/
LTC2264-12/LTC2263-12
15
22654312fb
TYPICAL PERFORMANCE CHARACTERISTICS
LTC2263-12: Integral Nonlinearity
(INL)
LTC2263-12: Differential
Nonlinearity (DNL)
OUTPUT CODE
0
–1.0
–0.4
–0.6
–0.8
INL ERROR (LSB)
–0.2
0
0.4
0.6
0.2
0.8
1.0
1024 2048 3072 4096
226512 G29
OUTPUT CODE
0
–1.0
–0.4
–0.2
–0.6
–0.8
DNL ERROR (LSB)
0
0.4
0.2
0.6
0.8
1.0
1024 2048 3072 4096
226512 G30
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
510
226512 G31
LTC2263-12: 8k Point FFT,
fIN = 5MHz, –1dBFS, 25Msps
LTC2263-12: 8k Point FFT,
fIN = 30MHz, –1dBFS, 25Msps
LTC2263-12: 8k Point FFT,
fIN = 70MHz, –1dBFS, 25Msps
LTC2263-12: 8k Point FFT,
fIN = 140MHz, –1dBFS, 25Msps
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
510
226512 G32
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
510
226512 G33
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10
5
226512 G34
LTC2263-12: 8k Point 2-Tone FFT,
fIN = 68MHz, 69MHz, –1dBFS,
25Msps
LTC2263-12: Shorted Input
Histogram
FREQUENCY (MHz)
0
–100
–110
–120
–70
–60
–80
–90
AMPLITUDE (dBFS)
–50
–30
–40
–20
–10
0
10
5
226512 G35
OUTPUT CODE
2049
2000
4000
6000
8000
0
12000
10000
COUNT
14000
16000
18000
2051 20522050 2053
226512 G36
LTC2264-12: SNR vs SENSE,
fIN = 5MHz, –1dBFS
SENSE PIN (V)
0.6
71
68
69
70
67
66
72
SNR (dBFS)
0.7 0.8 0.9 1.1 1.2 1.31
226512 G28
16
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
LTC2263-12: SNR vs Input
Frequency, –1dBFS, 2V Range,
25Msps
INPUT FREQUENCY (MHz)
0
72
71
70
69
68
67
66
SNR (dBFS)
50 100 150 200 250 300 350
226512 G37
TYPICAL PERFORMANCE CHARACTERISTICS
LTC2263-12: SFDR vs Input
Frequency, –1dBFS, 2V Range,
25Msps
INPUT FREQUENCY (MHz)
0
90
85
80
75
70
65
95
SFDR (dBFS)
50 100 150 200 250 300 350
226512 G38
LTC2263-12: SFDR vs Input Level,
fIN = 70MHz, 2V Range, 25Msps
INPUT LEVEL (dBFS)
–80
60
50
40
30
20
10
0
80
70
SFDR (dBc AND dBFS)
90
100
110
–70 –60 –50 –40 –30 –20 –10 0
226512 G39
dBFS
dBc
LTC2263-12: IVDD vs Sample Rate,
5MHz Sine Wave Input, –1dBFS
LTC2263-12: SNR vs SENSE,
fIN = 5MHz, –1dBFS
SENSE PIN (V)
0.6
71
68
69
70
67
66
72
SNR (dBFS)
0.7 0.8 0.9 1.1 1.2 1.31.0
226512 G41
SAMPLE RATE (Msps)
50
45
40
35
30
IVDD (mA)
0 5 10 15 20 25
226512 G40
SERIAL DATA RATE (Mbps)
350
300
250
200
150
100
50
0
PEAK-TO-PEAK JITTER (ps)
0 200 400 600 800 1000
226512 G42
DCO Cycle-Cycle Jitter vs Serial
Data Rate
LTC2265-12/
LTC2264-12/LTC2263-12
17
22654312fb
PIN FUNCTIONS
AIN1+ (Pin 1): Channel 1 Positive Differential Analog
Input.
AIN1 (Pin 2): Channel 1 Negative Differential Analog
Input.
VCM1 (Pin 3): Common Mode Bias Output, Nominally Equal
to VDD/2. VCM should be used to bias the common mode
of the analog inputs of channel 1. Bypass to ground with
a 0.1µF ceramic capacitor.
REFH (Pins 4, 5): ADC High Reference. Bypass to pins 6, 7
with a 2.2µF ceramic capacitor, and to ground with a 0.1µF
ceramic capacitor.
REFL (Pins 6, 7): ADC Low Reference. Bypass to pins 4, 5
with a 2.2µF ceramic capacitor, and to ground with a 0.1µF
ceramic capacitor.
VCM2 (Pin 8): Common Mode Bias Output, Nominally Equal
to VDD/2. VCM should be used to bias the common mode
of the analog inputs of channel 2. Bypass to ground with
a 0.1µF ceramic capacitor.
AIN2+ (Pin 9): Channel 2 Positive Differential Analog
Input.
AIN2 (Pin 10): Channel 2 Negative Differential Analog
Input.
VDD (Pins 11, 12, 39, 40): Analog Power Supply, 1.7V
to 1.9V. Bypass to ground with 0.1µF ceramic capacitors.
Adjacent pins can share a bypass capacitor.
ENC+ (Pin 13): Encode Input. Conversion starts on the
rising edge.
ENC (Pin 14): Encode Complement Input. Conversion
starts on the falling edge.
CS (Pin 15): In serial programming mode (PAR/SER = 0V),
CS is the serial interface chip select input. When CS is low,
SCK is enabled for shifting data on SDI into the mode
control registers. In parallel programming mode (PAR/SER
= VDD), CS selects 2-lane or 1-lane output mode. CS can
be driven with 1.8V to 3.3V logic.
SCK (Pin 16): In serial programming mode (PAR/SER
= 0V), SCK is the serial interface clock input. In parallel
programming mode (PAR/SER = VDD), SCK selects 3.5mA
or 1.75mA LVDS output currents. SCK can be driven with
1.8V to 3.3V logic.
SDI (Pin 17): In serial programming mode (PAR/SER =
0V), SDI is the serial interface data input. Data on SDI
is clocked into the mode control registers on the rising
edge of SCK. In parallel programming mode (PAR/SER =
VDD), SDI can be used to power down the part. SDI can
be driven with 1.8V to 3.3V logic.
GND (Pins 18, 33, 37, Exposed Pad Pin 41): ADC Power
Ground. The exposed pad must be soldered to the PCB
ground.
OGND (Pin 25): Output Driver Ground. Must be shorted
to the ground plane by a very low inductance path. Use
multiple vias close to the pin.
OVDD (Pin 26): Output Driver Supply, 1.7V to 1.9V. Bypass
to ground with a 0.1µF ceramic capacitor.
SDO (Pin 34): In serial programming mode (PAR/SER
= 0V), SDO is the optional serial interface data output.
Data on SDO is read back from the mode control registers
and can be latched on the falling edge of SCK. SDO is an
open-drain NMOS output that requires an external 2k pull-
up resistor of 1.8V to 3.3V. If readback from the mode
control registers is not needed, the pull-up resistor is not
necessary and SDO can be left unconnected. In parallel
programming mode (PAR/SER = VDD), SDO is an input that
enables internal 100Ω termination resistors on the digital
outputs. When used as an input, SDO can be driven with
1.8V to 3.3V logic through a 1k series resistor.
18
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
PAR/SER (Pin 35): Programming Mode Selection Pin.
Connect to ground to enable the serial programming
mode. CS, SCK, SDI and SDO become a serial interface
that controls the A/D operating modes. Connect to VDD
to enable parallel programming mode where CS, SCK,
SDI and SDO become parallel logic inputs that control a
reduced set of the A/D operating modes. PAR/SER should
be connected directly to ground or the VDD of the part and
not be driven by a logic signal.
VREF (Pin 36): Reference Voltage Output. Bypass to ground
with a 1µF ceramic capacitor, nominally 1.25V.
SENSE (Pin 38): Reference Programming Pin. Connect-
ing SENSE to VDD selects the internal reference and a
±1V input range. Connecting SENSE to ground selects
the internal reference and a ±0.5V input range. An external
reference between 0.625V and 1.3V applied to SENSE
selects an input range of ±0.8 • VSENSE.
LVDS OUTPUTS
The following pins are differential LVDS outputs. The
output current level is programmable. There is an op-
tional internal 100Ω termination resistor between the
pins of each LVDS output pair.
OUT2B/OUT2B+, OUT2A,OUT2A+ (Pins 19/20, 21/22):
Serial Data Outputs for Channel 2. In 1-lane output mode,
only OUT2A/OUT2A+ are used.
FR/FR+ (Pin 23/Pin 24): Frame Start Output.
DCO/DCO+ (Pin 27/Pin 28): Data Clock Output.
OUT1B/OUT1B+, OUT1A/OUT1A+ (Pins 29/30, 31/32):
Serial Data Outputs for Channel 1. In 1-lane output mode,
only OUT1A/OUT1A+ are used.
PIN FUNCTIONS
LTC2265-12/
LTC2264-12/LTC2263-12
19
22654312fb
FUNCTIONAL BLOCK DIAGRAM
Figure 1. Functional Block Diagram
PLL
DATA
SERIALIZER
SAMPLE-
AND-HOLD
12-BIT
ADC CORE
CHANNEL 1
ANALOG
INPUT
12-BIT
ADC CORE
CHANNEL 2
ANALOG
INPUT
1.8V
VDD
1.8VENC+ENC
OVDD
VDD/2
DIFF
REF
AMP
REF
BUF
2.2µF
0.1µF 0.1µF
0.1µF
REFH REFL
RANGE
SELECT
1.25V
REFERENCE
REFH REFL
OUT1A
OUT1B
OUT2A
OUT2B
DATA
CLOCK OUT
FRAME
OGND
VCM1
GND VCM2
0.1µF0.1µF SDOCS
SENSE
VREF
F
MODE
CONTROL
REGISTERS
SCKPAR/SER SDI
226512 F01
SAMPLE-
AND-HOLD
20
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
CONVERTER OPERATION
The LTC2265-12/LTC2264-12/LTC2263-12 are low power,
2-channel, 12-bit, 65Msps/40Msps/25Msps A/D convert-
ers that are powered by a single 1.8V supply. The analog
inputs should be driven differentially. The encode input can
be driven differentially for optimal jitter performance, or
single-ended for lower power consumption. To minimize
the number of data lines, the digital outputs are serial LVDS.
Each channel outputs two bits at a time (2-lane mode) or
one bit at a time (1-lane mode). Many additional features
can be chosen by programming the mode control registers
through a serial SPI port.
ANALOG INPUT
The analog inputs are differential CMOS sample-and-hold
circuits (Figure 2). The inputs should be driven differentially
around a common mode voltage set by the VCM1 or VCM2
output pins, which are nominally VDD/2. For the 2V input
range, the inputs should swing from VCM – 0.5V to VCM
+ 0.5V. There should be a 180° phase difference between
the inputs.
The two channels are simultaneously sampled by a
shared encode circuit (Figure 2).
INPUT DRIVE CIRCUITS
Input Filtering
If possible, there should be an RC lowpass filter right
at the analog inputs. This lowpass filter isolates the
drive circuitry from the A/D sample-and-hold switching
and limits wideband noise from the drive circuitry.
Figure 3 shows an example of an input RC filter. The
RC component values should be chosen based on the
application’s input frequency.
APPLICATIONS INFORMATION
Transformer Coupled Circuits
Figure 3 shows the analog input being driven by an RF
transformer with a center-tapped secondary. The center
tap is biased with VCM, setting the A/D input at its opti-
mal DC level. At higher input frequencies a transmission
line balun transformer (Figures 4 to 6) has better balance,
resulting in lower A/D distortion.
CSAMPLE
3.5pF
RON
25Ω
RON
25Ω
VDD
VDD
LTC2265-12
AIN+
226512 F02
CSAMPLE
3.5pF
VDD
AIN
ENC
ENC+
1.2V
10k
1.2V
10k
CPARASITIC
1.8pF
CPARASITIC
1.8pF
10Ω
10Ω
Figure 2. Equivalent Input Circuit. Only One of
the Two Analog Channels Is Shown.
25Ω
25Ω 25Ω
25Ω
50Ω
0.1µF
AIN+
AIN
12pF
0.1µF
VCM
LTC2265-12
ANALOG
INPUT
0.1µF T1
1:1
T1: MA/COM MABAES0060
RESISTORS, CAPACITORS
ARE 0402 PACKAGE SIZE
226512 F03
Figure 3. Analog Input Circuit Using a Transformer.
Recommended for Input Frequencies from 5MHz to 70MHz
LTC2265-12/
LTC2264-12/LTC2263-12
21
22654312fb
Amplifier Circuits
Figure 7 shows the analog input being driven by a high speed
differential amplifier. The output of the amplifier is AC-
coupled to the A/D so the amplifiers output common mode
voltage can be optimally set to minimize distortion.
25Ω
25Ω
50Ω
0.1µF
AIN+
AIN
4.7pF
0.1µF
VCM
ANALOG
INPUT
0.1µF
0.1µF
T1
T2
T1: MA/COM MABA-007159-000000
T2: MA/COM MABAES0060
RESISTORS, CAPACITORS ARE 0402 PACKAGE SIZE
226512 F04
LTC2265-12
25Ω
25Ω
50Ω
0.1µF
AIN+
AIN
1.8pF
0.1µF
VCM
ANALOG
INPUT
0.1µF
0.1µF
T1
T2
T1: MA/COM MABA-007159-000000
T2: COILCRAFT WBC1-1LB
RESISTORS, CAPACITORS ARE 0402 PACKAGE SIZE
226512 F05
LTC2265-12
25Ω
25Ω
50Ω
0.1µF
2.7nH
2.7nH
AIN+
AIN
0.1µF
VCM
ANALOG
INPUT
0.1µF
0.1µF
T1
T1: MA/COM ETC1-1-13
RESISTORS, CAPACITORS
ARE 0402 PACKAGE SIZE
226512 F06
LTC2265-12
25Ω
25Ω
200Ω
200Ω
0.1µF AIN+
AIN
12pF
0.1µF
VCM
LTC2265-12
226512 F07
++
ANALOG
INPUT
HIGH SPEED
DIFFERENTIAL
AMPLIFIER
0.1µF
Figure 5. Recommended Front-End Circuit for Input
Frequencies from 170MHz to 300MHz
Figure 6. Recommended Front-End Circuit for Input
Frequencies Above 300MHz
Figure 4. Recommended Front-End Circuit for Input
Frequencies from 70MHz to 170MHz
Figure 7. Front-End Circuit Using a High Speed
Differential Amplifier
APPLICATIONS INFORMATION
At very high frequencies an RF gain block will often have
lower distortion than a differential amplifier. If the gain
block is single-ended, then a transformer circuit (Figures
4 to 6) should convert the signal to differential before
driving the A/D.
22
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
Reference
The LTC2265-12/LTC2264-12/LTC2263-12 has an internal
1.25V voltage reference. For a 2V input range using the
internal reference, connect SENSE to VDD. For a 1V input
range using the internal reference, connect SENSE to
ground. For a 2V input range with an external reference,
apply a 1.25V reference voltage to SENSE (Figure 9).
The input range can be adjusted by applying a voltage to
SENSE that is between 0.625V and 1.30V. The input range
will then be 1.6 VSENSE.
The reference is shared by both ADC channels, so it is
not possible to independently adjust the input range of
individual channels.
The VREF, REFH and REFL pins should be bypassed, as
shown in Figure 8. The 0.1µF capacitor between REFH and
REFL should be as close to the pins as possible (not on
the backside of the circuit board).
APPLICATIONS INFORMATION
VREF
REFH
SENSE
TIE TO VDD FOR 2V RANGE;
TIE TO GND FOR 1V RANGE;
RANGE = 1.6 • VSENSE FOR
0.625V < VSENSE < 1.300V
1.25V
REFL
0.1µF2.2µF
INTERNAL ADC
HIGH REFERENCE
BUFFER
0.8x
DIFF AMP
INTERNAL ADC
LOW REFERENCE
1.25V BANDGAP
REFERENCE
0.625V
RANGE
DETECT
AND
CONTROL
F
0.1µF
0.1µF
LTC2265-12
226512 F08
Figure 8. Reference Circuit
SENSE
1.25V
EXTERNAL
REFERENCE
F
F
VREF
226512 F09
LTC2265-12
Figure 9. Using an External 1.25V Reference
VDD
LTC2265-12
226512 F10
ENC
ENC+
15k
VDD
DIFFERENTIAL
COMPARATOR
30k
Figure 10. Equivalent Encode Input Circuit
for Differential Encode Mode
Encode Input
The signal quality of the encode inputs strongly affects
the A/D noise performance. The encode inputs should
be treated as analog signals—do not route them next to
digital traces on the circuit board. There are two modes
of operation for the encode inputs: the differential encode
mode (Figure 10), and the single-ended encode mode
(Figure 11).
30k
ENC+
ENC
226512 F11
0V
1.8V TO 3.3V
LTC2265-12
CMOS LOGIC
BUFFER
Figure 11. Equivalent Encode Input Circuit
for Single-Ended Encode Mode
LTC2265-12/
LTC2264-12/LTC2263-12
23
22654312fb
APPLICATIONS INFORMATION
The differential encode mode is recommended for sinu-
soidal, PECL, or LVDS encode inputs (Figures 12 and 13).
The encode inputs are internally biased to 1.2V through
10k equivalent resistance. The encode inputs can be taken
above VDD (up to 3.6V), and the common mode range
is from 1.1V to 1.6V. In the differential encode mode,
ENC should stay at least 200mV above ground to avoid
falsely triggering the single-ended encode mode. For
good jitter performance ENC+ should have fast rise and
fall times.
The single-ended encode mode should be used with
CMOS encode inputs. To select this mode, ENC is con-
nected to ground and ENC+ is driven with a square wave
encode input. ENC+ can be taken above VDD (up to 3.6V)
so 1.8V to 3.3V CMOS logic levels can be used. The
ENC+ threshold is 0.9V. For good jitter performance
ENC+ should have fast rise and fall times.
Clock PLL and Duty Cycle Stabilizer
The encode clock is multiplied by an internal phase-locked
loop (PLL) to generate the serial digital output data. If the
encode signal changes frequency or is turned off, the PLL
requires 25µs to lock onto the input clock.
A clock duty cycle stabilizer circuit allows the duty cycle
of the applied encode signal to vary from 30% to 70%.
In the serial programming mode it is possible to disable
the duty cycle stabilizer, but this is not recommended. In
the parallel programming mode the duty cycle stabilizer
is always enabled.
DIGITAL OUTPUTS
The digital outputs of the LTC2265-12/LTC2264-12/
LTC2263-12 are serialized LVDS signals. Each channel
outputs two bits at a time (2-lane mode) or one bit at a
time (1-lane mode). The data can be serialized with 16-,
14-, or 12-bit serialization (see the Timing Diagrams sec-
tion for details).
The output data should be latched on the rising and falling
edges of the data clockout (DCO). A data frame output
(FR) can be used to determine when the data from a new
conversion result begins. In the 2-lane, 14-bit serialization
mode, the frequency of the FR output is halved.
The maximum serial data rate for the data outputs is
1Gbps, so the maximum sample rate of the ADC will de-
pend on the serialization mode as well as the speed grade
of the ADC (see Table 1). The minimum sample rate for
all serialization modes is 5Msps.
50Ω 100Ω
0.1µF
0.1µF
0.1µF
T1
T1 = MA/COM ETC1-1-13
RESISTORS AND CAPACITORS
ARE 0402 PACKAGE SIZE
50Ω
LTC2265-12
226512 F12
ENC
ENC+
ENC+
ENC
PECL OR
LVDS
CLOCK
0.1µF
0.1µF
226512 F13
LTC2265-12
Figure 12. Sinusoidal Encode Drive
Figure 13. PECL or LVDS Encode Drive
24
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
By default the outputs are standard LVDS levels: a 3.5mA
output current and a 1.25V output common mode volt-
age. An external 100Ω differential termination resistor
is required for each LVDS output pair. The termination
resistors should be located as close as possible to the
LVDS receiver.
The outputs are powered by OVDD and OGND which are
isolated from the A/D core power and ground.
Programmable LVDS Output Current
The default output driver current is 3.5mA. This current can
be adjusted by control register A2 in serial programming
mode. Available current levels are 1.75mA, 2.1mA, 2.5mA,
3mA, 3.5mA, 4mA and 4.5mA. In parallel programming
mode the SCK pin can select either 3.5mA or 1.75mA.
Optional LVDS Driver Internal Termination
In most cases, using just an external 100Ω termination
resistor will give excellent LVDS signal integrity. In addi-
tion, an optional internal 100Ω termination resistor can
be enabled by serially programming mode control register
A2. The internal termination helps absorb any reflections
caused by imperfect termination at the receiver. When the
internal termination is enabled, the output driver current
is doubled to maintain the same output voltage swing. In
parallel programming mode the SDO pin enables internal
termination. Internal termination should only be used with
1.75mA, 2.1mA or 2.5mA LVDS output current modes.
Table 1. Maximum Sampling Frequency for All Serialization Modes. Note That These Limits Are for the LTC2265-12. The Sampling
Frequency for the Slower Speed Grades Cannot Exceed 40MHz (LTC2264-12) or 25MHz (LTC2263-12).
SERIALIZATION MODE
MAXIMUM SAMPLING
FREQUENCY, fS (MHz) DCO FREQUENCY FR FREQUENCY SERIAL DATA RATE
2-Lane 16-Bit Serialization 65 4 • fSfS8 • fS
2-Lane 14-Bit Serialization 65 3.5 • fS0.5 • fS7 • fS
2-Lane 12-Bit Serialization 65 3 • fSfS6 • fS
1-Lane 16-Bit Serialization 62.5 8 • fSfS16 • fS
1-Lane 14-Bit Serialization 65 7 • fSfS14 • fS
1-Lane 12-Bit Serialization 65 6 • fSfS12 • fS
APPLICATIONS INFORMATION
DATA FORMAT
Table 2 shows the relationship between the analog input
voltage and the digital data output bits. By default the
output data format is offset binary. The 2’s complement
format can be selected by serially programming mode
control register A1.
In addition to the 12 data bits (D11 - D0), two additional
bits (DX and DY) are sent out in the 14-bit and 16-bit
serialization modes. These extra bits are to ensure com-
plete software compatibility with the 14-bit versions of
these A/Ds. During normal operation when the analog
inputs are not overranged, DX and DY are always logic 0.
When the analog inputs are overranged positive, DX and DY
become logic 1. When the analog inputs are overranged
negative, DX and DY become logic 0. DX and DY can also
be controlled by the digital output test pattern. See the
Timing Diagrams section for more information.
Table 2. Output Codes vs Input Voltage
AIN+ – AIN
(2V RANGE)
D11-D0
(OFFSET BINARY)
D11-D0
(2’s COMPLEMENT)
DX, DY
>+1.000000V
+0.999512V
+0.999024V
1111 1111 1111
1111 1111 1111
1111 1111 1110
0111 1111 1111
0111 1111 1111
0111 1111 1110
11
00
00
+0.000488V
0.000000V
–0.000488V
–0.000976V
1000 0000 0001
1000 0000 0000
0111 1111 1111
0111 1111 1110
0000 0000 0001
0000 0000 0000
1111 1111 1111
1111 1111 1110
00
00
00
00
–0.999512V
–1.000000V
≤–1.000000V
0000 0000 0001
0000 0000 0000
0000 0000 0000
1000 0000 0001
1000 0000 0000
1000 0000 0000
00
00
00
LTC2265-12/
LTC2264-12/LTC2263-12
25
22654312fb
APPLICATIONS INFORMATION
Digital Output Randomizer
Interference from the A/D digital outputs is sometimes
unavoidable. Digital interference may be from capacitive or
inductive coupling or coupling through the ground plane.
Even a tiny coupling factor can cause unwanted tones
in the ADC output spectrum. By randomizing the digital
output before it is transmitted off chip, these unwanted
tones can be randomized which reduces the unwanted
amplitude.
The digital output is randomized by applying an exclu-
sive-OR logic operation between the LSB and all other
data output bits. To decode, the reverse operation is
appliedan exclusive-OR operation is applied between
the LSB and all other bits. The FR and DCO outputs are
not affected. The output randomizer is enabled by serially
programming mode control register A1.
Digital Output Test Pattern
To allow in-circuit testing of the digital interface to the
A/D, there is a test mode that forces the A/D data outputs
(D11-D0, DX, DY) of all channels to known values. The
digital output test patterns are enabled by serially program-
ming mode control registers A3 and A4. When enabled,
the test patterns override all other formatting modes: 2’s
complement and randomizer.
Output Disable
The digital outputs may be disabled by serially program-
ming mode control register A2. The current drive for all
digital outputs, including DCO and FR, are disabled to save
power or enable in-circuit testing. When disabled, the com-
mon mode of each output pair becomes high impedance,
but the differential impedance may remain low.
Sleep and Nap Modes
The A/D may be placed in sleep or nap modes to conserve
power. In sleep mode the entire chip is powered down,
resulting in 1mW power consumption. Sleep mode is
enabled by mode control register A1 (serial program-
ming mode), or by SDI (parallel programming mode).
The amount of time required to recover from sleep mode
depends on the size of the bypass capacitors on VREF,
REFH and REFL. For the suggested values in Figure 8, the
A/D will stabilize after 2ms.
In nap mode any combination of A/D channels can be
powered down while the internal reference circuits and the
PLL stay active, allowing faster wake-up than from sleep
mode. Recovering from nap mode requires at least 100
clock cycles. If the application demands a very accurate DC
settling, then an additional 50µs should be allowed so the
on-chip references can settle from the slight temperature
shift caused by the change in supply current as the A/D
leaves nap mode. Nap mode is enabled by the mode control
register A1 in the serial programming mode.
DEVICE PROGRAMMING MODES
The operating modes of the LTC2265-12/LTC2264-12/
LTC2263-12 can be programmed by either a parallel
interface or a simple serial interface. The serial interface
has more flexibility and can program all available modes.
The parallel interface is more limited and can only program
some of the more commonly used modes.
Parallel Programming Mode
To use the parallel programming mode, PAR/SER should
be tied to VDD. The CS, SCK, SDI and SDO pins are binary
logic inputs that set certain operating modes. These pins
can be tied to VDD or ground, or driven by 1.8V, 2.5V or
3.3V CMOS logic. When used as an input, SDO should
be driven through a 1k series resistor. Table 3 shows the
modes set by CS, SCK, SDI and SDO.
Table 3. Parallel Programming Mode Control Bits (PAR/SER = VDD)
PIN DESCRIPTION
CS 2-Lane/1-Lane Selection Bit
0 = 2-Lane, 16-Bit Serialization Output Mode
1 = 1-Lane, 14-Bit Serialization Output Mode
SCK LVDS Current Selection Bit
0 = 3.5mA LVDS Current Mode
1 = 1.75mA LVDS Current Mode
SDI Power Down Control Bit
0 = Normal Operation
1 = Sleep Mode
SDO Internal Termination Selection Bit
0 = Internal Termination Disabled
1 = Internal Termination Enabled
26
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
APPLICATIONS INFORMATION
Serial Programming Mode
To use the serial programming mode, PAR/SER should be
tied to ground. The CS, SCK, SDI and SDO pins become
a serial interface that program the A/D mode control
registers. Data is written to a register with a 16-bit serial
word. Data can also be read back from a register to verify
its contents.
Serial data transfer starts when CS is taken low. The data
on the SDI pin is latched at the first 16 rising edges of
SCK. Any SCK rising edges after the first 16 are ignored.
The data transfer ends when CS is taken high again.
The first bit of the 16-bit input word is the R/W bit. The
next seven bits are the address of the register (A6:A0).
The final eight bits are the register data (D7:D0).
If the R/W bit is low, the serial data (D7:D0) will be written
to the register set by the address bits (A6:A0). If the R/W
bit is high, data in the register set by the address bits (A6:
Table 4. Serial Programming Mode Register Map (PAR/SER = GND)
REGISTER A0: RESET REGISTER (ADDRESS 00h)
D7 D6 D5 D4 D3 D2 D1 D0
RESET X X X X X X X
Bit 7 RESET Software Reset Bit
0 = Not Used
1 = Software Reset. All Mode Control Registers Are Reset to 00h. The ADC is momentarily placed in SLEEP mode.
This Bit Is Automatically Set Back to Zero at the End of the SPI Write Command.
The Reset Register is Write Only
Bits 6-0 Unused, Don’t Care Bits.
REGISTER A1: FORMAT AND POWER-DOWN REGISTER (ADDRESS 01h)
D7 D6 D5 D4 D3 D2 D1 D0
DCSOFF RAND TWOSCOMP SLEEP NAP_2 X X NAP_1
Bit 7 DCSOFF Clock Duty Cycle Stabilizer Bit
0 = Clock Duty Cycle Stabilizer On
1 = Clock Duty Cycle Stabilizer Off. This is Not Recommended.
Bit 6 RAND Data Output Randomizer Mode Control Bit
0 = Data Output Randomizer Mode Off
1 = Data Output Randomizer Mode On
Bit 5 TWOSCOMP Two’s Complement Mode Control Bit
0 = Offset Binary Data Format
1 = Two’s Complement Data Format
Bits 4, 3, 0 SLEEP: NAP_2: NAP_1 Sleep/Nap Mode Control Bits
000 = Normal Operation
0X1 = Channel 1 in Nap Mode
01X = Channel 2 in Nap Mode
1XX = Sleep Mode. Both Channels are disabled
Note: Any Combination of Channels Can Be Placed in Nap Mode.
Bits 1, 2 Unused, Don’t Care Bit
A0) will be read back on the SDO pin (see the Timing Dia-
grams section). During a readback command the register
is not updated and data on SDI is ignored.
The SDO pin is an open-drain output that pulls to ground
with a 200Ω impedance. If register data is read back through
SDO, an external 2k pull-up resistor is required. If serial
data is only written and readback is not needed, then SDO
can be left floating and no pull-up resistor is needed. Table
4 shows a map of the mode control registers.
Software Reset
If serial programming is used, the mode control registers
should be programmed as soon as possible after the power
supplies turn on and are stable. The first serial command
must be a software reset which will reset all register data bits
to logic 0. To perform a software reset, bit D7 in the reset
register is written with a logic 1. After the reset SPI write
command is complete, bit D7 is automatically set back to zero.
LTC2265-12/
LTC2264-12/LTC2263-12
27
22654312fb
REGISTER A2: OUTPUT MODE REGISTER (ADDRESS 02h)
D7 D6 D5 D4 D3 D2 D1 D0
ILVDS2 ILVDS1 ILVDS0 TERMON OUTOFF OUTMODE2 OUTMODE1 OUTMODE0
Bits 7-5 ILVDS2: ILVDS0 LVDS Output Current Bits
000 = 3.5mA LVDS Output Driver Current
001 = 4.0mA LVDS Output Driver Current
010 = 4.5mA LVDS Output Driver Current
011 = Not Used
100 = 3.0mA LVDS Output Driver Current
101 = 2.5mA LVDS Output Driver Current
110 = 2.1mA LVDS Output Driver Current
111 = 1.75mA LVDS Output Driver Current
Bit 4 TERMON LVDS Internal Termination Bit
0 = Internal Termination Off
1 = Internal Termination On. LVDS Output Driver Current is 2x the Current Set by ILVDS2:ILVDS0. Internal termination should only be
used with 1.75mA, 2.1mA or 2.5mA LVDS output current modes.
Bit 3 OUTOFF Output Disable Bit
0 = Digital Outputs are enabled.
1 = Digital Outputs are disabled.
Bits 2-0 OUTMODE2:OUTMODE0 Digital Output Mode Control Bits
000 = 2-Lanes, 16-Bit Serialization
001 = 2-Lanes, 14-Bit Serialization
010 = 2-Lanes, 12-Bit Serialization
011 = Not Used
100 = Not Used
101 = 1-Lane, 14-Bit Serialization
110 = 1-Lane, 12-Bit Serialization
111 = 1-Lane, 16-Bit Serialization
REGISTER A3: TEST PATTERN MSB REGISTER (ADDRESS 03h)
D7 D6 D5 D4 D3 D2 D1 D0
OUTTEST X TP11 TP10 TP9 TP8 TP7 TP6
Bit 7 OUTTEST Digital Output Test Pattern Control Bit
0 = Digital Output Test Pattern Off
1 = Digital Output Test Pattern On
Bit 6 Unused, Don’t Care Bit.
Bits 5-0 TP11:TP6 Test Pattern Data Bits (MSB)
TP11:TP6 Set the Test Pattern for Data Bit 11 (MSB) Through Data Bit 6.
REGISTER A4: TEST PATTERN LSB REGISTER (ADDRESS 04h)
D7 D6 D5 D4 D3 D2 D1 D0
TP5 TP4 TP3 TP2 TP1 TP0 TPX TPY
Bits 7-2 TP5:TP0 Test Pattern Data Bits (LSB)
TP5:TP0 Set the Test Pattern for Data Bit 7 Through Data Bit 0 (LSB).
Bits 1-0 TPX:TPY Set the Test Pattern for Extra Bits DX and DY. These Bits are for Compatibility with the 14-Bit Version of the A/D.
APPLICATIONS INFORMATION
28
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
GROUNDING AND BYPASSING
The LTC2265-12/LTC2264-12/LTC2263-12 requires a
printed circuit board with a clean unbroken ground plane.
A multilayer board with an internal ground plane in the
first layer beneath the ADC is recommended. Layout for
the printed circuit board should ensure that digital and
analog signal lines are separated as much as possible. In
particular, care should be taken not to run any digital track
alongside an analog signal track or underneath the ADC.
High quality ceramic bypass capacitors should be used at
the VDD, OVDD, VCM, VREF, REFH and REFL pins. Bypass
capacitors must be located as close to the pins as possible.
Of particular importance is the 0.1µF capacitor between
REFH and REFL. This capacitor should be on the same
side of the circuit board as the A/D, and as close to the
device as possible (1.5mm or less). Size 0402 ceramic
APPLICATIONS INFORMATION
capacitors are recommended. The larger 2.2µF capacitor
between REFH and REFL can be somewhat further away.
The traces connecting the pins and bypass capacitors must
be kept short and should be made as wide as possible.
The analog inputs, encode signals and digital outputs
should not be routed next to each other. Ground fill and
grounded vias should be used as barriers to isolate these
signals from each other.
HEAT TRANSFER
Most of the heat generated by the LTC2265-12/LTC2264-12/
LTC2263-12 is transferred from the die through the bot-
tom-side Exposed Pad and package leads onto the printed
circuit board. For good electrical and thermal performance,
the Exposed Pad must be soldered to a large grounded
pad on the PC board. This pad should be connected to the
internal ground planes by an array of vias.
LTC2265-12/
LTC2264-12/LTC2263-12
29
22654312fb
TYPICAL APPLICATIONS
Silkscreen Top Top Side
Inner Layer 2 GND Inner Layer 3
30
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
TYPICAL APPLICATIONS
Inner Layer 4 Inner Layer 5 Power
Bottom Side Silkscreen Bottom
LTC2265-12/
LTC2264-12/LTC2263-12
31
22654312fb
TYPICAL APPLICATIONS
LTC2265
3
2
1AIN1+
AIN1
VCM1
REFH
REFH
REFL
REFL
VCM2
AIN2+
AIN2
8
9
10
VDD
VDD
SENSE
GND
VREF
PAR/SER
SDO
GND
OUT1A+
OUT1A
3940 38 37 36
SDO
PAR/SER
SENSE
VDD
35 34 33 32 31
C59
0.1µF
C29
0.1µF
6
5
4
7
C30
0.1µF
C1
2.2µF
C3
0.1µF
C2
0.1µF
OVDD
AIN1
AIN1
AIN2
AIN2
226512 TA03
DIGITAL
OUTPUTS
DIGITAL
OUTPUTS
OUT1B+
OUT1B
DCO+
DCO
OVDD
OGND
FR+
FR
OUT2A+
OUT2A
23
24
25
26
27
28
29
30
22
21
C16
0.1µF
C4
F
C5
F
VDD
VDD
ENC+
ENC
CS
SCK
SDI
GND
OUT2B
OUT2B+
1211
VDD
13 14 15 16 17 18 19 20
C7
0.1µF
SPI BUS
C46
0.1µF
C47
0.1µF
ENCODE
CLOCK
ENCODE
CLOCK
LTC2265 Schematic
32
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PACKAGE DESCRIPTION
UJ Package
40-Lead (6mm × 6mm) Plastic QFN
(Reference LTC DWG # 05-08-1728)
6.00 ± 0.10
(4 SIDES)
NOTE:
1. DRAWING IS A JEDEC PACKAGE OUTLINE VARIATION OF (WJJD-2)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.20mm ON ANY SIDE, IF PRESENT
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE
PIN 1 TOP MARK
(SEE NOTE 6)
PIN 1 NOTCH
R = 0.45 OR
0.35 × 45°
CHAMFER
0.40 ± 0.10
4039
1
2
BOTTOM VIEW—EXPOSED PAD
4.50 REF
(4-SIDES)
4.42 ± 0.10
4.42 ± 0.10
4.42 ± 0.05
4.42 ± 0.05
0.75 ± 0.05 R = 0.115
TYP
0.25 ± 0.05
0.50 BSC
0.200 REF
0.00 – 0.05
(UJ40) QFN REV Ø 0406
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED
0.70 ± 0.05
4.50 ± 0.05
(4 SIDES)
5.10 ± 0.05
6.50 ± 0.05
0.25 ± 0.05
0.50 BSC
PACKAGE OUTLINE
R = 0.10
TYP
LTC2265-12/
LTC2264-12/LTC2263-12
33
22654312fb
REVISION HISTORY
REV DATE DESCRIPTION PAGE NUMBER
A 4/10 Revised Maximum Value for LTC2264-12 Sampling Frequency in Timing Characteristics
Updated Title of Curve G53 in Typical Performance Characteristics
Revised Descriptions and Comments in Related Parts Section
6
13
34
B 7/11 Revised Software Reset paragraph and Table 4 in Applications Information section 26
34
22654312fb
LTC2265-12/
LTC2264-12/LTC2263-12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 FAX: (408) 434-0507 www.linear.com
LINEAR TECHNOLOGY CORPORATION 2010
LT 0711 REV B • PRINTED IN USA
RELATED PARTS
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LTC2259-14/LTC2260-14/
LTC2261-14
14-Bit, 80Msps/105Msps/125Msps
1.8V ADCs, Ultralow Power
89mW/106mW/127mW, 73.4dB SNR, 85dB SFDR, DDR LVDS/DDR CMOS/CMOS
Outputs, 6mm × 6mm QFN-40
LTC2262-14 14-Bit, 150Msps 1.8V ADC, Ultralow Power 149mW, 72.8dB SNR, 88dB SFDR, DDR LVDS/DDR CMOS/CMOS Outputs,
6mm × 6mm QFN-40
LTC2263-14/LTC2264-14/
LTC2265-14
14-Bit, 25Msps/40Msps/65Msps
1.8V Dual ADCs, Ultralow Power
94mW/113mW/171mW, 73.7dB SNR, 90dB SFDR, Serial LVDS Outputs,
6mm × 6mm QFN-40
LTC2266-14/LTC2267-14/
LTC2268-14
14-Bit, 80Msps/105Msps/125Msps
1.8V Dual ADCs, Ultralow Power
203mW/243mW/299mW, 73.1dB SNR, 88dB SFDR, Serial LVDS Outputs,
6mm × 6mm QFN-40
LTC2266-12/LTC2267-12/
LTC2268-12
12-Bit, 80Msps/105Msps/125Msps
1.8V Dual ADCs, Ultralow Power
200mW/238mW/292mW, 70.6dB SNR, 88dB SFDR, Serial LVDS Outputs,
6mm × 6mm QFN-40
RF Mixers/Demodulators
LTC5517 40MHz to 900MHz Direct Conversion
Quadrature Demodulator
High IIP3: 21dBm at 800MHz, Integrated LO Quadrature Generator
LTC5527 400MHz to 3.7GHz High Linearity
Downconverting Mixer
24.5dBm IIP3 at 900MHz, 23.5dBm IIP3 at 1900MHz, NF = 12.5dB,
50Ω Single-Ended RF and LO Ports, 5V Supply
LTC5557 400MHz to 3.8GHz High Linearity
Downconverting Mixer
24.7dBm IIP3 at 1950MHz, 23.7dBm IIP3 at 2.6GHz, NF = 13.2dB, 3.3V Supply
Operation, Integrated Transformer
LTC5575 800MHz to 2.7GHz Direct Conversion
Quadrature Demodulator
High IIP3: 28dBm at 900MHz, Integrated LO Quadrature Generator, Integrated RF
and LO Transformer
Amplifiers/Filters
LTC6412 800MHz, 31dB Range, Analog-Controlled
Variable Gain Amplifier
Continuously Adjustable Gain Control, 35dBm OIP3 at 240MHz, 10dB Noise
Figure, 4mm × 4mm QFN-24
LTC6420-20 Dual Low Noise, Low Distortion
Differential ADC Drivers for 300MHz IF
Fixed Gain 10V/V, 2.2nV/√Hz Total Input Referred Noise, 46dBm OIP3 at 100MHz,
80mA Supply Current per Amplifier, 3mm × 4mm QFN-20
LTC6421-20 Dual Low Noise, Low Distortion
Differential ADC Drivers for 140MHz IF
Fixed Gain 10V/V, 2.2nV/√Hz Total Input Referred Noise, 42dBm OIP3 at 100MHz,
40mA Supply Current per Amplifier, 3mm × 4mm QFN-20
LTC6605-7/LTC6605-10/
LTC6605-14
Dual Matched 7MHz/10MHz/14MHz Filters
with ADC Drivers
Dual Matched 2nd Order Lowpass Filters with Differential Drivers,
Pin-Programmable Gain, 6mm × 3mm DFN-22
Signal Chain Receivers
LTM9002 14-Bit Dual Channel IF/Baseband Receiver
Subsystem
Integrated High Speed ADC, Passive Filters and Fixed Gain Differential Amplifiers