Document
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FEATURES
■ Sample Rate: 125Msps/105Msps
■ Single 3V Supply (2.85V to 3.4V)
■ Low Power: 395mW/320mW
■ 72.4dB SNR
■ 88dB SFDR
■ No Missing Codes
■ Flexible Input: 1VP-P to 2VP-P Range ■ 640MHz Full Power Bandwidth S/H
■ Clock Duty Cycle Stabilizer
■ Shutdown and Nap Modes
■ Pin Compatible Family
125Msps: LTC2253 (12-Bit), LTC2255 (14-Bit)
105Msps: LTC2252 (12-Bit), LTC2254 (14-Bit)
80Msps: LTC2229 (12-Bit), LTC2249 (14-Bit)
65Msps: LTC2228 (12-Bit), LTC2248 (14-Bit)
40Msps: LTC2227 (12-Bit), LTC2247 (14-Bit)
25Msps: LTC2226 (12-Bit), LTC2246 (14-Bit)
10Msps: LTC2225 (12-Bit), LTC2245 (14-Bit)
■
32-Pin
(5mm
×
5mm)
U
QFN
Package
APPLICATIO S
■ Wireless and Wired Broadband Communication ■ Imaging Systems ■ Ultrasound ■ Spectral Analysis ■ Portable Instrumentation
LTC2255/LTC2254
14-Bit, 125/105Msps Low Power 3V ADCs
DESCRIPTIO
The LTC®2255/LTC2254 are 14-bit 125Msps/105Msps, low power 3V A/D converters designed for digitizing high frequency, wide dynamic range signals. The LTC2255/ LTC2254 are perfect for demanding imaging and communications applications with AC performance that includes 72.3dB SNR and 85dB SFDR for signals at the Nyquist frequency.
DC specs include ±1LSB INL (typ), ±0.5LSB DNL (typ) and no missing codes over temperature. The transition noise is a low 1.3 LSBRMS.
A single 3V supply allows low power operation. A separate output supply allows the outputs to drive 0.5V to 3.3V logic.
A single-ended CLK input controls converter operation. An optional clock duty cycle stabilizer allows high performance at full speed for a wide range of clock duty cycles.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
REFH REFL
FLEXIBLE REFERENCE
ANALOG INPUT
+
INPUT S/H
–
14-BIT PIPELINED ADC CORE
CORRECTION LOGIC
CLOCK/DUTY CYCLE
CONTROL
CLK
OUTPUT DRIVERS
OVDD
D13 • • • D0
OGND
22554 TA01a
SNR (dBFS)
LTC2255: SNR vs Input Frequency, –1dB, 2V Range, 125Msps
75 74 73 72 71 70 69 68 67 66
65 0
50 100 150 200 250 300 350 INPUT FREQUENCY (MHz) 33554 G09
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LTC2255/LTC2254
ABSOLUTE AXI U RATI GS
OVDD = VDD (Notes 1, 2)
Supply Voltage (VDD) ................................................. 4V Digital Output Ground Voltage (OGND) ....... –0.3V to 1V Analog Input Voltage (Note 3) ..... –0.3V to (VDD + 0.3V) Digital Input Voltage .................... –0.3V to (VDD + 0.3V) Digital Output Voltage ................ –0.3V to (OVDD + 0.3V) Power Dissipation ............................................ 1500mW Operating Temperature Range
LTC2255C, LTC2254C ............................. 0°C to 70°C LTC2255I, LTC2254I ...........................–40°C to 85°C Storage Temperature Range ..................–65°C to 125°C
UW U PACKAGE/ORDER I FOR ATIO
VDD VCM SENSE MODE OF D13 D12 D11
TOP VIEW
ORDER PART NUMBER
32 31 30 29 28 27 26 25
AIN+ 1
24 D10
AIN– 2
23 D9
REFH 3
22 D8
REFH 4 REFL 5
33
21 OVDD
20 OGND
REFL 6
19 D7
VDD 7 GND 8
18 D6 17 D5
9 10 11 12 13 14 15 16
CLK SHDN
OE D0 D1 D2 D3 D4
UH PACKAGE 32-LEAD (5mm × 5mm) PLASTIC QFN
TJMAX = 125°C, θJA = 34°C/W EXPOSED PAD (PIN 33) IS GND MUST BE SOLDERED TO PCB
LTC2255CUH LTC2255IUH LTC2254CUH LTC2254IUH
QFN PART* MARKING
2255 2254
Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
CO VERTER CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 4)
PARAMETER Resolution (No Missing Codes) Integral Linearity Error Differential Linearity Error Offset Error Gain Error Offset Drift Full-Scale Drift
Transition Noise
CONDITIONS
Differential Analog Input (Note 5) Differential Analog Input (Note 6) External Reference
Internal Reference External Reference SENSE = 1V
LTC2255 MIN TYP MAX
● 14
● –5 ±1
5
● –1 ±0.5 1
● –12 ±2 12
● –2.5 ±0.5 2.5
±10
±30
±5
1.3
LTC2254 MIN TYP MAX 14 –5.5 ±1 5.5 –1 ±0.5 1 –12 ±2 12 –2.5 ±0.5 2.5
±10 ±30 ±5 1.3
UNITS Bits LSB LSB mV %FS
µV/°C ppm/°C ppm/°C LSBRMS
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LTC2255/LTC2254
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A ALOG I PUT The ● denotes the specifications which apply over the full operating temperature range, otherwise
specifications are at TA = 25°C. (Note 4)
SYMBOL
VIN VIN,CM IIN ISENSE IMODE tAP tJITTER CMRR
PARAMETER Analog Input Range (AIN+ –AIN–) Analog Input Common Mode Analog Input Leakage Current SENSE Input Leakage MODE Pin Leakage Sample-and-Hold Acquisition Delay Time Sample-and-Hold Acquisition Delay Time Jitter Analog Input Common Mode Rejection Ratio Full Power Bandwidth
CONDIT.