Document
LTC2175-14/ LTC2174-14/LTC2173-14
14-Bit, 125Msps/105Msps/ 80Msps Low Power Quad ADCs
Features
Description
n 4-Channel Simultaneous Sampling ADC n 73.1dB SNR n 88dB SFDR n Low Power: 558mW/450mW/376mW Total,
140mW/113mW/94mW 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 52-Pin (7mm × 8mm) QFN Package
Applications
n Communications n Cellular Base Stations n Software Defined Radios n Portable Medical Imaging n Multichannel Data Acquisition n Nondestructive Testing
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.
The LTC®2175-14/LTC2174-14/LTC2173-14 are 4-channel, simultaneous sampling 14-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 73.1dB SNR and 88dB spurious free dynamic range (SFDR). Ultralow jitter of 0.15psRMS allows undersampling of IF frequencies with excellent noise performance.
DC specs include ±1LSB INL (typ), ±0.3LSB DNL (typ) and no missing codes over temperature. The transition noise is a low 1.2LSBRMS.
The digital outputs are serial LVDS to minimize the number of data lines. Each channel outputs two bits at a time (2-lane mode). At lower sampling rates there is a one bit per channel option (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.
Typical Application
CHANNEL 1
ANALOG
S/H
INPUT
1.8V VDD
14-BIT ADC CORE
1.8V OVDD
CHANNEL 2
ANALOG
S/H
INPUT
CHANNEL 3
ANALOG
S/H
INPUT
14-BIT ADC CORE
14-BIT ADC CORE
DATA SERIALIZER
CHANNEL 4
ANALOG
S/H
INPUT
14-BIT ADC CORE
ENCODE INPUT
PLL
GND
OGND
OUT1A OUT1B
OUT2A OUT2B
OUT3A OUT3B
OUT4A OUT4B DATA CLOCK OUT FRAME
SERIALIZED LVDS OUTPUTS
217514 TA01
AMPLITUDE (dBFS)
LTC2175-14, 125Msps, 2-Tone FFT, fIN = 70MHz and 75MHz
0 –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120
0 10 20 30 40 50 60 FREQUENCY (MHz)
217514 TA01b
21754314fa
1
LTC2175-14/ LTC2174-14/LTC2173-14
Absolute Maximum Ratings
(Notes 1, 2)
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 Outp.