Electrical Specifications Subject to Change
LTC2258-14
LTC2257-14/LTC2256-14
14-Bit, 65/40/25Msps
Ultralow Power 1.8V ADCs
FEATURES
DESCRIPTION
The LTC®2258-14/LTC2257-14/LTC2256-14 are sam-
pling 14-bit A/D converters designed for digitizing high
frequency, wide dynamic range signals. They are perfect
for demanding communications applications with AC
performancethatincludes73.9dBSNRand88dBspurious
n
73.9dB SNR
n
88dB SFDR
n
Low Power: 81mW/49mW/35mW
Single 1.8V Supply
n
n
CMOS, DDR CMOS or DDR LVDS Outputs
n
free dynamic range (SFDR). Ultralow jitter of 0.17ps
Selectable Input Ranges: 1V to 2V
RMS
P-P
P-P
n
n
n
n
n
n
n
allows undersampling of IF frequencies with excellent
800MHz Full-Power Bandwidth S/H
noise performance.
Optional Data Output Randomizer
Optional Clock Duty Cycle Stabilizer
Shutdown and Nap Modes
DC specs include 1LSB INL (typical), 0.3LSB DNL (typi-
cal)andnomissingcodesovertemperature.Thetransition
Serial SPI Port for Configuration
noise is a low 1.2LSB
.
RMS
Pin Compatible 14-Bit and 12-Bit Versions
The digital outputs can be either full rate CMOS, double
data rate CMOS, or double data rate LVDS. A separate
output power supply allows the CMOS output swing to
range from 1.2V to 1.8V.
40-Pin (6mm × 6mm) QFN Package
APPLICATIONS
n
+
–
Communications
The ENC and ENC inputs may be driven differentially
or single ended with a sine wave, PECL, LVDS, TTL or
CMOS inputs. An optional clock duty cycle stabilizer al-
lows high performance at full speed for a wide range of
clock duty cycles.
n
Cellular Base Stations
n
Software Defined Radios
Portable Medical Imaging
Multi-Channel Data Acquisition
Nondestructive Testing
n
n
n
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-Tone FFT, fIN = 68MHz and 69MHz
1.8V
V
1.2V
0
–10
–20
–30
–40
–50
–60
–70
TO 1.8V
DD
OV
DD
D13
+
14-BIT
PIPELINED
ADC CORE
CMOS
OR
LVDS
•
•
•
CORRECTION
LOGIC
ANALOG
INPUT
OUTPUT
DRIVERS
INPUT
S/H
–
D0
–80
–90
OGND
–100
–110
–120
CLOCK/DUTY
CYCLE
CONTROL
0
20
10
FREQUENCY (MHz)
30
225814 TA01a
GND
65MHz
CLOCK
225814 TA01b
225814p
1