LTC2257-12_15 Datasheet, PDF (1/34 Pages) Linear Technology – 12-Bit, 65/40/25Msps Ultralow Power 1.8V ADCs

Features
n _{71.1dB SNR}
n _{88dB SFDR}
n _{Low Power: 79mW/47mW/34mW}
n _{Single 1.8V Supply}
n _{CMOS, DDR CMOS or DDR LVDS Outputs}
n _{Selectable Input Ranges: 1VP-P to 2VP-P}
n _{800MHz Full-Power Bandwidth S/H}
n _{Optional Data Output Randomizer}
n _{Optional Clock Duty Cycle Stabilizer}
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}
Applications
n _{Communications}
n _{Cellular Base Stations}
n _{Software Defined Radios}
n _{Portable Medical Imaging}
n _{Multi-Channel Data Acquisition}
n _{Nondestructive Testing}
LTC2258-12
LTC2257-12/LTC2256-12
12-Bit, 65/40/25Msps
Ultralow Power 1.8V ADCs
Description
The LTC^®2258-12/LTC2257-12/LTC2256-12 are sam-
pling 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 71.1dB SNR and 88dB spurious
free dynamic range (SFDR). Ultralow jitter of 0.17ps_RMS
allows undersampling of IF frequencies with excellent
noise performance.
DC specs include ±0.3LSB INL (typical), ±0.1LSB DNL
(typical) and no missing codes over temperature. The
transition noise is a low 0.3LSB_RMS.
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.
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.
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.
Typical Application
1.8V
V_DD
ANALOG
INPUT
+
INPUT
S/H
–
12-BIT
PIPELINED
ADC CORE
CORRECTION
LOGIC
CLOCK/DUTY
CYCLE
CONTROL
65MHz
GND
CLOCK
OUTPUT
DRIVERS
1.2V
TO 1.8V
OV_DD
D11
• CMOS
• OR
• LVDS
D0
OGND
225812 TA01a
For more information www.linear.com/LTC2258-12
LTC2258-12 2-Tone FFT,
f_IN = 68MHz and 69MHz
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
0
10
20
30
FREQUENCY (MHz)
225812 TA01b
225812fd
1