LTC2379-18 Datasheet, PDF (1/24 Pages) Linear Technology – 18-Bit, 1.6Msps, Low Power SAR ADC with 101dB SNR

Electrical Specifications Subject to Change
LTC2379-18
18-Bit, 1.6Msps, Low Power
SAR ADC with 101dB SNR
FEATURES
n _{1.6Msps Throughput Rate}
n _{±2LSB INL (Max)}
n _{Guaranteed 18-Bit No Missing Codes}
n _{Low Power: 18mW at 1.6Msps, 18μW at 1.6ksps}
n _{101dB SNR (typ) at fIN = 2kHz}
n _{Digital Gain Compression (DGC)}
n _{Guaranteed Operation to 125°C}
n _{2.5V Supply}
n _{Fully Differential Input Range ±VREF}
n _{VREF Input Range from 2.5V to 5.1V}
n _{No Pipeline Delay, No Cycle Latency}
n _{1.8V to 5V I/O Voltages}
n _{SPI-Compatible Serial I/O with Daisy-Chain Mode}
n _{Internal Conversion Clock}
n _{16-pin MSOP and 4mm × 3mm DFN Packages}
APPLICATIONS
n _{Medical Imaging}
n _{High Speed Data Acquisition}
n _{Portable or Compact Instrumentation}
n _{Industrial Process Control}
n _{Low Power Battery-Operated Instrumentation}
n _ATE
DESCRIPTION
The LTC^®2379-18 is a low noise, low power, high speed
18-bit successive approximation register (SAR) ADC.
Operating from a 2.5V supply, the LTC2379-18 has a ±
V_REF fully differential input range with V_REF ranging from
2.5V to 5.1V. The LTC2379-18 consumes only 18mW
and achieves ±2LSB INL maximum, no missing codes at
18-bits with 101dB SNR.
The LTC2379-18 has a high speed SPI-compatible se-
rial interface that supports 1.8V, 2.5V, 3.3V and 5V logic
while also featuring a daisychain mode. The fast 1.6Msps
throughput with no cycle latency makes the LTC2379-18
ideally suited for a wide variety of high speed applications.
An internal oscillator sets the conversion time, easing exter-
nal timing considerations. The LTC2379-18 automatically
powers down between conversions, leading to reduced
power dissipation that scales with the sampling rate.
The LTC2379-18 offers a digital gain compression (DGC)
feature that allows a full-scale input to be achieved with
inputs that swing between 10% and 90% of the ±V_REF
analog input range. This allows the input buffer ampli-
fier to be operated from a single positive supply without
headroom issues, resulting in a lower power system.
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
2.5V 1.8V TO 5V
10μF
V_REF
+
20Ω
3300pF
V_DD OV_DD CHAIN
IN⁺
RDL/SDI
0V
SDO
V_REF
0V
3300pF
LTC2379-18
SCK
–
20Ω
IN^–
3300pF
REF
BUSY
CNV
GND ^REF/DGC
SAMPLE CLOCK
V_REF
2.5V TO 5.1V
237918 TA01
47μF
(X5R, 0805 SIZE)
32k Point FFT f_S = 1.6Msps, f_IN = 2kHz
0
SNR = 101.2dB
–20
THD = –120dB
SINAD = 101.1dB
–40
SFDR = 121dB
–60
–80
–100
–120
–140
–160
–180
0
100 200 300 400 500 600 700 800
FREQUENCY (kHz)
237918 TA02
237918p
1