LTC2381-16
16-Bit, 250ksps, Low Power
SAR ADC with Serial Interface
FEATURES
DESCRIPTION
The LTC®2381-16 is a low noise, low power, high speed
16-bit successive approximation register (SAR) ADC.
Operating from a 2.5V supply, the LTC2381-16 has a
2.5V fully differential input range. The LTC2381-16
consumes only 3.25mW and achieves 2LSꢀ ꢁIL max,
no missing codes at 16-bits and 92dꢀ SIR.
n
250ksps Throughput Rate
n
2ꢀSꢁ INꢀ ꢂ(aꢃx
n
Guaranteed 16-ꢁit No (issing Codes
n
ꢀow Power: 3.25mW at 250ksps, 13μW at 1ksps
n
92dꢁ SNR ꢂtypx at f = 20kHz
IN
n
Eꢃtended Acquisition Time of 3.25μs Allows Use of
ꢀower Power Drivers
The LTC2381-16 has a high speed SPꢁ-compatible serial
interface that supports 1.8V, 2.5V, 3.3V and 5V logic
while also featuring a daisychain mode. The fast 250ksps
throughput with no cycle latency makes the LTC2381-16
ideally suited for a wide variety of high speed applica-
tions. An internal oscillator sets the conversion time,
easing external timing considerations. The LTC2381-16
automatically powers down between conversions, lead-
ing to reduced power dissipation that scales with the
sampling rate.
n
Guaranteed Operation to 125°C
n
2.5V Supply
n
Fully Differential ꢁnput Range 2.5V
n
External 2.5V Reference ꢁnput
n
Io Pipeline Delay, Io Cycle Latency
n
1.8V to 5V ꢁ/O Voltages
n
SPꢁ-Compatible Serial ꢁ/O with Daisy-Chain Mode
n
ꢁnternal Conversion Clock
n
16-pin MSOP and 4mm × 3mm DFI Packages
APPLICATIONS
The LTC2381-16 features a proprietary sampling
architecture that enables the ADC to begin acquiring the
next sample during the current conversion. The resulting
extended acquisition time of 3.25μs allows the use of
extremely low power ADC drivers.
n
Medical ꢁmaging
n
High Speed Data Acquisition
n
Portable or Compact ꢁnstrumentation
ꢁndustrial Process Control
Low Power ꢀattery-Operated ꢁnstrumentation
n
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.
n
n
ATE
TYPICAL APPLICATION
32k Point FFT fS = 250ksps, fIN = 20kHz
0
2.5V 1.8V TO 5V
SIR = 91.8dꢀ
–20
–40
THD = –106dꢀ
SꢁIAD = 91.6dꢀ
SFDR = 107dꢀ
10μF
0.1μF
AIALOG ꢁIPUT
0V TO 2.5V
–60
V
OV
DD
50Ω
50Ω
100Ω
3300pF
100Ω
CHAꢁI
RDL/SDꢁ
SDO
SCK
ꢀUSY
CIV
DD
+
–
ꢁI
–80
LT6350
LTC2381-16
–100
–120
–140
–160
–180
ꢁI
SAMPLE CLOCK
REF
GID
238116 TA01
2.5V
SꢁIGLE-EIDED-
TO-DꢁFFEREITꢁAL
DRꢁVER
47μF
(X5R, 0805 SꢁZE)
0
25
50
75
100
125
FREQUEICY (kHz)
238116 TA02a
238116f
1