Linear Technology LTC2377-18 with LTC6655-5/LT6350: 18-Bit, 500ksps, SAR ADC with 102dB SNR. Req DC718 or DC590 DC1783A- DC1783A-G 数据表

LTC2377-18

1

237718f

18-Bit, 500ksps, Low Power

SAR ADC with 102dB SNR

The LTC

®

2377-18 is a low noise, low power, high speed 

18-bit successive approximation register (SAR) ADC. 
Operating from a 2.5V supply, the LTC2377-18 has a 
±V

REF

 fully differential input range with V

REF

 ranging from 

2.5V to 5.1V. The LTC2377-18 consumes only 6.8mW and 
achieves ±1.75LSB INL maximum, no missing codes at 
18 bits with 102dB SNR.

The LTC2377-18 has a high speed SPI-compatible se-
rial interface that supports 1.8V, 2.5V, 3.3V and 5V logic 
while also featuring a daisy-chain mode. The fast 500ksps 
throughput with no cycle latency makes the LTC2377-18 
ideally suited for a wide variety of high speed applications. 
An internal oscillator sets the conversion time, easing exter-
nal timing considerations. The LTC2377-18 automatically 
powers down between conversions, leading to reduced 
power dissipation that scales with the sampling rate.

The LTC2377-18 features a unique digital gain compres-
sion (DGC) function, which eliminates the driver amplifier’s 
negative supply while preserving the full resolution of the 
ADC. When enabled, the ADC performs a digital scaling 
function that maps zero-scale code from 0V to 0.1 • V

REF

and full-scale code from V

REF

 to 0.9 • V

REF

. For a typical 

reference voltage of 5V, the full-scale input range is now 
0.5V to 4.5V, which provides adequate headroom for 
powering the driving amplifier from a single 5.5V supply.

n

  500ksps Throughput Rate

n

  ±1.75LSB INL (Max)

n

  Guaranteed 18-Bit No Missing Codes

n

  Low Power: 6.8mW at 500ksps, 6.8μW at 500sps

n

  102dB SNR (Typ) at f

n

  –124dB THD (Typ) at f

n

  Digital Gain Compression (DGC)

n

  Guaranteed Operation to 125°C

n

 2.5V Supply

n

  Fully Differential Input Range ±V

REF

n

  V

REF

 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-Lead MSOP and 4mm 

× 3mm DFN Packages

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 Medical Imaging

n

  High Speed Data Acquisition

n

  Portable or Compact Instrumentation

n

  Industrial Process Control

n

  Low Power Battery-Operated Instrumentation

n

 ATE

FREQUENCY (kHz)

0

50

100

150

250

200

–180

AMPLITUDE (dBFS)

–60

–40

–20

–80

–100

–120

–140

–160

0

237718 TA02

SNR = 102.3dB
THD = –124dB
SINAD = 102.2dB
SFDR = 125dB

SNR = 102.3dB
THD = –124dB
SINAD = 102.2dB
SFDR = 125dB

20Ω

V

REF

0V

V

REF

0V

20Ω

3300pF

6800pF

6800pF

–

+

V

REF

SAMPLE CLOCK

237718 TA01

10μF

0.1μF

2.5V

REF

1.8V TO 5V

2.5V TO 5.1V

47μF
(X5R, 0805 SIZE)

REF

GND

CHAIN

RDL/SDI

SDO

SCK

BUSY

CNV

REF/DGC

LTC2377-18

V

DD

OV

DD

IN

+

IN

–

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property of their respective owners.