LTC2308_15 Datasheet, PDF (1/20 Pages) Linear Technology – Low Noise, 500ksps, 8-Channel, 12-Bit ADC

LTC2308
Low Noise, 500ksps,
8-Channel, 12-Bit ADC
FEATURES
DESCRIPTION
n _{12-Bit Resolution}
n _{500ksps Sampling Rate}
n _{Low Noise: SINAD = 73.3dB}
n _{Guaranteed No Missing Codes}
n _{Single 5V Supply}
n _{Auto-Shutdown Scales Supply Current with Sample}
Rate
n _{Low Power: 17.5mW at 500ksps}
0.9mW Nap Mode
35μW Sleep Mode
n _{Internal Reference}
n _{Internal 8-Channel Multiplexer}
n _{Internal Conversion Clock}
n _{SPI/MICROWIRE}^TM _{Compatible Serial Interface}
n _{Unipolar or Bipolar Input Ranges (Software Selectable)}
n _{Separate Output Supply OVDD (2.7V to 5.25V)}
n _{24-Pin 4mm × 4mm QFN Package}
APPLICATIONS
n _{High Speed Data Acquisition}
n _{Industrial Process Control}
n _{Motor Control}
n _{Accelerometer Measurements}
n _{Battery Operated Instruments}
n _{Isolated and/or Remote Data Acquisition}
The LTC^®2308 is a low noise, 500ksps, 8-channel, 12-bit
ADC with an SPI/MICROWIRE compatible serial interface.
This ADC includes an internal reference and a fully differ-
ential sample-and-hold circuit to reduce common mode
noise. The internal conversion clock allows the external
serial output data clock (SCK) to operate at any frequency
up to 40MHz.
The LTC2308 operates from a single 5V supply and draws
just 3.5mA at a sample rate of 500ksps. The auto-shutdown
feature reduces the supply current to 200μA at a sample
rate of 1ksps.
The LTC2308 is packaged in a small 24-pin 4mm × 4mm
QFN. The internal 2.5V reference and 8-channel multiplexer
further reduce PCB board space requirements.
The low power consumption and small size make the
LTC2308 ideal for battery operated and portable appli-
cations, while the 4-wire SPI compatible serial interface
makes this ADC a good match for isolated or remote data
acquisition systems.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
5V
0.1μF
10μF
10μF
0.1μF
CH0
CH1
CH2
CH3
CH0-CH7
ANALOG INPUTS CH4
0V TO 4.096V UNIPOLAR
±2.048V BIPOLAR
CH5
CH6
CH7
COM
AV_DD
ANALOG
+
INPUT
MUX
–
DV_DD
LTC2308
OV_DD
2.7V TO 5.25 V
0.1μF
12-BIT
500ksps
ADC
SERIAL
PORT
INTERNAL
2.5V REF
SDI
SDO
SERIAL DATA LINK TO
ASIC, PLD, MPU, DSP
SCK
OR SHIFT REGISTER
CONVST
V_REF
2.2μF
GND
0.1μF
REFCOMP
10μF
2308 TA01
8192 Point FFT, f_IN = 1kHz
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
–140
0
f_SMPL = 500kHz
SINAD = 73.6dB
THD = –89.5dB
50 100 150 200 250
FREQUENCY (kHz)
2308 TA01b
2308fb
1