FEATURES
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/MICROWIRETM 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
LTC2308
Low Noise, 500ksps,
8-Channel, 12-Bit ADC
DESCRIPTION
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, 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
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
AVDD
ANALOG
+
INPUT
MUX
–
DVDD
LTC2308
OVDD
2.7V TO 5.25 V
0.1µF
12-BIT
500ksps
ADC
SERIAL
PORT
INTERNAL
2.5V REF
SDI
SDO
SCK
CONVST
SERIAL DATA LINK TO
ASIC, PLD, MPU, DSP
OR SHIFT REGISTER
VREF
2.2µF
GND
0.1µF
REFCOMP
10µF
2308 TA01
For more information www.linear.com/LTC2308
8192 Point FFT, fIN = 1kHz
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
–130
–140
0
fSMPL = 500kHz
SINAD = 73.6dB
THD = –89.5dB
50 100 150 200 250
FREQUENCY (kHz)
2308 TA01b
2308fc
1
