![](http://datasheet.mmic.net.cn/Linear-Technology/LTC2308IUF-TRPBF_datasheet_105407/LTC2308IUF-TRPBF_8.png)
LTC2308
8
2308fb
BLOCK DIAGRAM
PIN FUNCTIONS
AVDD (Pins 12, 13): 5V Analog Supply. The range of AVDD is
4.75V to 5.25V. Bypass AVDD to GND with a 0.1μF ceramic
and a 10μF tantalum capacitor in parallel.
CONVST (Pin 14): Conversion Start. A rising edge at
CONVSTbeginsaconversion.Forbestperformance,ensure
that CONVST returns low within 40ns after the conversion
starts or after the conversion ends.
SDI (Pin 15): Serial Data Input. The SDI serial bit stream
congures the ADC and is latched on the rising edge of
the rst 6 SCK pulses.
SCK (Pin 16): Serial Data Clock. SCK synchronizes the
serial data transfer. The serial data input at SDI is latched
on the rising edge of SCK. The serial data output at SDO
transitions on the falling edge of SCK.
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
SDI
SDO
SCK
CONVST
2308 BD
SERIAL
PORT
ANALOG
INPUT
MUX
REFCOMP
INTERNAL
2.5V REF
AVDD
DVDD
OVDD
GND
12-BIT
500ksps
ADC
LTC2308
8k
GAIN = 1.6384x
+
–
VREF
SDO (Pin 17): Serial Data Out. SDO outputs the data from
the previous conversion. SDO is shifted out serially on the
falling edge of each SCK pulse.
OVDD (Pin 19): Output Driver Supply. Bypass OVDD to
GND with a 0.1μF ceramic capacitor close to the pin. The
range of OVDD is 2.7V to 5.25V.
DVDD (Pin 21): 5V Digital Supply. The range of DVDD is
4.75V to 5.25V. Bypass DVDD to GND with a 0.1 μF ceramic
and a 10μF tantalum capacitor in parallel.
CH0-CH2 (Pins 22, 23, 24): Channel 0 to Channel 2
Analog Inputs. CH0-CH2 can be congured as single-
ended or differential input channels. See the Analog Input
Multiplexer section.
GND (Pin 25): Exposed Pad Ground. Must be soldered
directly to ground plane.