Linear Technology DC1337A - LTC2309: 12-bit, 8-channel SAR ADC with I²C I/F, req DC590 DC1337A DC1337A Fiche De Données

Codes de produits

DC1337A

LTC2309

2309fd

pIn FunCtIOns

REFCOMP (Pin 1): Reference Buffer Output. Bypass

to GND with 10µF and 0.1µF ceramic capacitors in

parallel. Nominal output voltage is 4.096V. The internal

reference buffer driving this pin is disabled by ground-

ing V

REF

, allowing REFCOMP to be overdriven by an

external source.
GND (Pins 2, 8 , 9): Ground. All GND pins must be

connected to a solid ground plane.
V

(Pins 3, 10): 5V Supply. The range of V

is 4.75V

to 5.25V. Bypass V

to GND with a 10µF ceramic ca-

pacitor in parallel with two 0.1µF ceramic capacitors,

one located as close as possible to each pin.
AD0 (Pin 4): Chip Address Control Pin. This pin is con-

figured as a three-state (LOW, HIGH, floating) address

control bit for the device I

C address. See Table 2 for

address selection.
AD1 (Pin 5): Chip Address Control Pin. This pin is

configured as a three-state (LOW, HIGH, floating)

address control bit for the device I

C address. See

Table 2 for address selection.
SCL (Pin 6): Serial Clock Pin of the I

C Interface. The

LTC2309 can only act as a slave and the SCL pin only

accepts an external serial clock. Data is shifted into

the SDA pin on the rising edges of the SCL clock and

output through the SDA pin on the falling edges of the

SCL clock.

SDA (Pin 7): Bidirectional Serial Data Line of the I

Interface. In transmitter mode (read), the conversion

result is output at the SDA pin, while in receiver mode

(write), the D

word is input at the SDA pin to con-

figure the ADC. The pin is high impedance during the

data input mode and is an open-drain output (requires

an appropriate pull-up device to V

) during the data

output mode.
CH0-CH7 (Pins 11-18): Channel 0 to Channel 7 Analog

Inputs. CH0-CH7 can be configured as single-ended

or differential input channels. See the Analog Input

Multiplexer section.
COM (Pin 19): Common Input. This is the reference

point for all single-ended inputs. It must be free of

noise and should be connected to ground for unipolar

conversions and midway between GND and REFCOMP

for bipolar conversions.
V

REF

(Pin 20): 2.5V Reference Output. Bypass to GND

with a minimum 2.2µF ceramic capacitor. The internal

reference may be overdriven by an external 2.5V refer-

ence at this pin.

(TSSOP)