LTC2487
pin FuncTions
+
–
+
–
selectedinputs(IN andIN )provideabipolarinputrange
REF , REF (Pin 13, Pin 14): Differential Reference Input.
+
–
V = (IN – IN ) from –0.5 • V /Gain to 0.5 • V /Gain.
The voltage on these pins can have any value between
IN
REF
REF
Outside this input range, the converter produces unique
over-range and under-range output codes.
GND and V as long as the reference positive input,
CC
+
REF , remains more positive than the negative reference
–
input, REF , by at least 0.1V. The differential voltage (V
REF
CH0 to CH3 (Pin 8-Pin 11): Analog Inputs. May be pro-
grammed for single-ended or differential mode.
+
–
= REF – REF ) sets the full-scale range (–0.5 • V /Gain
REF
to 0.5 • V /Gain) for all input channels.
REF
V
(Pin12):PositiveSupplyVoltage. BypasstoGNDwith
CC
Exposed Pad (Pin 15): Ground. This pin is ground and
mustbesolderedtothePCBgroundplane.Forprototyping
purposes, this pin may remain floating.
a 10µF tantalum capacitor in parallel with a 0.1µF ceramic
capacitor as close to the part as possible.
FuncTional block DiagraM
INTERNAL
OSCILLATOR
V
CC
TEMP
SENSOR
GND
F
AUTOCALIBRATION
AND CONTROL
O
(INT/EXT)
+
–
REF
REF
1.7k
+
–
CH0
CH1
CH2
CH3
COM
+
–
IN
IN
DIFFERENTIAL
3RD ORDER
∆Σ MODULATOR
SDA
SCL
CA0
CA1
MUX
2
I C
INTERFACE
DECIMATING FIR
ADDRESS
2487 BD
2487fa
ꢀꢀ
Linear [ Linear ]
