LTC2481_1 Datasheet, PDF (10/40 Pages) Linear Technology – 16-Bit ΔΣ ADC with Easy Drive Input Current Cancellation and I2C Interface

LTC2481
TYPICAL PERFORMANCE CHARACTERISTICS
Offset Error vs V_CC
(2x Speed Mode)
250
V_REF = 2.5V
V_IN = 0V
200
V_IN(CM) = GND
T_A = 25°C
150
100
50
0
2.7 3
3.5 4 4.5
V_CC (V)
5 5.5
2481 G36
Offset Error vs V_REF
(2x Speed Mode)
240
V_CC = 5V
230 ^VIN ^{= 0V}
V_IN(CM) = GND
220 ^{TA = 25°C}
210
200
190
180
170
160
0
1
2
3
V_REF (V)
4
5
2481 G37
PSRR vs Frequency at V_CC
(2x Speed Mode)
0
–20
VR_CECF+==42.1.5VVDC
REF^– = GND
IN⁺ = GND
–40 _IN^– _{= GND}
T_A = 25°C
–60
–80
–100
–120
–140
1
10 100 1k 10k 100k 1M
FREQUENCY AT V_CC (Hz)
2481 G38
PSRR vs Frequency at V_CC
(2x Speed Mode)
0
–20
VR_CECF+==42.1.5VVDC ±1.4V
REF^– = GND
IN⁺ = GND
–40 IN^– = GND
T_A = 25°C
–60
–80
–100
–120
PSRR vs Frequency at V_CC
(2x Speed Mode)
0
VR_CECF+==42.1.5VVDC ±0.7V
–20 _REF– _{= GND}
IN⁺ = GND
–40 IN^– = GND
T_A = 25°C
–60
–80
–100
–120
–140
0 20 40 60 80 100 120 140 160 180 200 220
FREQUENCY AT V_CC (Hz)
2481 G39
–140
30600
30650 30700 30750
FREQUENCY AT V_CC (Hz)
30800
2481 G40
PIN FUNCTIONS
REF⁺ (Pin 1), REF^– (Pin 3): Differential Reference Input.
The voltage on these pins can have any value between
GND and V_CC as long as the reference positive input,
REF⁺, is more positive than the reference negative input,
REF^–, by at least 0.1V.
V_CC (Pin 2): Positive Supply Voltage. Bypass to GND
(Pin 8) with a 1μF tantalum capacitor in parallel with 0.1μF
ceramic capacitor as close to the part as possible.
IN⁺ (Pin 4), IN^– (Pin 5): Differential Analog Input. The
voltage on these pins can have any value between GND
– 0.3V and V_CC + 0.3V. Within these limits the converter
bipolar input range (V_IN = IN⁺ – IN^–) extends from –0.5
• V_REF /GAIN to 0.5 • V_REF/GAIN. Outside this input
range the converter produces unique overrange and
underrange output codes.
2481fc
10