Datasheet

LTC2484
10
2484fd
TYPICAL PERFORMANCE CHARACTERISTICS
Offset Error vs V
CC
(2x Speed Mode)
Offset Error vs V
REF
(2x Speed Mode)
PSRR vs Frequency at V
CC
(2x Speed Mode)
PSRR vs Frequency at V
CC
(2x Speed Mode)
PSRR vs Frequency at V
CC
(2x Speed Mode)
V
CC
(V)
2 2.5
0
OFFSET ERROR (μV)
100
250
3
4
4.5
2484 G36
50
200
150
3.5
5
5.5
V
REF
= 2.5V
V
IN
= 0V
V
IN(CM)
= GND
f
O
= GND
T
A
= 25°C
V
REF
(V)
0
OFFSET ERROR (μV)
190
200
210
3
5
2484 G37
180
170
160
12 4
220
230
240
V
CC
= 5V
V
IN
= 0V
V
IN(CM)
= GND
f
O
= GND
T
A
= 25°C
FREQUENCY AT V
CC
(Hz)
1
0
–20
–40
–60
–80
–100
–120
–140
1k 100k
2484 G38
10 100
10k 1M
REJECTION (dB)
V
CC
= 4.1V DC
REF
+
= 2.5V
REF
–
= GND
IN
+
= GND
IN
–
= GND
f
O
= GND
T
A
= 25°C
FREQUENCY AT V
CC
(Hz)
0
–140
REJECTION (dB)
–120
–80
–60
–40
0
20
100
140
2484 G39
–100
–20
80
180
220200
40
60
120 160
V
CC
= 4.1V DC ±1.4V
REF
+
= 2.5V
REF
–
= GND
IN
+
= GND
IN
–
= GND
f
O
= GND
T
A
= 25°C
FREQUENCY AT V
CC
(Hz)
30600
–60
–40
0
30750
2484 G40
–80
–100
30650 30700 30800
–120
–140
–20
REJECTION (dB)
V
CC
= 4.1V DC ±0.7V
REF
+
= 2.5V
REF
–
= GND
IN
+
= GND
IN
–
= GND
f
O
= GND
T
A
= 25°C
PIN FUNCTIONS
SDI (Pin 1): Serial Data Input. This pin is used to select
the line frequency rejection, input, temperature sensor
and 2x speed mode. Data is shifted into the SDI pin on
the rising edge of serial clock (SCK).
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.
V
REF
(Pin 3): Positive Reference Input. The voltage on
this pin can have any value between 0.1V and V
CC
. The
negative reference input is GND (Pin 8).
IN
+
(Pin 4), IN
–
(Pin 5): Differential Analog Inputs. The volt-
age 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
to