Datasheet

LTC2415/LTC2415-1
17
sn2415 24151fs
APPLICATIO S I FOR ATIO
WUU
U
Table 3a. LTC2415 State Duration
State Operating Mode Duration
CONVERT Internal Oscillator F
O
= LOW, (60Hz Rejection) 66.6ms, Output Data Rate ≤ 15 Readings/s
F
O
= HIGH, (50Hz Rejection) 80ms, Output Data Rate ≤ 12.4 Readings/s
External Oscillator F
O
= External Oscillator with Frequency 10278/f
EOSC
s, Output Data Rate ≤ f
EOSC
/10278 Readings/s
f
EOSC
kHz (f
EOSC
/2560 Rejection)
SLEEP As Long As CS = HIGH Until CS = LOW and SCK
DATA OUTPUT Internal Serial Clock F
O
= LOW/HIGH, (Internal Oscillator) As Long As CS = LOW But Not Longer Than 1.67ms (32 SCK cycles)
F
O
= External Oscillator with As Long As CS = LOW But Not Longer Than 256/f
EOSC
ms (32 SCK cycles)
Frequency f
EOSC
kHz
External Serial Clock with Frequency f
SCK
kHz As Long As CS = LOW But Not Longer Than 32/f
SCK
ms (32 SCK cycles)
INPUT FREQUENCY DEVIATION FROM NOTCH FREQUENCY (%)
–12–8–404812
REJECTION (dB)
2415 F07a
–60
–70
–80
–90
–100
–110
–120
–130
–140
Table 3b. LTC2415-1 State Duration
State Operating Mode Duration
CONVERT Internal Oscillator F
O
= LOW 72.8ms, Output Data Rate ≤ 14 Readings/s
Simultaneous 50Hz/60Hz Rejection
External Oscillator F
O
= External Oscillator with Frequency 10278/f
EOSC
s, Output Data Rate ≤ f
EOSC
/10278 Readings/s
f
EOSC
kHz (f
EOSC
/2560 Rejection)
SLEEP As Long As CS = HIGH Until CS = LOW and SCK
DATA OUTPUT Internal Serial Clock F
O
= LOW (Internal Oscillator) As Long As CS = LOW But Not Longer Than 1.83ms (32 SCK cycles)
F
O
= External Oscillator with As Long As CS = LOW But Not Longer Than 256/f
EOSC
ms (32 SCK cycles)
Frequency f
EOSC
kHz
External Serial Clock with Frequency f
SCK
kHz As Long As CS = LOW But Not Longer Than 32/f
SCK
ms (32 SCK cycles)
Figure 7c. LTC2415/LTC2415-1
Normal Mode Rejection When Using
an External Oscillator of Frequency
f
EOSC
with Running Averages
Figure 7b. LTC2415-1 Normal Mode
Rejection When Using an Internal
Oscillator with Running Averages
48 50 52 54 56 58 60 62
DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz)
NORMAL MODE REECTION RATIO (dB)
2415 F07b
–80
–90
–100
–100
–120
–130
–140
DIFFERENTIAL INPUT SIGNAL FREQUENCY
DEVIATION FROM NOTCH FREQUENCY f
EOSC
/2560(%)
–12–8–404812
NORMAL MODE REJECTION (dB)
2415 F07c
–80
–85
–90
–95
–100
–105
–110
–115
–120
–125
–130
–135
–140
Figure 7a. LTC2415/LTC2415-1 Normal Mode
Rejection When Using an External Oscillator
of Frequency f
EOSC
without Running Averages
state and the converter is in the Internal SCK mode, the
serial clock duty cycle may be affected but the serial data
stream will remain valid.
Table 3b summarizes the duration of each state and the
achievable output data rate as a function of F
O
.
Serial Interface Pins
The LTC2415/LTC2415-1 transmit the conversion results
and receive the start of conversion command through a
synchronous 3-wire interface. During the conversion and
sleep states, this interface can be used to assess the
converter status and during the data output state it is used
to read the conversion result.