LTC2447IUHF#PBF Linear Technology, LTC2447IUHF#PBF Datasheet - Page 19

• Manufacturer Part Number: LTC2447IUHF#PBF
• Description: IC ADC 24BIT 8CH HI SPEED 38QFN
• Manufacturer: Linear Technology

Specifications of LTC2447IUHF#PBF

• Number Of Bits: 24
• Sampling Rate (per Second): 8k
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 40mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 38-WFQFN, Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIO S I FOR ATIO
If CS remains LOW longer than t
edge of SCK will occur and the conversion result is serially
shifted out of the SDO pin. The data output cycle begins on
this first rising edge of SCK and concludes after the 32nd
rising edge. Data is shifted out the SDO pin on each falling
edge of SCK. The internally generated serial clock is output
to the SCK pin. This signal may be used to shift the
conversion result into external circuitry. EOC can be
latched on the first rising edge of SCK and the last bit of the
conversion result on the 32nd rising edge of SCK. After the
32nd rising edge, SDO goes HIGH (EOC = 1), SCK stays
HIGH and a new conversion starts.
Typically, CS remains LOW during the data output state.
However, the data output state may be aborted by pulling
CS HIGH anytime between the first and 32nd rising edge
CONVERSION
BUSY
SDO
SCK
SDI
CS
SLEEP
U
DATA OUTPUT
DON'T CARE
U
<t
1
EOC(TEST)
5
Figure 8. Internal Serial Clock, Reduced Data Output Length
EOCtest
W
CONVERSION
USER SELECTABLE
Hi-Z
REFERENCES
, the first rising
0.1V TO V
ANALOG
INPUTS
BIT 31
EOC
1µF
4.5V TO 5.5V
1
CC
U
BIT 30
“0”
2
28
29
30
11
10
24
23
12
22
8
9
7
V
REFG
REFG
REF01
REF01
REF67
REF67
CH0
CH1
CH2
CH7
COM
CC
. .
.
BIT 29
SIG
. . .
LTC2446
3
DON'T CARE
+
–
DATA OUTPUT
+
–
+
–
BUSY
BIT 28 BIT 27 BIT 26 BIT 25
SDO
GND
SCK
MSB
SDI
of SCK, see Figure 8. On the rising edge of CS, the device
aborts the data output state and immediately initiates a
new conversion. This is useful for systems not requiring
all 32 bits of output data, aborting an invalid conversion
cycle, or synchronizing the start of a conversion. Thirteen
serial input data bits are required in order to properly
program the speed/resolution and input channel. If the
data output sequence is aborted prior to the 13th rising
edge of SCK, the new input data is ignored, and the
previously selected speed/resolution and channel are used
for the next conversion cycle. If a new channel is being
programmed, the rising edge of CS must come after the
14th falling edge of SCK in order to store the data input
sequence.
4
CS
F
O
37
2
1,4,5,6,31,32,33
34
38
35
36
5
4-WIRE
SPI INTERFACE
6
= EXTERNAL OSCILLATOR
= INTERNAL OSCILLATOR
Hi-Z
LTC2446/LTC2447
CONVERSION
TEST EOC
DON'T CARE
SLEEP
24467 F08
<t
EOC(TEST)
19
24467fa