ltc2439-1ign-trpbf Linear Technology Corporation, ltc2439-1ign-trpbf Datasheet - Page 7

• Manufacturer Part Number: ltc2439-1ign-trpbf
• Description: 8-/16-channel 16-bit No Latency ??tm Adc
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
FU CTIO AL BLOCK DIAGRA
TEST CIRCUITS
CONVERTER OPERATION
Converter Operation Cycle
The LTC2439-1 is a multichannel, low power, delta-sigma
analog-to-digital converter with an easy-to-use 4-wire se-
rial interface (see Figure 1). Its operation is made up of three
states. The converter operating cycle begins with the con-
version, followed by the low power sleep state and ends with
the data input/output (see Figure 2). The 4-wire interface
consists of serial data input (SDI), serial data output (SDO),
serial clock (SCK) and chip select (CS).
Initially, the LTC2439-1 performs a conversion. Once the
conversion is complete, the device enters the sleep state.
The part remains in the sleep state as long as CS is HIGH.
While in the sleep state, power consumption is reduced by
nearly two orders of magnitude. The conversion result is
held indefinitely in a static shift register while the converter
is in the sleep state.
U
GND
U
V
CC
SDO
U
CH15
REF
REF
COM
CH0
CH1
Hi-Z TO V
V
V
1.69k
OL
OH
+
–
U
TO V
TO Hi-Z
•
•
•
OH
OH
MUX
241418 TC01
W
C
LOAD
= 20pF
IN
IN
+
–
∆Σ MODULATOR
U
–
DIFFERENTIAL
3RD ORDER
W
+
Figure 1
ADDRESS
AUTOCALIBRATION
DECIMATING FIR
AND CONTROL
Figure 2. LTC2439-1 State Transition Diagram
FALSE
SDO
OSCILLATOR
IN
INTERFACE
INTERNAL
ADDRESS INPUT
+
SERIAL
DATA OUTPUT
= CH0, IN
Hi-Z TO V
V
V
POWER UP
CONVERT
CS = LOW
OH
OL
SCK
SLEEP
24391 F01
AND
V
TO Hi-Z
TO V
CC
TRUE
1.69k
241418 TA03
–
OL
C
OL
= CH1
LOAD
24391 F02
= 20pF
LTC2439-1
F
(INT/EXT)
SDI
SCK
SDO
CS
O
24391fa
7