Linear Technology LTC2440CGN, High Speed Delta Sigma ADC, (req DC590) DC570A DC570A 数据表
产品代码
DC570A
LTC2440
1
2440fd
2440 TA01
2440 TA01
REFERENCE VOLTAGE
0.1V TO V
CC
ANALOG INPUT
–0.5V
REF
TO 0.5V
REF
3-WIRE
SPI INTERFACE
SPI INTERFACE
6.9Hz, 200nV NOISE,
50/60Hz REJECTION
50/60Hz REJECTION
880Hz OUTPUT RATE,
2μV NOISE
2μV NOISE
10-SPEED SERIAL
PROGRAMMABLE
PROGRAMMABLE
V
CC
4.5V TO 5.5V
4
V
CC
BUSY
f
O
REF
+
SCK
IN
+
IN
–
SDO
GND
CS
EXT
SDI
LTC2440
REF
–
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
24-Bit High Speed
Differential Δ∑ ADC with
Selectable Speed/Resolution
The LTC
®
2440 is a high speed 24-bit No Latency Δ∑
TM
ADC with 5ppm INL and 5μV offset. It uses proprietary
delta-sigma architecture enabling variable speed and reso-
lution with no latency. Ten speed/resolution combinations
(6.9Hz/200nV
delta-sigma architecture enabling variable speed and reso-
lution with no latency. Ten speed/resolution combinations
(6.9Hz/200nV
RMS
to 3.5kHz/25μV
RMS
) are programmed
through a simple serial interface. Alternatively, by tying a
single pin HIGH or LOW, a fast (880Hz/2μV
single pin HIGH or LOW, a fast (880Hz/2μV
RMS
) or ultralow
noise (6.9Hz, 200nV
RMS
, 50/60Hz rejection) speed/reso-
lution combination can be easily selected. The accuracy
(offset, full-scale, linearity, drift) and power dissipation
are independent of the speed selected. Since there is no
latency, a speed/resolution change may be made between
conversions with no degradation in performance.
(offset, full-scale, linearity, drift) and power dissipation
are independent of the speed selected. Since there is no
latency, a speed/resolution change may be made between
conversions with no degradation in performance.
Following each conversion cycle, the LTC2440 automati-
cally enters a low power sleep state. Power dissipation
may be reduced by increasing the duration of this sleep
state. For example, running at the 3.5kHz conversion speed
but reading data at a 100Hz rate draws 240μA average
current (1.1mW) while reading data at a 7Hz output rate
draws only 25μA (125μW).The LTC2440 communicates
through a fl exible 3-wire or 4-wire digital interface that is
compatible with the LTC2410 and is available in a narrow
16-lead SSOP package.
cally enters a low power sleep state. Power dissipation
may be reduced by increasing the duration of this sleep
state. For example, running at the 3.5kHz conversion speed
but reading data at a 100Hz rate draws 240μA average
current (1.1mW) while reading data at a 7Hz output rate
draws only 25μA (125μW).The LTC2440 communicates
through a fl exible 3-wire or 4-wire digital interface that is
compatible with the LTC2410 and is available in a narrow
16-lead SSOP package.
Simple 24-Bit 2-Speed Acquisition System
n
Up to 3.5kHz Output Rate
n
Selectable Speed/Resolution
n
2μV
RMS
Noise at 880Hz Output Rate
n
200nV
RMS
Noise at 6.9Hz Output Rate with
Simultaneous 50/60Hz Rejection
n
0.0005% INL, No Missing Codes
n
Autosleep Enables 20μA Operation at 6.9Hz
n
<5μV Offset (4.5V < V
CC
< 5.5V, –40°C to 85°C)
n
Differential Input and Differential Reference with
GND to V
CC
Common Mode Range
n
No Latency, Each Conversion is Accurate Even After
an Input Step
n
Internal Oscillator—No External Components
n
Pin Compatible with the LTC2410
n
24-Bit ADC in Narrow 16-Lead SSOP Package
n
High Speed Multiplexing
n
Weight Scales
n
Auto Ranging 6-Digit DVMs
n
Direct Temperature Measurement
n
High Speed Data Acquisition
Speed vs RMS Noise
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
No Latency Δ∑ is a trademark of Linear Technology Corporation. All other trademarks are
the property of their respective owners.
the property of their respective owners.
CONVERSION RATE (Hz)
1
0.1
RMS NOISE (μV)
1
10
100
10
100
2440 TA02
1000
10000
V
CC
= 5V
V
REF
= 5V
V
IN
+
= V
IN
–
= 0V
2μV AT 880Hz
200nV AT 6.9Hz
(50/60Hz REJECTION)