LTC2404_15 Datasheet, PDF (1/36 Pages) Linear Technology – 4-/8-Channel 24-Bit Power No Latency ADCs

FEATURES
s _{Pin Compatible 4-/8-Channel 24-Bit ADCs}
s _{Single Conversion Digital Filter Settling Time}
Simplifies Multiplexing
s _{4ppm INL, No Missing Codes}
s _{4ppm Full-Scale Error}
s _{0.5ppm Offset}
s _{0.3ppm Noise}
s _{Internal Oscillator—No External Components}
Required
s _{110dB Min, 50Hz/60Hz Notch Filter}
s _{Reference Input Voltage: 0.1V to VCC}
s _{Live Zero—Extended Input Range Accommodates}
12.5% Overrange and Underrange
s _{Single Supply 2.7V to 5.5V Operation}
s _{Low Supply Current (200µA) and Auto Shutdown}
U
APPLICATIO S
s _{Weight Scales}
s _{Direct Temperature Measurement}
s _{Gas Analyzers}
s _{Strain Gauge Transducers}
s _{Instrumentation}
s _{Data Acquisition}
s _{Industrial Process Control}
s _{6-Digit DVMs}
LTC2404/LTC2408
4-/8-Channel 24-Bit µPower
No Latency ∆Σ^TM ADCs
DESCRIPTIO
The LTC^®2404/LTC2408 are 4-/8-channel 2.7V to 5.5V
micropower 24-bit A/D converters with an integrated
oscillator, 4ppm INL and 0.3ppm RMS noise. They use
delta-sigma technology and provide single cycle digital
filter settling time (no latency delay) for multiplexed
applications. The first conversion after the channel is
changed is always valid. Through a single pin the LTC2404/
LTC2408 can be configured for better than 110dB rejec-
tion at 50Hz or 60Hz ±2%, or can be driven by an external
oscillator for a user defined rejection frequency in the
range 1Hz to 120Hz. The internal oscillator requires no
external frequency setting components.
The converters accept any external reference voltage from
0.1V to V_CC. With their extended input conversion range of
–12.5% V_REF to 112.5% V_REF the LTC2404/LTC2408
smoothly resolve the offset and overrange problems of
preceding sensors or signal conditioning circuits.
The LTC2404/LTC2408 communicate through a flexible
4-wire digital interface which is compatible with SPI and
MICROWIRE^TM protocols.
, LTC and LT are registered trademarks of Linear Technology Corporation.
No Latency ∆Σ is a trademark of Linear Technology Corporation.
MICROWIRE is a trademark of National Semiconductor Corporation.
TYPICAL APPLICATIO
0.1V TO V_CC
2.7V TO 5.5V
7
4
3
2, 8
ANALOG
INPUTS
–0.12V_REF TO
1.12V_REF
MUXOUT
9 CH0
10 CH1
11 CH2
12 CH3
4-/8-CHANNEL
13 CH4*
MUX
14 CH5*
15 CH6*
17 CH7*
ADCIN V_REF V_CC
24-BIT
∆Σ ADC
CSADC ²³
CSMUX ²⁰
SCK ¹⁹
CLK ²⁵
D_IN ²¹
SDO ²⁴
LTC2404/LTC2408
GND
26
F_O
1, 5, 6, 16, 18, 22, 27, 28
2404/08 TA01
*THESE PINS ARE NO CONNECTS ON THE LTC2404
1µF
SERIAL DATA LINK
MICROWIRE AND
SPI COMPATABLE
MPU
V_CC
= INTERNAL OSC/50Hz REJECTION
= EXTERNAL CLOCK SOURCE
= INTERNAL OSC/60Hz REJECTION
Total Unadjusted Error vs Output Code
10
8
V_DD = 5V
V_REF = 5V
6 ^{TA = 25°C}
F_O = LOW
4
2
0
–2
–4
–6
–8
–10
0
8,338,608
OUTPUT CODE (DECIMAL)
16,777,215
2404/08 TA02
1