Datasheet LTC2471, LTC2473 (Analog Devices) - 6

LTC2471/LTC2473
Typical perForMance characTerisTics (TA = 25°C, unless otherwise noted) Power Supply Rejection vs Frequency Applied to VCC Conversion Time vs Temperature VREF vs VCC
0 4.4 1.250345 T T A = 25°C A = 25°C 1.250340 –20 4.3 VCC = 2.7V 1.250335 –40 4.2 1.250330 (V) –60 4.1 VCC = 4.1V 1.250325 V REF REJECTION (dB) 1.250320 –80 4.0 CONVERSION TIME (ms) 1.250315 V –100 3.9 CC = 5.5V 1.250310 –120 3.8 1.250305 1 10 100 1k 10k 100k 1M 10M –50 –25 0 25 50 75 100 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 FREQUENCY AT VCC (Hz) TEMPERATURE (°C) VCC (V) 24713 G010 24713 G11 24713 G12
pin FuncTions REFOUT (Pin 1):
Reference Output Pin. Nominally 1.25V,
SDA (Pin 6):
Bidirectional Serial Data Line of the I2C Inter- this voltage sets the full-scale input range of the ADC. For face. The conversion result is output through the SDA pin. noise and reference stability connect to a 0.1µF capacitor The pin is high impedance unless the LTC2471/LTC2473 tied to GND. This capacitor value must be less than or is in the data output mode. While the LTC2471/LTC2473 is equal to the capacitor tied to the reference compensa- in the data output mode, SDA is an open drain pull down tion pin (COMP). REFOUT must not be overdriven by an (which requires an external 1.7k pull-up resistor to VCC). external reference.
REF– (Pin 8):
Negative Reference Input to the ADC. The
COMP (Pin 2):
Internal Reference Compensation Pin. For voltage on this pin sets the zero input to the ADC. This low noise and reference stability, tie a 0.1μF capacitor to pin should tie directly to ground or the ground sense of GND. the input sensor.
A0 (Pin 3):
Chip Address Control Pin. The A0 pin can be
IN+ (LTC2473), IN (LTC2471) (Pin 9):
Positive input volt- tied to GND or VCC. If A0 is tied to GND, the LTC2471/ age for the LTC2473 differential device. ADC input for the LTC2473 I2C address is 0010100. If A0 is tied to VCC, the LTC2471 single-ended device. LTC2471/LTC2473 I2C address is 1010100.
IN– (LTC2473), GND (LTC2471) (Pin 10):
Negative input
GND (Pins 4, 7, 11, (Exposed Pad Pin 13 – DFN Package
voltage for the LTC2473 differential device. GND for the
Only)):
Ground. Connect exposed pad directly to the ground LTC2471 single-ended device. plane through a low impedance connection.
VCC (Pin 12):
Positive Supply Voltage. Bypass to GND with
SCL (Pin 5):
Serial Clock Input of the I2C Interface. The a 10μF capacitor in parallel with a low-series-inductance LTC2471/LTC2473 can only act as an I2C slave and the SCL 0.1μF capacitor located as close to pin 12 as possible. pin only accepts an external serial clock. Data is shifted into the SDA pin on the rising edges of SCL and output through the SDA pin on the falling edges of SCL. 24713fb 6 For more information www.linear.com/LTC2471 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Analog Inputs Power Requirements I2C Inputs and Outputs I2C Timing Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Revision History Typical Application Related Parts