Datasheet

ADS8509
SLAS324C –OCTOBER 2004–REVISED APRIL 2010 www.ti.com
Table 2. Input Range Connections (See Figure 29 and Figure 30 for Complete
Information)
ANALOG CONNECT R1
IN
VIA CONNECT R2
IN
VIA CONNECT
IMPEDANCE
INPUT RANGE 200 Ω TO 100 Ω TO R3 TO
±10 V V
IN
AGND CAP 11.5 kΩ
±5 V AGND V
IN
CAP 6.7 kΩ
±3.33 V V
IN
V
IN
CAP 5.4 kΩ
0 V to 10 V AGND V
IN
AGND 6.7 kΩ
0 V to 5 V AGND AGND V
IN
5.0 kΩ
0 V to 4 V V
IN
AGND V
IN
5.4 kΩ
Table 3. Control Truth Table
SPECIFIC FUNCTION CS R/C BUSY EXT/INT DATACLK PWRD SB/BTC OPERATION
Initiate conversion and 1 > 0 0 1 0 Output 0 x Initiates conversion n. Data from conversion n - 1
output data using internal clocked out on DATA synchronized to 16 clock
0 1 > 0 1 0 Output 0 x
clock pulses output on DATACLK.
1 > 0 0 1 1 Input 0 x Initiates conversion n.
0 1 > 0 1 1 Input 0 x Initiates conversion n.
Initiate conversion and
1 > 0 1 1 1 Input x x Outputs data with or without SYNC pulse. See
output data using external
section READING DATA.
clock
1 > 0 1 0 1 Input 0 x Outputs data with or without SYNC pulse. See
section READING DATA.
0 0 > 1 0 1 Input 0 x
No actions 0 0 0 > 1 x x 0 x This is an acceptable condition.
x x x x x 0 x Analog circuitry powered. Conversion can
proceed..
Power down
x x x x x 1 x Analog circuitry disabled. Data from previous
conversion maintained in output registers.
x x x x x x 0 Serial data is output in binary 2's complement
format.
Select output format
x x x x x x 1 Serial data is output in straight binary format.
Table 4. Output Codes and Ideal Input Voltages
DIGITAL OUTPUT
BINARY 2'S STRAIGHT
DESCRIPTI
ANALOG INPUT COMPLEMENT BINARY
ON
(SB/BTC LOW) (SB/BTC HIGH)
BINARY CODE HEX CODE BINARY CODE HEX CODE
Full-scale
±10 ±5 ±3.33 V 0 V to 10 V 0 V to 5 V 0 V to 4 V
range
Least
significant 305 mV 153 mV 102 mV 153 mV 76 mV 61 mV
bit (LSB)
Full scale 4.999847
9.999695 V 3.333231 V 9.999847 V 4.999924 V 3.999939 V 0111 1111 1111 1111 7FFF 1111 1111 1111 1111 FFFF
(FS - 1LSB) V
Midscale 0 V 0 V 0 V 5 V 2.5 V 2 V 0000 0000 0000 0000 0000 1000 0000 0000 0000 8000
One LSB
below –305 mV 153 mV ±102 µV 4.999847 V 2.499924 V 1.999939 V 1111 1111 1111 1111 FFFF 0111 1111 1111 1111 7FFF
midscale
–Full scale –10 V –5 V –3.333333 V 0 V 0 V 0 V 1000 0000 0000 0000 8000 0000 0000 0000 0000 0000
20 Copyright © 2004–2010, Texas Instruments Incorporated
Product Folder Link(s): ADS8509