Datasheet

Data Sheet AD7610
Rev. A | Page 17 of 32
TRANSFER FUNCTIONS
Using the OB/
2C
digital input or via the configuration register,
the AD7610 offers two output codings: straight binary and twos
complement. See Figure 26 and Table 7 for the ideal transfer char-
acteristic and digital output codes for the different analog input
ranges, V
IN
. Note that when using the configuration register, the
OB/
2C
input is a don’t care and should be tied to either high or low.
000...000
000...001
000...010
111...101
111...110
111...111
ADC CODE (Straight Binary)
ANALOG INPUT
+FSR – 1.5 LSB
+FSR – 1 LSB–FSR + 1 LSB
–FSR
–FSR + 0.5 LSB
06395-026
Figure 26. ADC Ideal Transfer Function
Table 7. Output Codes and Ideal Input Voltages
V
REF
= 5 V Digital Output Code
Description V
IN
= 5 V V
IN
= 10 V V
IN
= ±5 V V
IN
= ±10 V Straight Binary Twos Complement
FSR −1 LSB 4.999924 V 9.999847 V +4.999847 V +9.999695 V 0xFFFF
1
0x7FFF
1
FSR − 2 LSB
4.999847 V
9.999695 V
+4.999695 V
+9.999390 V
0xFFFE
0x7FFE
Midscale + 1 LSB 2.500076 V 5.000153 V +152.6 µV +305.2 µV 0x8001 0x0001
Midscale 2.5 V 5.000000 V 0 V 0 V 0x8000 0x0000
Midscale − 1 LSB 2.499924 V 4.999847 V −152.6 µV −305.2 µV 0x7FFF 0xFFFF
−FSR + 1 LSB 76.3 µV 152.6 µV −4.999847 V −9.999695 V 0x0001 0x8001
−FSR 0 V 0 V −5 V −10 V 0x0000
2
0x8000
2
1
This is also the code for overrange analog input (V
IN+
− V
IN−
above V
REF
− V
REFGND
).
2
This is also the code for overrange analog input (V
IN+
− V
IN−
below V
REF
− V
REFGND
).