AD7776/AD7777/AD7778

–11–

REV. 0

RTN is tied to REFOUT then the analog input range becomes

0 V to 2 V. The fixed 2 V analog input voltage span of the ADC

can range from 1 V to 3 V (RTN = 0 V) to 0 V to 2 V (RTN =

2 V), i.e., with proper biasing, an input signal range from 0.3 V

to 2.3 V can be covered. Both the relative accuracy and differen-

tial nonlinearity performance remains essentially unchanged in

this mode while the SNR and THD performance are typically

2 dB to 3 dB worse than standard.

Changing the Analog Input Voltage Range

By biasing the RTN pin above AGND it is possible to change

± V

be described as

where 0 V

≤ V

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

R-24

24-Lead Wide-Body SOIC

PIN 1

0.299 (7.6)

0.291 (7.4)

13

12

1

24

0.419 (10.65)

0.394 (10.00)

0.013 (0.32)

0.009 (0.23)

0.005 (1.27)

0.015 (0.40)

0.614 (15.6)

0.598 (15.2)

0.104 (2.65)

0.093 (2.35)

0.012 (0.3)

0.004 (0.1)

0.019 (0.49)

0.014 (0.35)

0.050 (1.27)

BSC

R-28

28-Lead Wide-Body SOIC

PIN 1

0.299 (7.60)

0.291 (7.39)

15

14

1

28

0.414 (10.52)

0.398 (10.10)

0.03 (0.76)

0.02 (0.51)

0.013 (0.32)

0.009 (0.23)

0.042 (1.067)

0.018 (0.457)

0.708 (18.02)

0.696 (17.67)

0.096 (2.44)

0.089 (2.26)

0.01 (0.254)

0.006 (0.15)

0.019 (0.49)

0.014 (0.35)

0.050 (1.27)

BSC

1. LEAD NO. 1 IDENTIFIED BY A DOT.

2. SOIC LEADS WILL BE EITHER TIN PLATED OF SOLDER DIPPED

IN ACCORDANCE WITH MIL-M-38510 REQUIREMENTS.