a
Bridge Transducer ADC
AD7730/AD7730L
T he modulator output is processed by a low pass programmable
digital filter, allowing adjustment of filter cutoff, output rate and
settling time.
KEY FEATURES
Resolution of 230,000 Counts (Peak-to-Peak)
Offset Drift: 5 nV/ ꢀC
Gain Drift: 2 ppm / ꢀC
T he part features two buffered differential programmable gain
analog inputs as well as a differential reference input. T he part
operates from a single +5 V supply. It accepts four unipolar
analog input ranges: 0 mV to +10 mV, +20 mV, +40 mV and
+80 mV and four bipolar ranges: 10 mV, 20 mV, 40 mV
and 80 mV. T he peak-to-peak resolution achievable directly
from the part is 1 in 230,000 counts. An on-chip 6-bit DAC
allows the removal of T ARE voltages. Clock signals for synchro-
nizing ac excitation of the bridge are also provided.
Line Frequency Rejection: >150 dB
Buffered Differential Inputs
Program m able Filter Cutoffs
Specified for Drift Over Tim e
Operates w ith Reference Voltages of 1 V to 5 V
ADDITIONAL FEATURES
Tw o-Channel Program m able Gain Front End
On-Chip DAC for Offset/ TARE Rem oval
FASTStep™ Mode
AC or DC Excitation
Single Supply Operation
T he serial interface on the part can be configured for three-wire
operation and is compatible with microcontrollers and digital
signal processors. T he AD7730 contains self-calibration and
system calibration options, and features an offset drift of less
than 5 nV/°C and a gain drift of less than 2 ppm/°C.
APPLICATIONS
Weigh Scales
Pressure Measurem ent
T he AD7730 is available in a 24-pin plastic DIP, a 24-lead
SOIC and 24-lead T SSOP package. T he AD7730L is available
in a 24-lead SOIC and 24-lead T SSOP package.
GENERAL D ESCRIP TIO N
T he AD7730 is a complete analog front end for weigh-scale and
pressure measurement applications. T he device accepts low-
level signals directly from a transducer and outputs a serial
digital word. T he input signal is applied to a proprietary pro-
grammable gain front end based around an analog modulator.
NO TE
T he description of the functions and operation given in this data
sheet apply to both the AD7730 and AD7730L. Specifications
and performance parameters differ for the parts. Specifications
for the AD7730L are outlined in Appendix A.
FUNCTIO NAL BLO CK D IAGRAM
REF IN(–)
DV
REF IN(+)
AV
DD
DD
AD7730
REFERENCE DETECT
VBIAS
AV
100nA
DD
STANDBY
SYNC
AIN1(+)
AIN1(–)
SIGMA-DELTA A/D CONVERTER
BUFFER
SIGMA-
DELTA
PROGRAMMABLE
DIGITAL
+
MODULATOR
FILTER
MUX
PGA
+/–
100nA
AGND
AIN2(+)/D1
AIN2(–)/D0
MCLK IN
CLOCK
GENERATION
6-BIT
DAC
SERIAL INTERFACE
AND CONTROL LOGIC
MCLK OUT
REGISTER BANK
SCLK
CS
CALIBRATION
MICROCONTROLLER
DIN
ACX
AC
DOUT
EXCITATION
CLOCK
ACX
AGND
DGND
POL
RDY
RESET
FASTStep is a trademark of Analog Devices, Inc.
B
REV.
Inform ation furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assum ed by Analog Devices for its
use, nor for any infringem ents of patents or other rights of third parties
which m ay result from its use. No license is granted by im plication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norw ood, MA 02062-9106, U.S.A.
Tel: 781/ 329-4700 World Wide Web Site: http:/ / w w w .analog.com
781/461-3113
2012
Fax:
© Analog Devices, Inc.,
5秒后页面跳转
英伟达新AI芯片Rubin或提前半年亮相
苹果iPhone 17将全系采用三星/LG显示LTPO OLED面板
三星深化印度制造布局，供应链本地化进程加速
芯擎科技“星辰一号”自动驾驶芯片点亮成功，2025年量产在即
微信公众号
抖音公众号
浙公网安备 33010502006866号 浙ICP备10014259号-119
营业执照ICP证
数据手册
替代型号
如果您发现信息不准确，
