link to page 21 link to page 21 Data SheetAD524+VS+VS+INPUT2 ++10V88RG11610kΩG = 102 +13410350Ω350ΩRG16G = 100112AD524951314-BIT10G = 1000611G = 10012AD524CADC9350Ω350Ω0V TO 2VRG23611F.S.7–INPUT1 –RG321–739kΩV–VREFS–VS–VAD589R3S+VS20kΩR5 052 20kΩ 0- 050 0 151416C1MSB+VS Figure 52. Typical Bridge Application 41/2DATAOUT1R4INPUTS LSB12 –810kΩAD71211AD752416 –ERROR BUDGET ANALYSISOUT2CS1223 +71/25 + 4 To illustrate how instrumentation amplifier specifications are WR13R6AD71235kΩ applied, review a typical case where an AD524 is required to –V 0 S 05 0- amplify the output of an unbalanced transducer. Figure 52 GND 050 0 shows a differential transducer, unbalanced by 100 Ω, supplying Figure 50. Software Controllable Offset a 0 mV to 20 mV signal to an AD524C. The output of the IA In many applications, complex software algorithms for auto- feeds a 14-bit ADC with a 0 V to 2 V input voltage range. The zero applications are not available. For those applications, operating temperature range is −25°C to +85°C. Therefore, the Figure 51 provides a hardware solution. largest change in temperature, ΔT, within the operating range is +VS from ambient to +85°C (85°C − 25°C = 60°C). +21516RG8 In many applications, differential linearity and resolution are of 11610 prime importance in cases where the absolute value of a variable is 1413VOUT12AD5249 less important than changes in value. In these applications, only 139101160.1µF LOWRGCH2 the irreducible errors (45 ppm = 0.004%) are significant. Further- 3LEAKAGE7–1 more, if a system has an intelligent processor monitoring the 1kΩ–V– analog-to-digital output, the addition of an autogain/auto-zero S1211AD711+ cycle removes all reducible errors and may eliminate the require- ment for initial calibration. This also reduces errors to 0.004%. VDD8VSS1AD7510KDGND2A1A2A3A4200µs 051 ZERO PULSE 00- 005 Figure 51. Auto-Zero Circuit Rev. G | Page 21 of 25 Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS CONNECTION DIAGRAMS ESD CAUTION TYPICAL PERFORMANCE CHARACTERISTICS TEST CIRCUITS THEORY OF OPERATION INPUT PROTECTION INPUT OFFSET AND OUTPUT OFFSET GAIN INPUT BIAS CURRENTS COMMON-MODE REJECTION GROUNDING SENSE TERMINAL REFERENCE TERMINAL PROGRAMMABLE GAIN AUTO-ZERO CIRCUITS ERROR BUDGET ANALYSIS REFERENCES OUTLINE DIMENSIONS ORDERING GUIDE