AD2S99APZ

Programmable a Oscillator AD2S99 FEATURES FUNCTIONAL BLOCK DIAGRAM Programmable Sinusoidal Oscillator Synthesized Synchronous Reference Output Programmable Output Frequency Range: 2 kHz20 kHz PUSH/ EXC TO PULL Loss-of-Signal Indicator TRANSDUCER O/P STAGE EXC 20-Pin PLCC Package Low Cost FBIAS FREQUENCY SINE WAVE SEL1 APPLICATIONS SELECT GENERATOR SEL2 Excitation Source for: SYNREF Resolvers SYNCHRONOUS PHASE Synchros REFERENCE DETECT LOGIC LVDTs LOS AD2S99 RVDTs Pressure Transducers SIN COS Load Cells FROM AC Bridges TRANSDUCER GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD2S99 programmable sinusoidal oscillator provides sine Dynamic Phase Compensation wave excitation for resolvers and a wide variety of ac transduc- The AD2S99 dynamically compensates for any phase variation ers. The AD2S99 also provides a synchronous reference output in a transducer by phase locking its synchronous reference out- signal (3 V p-p square wave) that is phase locked to its SIN and put to the transducers secondary windings. COS inputs. In an application, the SIN and COS inputs are Programmable Excitation Frequency connected to the transducers secondary windings. The excitation frequency is easily programmed to 2 kHz, 5 kHz, The synchronous reference output compensates for temperature 10 kHz, or 20 kHz by using the frequency select pins. Interme- and cabling dependent phase shifts and eliminates the need for diate frequencies are available by adding an external resistor. external preset phase compensation circuits. The synchronous Signal Loss Detection reference output can be used as a zero crossing reference for The AD2S99 has the ability to detect if both the transducer sec- resolver-to-digital converters such as Analog Devices AD2S80A, ondary winding connections become disconnected from its SIN AD2S82A, AD2S83 and AD2S90. and COS inputs. The LOS output pin pulls high when a sig- The AD2S99 is packaged in a 20-pin PLCC and operates over nal loss is detected. 40C to +85C. Integration The AD2S99 integrates the transducer excitation, synchronous reference, and loss of signal detection functions into a small, cost effective package. REV. B Analog Devices, Inc., 1995 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A. which may result from its use. No license is granted by implication or Tel: 617/329-4700 Fax: 617/326-8703 otherwise under any patent or patent rights of Analog Devices.AD2S99SPECIFICATIONS (V = 64.75 V to 65.25 V 408C to +858C unless otherwise noted) S Parameter Min Typ Max Units Test Conditions FREQUENCY OUTPUT RANGE SEL1 SEL2 2 kHz 2000 Hz V V SS SS 5 kHz 5000 Hz V GND SS 10 kHz 10000 Hz GND V SS 20 kHz 20000 Hz GND GND ACCURACY Frequency 10 % AP Grade +25C 20 % AP Grade 40C to +85C 5 % BP Grade +25C 10 % BP Grade 40C to +85C Amplitude 3 10 % AP Grade +25C 20 % AP Grade 40C to +85C 3 5 % BP Grade +25C 10 % BP Grade 40C to +85C Power Supply Rejection Ratio 0.002 V p-p/V Output Variation as Function of Change in Power Supply Voltage ANALOG OUTPUTS Amplitude EXC, EXC 2 V rms EXC to GND, EXC to GND SYNREF 3 V p-p Square Wave SYNREF OFFSET 200 mV Current Drive Capability EXC, EXC V = 5 V 8 mA rms R = 500 EXC to EXC S LOAD C = 1000 pF LOAD Capacitive Drive 1000 pF Total Harmonic Distortion EXC, EXC 25 dB ANALOG INPUTS SIN, COS Amplitude 1.8 2.0 2.2 V rms Phase Lock Range 45 +45 Degrees Additional Phase Delay 10 Degrees AP Grade 10 Degrees BP Grade FREQUENCY SELECT INPUTS 1 SEL1, SEL2 V AGND V dc SS LOS OUTPUT Output Low Voltage 0.7 V dc I = 400 A OL Output High Voltage V V dc 50 k Pull Up to V (Open DD DD Drain Output) SIN, COS LOS Threshold 0.5 0.6 0.8 V rms POWER SUPPLIES V +4.75 +5.25 V dc DD V 4.75 5.25 V dc SS Quiescent Current I , I 8 15 mA No Load DD SS TEMPERATURE RANGE Operating 40 +85 C Storage 65 +150 C NOTES 1 Frequency select pins SEL1 and SEL2 must be connected to appropriate voltage levels before power is applied. Specifications subject to change without notice. 2 REV. B