SPT774

SPT774 FAST, COMPLETE 12-BIT µP COMPATIBLE A/D CONVERTER WITH SAMPLE/HOLD FEATURES • Improved Higher Performance Version of the HADC574Z • Complete 12-Bit A/D Converter with Sample/Hold, Reference and Clock • Low Power Dissipation (120 mW Max) • 12-Bit Linearity (Over Temp) • 8 µs Max Conversion Time • Single +5 V Supply • Full Bipolar and Unipolar Input Range APPLICATIONS • • • • • Data Acquisition Systems 8 or 12-Bit µP Input Functions Process Control Systems Test and Scientific Instruments Personal Computer Interface GENERAL DESCRIPTION The SPT774 is a complete, 12-bit successive approximation A/D converter manufactured in CMOS technology. The device is an improved version of the HADC574Z. Included on chip are an internal reference, clock, and a sample-and-hold. The S/H is an additional feature not available on similar devices. The SPT774 features 8 µs (max) conversion time of 10 or 20 V input signals. Also, a three-state output buffer is added for direct interface to an 8-, 12- or 16-bit µP bus. The SPT774 has standard bipolar and unipolar input ranges of 10 V and 20 V that are controlled by a bipolar offset pin and laser trimmed for specified linearity, gain and offset accuracy. The power supply is +5 V. The device also has an optional mode control voltage which may be used depending on the application. With a maximum dissipation of 120 mW at the specified voltages, power consumption is about five times lower than that of currently available devices. The SPT774 is available in 28-lead ceramic sidebrazed DIP, PDIP and SOIC packages in the commercial temperature range. BLOCK DIAGRAM Nibble A Output Nibble B Three-State Buffers And Control Nibble C STS 12-Bit SAR + Comp Clock 12-Bit Capacitance DAC Offset/Gain Trim Control Logic Ref 20 V In 10 V In BIP Off 12/8 CS Ao R/C CE Ref Out AGND ABSOLUTE MAXIMUM RATINGS (Beyond which damage may occur) 1 25 °C Supply Voltages Mode Control Voltage (VEE to DGND) .................... 0 to +7 V Logic Supply Voltage (VDD to DGND) ................... 0 to +7 V Analog to Digital Ground (AGND to DGND) ................. ±1 V Input Voltages Control Input Voltages (to DGND) (CE, CS, Ao, 12/8, R/C) ......................... -0.5 to VDD +0.5 V Analog Input Voltage (to AGND) (REF IN, BIP OFF, 10 VIN) ...................................... ±16.5 V 20 V VIN Input Voltage (to AGND) .............................. ±24 V Note: Output Reference Output Voltage .............. Indefinite Short to GND Momentary Short to VDD Temperature Operating Temperature, Ambient .................... 0 to +70 °C Junction ......................... +165 °C Lead Temperature, (Soldering 10 Seconds) ........... +300 °C Storage Temperature .................................... -65 to +150 °C Operation at any Absolute Maximum Rating is not implied. See Operating Conditions for proper nominal applied conditions in typical applications. ELECTRICAL SPECIFICATIONS TA = TMIN to TMAX, VEE = 0 to +5 V, VDD = +5 V, fS = 117 kHz, fIN = 10 kHz, unless otherwise specified.. PARAMETER TEST CONDITIONS TEST LEVEL MIN SPT774C TYP MAX MIN SPT774B TYP MAX UNITS DC ELECTRICAL CHARACTERISTICS Resolution Linearity Error Differential Linearity Unipolar Offset; 10 V, 20 V Bipolar Offset; ±5 V, ±10 V Full Scale Calibration Error1 Full Scale Calibration Error1 Temperature Coefficients Unipolar Offset Bipolar Offset Full Scale Calibration Power Supply Rejection +4.75 V