NTE2050 & NTE2051 Integrated Circuit 31/2–Digit Single Chip A/D Converter Description: The NTE2050 and NTE2051 are high performance, low power 3–1/2 digit A/D converters containing all the necessary active devices on a single CMOS IC. Included are seven segment decoders, display drivers, reference and a clock. The NTE2051 is designed to interface with a liquid crystal display (LCD) and includes a backplane drive; the NTE2050 will directly drive an instrument–size light emitting diode (LED) display. The NTE2050 and NTE2051 bring together an unprecedented combination of high accuracy, versatility, and true economy. High accuracy like auto–zero to less than 10µV, zero drift of less than 1µV/°C, input bias current of 10pA max., and roll–over error of less than one count. The versatility of true differential input and reference is useful in all systems, but gives the designer an uncommon advantage when measuring load cells, strain gauges and other bridge–type transducers. And, finally, the true economy of single power supply operation (NTE2051), enabling a high performance panel meter to be built with the addition of only 7 passive components and a display. Features: D Guaranteed Zero Reading for 0 Volts Input on all Scales D True Polarity at Zero for Precise Null Detection D Input Current: 1pA Typ D True Differential Input and Reference D Direct Display Drive – No External Components Required: NTE2050 (LED) NTE2051 (LCD) D Low Noise – Less than 15µVP–P D On–Chip Clock and Reference D Low Power Dissipation – Typically Less than 10mW D No Additional Active Circuits Required Absolute Maximum Ratings: Supply Voltage, NTE2051, V+ to V– . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V NTE2050, V+ to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +6V NTE2050, V– to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –9V Analog Input Voltage (Either Input, Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V+ to V– Reference Input Voltage (Either Input) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V+ to V– Clock Input, NTE2051 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TEST to V+ NTE2050 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND to V+ Power Dissipation (Note 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800mW Operating Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +70°C Storage Temperature Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65° to +160°C Lead Temperature (During Soldering, 60sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300°C Note 1. Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or another conditions above those indicated in the operational section of the specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 2. Input voltages may exceed the supply voltages provided the input current is limited to ±100µA. Note 3. Dissipation rating assumes device is mounted with all leads soldered to printed circuit board. Electrical Characteristics: (TA = +25°C, fclock = 48kHz unless otherwise specified) Parameter Test Conditions Min Typ –000.0 ±000.0 999 999/1000 1000 Digital Reading Rollover Error (Difference in –VIN = +VIN ] 200mV Reading for Equal Positive and Negative Reading near Full Scale) –1 ±.2 +1 Counts Linearity (Maximum Deviation Full Scale = 200mV from Best Straight Line Fit) or Full Scale = 2V –1 ±.2 +1 Counts Zero Input Reading VIN = 0V Full Scale = 200mV Ratiometric Reading VIN = VREF VREF = 100mV Max Unit +000.0 Digital Reading Common Mode Rejection Ratio VCM = ±1V, VIN = 0V Full Scale = 200mV – 50 – µV/V Noise (Peak–Peak Value not Exceeded 95% of Time) VIN = 0V Full Scale = 200mV – 15 – µV Leakage Current | Input VIN = 0 – 1 10 pA Zero Reading Drift VIN = 0, 0° < TA < +70°C – 0.2 1.0 µV/°C Scale Factor Temperature Coefficient VIN = 199.0mV 0° < TA < +70°C (Ext. Ref. 0ppm/°C) – 1 5 ppm/°C V+ Supply Current (Does Not Include LED Current for NTE2050) VIN = 0 – 0.8 1.8 mA – 0.6 1.8 mA V– Supply Current (NTE2050 Only) Electrical Characteristics (Cont’d): (TA = +25°C, fclock = 48kHz unless otherwise specified) Parameter Min Typ Max Unit Analog Common Voltage Common 25kΩ Between Common (With Respect to Positive Supply) & Positive Supply 2.4 2.8 3.2 V Temperature Coefficient of Analog 25kΩ Between Common Common (With Respect to & Positive Supply Positive Supply) – 80 – ppm/°C Peak–Peak Segment Drive Voltage, V+ to V– = 9V, Note 4 Peak–Peak Backplane Drive Voltage (NTE2051 Only) 4 5 6 V Segment Sinking Current (NTE2050 Only) (Except Pin19) (Pin19 Only) Test Conditions mA V+ = 5V Segment Voltage = 3V 5 10 8 16 – – Note 4. Back plane drive is in phase with segment drive for “off” segment, 180° outp of phase for “on” segment. Frequency is 20 times conversion rate. Average DC component is less than 50mV. Pin Connection Diagram Units V(+) 1 40 OSC 1 Units D1 2 39 OSC 2 Units C1 3 38 OSC 3 Units B1 4 37 Test Units A1 5 36 Ref High Units F1 6 35 Ref Low Units G1 7 34 C (+) Ref Units E1 8 33 C (–) Tens D2 9 32 Common Tens C2 10 31 In High Tens B2 11 30 In Low Tens A2 12 29 A/Z Tens F2 13 28 Buff Tens E2 14 27 Int 100’s D3 15 26 V (–) 100’s B3 16 25 G2 Tens 100’s F3 17 24 C3 100’s 100’s E3 18 23 A3 100’s AB4 19 22 G3 100’s Polarity (–) 20 21 BP/GND* Note: Pin21 is GND on the NTE2050 40 21 1 20 .550 (13.9) Max 2.055 (52.2) .155 (3.9) .100 (2.54) .019 (0.5) .137 (3.5) .650 (16.5)