TC7126/A 3-1/2 Digit Analog-to-Digital Converters Features: General Description: Internal Reference with Low Temperature Drift: The TC7126A is a 3-1/2 digit CMOS Analog-to-Digital Converter (ADC) containing all the active components - TC7126: 80ppm/C, Typical necessary to construct a 0.05% resolution measure- - TC7126A: 35ppm/C, Typical ment system. Seven-segment decoders, digit and Zero Reading with Zero Input polarity drivers, voltage reference, and clock circuit are Low Noise: 15V P-P integrated on-chip. The TC7126A directly drives a High Resolution: 0.05% Liquid Crystal Display (LCD), and includes a backplane Low Input Leakage Current: 1pA Typ., 10pA Max. driver. Precision Null Detectors with True Polarity at Zero A low-cost, high resolution indicating meter requires only a display, four resistors, and four capacitors. The High-Impedance Differential Input TC7126As extremely low-power drain and 9V battery Convenient 9V Battery Operation with Low-Power operation make it ideal for portable applications. Dissipation: 500 W Typ., 900 W Max. The TC7126A reduces linearity error to less than 1 count. Rollover error (the difference in readings for Applications: equal magnitude, but opposite polarity input signals) is Thermometry below 1 count. High-impedance differential inputs 12 Bridge Readouts: Strain Gauges, Load Cells, offer 1pA leakage current and a 10 input imped- Null Detectors ance. The 15 V noise performance ensures a rock P-P Digital Meters and Panel Meters: solid reading, and the auto-zero cycle ensures a zero display reading with a 0V input. - Voltage/Current/Ohms/Power, pH The TC7126A features a precision, low drift internal Digital Scales, Process Monitors voltage reference and is functionally identical to the TC7126. A low drift external reference is not normally Device Selection Table required with the TC7126A. Package Temperature Package Code Range CPL 40-Pin PDIP 0 C to +70 C IPL 40-Pin PDIP (TC7126 Only) -25 C to +85 C CKW 44-Pin PQFP 0 C to +70 C CLW 44-Pin PLCC 0 C to +70 C 2002-2012 Microchip Technology Inc. DS21458D-page 1TC7126/A Package Type 44-Pin PLCC 44-Pin PQFP 6 543 2 1 44 43 42 41 40 44 43 42 41 40 39 38 37 36 35 34 NC 33 NC 1 V - F 7 39 REF 1 NC 2 32 G G C + 2 1 8 38 REF 31 C TEST 3 E 3 9 37 C - 1 REF ANALOG A OSC3 4 30 3 D 10 36 2 COMMON 29 G NC 5 3 C 35 V + TC7126CKW 11 IN 2 TC7126CLW TC7126ACKW 28 BP TC7126ACLW OSC2 6 34 NC 12 NC OSC1 7 27 POL B V - 2 13 33 IN AB 26 V+ 8 4 A 14 32 C 2 AZ D 25 E 9 1 3 F 15 31 2 V BUFF C 24 F 10 1 3 E 16 30 V 2 INT B B 11 23 1 3 D 17 29 V- 3 25 26 27 28 18 19 20 21 22 23 24 12 13 14 15 16 17 18 19 20 21 22 40-Pin PDIP (Normal) 44-Pin PDIP (Reverse) OSC1 V+ 1 40 OSC1 1 40 V+ Normal Pin Reverse Pin D OSC2 D 2 Configuration 39 OSC2 2 Configuration 39 1 1 C 3 38 OSC3 3 38 C OSC3 1 1 B 4 37 TEST 4 37 B TEST 1 1 A V + A 1 s 5 36 V + 5 36 1 REF 1 1 s REF F V - F 6 35 V - REF 6 35 1 1 REF G 34 C + G 7 C + REF 7 34 1 REF 1 TC7126CPL TC7126RCPL C - E 8 33 C - 8 33 E 1 REF 1 TC7126ACPL REF TC7126ARCPL ANALOG TC7126IPL ANALOG TC7126RIPL D 9 32 9 32 D 2 2 COMMON COMMON TC7126AIPL TC7126ARIPL C 10 31 V + V + 10 31 C IN 2 IN 2 V - B 11 30 V - 11 30 B 2 IN IN 2 10 s 10 s C A 12 29 C 29 A AZ 12 2 AZ 2 V F 13 28 13 28 F V BUFF 2 2 BUFF V E 14 27 14 27 E V INT 2 INT 2 D 15 26 V- V- 15 26 D 3 3 B B 16 25 G 16 25 3 G 2 3 2 100 s 100 s F 24 C 24 F 17 C 17 3 3 3 3 100 s 100 s A 18 23 A 18 23 E E 3 3 3 3 AB 19 22 G 19 22 AB 1000 s 1000 s G 3 4 3 4 20 21 BP 20 21 POL POL BP (Minus Sign) (Backplane) (Backplane) (Minus Sign) NC = No Internal Connection DS21458D-page 2 2002-2012 Microchip Technology Inc. A B 1 3 F B 1 3 C E 3 1 AB D 4 1 V+ POL NC NC BP OSC1 G OSC2 3 A OSC3 3 C TEST 3 V + G REF 2 A V + REF 1 F V - 1 REF G C + REF 1 C - E 1 REF ANALOG D 2 COMMON C V + 2 IN V - B IN 2 C A 2 AZ V F BUFF 2 E V INT 2 D V- 3