Datasheet LT1236 (Analog Devices) - 10

LT1236
U TYPICAL APPLICATIONS Strain Gauge Conditioner for 350
Ω
Bridge Negative Shunt Reference Driven by Current Source
R1 357Ω 1/2W LT1236-10 28mA OUT LT1236-10 28.5mA GND 15V IN OUT 5V GND 350Ω STRAIN R3 –10V (ILOAD ≤ 1mA) GAUGE BRIDGE** 2M 2.5mA R2 + 20k 3 2 – LM334 6 6 V LM301A† R4 LT1012C OUT – X100 2 20k 3 1 + R5 100pF 8 27Ω 2M R6* 2M –5V –11V TO – 40V LT1236 TA13 357Ω 1/2W –15V *THIS RESISTOR PROVIDES POSITIVE FEEDBACK TO BRIDGE IS ULTRA-LINEAR WHEN ALL LEGS ARE ** THE BRIDGE TO ELIMINATE LOADING EFFECT OF ACTIVE, TWO IN COMPRESSION AND TWO IN TENSION, THE AMPLIFIER. EFFECTIVE ZIN OF AMPLIFIER OR WHEN ONE SIDE IS ACTIVE WITH ONE COMPRESSED STAGE IS ≥ 1MΩ. IF R2 TO R5 ARE CHANGED, AND ONE TENSIONED LEG SET R6 = R3 OFFSET AND DRIFT OF LM301A ARE VIRTUALLY † ELIMINATED BY DIFFERENTIAL CONNECTION OF LT1012C LT1236 TA08
Precision DAC Reference with System TC Trim 2-Pole Lowpass Filtered Reference
1µF V LT1236-10 MYLAR IN 15V IN OUT – GND 8.87k LT1236 LT1001 VREF 1% V IN OUT IN + R1 GND R2 D1 50k 36k 36k TOTAL NOISE 1N457 ROOM TEMP 0.5µF 10k TRIM f = 10Hz MYLAR ≤2µVRMS 1% 10.36k 50k 1Hz ≤ f ≤ 10kHz 1.24k 1% TC TRIM* 1% 10k D2 200k 1% 1N457 1% –VREF LT1236 TA12 50k 1mA 8.45k TRIMS 1mA REFERENCE CURRENT * TC BY ±40ppm/°C. THIS TRIM DAC SCHEME HAS VERY LITTLE EFFECT ON ROOM TEMPERATURE CURRENT TO MINIMIZE ITERATIVE TRIMMING LT1236 TA16 10