Datasheet LT1126, LT1127 (Analog Devices) - 7

LT1126/LT1127
U U W U APPLICATIO S I FOR ATIO High Speed Operation
with RS and RF in the kilohm range, this pole can create excess phase shift and even oscillation. A small capacitor When the feedback around the op amp is resistive (RF), a (C pole will be created with R F) in parallel with RF eliminates this problem. With F, the source resistance and R capacitance (R S (CS + CIN) = RF CF, the effect of the feedback pole is S, CS), and the amplifier input capacitance completely removed. (CIN ≈ 2pF). In low closed loop gain configurations and CF RF – C OUTPUT IN RS CS + 1126-7 AI01
O U TYPICAL APPLICATI S Gain Error vs Frequency Gain 1000 Amplifier with 0.01% Accuracy, DC to 5Hz Closed Loop Gain = 1000
1.0 TYPICAL 340k 15k 20k PRECISION 1% 5% TRIM OP AMP 365Ω +15V 0.1 1% – LT1126 OUTPUT + GAIN ERROR (%) 0.01 RN60C FILM RESISTORS LT1126/LT1127 INPUT –15V THE HIGH GAIN AND WIDE BANDWIDTH OF THE LT1126/LT1127 IS USEFUL IN LOW FREQUENCY HIGH CLOSED CLOSED LOOP GAIN GAIN ERROR = LOOP GAIN AMPLIFIER APPLICATIONS. A TYPICAL PRECISION OP AMP MAY HAVE AN OPEN LOOP GAIN OF ONE OPEN LOOP GAIN MILLION WITH 500kHz BANDWIDTH. AS THE GAIN ERROR PLOT SHOWS, THIS DEVICE IS CAPABLE OF 0.1% 0.001 AMPLIFYING ACCURACY UP TO 0.3Hz ONLY. EVEN INSTRUMENTATION RANGE SIGNALS CAN VARY AT A FASTER 0.1 1 10 100 RATE. THE LT1126/LT1127 “GAIN PRECISION — BANDWIDTH PRODUCT” IS 330 TIMES HIGHER, AS SHOWN. 1126-7 TA02 FREQUENCY (Hz) 1126-7 TA03 11267fa 7