Datasheet LT1002 (Analog Devices) - 8

LT1002
W U TYPICAL PERFORMANCE CHARACTERISTICS Output Short Circuit Current Output Swing vs. Load Resistance vs Time
16 50 40 –55°C NEGATIVE SWING 12 30 25°C 20 125°C POSITIVE SWING 10 VS = ±15V 8 SOURCING –10 125°C –20 25°C OUTPUT SWING (VOLTS) SINKING 4 –30 –55°C V SHORT CIRCUIT CURRENT (mA) S = ±15V –40 TA = 25°C 0 –50 100 300 1000 3k 10k 0 1 2 3 4 LOAD RESISTANCE (Ω) TIME FROM OUTPUT SHORT (MINUTES) 1002 G28 1002 G29
U U W U APPLICATIONS INFORMATION
The LT1002 dual amplifier may be inserted directly into nately, the guaranteed offset voltage match of the LT1002 OP-10, OP207, OP227 sockets with or without removal of is very low, in most applications offset adjustment will be external nulling potentiometers. unnecessary.
Standard Adjustment Offset Voltage Adjustment
The input offset voltage of the LT1002, and its drift with temperature, are permanently 10k trimmed at wafer testing to a low level. However, if further or 15V 20k adjustment of V 1 OS is necessary, nulling with a 10k or 20k (8) potentiometer will not degrade drift with temperature. 3 – 2 (9) Trimming to a value other than zero creates a drift of (V (10) 1/2 14 (7) OS/ INPUT LT1002 OUTPUT 13 (6) 300)µV/°C, e.g. if V 4 + OS is adjusted to 300µV, the change in (11) 12 (5) drift will be 1µV/°C. The adjustment range with a 10k or 20k pot is approximately ±2.5mV. If less adjustment –15V 1002 TA03 range is needed, the sensitivity and resolution of the
Improved Sensitivity Adjustment
nulling can be improved by using a smaller pot in conjunc- tion with fixed resistors. The example has an approximate null range of ±100µV. 7.5k 1k 15V In matching applications, both amplifiers can be trimmed 7.5k 1 (8) to zero, or the offset of one amplifier can be trimmed to 3 – 2 (9) match the offset of the other. Offset adjustment, however, 14 (10) 1/2 (7) slightly degrades the gain, common-mode and power- INPUT LT1002 OUTPUT 4 + 13 (6) supply rejection match between the two op amps. Fortu- (11) 12 (5) –15V 1002 TA04 1002fb 8