Datasheet CA3140, CA3140A (Intersil) - 9

CA3140, CA3140A
the CA3140 is used as a unity gain voltage follower. This input offset voltage) due to the application of large resistance prevents the possibility of extremely large input differential input voltages that are sustained over long signal transients from forcing a signal through the input periods at elevated temperatures. protection network and directly driving the internal constant Both applied voltage and temperature accelerate these current source which could result in positive feedback via the changes. The process is reversible and offset voltage shifts of output terminal. A 3.9kΩ resistor is sufficient. the opposite polarity reverse the offset. Figure 9 shows the The typical input current is on the order of 10pA when the typical offset voltage change as a function of various stress inputs are centered at nominal device dissipation. As the voltages at the maximum rating of 125oC (for metal can); at output supplies load current, device dissipation will increase, lower temperatures (metal can and plastic), for example, at raising the chip temperature and resulting in increased input 85oC, this change in voltage is considerably less. In typical current. Figure 7 shows typical input terminal current versus linear applications, where the differential voltage is small and ambient temperature for the CA3140. symmetrical, these incremental changes are of about the same magnitude as those encountered in an operational It is well known that MOSFET devices can exhibit slight amplifier employing a bipolar transistor input stage. changes in characteristics (for example, small changes in
E -75 10K SUPPLY VOLTAGE: VS =
±
15V AS SUPPLY VOLTAGE: V ) S =
±
15V ) T -90 H A = 25oC RL = 2k
Ω
, P ES (dB 100 -105 E C
φ
OL L = 0pF R -120 OOP G AIN E 1K A) G 80 -135 (D p E G PEN L A -150 O LT 60 O 100 P V RL = 2k
Ω
, C T CURRENT ( OO 40 L = 100pF U P N L IN 10 PE 20 O 0 1 101 102 103 104 105 106 107 108 -60 -40 -20 0 20 40 60 80 100 120 140 FREQUENCY (Hz) TEMPERATURE (oC) FIGURE 6. OPEN LOOP VOLTAGE GAIN AND PHASE vs FIGURE 7. INPUT CURRENT vs TEMPERATURE FREQUENCY S S N RL =
∞
IO ION S 0 1.5 UR URS C +V -0.5 ICR AT TA = 125oC C -V +V 1.0 ICR AT TA = 125oC -) OUT AT TA = 125oC +VICR AT TA = 25oC E EX (V -V +V ICR AT TA = 25oC E EX G 7 (V+) -1.0 OUT AT TA = 25oC +V G ICR AT TA = -55oC 0.5 -V -V A OUT FOR +V ICR AT TA = -55oC OUT AT TA = -55oC LTA T L T O A = -55oC to 125oC -1.5 O 0 V T RMINAL 4 U E T P TERMINAL -2.0 -0.5 UT OM OM O FR -2.5 FR D OUTPUT V -1.0 AND T -3.0 -1.5 U INP INPUT AN 0 5 10 15 20 25 0 5 10 15 20 25 SUPPLY VOLTAGE (V+, V-) SUPPLY VOLTAGE (V+, V-) FIGURE 8. OUTPUT VOLTAGE SWING CAPABILITY AND COMMON MODE INPUT VOLTAGE RANGE vs SUPPLY VOLTAGE
9 FN957.10 July 11, 2005