Datasheet MAX4165 (Analog Devices) - 9

High-Output-Drive, Precision, Low-Power, Single- Supply, Rail-to-Rail I/O Op Amps with Shutdown MAX4165–MAX4169 Applications Information
6.5V
Package Power Dissipation Warning: Due to the high output current drive, this op amp can exceed the absolute maximum power-dissi-
R
pation rating.
As a general rule, as long as the peak cur- rent is less than or equal to 80mA, the maximum package C power dissipation will not be exceeded for any of the VIN = 3Vp-p package types offered. There are some exceptions to this rule, however. The absolute maximum power-dissipation R MAX4165 MAX4166 rating of each package should always be verified using the following equations. The following equation gives an 60Ω approximation of the package power dissipation: P V I COS IC DISS ( ) ≅ RMS RMS θ where: VRMS = the RMS voltage from VCC to VOUT Figure 1. A Circuit Example where the MAX4165/MAX4166 is when sourcing current Being Used in Single-Supply Operation = the RMS voltage from VOUT to VEE when sinking current 6.5V IRMS = the RMS current flowing out of or into the op amp and the load θ = the phase difference between the R voltage and the current. For resistive C loads, COS θ = 1. VIN = 3Vp-p CC For example, the circuit in Figure 1 has a package power dissipation of 157mW. R MAX4165 MAX4166 V V ≅ (V − V PEAK 60Ω RMS CC DC ) − 2 . 1 5V CC = 1 = . 6 5V − . 3 25V − = . 2 189VRMS 2π RL fL 2 I . 3 25V . 1 5V / 60Ω I ≅ I + PEAK Figure 2. A Circuit Example where Adding a Coupling RMS DC = + 2 60Ω 2 Capacitor Greatly Reduces the Power Dissipation of Its Package = . 71 84mARMS Therefore, PIC(DISS) = VRMS IRMS COS θ Therefore, PIC(DISS) = VRMS IRMS COS θ = 157mW = 38.6mW Adding a coupling capacitor improves the package power dissipation because there is no DC current to The absolute maximum power-dissipation rating of this the load, as shown in Figure 2. package would be exceeded if the configuration in Figure 1 were used with all four of the MAX4169ESD’s VPEAK amplifiers at a high ambient temperature of +75°C V ≅ (V − V RMS CC DC ) − (157mW x 4 amplifiers = 628mW + a derating of 2 8.33mW/°C x 5°C = 669mW). Note that 669mW just . 1 5V = . 6 5V − . 3 25V − = . 2 189V exceeds the absolute maximum power dissipation of RMS 2 667mW for the 14-pin SO package (see the Absolute Maximum Ratings section). I . 1 5V / 60Ω I ≅ I + PEAK RMS DC = 0A + 2 2 = . 17 mA 67 RMS
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