AMC2244 Datasheet, PDF (7/11 Pages) ADDtek Corp – DUAL/Triple/QUAD LOW-POWER 60MHz UNITY-GAIN STABLE OP AMPLIFIERS

AMC2244/AMC2344/AMC2444
APPLICATION INFORMATION
Product Description
The AMC2244/AMC2344/AMC2444 are low-power wideband monolithic operational amplifiers implemented with a
classical voltage-feedback topology. This allows them to be used in a variety of applications where current-feedback
amplifiers are not appropriate. For example, a capacitor to be placed in the feedback path, making it an excellent
choice for applications such as active filters, sample-and-holds, or integrators. Similarly, because of the ability to use
diodes in the feedback network, the AMC2244/AMC2344/AMC2444 are an excellent choice for applications such as
fast log amplifiers.
Power Dissipation
In order to prevent the junction temperature to exceed 150°C , it is important to calculate the maximum junction
temperature (T_Jmax) for all applications to determine if power-supply voltages, load conditions, or package type need
to be modified such that the AMC2244/AMC2344/AMC2444 remain in the safe operating area. These parameters are
related as follows:
T_{Jmax =} T_max + (θ_JA× PDmaxtotal)
Where PDmaxtotal is the sum of the maximum power dissipation of each amplifier in the package (PDmax).
PDmax for each amplifier can be calculated as follows :
PDmax= ( 2 × V_S × I_Smax + (V_S - V_outmax) × ( V_outmax /R_L))
where:
T_max =Maximum Ambient Temperature
θ_JA = Thermal Resistance of the Package
PDmax = Maximum Power Dissipation of 1 Amplifier
V_S = Supply Voltage
I_Smax = Maximum Supply Current of 1 Amplifier
V_outmax = Maximum Output Voltage Swing of the Application
R_L = Load Resistance
To serve as a guide for the user, we can calculate maximum allowable supply voltages for the example of the video
cable-driver below since we know that T_Jmax = 150°C, T_max = 75°C, I_Smax = 8.2 mA, and the package θ_JAs are shown in
Table 1. If we assume (for this example ) that we are driving a back-terminated video cable, then the maximum
average value (over duty-cycle) of V_outmax is 1.4V, and R_L = 150Ω, giving the results seen in Table 1.
Table 1
Device
Package
AMC2244M
8P DIP
AMC2244DM
8P SOIC
AMC2344N/AMC2444N 14P DIP
AMC2344D/AMC2444D 14P SOIC
θ_JA
95°C /W
125°C /W
70°C /W
110°C /W
PDmax @ T_max
0.789W @ 75°C
0.600W @ 75°C
1.071W @ 75°C
0.682W @ 75°C
Max V_S
±16.6V
±12.1V
±11.5V
±7.5V
Copyright © 2006 2006 ADDtek Corp.
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DD006_E -- JUNE 2006