1206 1 Watt RF Power Resistor

sábado, 29 de mayo de 2010

1206 1 Watt RF Power Resistor

Construction:

High Purity Alumina
Nickel alloy thin-film resistive element
Epoxy-resin overcoat
Pre-tinned (Sn100, matte) terminations over Ni barrier is standard

Features:

TCR's to ± 25ppm/ºCTolerances less than ± 1% available
Standard and custom sizes & terminations available (Sn60Pb40 option)
High volume production, suitable for commercial and special applicationsCompetitive pricing
Competitive pricing

Description:

These power resistors are designed to tolerate high current and establish a low thermal resistance interface with the circuit board. A lower thermal resistance more efficiently sinks heat to the board, enabling a larger effective area for heat dissipation. As a result, much lower surface temperatures are achievable in comparison to standard chip resistors for the same chip size and applied power.

Dimensions:

Electrical Specifications:

Notes:

Dependent on effective thermal conductivity/resistance of board construction/land design and size of board - greater power capability for board/land with lower thermal resistance. For relatively high thermal resistance mountings, the power resistors are capable of generating sufficient heat to reflow solder bonds without device damage.
Refer to Thermal Performance Plot below.
Per MIL-PRF-55342 (-55/25/125ºC).
Per MIL-PRF-55342.
Per IEC 60115-1.
Derating curves are derived from the thermal performance plots.

Thermal Performance:

Notes:

Plots produced by characterization of thermal coefficients determined from experimental measurements (by thermal imaging camera) at thermal equilibrium with parts mounted to various boards (with homogeneous thermal conductivity to minimize uncertainty) per recommended solder pad dimensions and with boards pressed against a Cu carrier/heat-sink (not ideal) with a thermal compound interface in a static environment (no air flow).
Heat flow primarily through thickness of board with virtually zero lateral heat transfer in board.
Thermal resistance of test boards were calculated based on material manufacturer specified thermal conductivity (20ºC) via the following: Thermal Resistance (ºC/W) = L / (k • A), where Thermal Conductivity, k (W/m•K) = (L / (A • ΔT)) • ΔQ/Δt, L =Thickness of board in meters and A = area of chip resistor in meters.
The relationships between peak surface temperature rise, power, and board thermal resistance are linear, but the x-axis is plotted in log-scale to offer greater resolution at lower board thermal resistances.