PI3740-00 Datasheet, PDF (27/48 Pages) Vicor Corporation – Parallel capable with single wire current sharing

PI3740-00
Where the symbol in Figure 40 is defined as the following:
φ_INT-TOP
is defined as the thermal impedance from the hottest component junction inside the SiP to the top side
of the package.
φ_INT-PCB
is defined as the thermal impedance from the hottest component junction inside the SiP to the circuit board it is
mounted on, assuming all customer PCB connections at one temperature.
φ_INT-VIN
φ_INT-VS1
is defined as the thermal impedance from the hottest component junction inside the SiP to the circuit board it is
mounted on at the V_IN pad.
is defined as the thermal impedance from the hottest component junction inside the SiP to the circuit board it is
mounted on at the VS1 pad.
φ_INT-PGND
is defined as the thermal impedance from the hottest component junction inside the SiP to the circuit board it is
mounted on at the PGND pad.
φ_INT-VS2
is defined as the thermal impedance from the hottest component junction inside the SiP to the circuit board it is
mounted on at the VS2 pad.
φ_INT-VOUT
is defined as the thermal impedance from the hottest component junction inside the SiP to the circuit board it is
mounted on at the V_OUT pad.
φ_INT-SGND
is defined as the thermal impedance from the hottest component junction inside the SiP to the circuit board it is
mounted on at the SGND pad.
The following equation can predict the junction temperature based on the heat load applied to the SiP and the known ambient conditions
with the simplified thermal circuit model:
T_INT =
PD +
T T _TOP
Φ ⁺ Φ _INT-TOP
PCB
INT-PCB
1
1
(7)
Φ ⁺ Φ _INT-TOP
INT-PCB
Device
φ_INT-TOP
(°C / W)
φ_INT-VIN
(°C / W)
PI3740-00-LGIZ
39.07
3.28
Table 4 — PI3740-00 SiP Thermal Impedance
Thermal Impedance
φ_INT-VS1
(°C / W)
13.1
φ_INT-PGND
(°C / W)
5.89
φ_INT-VS2
(°C / W)
14.11
φ_INT-VOUT
(°C / W)
4.48
φ_INT-SGND
(°C / W)
54.03
Thermal Impedance with
the simplified version
φ_INT-TOP
(°C / W)
φ_INT-PCB
(°C / W)
39.07
1.15
Cool-Power^® ZVS Switching Regulators
Page 27 of 48
Rev 1.4
04/2017
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