Application results

OptiMOS™ 6 100V has been designed primarely to address high switching frequency applications such as swtich mode power supply (e.g. telecom, server, charger, adapter, TV...).

Stay tuned for more information on motor control and solar applications to see all the advantages that this technology can bring!

Soft switching topology

Infineon graph OptiMOS™ 6 absolute efficiency and delta loss

Soft switching happens when either the voltage or current is zero before the switch is turned on or off. This has benefits, like the reduction of total switching losses. Soft switching is usually a proprieties of resonant converters. In some cases, it would be possible to achieve soft-switching even in hard-switched PWM topologies: one approach is to introduce auxiliary circuits that enable soft switching for the control MOSFET, while recovering the energy otherwise lost and improving the efficiency.

A possible application is a ZVS inverting buck boost -(36...60) V to 12 V DC/DC converter. In this topology, an active clamp circuit recovers, in a lossless way, Qrr from the SR switch towards the output, while achieving ZVS for the control switch.

Best-in-class products in the newly released OptiMOS™ 6 technology (ISC022N10NM6) are compared to OptiMOS™ 5 (BSC027N10NS5) in SuperSO8 (PQFN 5x6) package in this application. The result is stunning: OptiMOS™ 6 in 2.2 mΩ achieves roughly 1% better efficiency across all the line and load conditions, compared to the 2.7 mΩ product in OptiMOS™ 5.

The improvement in efficiency is explainable as the joint contribution of

  • the lower driving losses, thanks to approximatively 20% lower (typ) Qg,
  • lower turn-off losses due the lower Qgd – an improvement just shy of 40%
  • and lower conduction losses with a 18% lower RDS(on).

The improvement in efficiency lowers the total losses by 7 W, a very remarkable improvement allowing easier thermal management and increased power density. ISC022N10NM6 represents the lowest RDS(on) available in the market for SuperSO8 (PQFN 5x6) package in 100V.

Hard switching topology: telecom quarter brick intermediate bus converter

Hard switching occurs when there is an overlap between voltage and current when switching the transistor on and off.

V x I crossover losses are the main source of losses during turn-off, while Qoss associated losses (due to the charge stored in the output capacitance) dominates the turn-on transient.

In high switching frequency SMPS, switching losses represent a substantial share of the total losses. Turn-off losses are reduced by lowering the gate-to-drain charge Qgd, that would result in a faster voltage transition. Turn-on losses are minimized by a low value for the output charge Qoss.

Infineon image graph delta loss comparisson

OptiMOS™ 6 100V, showing leading FOMgd and FOMoss figure-of-merits, enables remarkable efficiency improvement when compared to the previous available technology. In a telecom quarter brick 250 kHz, 600 W 48Vin/12Vout full bridge/full bridge, ISC060N10NM6 (6 mΩ) achieves up to +0.4% better efficiency and lower temperature compared to BSC050N10NS5 (5 mΩ). This benefits in higher system realibility as lower system cost.

Infineon image graph OptiMOS™ 6 100V electricity saving

A 250 kHz, 600 W telecom quarter brick 48Vin/12Vout full bridge featuring center-tap rectifier was used to compare 2.7 mΩ 100V SuperSO8 MOSFETs on the secondary side.

ISC027N10NM6 achieved 0.46% better efficiency compared to BSC027N10NS5 which results in about 3 W lower losses.

This directly translates in a dramatic temperature improvement with ~12°C difference at full load, which enables easier thermal designs and improved lifetime up to 75%*

 

* Estimated value. Reliability model considers GOX breakdown and HTGS drifts

Battery Operated BLDC Motor Drive

Switching losses in a hard switching converter represent a large share of the total losses in BLDC Motor inverters. For this reason, a good trade-off between RDS(on) and charges Qg and Qgd is needed.

 An efficiency comparison between OptiMOS™ 5 (BSC027N10NS5, RDS(on) = 2.7 mΩ) and OptiMOS™ 6 (ISC022N10NM6, RDS(on) = 2.2 mΩ) demonstrated that in this application where conduction losses play a significant role, OptiMOS™ 6 (ISC022N10NM6) was able to achieve better efficiency than OptiMOS™ 5 (BSC027N10NS5) due to lower switching losses and RDS(on). Furthermore, due to the lower turn-off switching losses, the new product produces 10° C lower case temperature at full load compared to the OptiMOS™ 5 version.

These OptiMOS™ 6 power MOSFETs in SuperSO8 package are suitable for battery operated applications requiring efficiency optimization such as power tools, gardening tools, robots and drones.

Solar energy systems

Switching losses in a hard switching converter represent a large share of the total losses in solar power optimizers. For this reason, a good balance between RDS(on) and charges is needed. Recommended products for a power optimizer (synchronous buck stage) are 100 V power MOSFETs in SuperSO8 package, with RDS(on) in the range of 5-6 mΩ.

A efficiency comparison between OptiMOS™ 5 (BSC050N10NS5, RDS(on) = 5 mΩ) and OptiMOS™ 6 (ISC060N10NM6, RDS(on) = 6 mΩ) demonstrated that even with 18 percent higher RDS(on), OptiMOS™ 6 (ISC060N10NM6) achieved better efficiency than OptiMOS™ 5, due to lower switching losses. Furthermore, due to the lower turn-off switching losses, the new product produces 6° C lower case temperature at full load compared to the OptiMOS™ 5 version.