ROHM Debuts a Line of -40V/-60V P-Channel MOSFETs in Single and Dual Configurations
The new devices will serve to alleviate some of the “efficiency gap” between P-Channel and N-Channel devices
N-Channel devices generally do provide greater efficiency than do their P-Channel cousins. But when N-channel MOSFETs are employed on the high side, they need to be fed with a gate voltage higher than the input voltage. It can be done and it is done, but it presents issues. In the same situation, P-channel MOSFETs can be driven with a gate voltage lower than the input voltage, avoiding complexities.
ROHM’s 24-member line of P-channel MOSFETs, as illustrated below, are said by the company to represent a significant improvement when compared to conventional devices.
Image courtesy of ROHM
The new -40 V and 60 VDS devices, fabricated utilizing 5th generation process refinements, work with 24 volt inputs. For the -40 volt and -60 volt devices, RDS(ON) improvements of 62% and 52%, respectively, are specified.
This raises the possibility for designers to enjoy greater efficiencies, while at the same time to avoid using N-Channel devices in applications not otherwise favoring them.
Available in Single and in Dual MOSFET Packages
All units work with -4.5 Volt drive voltages. Within both the single MOSFET and dual MOSFET subsections, the units are equally divided between -40 and -60 VDSS devices.
The Dual P-Channel MOSFET Devices are detailed here by ROHM:
- Drain currents range from -2.5 to -8.5 amps
- RDS(ON)s range from 0.015 and and 0.25 mΩ
- Total gate charges (QG) range from 3.2 to 25 nC
These devices are variously available in TSMT8, SOP8 and DFN2020-8D packages.
ROHM also details the Single P-Channel MOSFET units:
- Drain currents range from -3.5 and -78 amps
- RDS(ON)s range from 0.0052 and 0.078 mΩ
- Total gate charges (QG) range from 8.5 to 130 nC
In addition to the package sizes used by the dual MOSFET units, these devices are also featured in T0-252, HSMT8 (3.3 x 3.3 mm), SOT-457T and HSOP8S (5 x 6 mm) packages.
Beating the Reliability vs RDS(ON) Tradeoff
Fifth Generation design allows ROHM to improve reliability and mitigate electric field concentration at the gate trench corner where the electric field is most concentrated. Thus, it was possible to increase semiconductor reliability against element degradation with temperature, while at the same time not sacrificing the superior RDS(ON) characteristics that these MOSFETs exhibit.
N-Channel Devices Remain
P-channel MOSFETs conduct when a voltage negative with respect to the Source is applied to the Gate. This allows it to be driven with a voltage lower than the input voltage, simplifying circuit configuration.
N-channel MOSFETs work in the other way – they conduct when a voltage that is positive with respect to the source is applied to the gate. As a rule, the critical RSD(ON) specification is better for N-channel MOSFETs
There is no reason to abandon this advantage, useful in so many design cases. Thus ROHM is also reaffirming its commitment to N-Channel MOSFETs. The company is now using next-gen processes to develop future N-channel semiconductors with improved reliability and characteristics calculated to reduce application design loads.
The 24 model lineup will serve applications such as:
- Factory automation
- Industrial PLCs
- Commercial air conditioning systems
- Small appliances