Brushless DC (BLDC) motors offer many advantages over brushed DC motors, including higher efficiency, lower electric noise, little to no maintenance, a longer lifetime and better thermal performance.
The BLDC design can be complicated by myriad choices in components, which typically requires an engineer to navigate through numerous datasheets to match Gate Drivers with FETs and IGBTs. To simplify the process, onsemi has created a set of useful "1st Order Approximation" selection tables based on a number of key design considerations.
These selection tables (see below) match Gate Drivers to Switches; N-FETs (<300V) and IGBTs (>300V) for the following motor voltages; 12V, 24V, 48V, 60V, 120V, 200V, 300V, 400V; as well as 650V w/ IPMs spanning 90W to 6kW.
Explore Selection Tables:
12V & 24V (N-FETs) | 48V & 60V (N-FETs) | 120V & 200V (N-FETs) | 300V & 400V (IGBTs) | 300V, 400V & 650V (IPMs)
3-Phase BLDC Block Diagram
This is a block diagram for a typical 3-phase BLDC. The processor controls (PWM) each gate driver in order to sequence (turn on or off) the HS (high side) /LS (low side) FETs. This sequencing, or commutation, of the FETs energizes the 3-phase windings (U, V and W) causing the motor to spin. ISENSE tells the controller what the current is for each phase (U, V or W) at any given time. Hall Effect Sensors tell the controller where the rotor is relative to its 360 degree electrical rotation. With sensorless BLDCs, Hall Effect Sensors are not needed.
Webinar
A New Starting Point for BLDC Design
The BLDC design process includes navigating vast portfolios of Gate Drivers, FETs and IGBTs. onsemi provides a new starting point based on cost and many engineering considerations to jump start and expedite the complicated BLDC design process.
Resources
Documents:
Videos:
Blog Articles:
12V & 24V (N-FETs)
The Table below depicts a “1st Order Approximation” matching of Gate Drive to FETs, for 12V motors ranging from 93W (1/8 HP) to 372W (½ HP), and 24V motors ranging from 186W (1/4 HP) to 1.117kW (1 ½ HP). The engineering considerations for this table are listed in the bullets below.
1st Order Approximation Considerations (conservative):
- Trapezoidal Commutation (15kHz): 33% Duty Cycle for each FET
- Junction Isolated Gate driver, 85°C Max Ambient Temp
- Matching Gate Drive (iG) Amps, to FET Gate Charge (QGTOT) nC, for a worst case 50ns On/Off Time
- FET VDSS Voltage = 2-3x Motor Voltage
- FET Power Dissipation Max = ~25°C below max operating die temp (no Heat Sink), ~50°C w/ Heat Sink
- FET ID Rating 3x IPHASE
| Motor HP: | Power: | DC Rail (VM): | DC Motor Current (IPHASE) RMS: | N-FET Examples: | Rdson @ VGS =10V | Total Gate Charge QGTOT : | Calculated FET Gate Drive (iG) 50ns: | N-FET Package: | Heat Sink: | Gate Driver (source / sink): | Gate Driver Example: |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/8 | 93W | 12V | 9.55A | NTTFS4929 (30V) | 11mΩ | 16.3 nC | 0.326 A | 3.3 x 3.3mm | No | 0.35A/0.65A | FAN7888 (1x) |
| 1/4 | 186W | 19.09A | NTMFS4821N (30V) | 6.95mΩ | 25nC | 0.5A | 5 x 6mm | 0.5A/0.8A | NCP81080 (3x) | ||
| 1/2 | 372W | 38.18 | NTMFS4C022N (30V) | 1.7mΩ | 45.2nC | 0.904A | 2.5A/2.5A | FAN73933 (3x) | |||
| 1/4 | 186W | 24V | 9.55A | NTMFS020N06C (60V) | 19.6mΩ | 5.7nC | 0.114A | 0.25A/0.5A | NCP5109 (3x) | ||
| 1/2 | 372W | 19.09A | NTMFS5844NL (60V) | 12mΩ | 30nC | 0.6A | 2.5A/2.5A | FAN73933 (3x) | |||
| 1 | 745W | 38.18A | NTMFS5C628NL (60V) | 2.4mΩ | 52nC | 1.04A | 2.5A/2.5A | FAN73933 (3x) | |||
| 1 1/4 | 931.25W | 47.73A | NTMFS5C612NL (60V) | 1.5mΩ | 91nC | 1.82A | 2.5A/2.5A | FAN73933 (3x) | |||
| 1 1/2 | 1117.5W | 57.27A | NTMFS5C604NL (60V) | 1.2mΩ | 120nC | 2.4A | 3.5A/3A | NCP51530 (3x) |
48V & 60V (N-FETs)
The Table below depicts a “1st Order Approximation” matching of Gate Drive to FETs, for 48V motors ranging from 186W (1/4 HP) to 1.49kWW (2 HP), and 60V motors ranging from 186W (1/4 HP) to 1.49kW (2 HP). The engineering considerations for this table are listed in the bullets below.
1st Order Approximation Considerations (conservative):
- Trapezoidal Commutation (15kHz): 33% Duty Cycle for each FET
- Junction Isolated Gate driver, 85°C Max Ambient Temp
- Matching Gate Drive (iG) Amps, to FET Gate Charge (QGTOT) nC, for a worst case 50ns On/Off Time
- FET Power Dissipation Max = ~25°C below max operating die temp (no Heat Sink), ~50°C w/ Heat Sink
- FET VDSS Voltage = 2-3x Motor Voltage
- FET ID Rating 3x IPHASE
| Motor HP: | Power: | DC Rail (VM): | DC Motor Current (IPHASE) RMS: | N-FET Examples: | Rdson @ VGS =10V | Total Gate Charge QGTOT : | Calculated FET Gate Drive (iG) 50ns: | N-FET Package: | Heat Sink: | Gate Driver (source / sink): | Gate Driver Example: |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/8 | 186.25W | 48V | 4.77A | NTMFS015N10MCL (100V) | 12.2mΩ | 19nC | 0.38A | 5 x 6mm | No | 0.5A/0.8A | NCP81080 (3x) |
| 1/2 | 372.5W | 9.55A | NTMFS015N10MCL (100V) | 12.2mΩ | 19nC | 0.38A | 0.5A/0.8A | NCP81080 (3x) | |||
| 1 | 745W | 19.09A | NTMFS005N10MCL (100V) | 5.1mΩ | 55nC | 1.1A | 2.5A/2.5A | FAN73933 (1x) | |||
| 2 | 1490W | 38.18A | NTMTSC002N10MC (100V) | 2mΩ | 89nC | 1.78A | 8 x 8mm | 2.5A/2.5A | FAN73933 (1x) | ||
| 1/8 | 186.25W | 60V | 3.82A | NTMFS008N12MC (120V) | 8mΩ | 33nC | 0.66A | 5 x 6mm | 2.5A/2.5A | FAN73933 (1x) | |
| 1/2 | 372.5W | 7.64A | NTMFS008N12MC (120V) | 8mΩ | 34nC | 0.68A | 2.5A/2.5A | FAN73933 (1x) | |||
| 1 | 745W | 15.27A | NTMFS008N12MC (120V) | 8mΩ | 34nC | 0.68A | 2.5A/2.5A | FAN73933 (1x) | |||
| 2 | 1490W | 30.55A | NTBGS4D1N15MC (150V) | 4.1mΩ | 88.9nC | 1.778A | D2PAK7 | 2.5A/2.5A | FAN73933 (1x) |
120V & 200V (N-FETs)
The Table below depicts a “1st Order Approximation” matching of Gate Drive to FETs, for 120V motors ranging from 186W (1/4 HP) to 1.86kW (2½ HP), and 200V motors ranging from 186W (1/4 HP) to 2.98kW (4 HP). The engineering considerations for this table are listed in the bullets below.
1st Order Approximation Considerations (conservative):
- Trapezoidal Commutation (15kHz): 33% Duty Cycle for each FET
- Junction Isolated Gate driver, 85°C Max Ambient Temp
- Matching Gate Drive (iG) Amps, to FET Gate Charge (QGTOT) nC, for a worst case 50ns On/Off Time
- FET Power Dissipation Max = ~25°C below max operating die temp (no Heat Sink), ~50°C w/ Heat Sink
- FET VDSS Voltage = 2-3x Motor Voltage
- FET ID Rating 3x IPHASE
| Motor HP: | Power: | DC Rail (VM): | DC Motor Current (IPHASE) RMS: | N-FET Examples: | Rdson @ VGS =10V | Total Gate Charge QGTOT : | Calculated FET Gate Drive (iG) 50ns: | N-FET Package: | Heat Sink: | Gate Driver (source / sink): | Gate Driver Example: |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/4 | 186.25W | 120V | 1.91A | FQB11N40C (400V) | 530mΩ | 15nC | 0.3A | D2PAK | No | 0.5A/0.8A | NCP81080 (3x) |
| 3/4 | 558.75W | 5.73A | FDP24N40 (400V) | 175mΩ | 46nC | 0.92A | TO-220 | Yes | 2.5A/2.5A | FAN73933 (3x) | |
| 1 1/2 | 1.117kW | 11.45A | FDPF44N25TRDTU (250V) | 69mΩ | 47nC | 0.94A | TO-220F | 2.5A/2.5A | FAN73933 (3x) | ||
| 2 1/2 | 1.862kW | 19.09A | FDPF44N25TRDTU (250V) | 69mΩ | 47nC | 0.94A | TO-220F | 2.5A/2.5A | FAN73933 (3x) | ||
| 1/4 | 186.25W | 200V | 1.15A | FDD6N50 (500V) | 900mΩ | 12.8nC | 0.256A | DPAK | No | 0.5A/0.8A | NCP81080 (3x) |
| 1/5 | 372.5W | 2.29A | FDP7N50 (500V) | 900mΩ | 12.8nC | 0.256A | TO-220 | Yes | 0.5A/0.8A | NCP81080 (3x) | |
| 1 | 745W | 4.58A | FCP190N65S3R0 (650V) | 190mΩ | 33nC | 0.66A | TO-220 | 2.5A/2.5A | FAN73933 (3x) | ||
| 1 1/2 | 1.117kW | 6.87A | FCPF190N60-F154 (600V) | 199mΩ | 57nC | 1.14A | TO-220F | 2.5A/2.5A | FAN73933 (3x) | ||
| 2 | 1.49kW | 9.16A | NTPF095N65S3H (600V) | 95mΩ | 58nC | 1.16A | TO-220F | 2.5A/2.5A | FAN73933 (3x) | ||
| 4 | 2.98kW | 18.33A | NTH4LN067N65S3H (650V) | 67mΩ | 80nC | 1.6A | TO-247 | 2.5A/2.5A | FAN73933 (3x) |
300V & 400V (IGBTs)
The Table below depicts a “1st Order Approximation” matching of Gate Drive to IGBTs, for 300V motors ranging from 372W (1/2 HP) to 4.47kW (6 HP), and 400V motors ranging from 372W (1/2 HP) to 5.96kW (8 HP). The engineering considerations for this table are listed in the bullets below.
1st Order Approximation Considerations (conservative):
- Trapezoidal Commutation (15kHz): 33% Duty Cycle for each IGBT
- Junction Isolated Gate driver, 85°C Max Ambient Temp
- Matching Gate Drive (iG) Amps, to IGBT Gate Charge (QGTOT) nC, for a worst case 200ns On/Off Time
- IGBT Power Dissipation Max = Switching Loss (15Khz) x Conduction Loss x Diode loss
- IGBT Power Dissipation Max = ~50°C below max operating die temp w/ Heat Sink
- IGBT VCES = 2-3x Motor Voltage
- IGBT IC Rating 3x IPHASE
| Motor HP: | Power: | DC Rail (VM): | DC Motor Current (IPHASE) RMS: | IGBT Examples: | Total Loss (W): | Total Gate Charge QGTOT w/ VGE 15V: | Calculated IGBT Gate Drive (iG) 200ns: | IGBT Package: | Heat Sink: | Gate Driver (source / sink/UVLO): | Gate Driver Example: |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ½ | 372.5W | 300V | 1.53A | FGP10N60UNDF (600V) | 10.02 | 37nC | 0.185A | TO-220 | Yes | 0.35A/0.65A/8.2V | FAN7388 (1x) |
| 1 | 745W | 3.05A | FGP10N60UNDF (600V) | 14.41 | 37nC | 0.185A | TO-220 | 0.35A/0.65A/8.2V | FAN7388 (1x) | ||
| 2 | 1.49kW | 6.11A | FGAF20S65AQ (650V) | 22.75 | 38nC | 0.19A | TO-3PF | 0.35A/0.65A/8.2V | FAN7388 (1x) | ||
| 4 | 2.98kW | 12.22A | FGAF40S65AQ (650V) | 38.27 | 75nC | 0.375A | TO-3PF | 2.5A/2.5A/9V | FAN73933 (3x) | ||
| 6 | 4.47kW | 18.33 | FGHL75T65MQDT (650V) | 126.8 | 149nC | 0.745A | TO-247-3L | 2.5A/2.5A/9V | FAN73933 (3x) | ||
| ½ | 372.5W | 400V | 1.15A | FGP10N60UNDF (600V) | 10.02 | 37nC | 0.185A | TO-220 | 0.35A/0.65A/8.2V | FAN7388 (1x) | |
| 1 | 745W | 2.29A | FGP10N60UNDF (600V) | 14.41 | 37nC | 0.185A | TO-220 | 0.35A/0.65A/8.2V | FAN7388 (1x) | ||
| 2 | 1.49kW | 4.58A | FGAF20S65AQ (650V) | 22.75 | 38nC | 0.19A | TO-3PF | 0.35A/0.65A/8.2V | FAN7388 (1x) | ||
| 4 | 2.98kW | 9.16A | FGAF30S65AQ (650V) | 35.07 | 58nC | 0.29A | TO-3PF | 0.35A/0.65A/8.2V | FAN7388 (1x) | ||
| 6 | 4.47kW | 13.75A | FGHL50T65MQDT (650V) | 80.23 | 99nC | 0.495A | TO-247 | 2.5A/2.5A/9V | FAN73933 (3x) | ||
| 8 | 5.96kW | 18.33A | FGA6065ADF (650V) | 114.4 | 84nC | 0.420A | TO-3P-3L | 2.5A/2.5A/9V | FAN73933 (3x) |
300V, 400V & 650V (IPMs)
The Table below depicts a “1st Order Approximation” IPMs (Integrated Power Modules), for 300V motors ranging from 372W (1/2 HP) to 4.47kW (6 HP), 400V motors ranging from 372W (1/2 HP) to 5.96kW (8 HP), and 650V motors ranging from 372W (1/2 HP) to 5.96kW (8 HP). The engineering considerations for this table are listed in the bullets below.
| Motor HP: | Power: | DC Rail (VM): | DC Motor Current (IPHASE) RMS: | IPM Examples: | VCES Rating: | IC Rating : | VCE(SAT)s: | IPM Package: |
|---|---|---|---|---|---|---|---|---|
| ½ | 372.5W | 300V | 1.53A | NFAQ0860L33T | 600V | 8A | 2.4V | DIP-S6 |
| 1 | 745W | 3.05A | NFAQ1060L36T | 10A | 1.9V | DIP-S6 | ||
| 2 | 1.49kW | 6.11A | FNA41560T2 | 15A | 1.6V | SPM45 | ||
| 4 | 2.98kW | 12.22A | FNB33060T | 30A | 1.6V | SPM3V | ||
| 6 | 4.47kW | 18.33 | FNB34060T | 40A | 1.5V | SPM3V | ||
| ½ | 372.5W | 400V | 1.15A | STK5C4U332J-E | 3A | 1.3V | DIP-S | |
| 1 | 745W | 2.29A | NFAQ0860L33T | 8A | 2.4V | DIP-S6 | ||
| 2 | 1.49kW | 4.58A | NFAQ1060L36T | 10A | 1.9V | DIP-S6 | ||
| 4 | 2.98kW | 9.16A | FSBB20CH60D | 20A | 2V | SPM3V | ||
| 6 | 4.47kW | 13.75A | FNB33060T | 30A | 1.6V | SPM3V | ||
| 8 | 5.96kW | 18.33A | FNB34060T | 40A | 1.5V | SPM3V | ||
| ½ | 372.5W | 650V | 0.7A | FSBB10CH120D | 1200V | 10A | 2.2V | SPM3 |
| 1 | 745W | 1.41A | FSBB10CH120D | 10A | 2.2V | SPM3 | ||
| 2 | 1.49kW | 2.82A | FSBB10CH120D | 10A | 2.2V | SPM3 | ||
| 4 | 2.98kW | 5.64A | FSBB15CH120D | 15A | 2V | SPM3 | ||
| 6 | 4.47kW | 8.46A | FSBB20CH120D | 20A | 2.2V | SPM34 | ||
| 8 | 5.96kW | 11.28A | FNA22512A | 25A | 1.9V | SPM34 |