STW20NK50Z N-channel Power MOSFET

Figure 1 STW20NK50Z	Figure 2 TO-247 Package	Figure 3 Symbol
	1. GATE 2. DRAIN 3. SOURCE

WHAT IS STW20NK50Z?
STW20NK50Z N-channel 500 V, 0.23 Ω, 20 A SuperMESH™ Power MOSFET
This device is an N-channel Zener-protected Power MOSFET developed using STMicroelectronics’ SuperMESH™ technology. In addition to a significant reduction in on state resistance, this device is designed to ensure a high level of dv/dt capability for the most demanding applications.

Low on state resistance makes it suitable for power electronics converters utilized in power conversion & control. High dv/dt capability makes it superior in high voltage applications like photovoltaic power generations and VFDs.

Fig.1 shows STW20NK50Z MOSFER IC, Fig.2 shows layout of TO-247 Package and Fig.3 shows symbol for STW20NK50Z.

PIN CONFIGURATION
Table 1

PIN NUMBER	PIN NAME	DESCRIPTION
1	Gate	Controls the biasing of the MOSFET
2	Drain	Current flows in through Drain
3	Source	Current flows out through Source

FEATURES

Extremely high dv/dt capability
100% avalanche tested
Gate charge minimized
Very low intrinsic capacitance

ALTERNATIVES FOR STW20NK50Z
Table 2

TRANSISTOR TYPE		ON_MAX
STW20NK50Z	500 V	0.27 Ω	20 A	190 W
STW32N55M5	550 V	0.1 Ω	29 A	190 W
STW32NM50N	500 V	0.13 Ω	22 A	190 W
STW33N60M2	600 V	0.125 Ω	26 A	190 W
STW34NM60N	600 V	0.105 Ω	31.5 A	250 W

APPLICATION

High Current, High Speed Switching
Ideal for Off-Line Power Supplies, Adaptors And PFC

WHERE TO USE STW20NK50Z

Major load of industrial sectors are VFDs. Efficiency of VFDs depends on the converters used to drive the motors. Low on state resistance of STW20NK50Z reduce conduction losses and makes VFDs efficient. So low on state resistance along with high dv/dt in STW20NK50Z makes it perfect choice for VFDs.

2-D VIEW AND FOOTPRINT
Table 3

Dim.	mm
Dim.	Min.	Typ.	Max.
A	4.85		5.15
A1	2.20		2.60
b	1.0		1.40
b1	2.0		2.40
b2	3.0		3.40
c	0.40		0.80
D	19.85		20.15
E	15.45		15.75
e		5.45
L	14.20		14.80
L1	3.70		4.30
L2		18.50
P	3.55		3.65
R	4.50		5.50
S		5.50

Figure 4 2-Dimentional View

Figure 4-3 Footprint

HOW STW20NK50Z WORK?

STW20NK50Z MOSFET can be use in any power electronics circuit like inverter, DC-DC converter or controlled rectifier. As mentioned previously STW20NK50Z has three terminals Gate(G), Drain(D) and Source(S). Drain and Source are called power terminals whereas Gate terminal is known as control terminal. As shown in fig. gate pulses need to be provided between Gate and Source to turn on the MOSFET. Maximum current carrying capacity of STW20NK50Z is 20A hence, one can utilize this MOSFET in an application which require current flow of lesser than 20A.

Figure 5 Use of STW20NK50Z

To use STW20NK50Z in DC/DC Converters or Multilevel Inverters, driver ICs like TLP250 or IR2101 are required. Circuit diagram of STW20NK50Z along with driver TLP250 is shown in Fig.6. MOSFET Drivers are used to fulfill two objectives 1) to provide isolation (to control circuit from power circuit). 2) to amplification (5V pulse/3.3 V pulse from controller amplifies to >10V to effectively drive MOSFET). As shown in fig.6 TLP250 has inbuilt optocoupler along with two transistor amplification circuit. Pin configuration and appropriate connections are summarized in Table.4.

Figure 6 STW20NK50Z along with TLP250

Table 4 Connection of TLP250 with STW20NK50Z

Pin Number	Pin Name	Connection	Description
2	Anode	To the output pin of controller	Input pulse of 3.3 V/5V to the driver circuit
3	Cathode	To the ground of controller	Ground of input side circuit
8		To the isolated supply with output voltage >10 V	Supply for driver circuit
5	GND	To the GND of isolated supply	Ground of external driver supply
6,7	OUTPUT	To the Gate of STW20NK50Z. (Resistor is connected to limit the gate current)	6 and 7 pins are internally shorted and provide amplified pulse provided at pin 2.

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