AN11641
Rev. 2.0 — 25 July 2024

Application note

Relay replacement by Nexperia highpower bipolar transistors in LFPAK56

Abstract:

This application note describes Nexperia Semiconductor's low collector-emitter saturation voltage bipolartransistor PHPT portfolio. It gives a guideline which parameters must be taken into account to drive abrushed DC motor.

Keywords:

High-power bipolar transistors, PHPT series, LFPAK56, relay

AN11641

Nexperia

Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

1. Introduction
Nexperia's bipolar power transistors in LFPAK use the latest BISS (Breakthrough In Small Signal)transistor technology. They include mesh-emitter-design technology IP-platform to achieve highpower devices with low VCEsat (collector-emitter saturation voltage) voltage drop and high current
gain. By this upmarket development, Nexperia wants to extend its powerful and successful BISS
transistor portfolio into the medium power and high-power range in order to reach full traction for
its high-power low VCEsat and high-current mesh-emitter technology. To achieve this aim Nexperia
uses a package supporting the high power dissipation demand of its transistor portfolio. LFPAK
offers superior low thermal impedance Zth and therefore high thermal power capability up to 5 W.
Key parameters are current distribution (which should be as homogenous as possible) over chipvolume, and little spreading resistance in the metallization on the front of the chip. In the case of
BISS transistors, a homogeneous current distribution in the chip is achieved by the latest meshemitter-design technology IP-platform, which breaks the transistor down into corresponding cellstructures. Soft-solder capable front and back metallization combine this wafer technology with the
LFPAK-package platform requirements introducing new-developed metal stack interfaces for chip
front and back interface. They are optimized for low-resistivity contact of all transistor terminals tothe package outline.
The high-performance/high-reliability package platform LFPAK provides clip-bond for emitter andbase contact. This achieves low electrical and thermal resistivity of the devices on all terminals.
The electrical package resistivity is below 1 mΩ. The overall thermal impedance of the powertransistors in the current chip-size range is below 6 K/W. Soft-solder die and clip attach establish arugged package architecture with up to Tj(max) = 175 °C high-temperature capability.

1.1. Features and benefits
•
•
•
•
•
•
•
•

High power dissipation (Ptot)
Suitable for high-temperature applications (175 °C)
Space-saving 5 mm × 6 mm: package outline is half the size of equivalent transistors in DPAK,
SOT223, and other packages
Low profile (1 mm)
High reliability and mechanical ruggedness thanks to solid copper clip (no wires)
High energy efficiency due to less heat generation
AEC-Q101 qualified
Future-proof, growing portfolio

2. Brushed DC motor control
Modern DC motors are used in various automotove applications:
•
•
•
•
•
•

Power windows
WipersBlower motors (heating / cooling)
Trunk lifter
Steering wheel adjustment
Seat adjustment

Many of these applications use relays for driving the brushed DC motor. This application noteshows which parameter must be taken into account to replace relays by bipolar transistors in Hbridge configuration controlled by a Pulse Width Modulation (PWM) signal.
The DC brushed motor used for this application note has following characteristics:•••

Nominal operating voltage: 12 V
Nominal operating current: 3 A
Blocked operating current: 8 A

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

2.1. Relay operation
GND
12 V

GND

M

K2

K1

K2

12 V

K1

aaa-017884

Each tactile switch turns a relay on allowing the motor to turn in either direction.
Fig. 1.

Relay schematic

2.2. Bipolar Junction Transistor (BJT) H-bridge operation

33 Ω/2 W

T9

T10
PHTP60410PY

PMEG6030ETPPMEG6030ETPPHTP60410PY

33 Ω/2 WM

33 Ω/2 W

T7

T8
PHTP60410NY

PMEG6030ETPPMEG6030ETP

33 Ω/2 W

PHTP60410NY

aaa-017885

A PWM signal is used to control T9 / T8 or T10 / T7 to turn the motor left or right.
Fig. 2.

Schematic H-bridge configuration

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

3. Parameters of Nexperia high-power bipolar transistors (PHPT series)
Due to the maximum motor current of 8 A, the voltage across collector and emitter must be alignedwith the power dissipation of the LFPAK56 package. Fig. 3 shows a typical value for VCEsat of
PHPT60410NY.
aaa-014219

1
VCEsat
(V)
10-1
(1)
(2)

10-2

(3)
(4)

10-3
10-1

1

10

102

103
104
IC (mA)

Tamb = 25 °C(1) IC/IB = 100(2) IC/IB = 50
(3) IC/IB = 20
(4) IC/IB = 10
Fig. 3.

PHPT60410NY: Collector-emitter saturation voltage as a function of collector
current; typical values

At hFE = 50 (base current IB = 160 mA) and at maximum motor current (IC(max)), a 300 mV voltage
drop across collector and emitter must be expected. The outcome of this is Ptot = 2.4 W incontinuous mode.
For this application note, following PWM parameters have been chosen:••

PWM frequency = 125 Hz / tp = 8 ms
Duty cycle = 0.5

Fig. 4 shows the thermal impedance of a PHPT60410NY under these conditions.

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56
aaa-014225

103
Zth(j-a)(K/W)
102

duty cycle = 1
0.75
0.33

10

0.1

0.5
0.2
0.05

0.02
1

0.01
0.25

0
10-1
10-5

10-4

10-3

10-2

10-1

1

10

102

tp (s)

103

FR4 PCB, standard footprint
Fig. 4.

PHPT60410NY: Transient impedance from junction to ambient as a function of pulse duration; typicalvaluesGiven that:

Ptot =

T j(max) T amb
Rth(j-a)(1)

then, at Tj(max) = 175 °C and Zth(j-a) = 50 K/W; when mounted on a standard footprint:••

Ptot = 3 W at Tamb = 25 °C
Ptot = 2.4 W at Tamb = 55 °C

4. Demoboard
In order to verify all theoretical approaches, Nexperia designed a test board with a PWM-driven Hbridge and for comparison two relays to drive a brushed DC motor. Each tactile switch turns the
motor left or right. The relay part is isolated from the PWM stage.

aaa-017886

Fig. 5.

Test board with a PMW-driven H-bridge

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

4.1. Electrical verification

aaa-017887

Fig. 6.

PWM signal
Fig. 6 shows the PWM control signal running with a frequency of 130 Hz and a duty cycle δ of 0.5.
The PWM is generated by a simple NE555 circuit. At a jumper, the signal can be disconnectedfrom the tactile switches. That is why the frequency decreases to 125 Hz during motor operation.

aaa-017888

Fig. 7.

Signal at base resistor of high-side PNP transistor
The peak base current IB can be calculated with voltage V = 10 V and resistance R = 33 Ω. The
outcome of this is IB = 300 mA; the average value of IB = 150 mA.

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

aaa-017889

Fig. 8.

Signal at base resistor of low-side NPN transistor
The peak base current is 288 mA and the average base current is 144 mA.
In real application, the transistors are running at a slightly higher hFE. The base resistor andworkpoint were calculated with respect to high blocking current of 8 A. In normal application, themotor current is measured by a microcontroller in order to stop the turning of the motor on security
reason. The following scope trace (Fig. 9) was measured across a resistor of 235 mΩ and shows
following motor current:

aaa-017890

Fig. 9.

Motor current
The peak motor current is 4.25 A. In average, the motor is running with 2.125 A. From this,hFE = 15 in normal operation mode.

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

4.2. Thermal results
All measurements were performed with a motor in normal operation mode.

aaa-017892

Fig. 10. High-side PNP transistor: collector padtemperature (cursor) approximately 37 °C

aaa-017893

Fig. 11. Low-side NPN transistor: collector padtemperature (cursor) approximately 36 °C

4.3. EMI results
Equipment used to measure the ElectroMagnetic Interference (EMI) performance of the H-bridgewith PHPT-series (VCE = 40 V, IC = 10 A) versus a standard automotive relay (12 V; 50 mA coilcurrent, 15 A max):
•
•
•
•
•

Power supply: WIMO GSV3000
Artificial network: Schwarzbeck NNBM 8125
LFPAK demoboard
DC Motor: Bosch AHC 12 V
EMI test receiver: Rohde and Schwarz ESCI3

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

4.3.1. Board-powered no-switchingaaa-017894

110
Level
(dBµV)
70

30

-10
10-1

1

10

f (MHz)102

Fig. 12. Powered Device Under Test (DUT) (no action)

4.3.2. Relay operated
aaa-017895

110
Level
(dBµV)
70

30

-10
10-1

1

10

f (MHz)102

Maximum at 32 MHz = 55 dBµV
Fig. 13. Powered DUT (relay)

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

4.3.3. H-bridge operated
aaa-017896

110
Level
(dBµV)
70

30

-10
10-1

1

10

f (MHz)102

Maximum at 16.5 MHz = 49 dBµV
Fig. 14. Powered DUT (BJT)

4.3.4. H-bridge operated in PWM Modeaaa-018296

110
Level
(dBµV)
70

30

-10
10-1

1

10

f (MHz)102

Maximum at 366 kHz = 59 dBµV
Fig. 15. Powered DUT (PWM)

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

5. Results
If all necessary parameters are taken into account, relays can be replaced by bipolar transistors,
like Nexperia’s PHPT-series in LFPAK.
The advantages of a silicon-based solution compare to relay are:••••Reliable performance over lifetime (AEC-Q101)
Significantly better EMI performance
No contact bouncing
Less board space

6. Product portfolio in LFPAKTable 1. Nexperia’s high-power bipolar transistor product portfolio in LFPAK
Type number
Configuration
VCEO
IC

AEC-Q101

PHPT60406NY

NPN

40 V

6A

YES

PHPT60406PY

PNP

40 V

6A

YES

PHPT60410NY

NPN

40 V

10 A

YES

PHPT60410PY

PNP

40 V

10 A

YES

PHPT60603NY

NPN

60 V

3A

YES

PHPT60603PY

PNP

60 V

3A

YES

PHPT60606NY

NPN

60 V

6A

YES

PHPT60606PY

PNP

60 V

6A

YES

PHPT60610NY

NPN

60 V

10 A

YES

PHPT60610PY

PNP

60 V

10 A

YES

PHPT61002NYC

NPN

100 V

2A

NO

PHPT61002PYC

PNP

100 V

2A

NO

PHPT61003NY

NPN

100 V

3A

YES

PHPT61003PY

PNP

100 V

3A

YES

PHPT61006NY

NPN

100 V

6A

YES

PHPT61006PY

PNP

100 V

6A

YES

PHPT61010NY

NPN

100 V

10 A

YES

PHPT61010PY

PNP

100 V

10 A

YES

7. Revision history
Table 2. Revision history
Revision
Date
numberDescription

2.0

2024-07-25

Document updated to latest Nexperia format.

1.0

2015-05-21

Initial version

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

8. Legal information
Definitions
Draft — The document is a draft version only. The content is still underinternal review and subject to formal approval, which may result in
modifications or additions. Nexperia does not give any representations or
warranties as to the accuracy or completeness of information included hereinand shall have no liability for the consequences of use of such information.

Disclaimers
Limited warranty and liability — Information in this document is believed
to be accurate and reliable. However, Nexperia does not give any
representations or warranties, expressed or implied, as to the accuracy
or completeness of such information and shall have no liability for theconsequences of use of such information. Nexperia takes no responsibility
for the content in this document if provided by an information source outsideof Nexperia.
In no event shall Nexperia be liable for any indirect, incidental, punitive,
special or consequential damages (including - without limitation - lost
profits, lost savings, business interruption, costs related to the removalor replacement of any products or rework charges) whether or not suchdamages are based on tort (including negligence), warranty, breach ofcontract or any other legal theory.
Notwithstanding any damages that customer might incur for any reason
whatsoever, Nexperia’s aggregate and cumulative liability towards customer
for the products described herein shall be limited in accordance with theTerms and conditions of commercial sale of Nexperia.
Right to make changes — Nexperia reserves the right to make changes
to information published in this document, including without limitation
specifications and product descriptions, at any time and without notice. This
document supersedes and replaces all information supplied prior to the
publication hereof.
Suitability for use — Nexperia products are not designed, authorized or
warranted to be suitable for use in life support, life-critical or safety-criticalsystems or equipment, nor in applications where failure or malfunctionof an Nexperia product can reasonably be expected to result in personal
injury, death or severe property or environmental damage. Nexperia and its
suppliers accept no liability for inclusion and/or use of Nexperia products insuch equipment or applications and therefore such inclusion and/or use is at
the customer’s own risk.
Applications — Applications that are described herein for any of theseproducts are for illustrative purposes only. Nexperia makes no representation
or warranty that such applications will be suitable for the specified use
without further testing or modification.
Customers are responsible for the design and operation of their applications
and products using Nexperia products, and Nexperia accepts no liability forany assistance with applications or customer product design. It is customer’ssole responsibility to determine whether the Nexperia product is suitableand fit for the customer’s applications and products planned, as well as
for the planned application and use of customer’s third party customer(s).
Customers should provide appropriate design and operating safeguards tominimize the risks associated with their applications and products.
Nexperia does not accept any liability related to any default, damage, costs
or problem which is based on any weakness or default in the customer’s
applications or products, or the application or use by customer’s third party
customer(s). Customer is responsible for doing all necessary testing for thecustomer’s applications and products using Nexperia products in order toavoid a default of the applications and the products or of the application or
use by customer’s third party customer(s). Nexperia does not accept any
liability in this respect.
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a priorauthorization from competent authorities.
Translations — A non-English (translated) version of a document is forreference only. The English version shall prevail in case of any discrepancy
between the translated and English versions.

Trademarks
Notice: All referenced brands, product names, service names andtrademarks are the property of their respective owners.

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

List of Tables
Table 1. Nexperia’s high-power bipolar transistor
product portfolio in LFPAK................................................. 11
Table 2. Revision history....................................................11

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List of Figures
Fig. 1. Relay schematic........................................................3
Fig. 2. Schematic H-bridge configuration............................. 3
Fig. 3. PHPT60410NY: Collector-emitter saturation
voltage as a function of collector current; typical values...... 4
Fig. 4. PHPT60410NY: Transient impedance fromjunction to ambient as a function of pulse duration;
typical values........................................................................5
Fig. 5. Test board with a PMW-driven H-bridge................... 5
Fig. 6. PWM signal...............................................................6
Fig. 7. Signal at base resistor of high-side PNP transistor... 6
Fig. 8. Signal at base resistor of low-side NPN transistor.... 7
Fig. 9. Motor current.............................................................7
Fig. 10. High-side PNP transistor: collector padtemperature (cursor) approximately 37 °C...........................8
Fig. 11. Low-side NPN transistor: collector padtemperature (cursor) approximately 36 °C...........................8
Fig. 12. Powered Device Under Test (DUT) (no action)....... 9
Fig. 13. Powered DUT (relay).............................................. 9
Fig. 14. Powered DUT (BJT)............................................. 10
Fig. 15. Powered DUT (PWM)........................................... 10

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Relay replacement by Nexperia high-power bipolar transistors in LFPAK56

Contents
1. Introduction................................................................... 2
1.1. Features and benefits..................................................2
2. Brushed DC motor control.......................................... 2
2.1. Relay operation........................................................... 3
2.2. Bipolar Junction Transistor (BJT) H-bridge operation.. 3
3. Parameters of Nexperia high-power bipolartransistors (PHPT series).................................................. 4
4. Demoboard.................................................................... 5
4.1. Electrical verification.................................................... 6
4.2. Thermal results............................................................8
4.3. EMI results...................................................................8
4.3.1. Board-powered no-switching.................................... 9
4.3.2. Relay operated......................................................... 9
4.3.3. H-bridge operated...................................................10
4.3.4. H-bridge operated in PWM Mode........................... 10
5. Results.........................................................................11
6. Product portfolio in LFPAK....................................... 11
7. Revision history..........................................................11
8. Legal information........................................................12© Nexperia B.V. 2024. All rights reserved

For more information, please visit: http://www.nexperia.com
For sales office addresses, please send an email to: salesaddresses@nexperia.com
Date of release: 25 July 2024

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