3kW Interleaved Digital PFC with STNRGPF01

PFC Interleaved Overview

3kW Interleaved PFC

Solution

Productsfor Digital PFC

3kW Digital PFCPerformance

STNRGPF01: a new driver specifically developed for interleaved PFCs

PFC – Interleaved ConceptInterleaving consist in paralleling two or more stages rated for a lower output power instead of a single one rated

for the nominal power of the application. The channels maintain an out of phase operation given by:

Out of phase (degree) = 360°𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛𝑛 𝑜𝑜𝑜𝑜 𝑐𝑐𝑐𝑐𝑐𝑛𝑛𝑛𝑛𝑛𝑛𝑐𝑐𝑐𝑐

Two Channel Interleaved PFC

Overview

PFC – Interleaving Concept • Benefits

• Interleaved architectures offer several benefits:• Magnetics volume reduction• EMI filter reduction• Output capacitor RMS current value reduction• Better power management for the switches

• Considerations• The complexity in circuit management increases with increasing number of channels.• Digital solutions are preferred to analog ones for their flexibility and programmability.

Consequently costly microcontrollers with high computing power are often needed.

Inductors comparison for 3kW PFC

Core: EE70L= 150µHSize: h=70mm, W=66mm, D=31mmVolume=143cm3

Single Channel

Interleaved 3 Channels

45% Less!

Core: PQ3230L= 120µHSize: h=30mm, W=32mm, D=27mmVolume=26cm3

Total Volume=78cm3

Fsw=100kHz

EMI Filter

• Interleaved approach reduces the size of the EMI filter thanks to the higher equivalent switching frequency.

• Benefits will be obtained by increasing the number of channels because the ripple current is reduced.• For instance, for three phases, the inductor ripple current is completely cancelled at

33% and 66% duty-cycle.

• Possible to work at lower frequency increasing the total efficiency

Output Capacitor Ripple Current Reduction• The inductor ripple current reduction (also for the output capacitor) brings

many benefits, especailly in terms of RMS current reduction.

Capacitors with higher ESR can be used Lower cost

0.50 1

0

0.5

1

%D

I 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑁𝑁𝑐𝑐𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁𝑁

Single Channel

Double Channel

Triple Channel

Impact on Power Switch Selection

• For switches, the increased number of phases does not imply a proportional cost increase.

• Switch is smaller because it must manage only a percentage of total Power.

• Possible to better distribute the power dissipation over the channels.

3kW Three Channels Interleaved PFC

Key Products• STNRGPF01 (Digital controller for PFC)• PM8834D (Double Channel low side driver)• ALTAIR05-800 (Off-line primary-sens. switch. reg.)• STW40N60M2 (MDmesh II Plus low Qg ) • STPSC1206 Schottky silicon carbide diode• TSV911 (High speed OP)• LMV358 (Standard OP)• M74HC132 (Quad NAND Gate)

Key specifications: • Pout = 3kW @ Vin = 230Vac; 1.5kW @ Vin = 110Vac• Vout = 400V• PF > 0.98 @ 20% load• THD < 5% @ 20% load• CCM with analog current control loop (cycle by cycle regulation)• Input Voltage feed forward• Load feed forward• Working frequency = 111kHz per channel• Thermal protection set at 120°C• Current protection set at 33A• Direct fan driving• Current reference realized by internal map (200 pt)

High Power Density = 52W/inc3!

The device performances have been evaluated developing a 3kW Three channels PFC

L=24,5 cm; W=11 cm; H=3,5 cm (including heatsink area)

3kW PFC Interleaved SolutionDigital controller: STNRGPF01

EMI filter

&Rect

AC input

STNRGPF01

AC LINE MONITOR

LMV358

CH0 CH1 CH2

LOAD

VBUS

IINPUTCURRENT

TSV911TSV911

TSV911

F/FF/F

Block Diagram of the 3kW Interleaved Digital PFC

STNRGPF01: Application Control SchemeThe STNRGPF01 implements a mixed signal (analog/digital) control offering the advantages of very high enddigital solutions without the limits of analog ones. The inner current loop is implemented with an analogProportional-Integral (PI) compensator, ensuring cycle by cycle control. The outer voltage loop is performed by adigital PI controller with fast dynamic response.

STNRGPF01 Concept

STNRGPF01 is a digital configurable IPFC ASIC that is able to drive up to three interleaved channels. It works in CCM at fixed frequency with average current mode control

It can cover several functions and interleaved PFC configurations:• Double channel• Triple channel• Inrush current control• Three Phases configurati

The device can be configured by a dedicated software (eDesignSuite) in order to be customized for the specific application

eDesignSuite supporting STNRGPF01

Software generation

BoM + SCHEMATIC

eDesignSuite smart configurator for STNRGPF01 offer thepossibility to customize the device to better meet the enduser application needs.

Libraries & IPs

Database

Build

Experimental results: Steady state

Duty cycle Inductors current

PWM master

Experimental Results: ITHD%

0

1

2

3

4

5

6

7

0 500 1000 1500 2000 2500 3000 3500

%

W

ITHD%

ITHD115 ITHD230

PF>0.99, Load>20%

Experimental Results: Efficiency

90

91

92

93

94

95

96

97

98

99

100

0 500 1000 1500 2000 2500 3000

%

W

Efficiency

Eff 115V Eff 230V

Products for Digital PFC

•The leading technology for hard-switching topologies

Key Features• Industry’s lowest

RDS(on) in the Market• High switching speed• 550 / 650V classes

Benefits• highest efficiency in the

application• Smaller form factor of

final system• Especially targeted for

hard switching (PFC, Boost, TTF, Flyback)

MDmesh TM

M5-SeriesThe best fit for resonant

/ LLC topologies

Key Features• Up to 30% lower Qg

(equivalent die size)• Optimized Coss profile• 400 / 500/ 600 / 650V

classes

Benefits• Reduced switching losses

through optimized (Qg) (Ciss, Coss)

• Enhanced immunity vs ESD & Vgs spikes in the application

• Especially targeted for HB LLC, TTF, Flyback..)

MDmesh TM

M2-SeriesState-of-the-arte in the

VHV (Very-High-Voltage) Class

Key Features• Extremely good RDS(on) at

very high BVDSS• High switching speed• 800 / 850 / 950V classes

available now• 1050 / 1.2k / 1.5kV classes

in development

Benefits• High efficiency with lower

design complexity• Especially targeted for

flyback LED topologies and high voltage range in the application

SuperMESH TM

K5-SeriesThe best fit for F/B ZVS

topologies

Key Features• Integrated fast body diode• Softer commutation

behavior • Back-to-Back G-S zener

protected• 500 / 600 / 650V classes

Benefits• Reduced switching losses

through optimized (Qg) (Ciss, Coss)

• High peak diode dV/dtcapabilities

• Best use in Full Bridge ZVS

MDmesh TM

DM2-Series

HV Silicon Power MOSFET Technologies

Chargers, Adapters , SilverBox, LED lighting, Server, Telecom, Solar , UPS, LCD TV

Extremely low Qg

Optimized for light load conditions

400V,500V,600V and 650V BVdss rated

MDmesh™ M2

Low conduction and switching losses in low/medium power PFCand soft switching

Especially targeted resonant topologies (LLC)

Easy to drive

PM8834 high current IGBT and MOSFET driver

FEATURES PM8834

Applications: LV applications 600V DC/DC converters 1200V boost converter PFC UPS systems

Basic dual-channel driver without features

Two independents driving channels 4A current driving capability for each driver Up to 8A for simultaneous operation Up to 19V supply Designed as low side driver ENABLE inputs Industry standards pin-out -40°C/ 105°C temperature range SO8 or MSOP 8L-EP package

4A low side driver with two independent driving channels

ALTAIR04-05900V ALL PRIMARY side FLYBACK CONVERTER (CONTROLLER +MOSFET)

900V MOSFET option

All primary side CC-CV with ±5 % tolerance

Quasi resonant operations

70mW PIN @ 230VAC @ no load

eDesign suite simulator

Spice Models on st.com

Application notes: AN3290, AN4154

Evaluation kits: STEVAL-ISA133V1, STEVAL-ISA105V1 (Altair04), STEVAL-ISA176V1 (Altair05)

Collaterals

Smart HomeKey features

Application

ALTAIR04 ALTAIR05

BVDSS 900 V 800 V

Max RDSon 19 Ω 14 Ω

VDD 8.5V ÷ 23.5V 8.5V ÷ 23.5V

Power 6 W 8 W

Collaterals

Parameters

Smart Meter

STNRGPF01

STNRGPF01

PWM0

CCO_Clk

DIGIN[1]

PWM1

PWM2

DIGIN[2]

DIGIN[3]

PWM5

PWM0

CLOCK

SYNCR[1]

SET[1]

RESET[1]

SYNCR[2]

GPIO0[4]

GPIO0[5]

N C

RESET2

N C

NRST

VDD

VSS

ADCIN0

ADCIN1

ADCIN2

ADCIIN3

ADCIN4

ADCIN5

ADCIN6

ADCIN7

GPIO0[3]

GPIO0[2]

RELAY

FAN

UART_rx

UART_tx

VSSA

VDDA

CPP0

CPP1

CPM32

CPP2

CPP3

RTX

PTX

OCP1

OCP

TRIANG_REF

OUT_PI[2]

OUT_PI[3]

RES

RES

RES

RES

VOUT

IOUT

TEMP

VIN

VOUT

PFC_FAULT

PFC_OK

SET2

ZVD

ENABLE

SIN_REF

VSSA

VDDA

SWIM

NRST

VDD

VSS

VOUT

PWM4

DIGIN[4]

DIGIN[5]

PWM3

Key Features:

•Interleaved boost PFC •Up to 3 interleaved channels •CCM, fixed frequency •Average current control, cycle-by-cycle •Inrush current control •Burst mode support •Overcurrent and thermal protection •Soft start-up •Flexible phase-shedding strategy

• High operating frequency with small PFC inductor• suitable for high power-density applications• Low ripple current (input/output)• Simpler integration with other applications

•Flexible design customization to meet specific customer needs •Firmware

• Turnkey solution for quick design• eDesign Suite GUI for application configuration

•Embedded memory data retention 15 years with ECC •Communication interfaces

• UART asynchronous protocol for bootloader support•Operating temperature: -40 °C to 105 °C