STR-W6754 - Allegro MicroSystems, LLC

SANKEN ELECTRIC CO., LTD.

http://www.sanken-ele.co.jp/en/

GND

LowB

GND

For ErrAmp, Sanken SE series device recommended

For SI, Sanken linear regulator IC recommended

33 77

ROCP

ErrAmp

Standby

ON/OFF

Standby

Out

STR-W6754

Controller

(MIC)

S/GND OCP/BD SS/OLP

STR-W6754

Description

The STR-W6754 is a quasi-resonant topology IC designed for

SMPS applications. It shows lower EMI noise characteristics

than conventional PWM solutions, especially at greater than

2 MHz. It also provides a soft-switching mode to turn on the

internal MOSFET at close to zero voltage (VDS bottom point)

by use of the resonant characteristic of primary inductance

and a resonant capacitor.

The package is a fully molded TO-220, which contains the

controller chip (MIC) and MOSFET, enabling output power up

to 100 W with universal input or 160 W with a 230 VAC input.

The bottom-skip mode skips the first bottom of VDS and turns

on the MOSFET at the second bottom point, to minimize an

increase of operating frequency at light output load, improving

system-level efficiency over the entire load range.

There are two standby modes available to reduce the input power

under very light load conditions. The first is Auto-Standby

mode, which is internally triggered by periodic sensing, and

the other is a manual standby mode, which is executed by

clamping the secondary output. In general applications, the

manual standby mode reduces the input power further compared

to Auto-Standby mode.

The soft-start mode minimizes surge voltage and reduces

power stress to the MOSFET and to the secondary rectifying

Features and Benefits

▪ Quasi-resonant topology IC  Low EMI noise and soft

switching

▪ Bottom-skip mode  Improved system efficiency over

the entire output load by avoiding increase of switching

frequency

▪ Auto-Standby mode  Lowers input power at very light

output load condition

▪ Avalanche-guaranteed MOSFET  Improves system-level

reliability and does not require VDSS derating

▪ 650 V / 0.96 Ω

▪ Various protections  Improved system-level reliability

Quasi-Resonant Topology

Primary Switching Regulators

Typical Application Diagram

Package: 6-pin TO-220

Not to scale

Continued on the next page…

28103.32

SANKEN ELECTRIC CO., LTD.

28103.32

Quasi-Resonant Topology

Primary Switching Regulators

STR-W6754

diodes during the start-up sequence. Various protections such as

overvoltage, overload, overcurrent, maximum on-time protections

and avalanche-energy-guaranteed MOSFET secure good system-

level reliability.

Applications include the following:

▪ Set Top Box

▪ LCD PC monitor, LCD TV

▪ Printer, Scanner

▪ SMPS power supplies

Selection Guide

Part Number Package

STR-W6754 TO-220

Features and Benefits (continued) Description (continued)

All performance characteristics given are typical values for circuit or

system baseline design only and are at the nominal operating voltage and

an ambient temperature, TA, of 25°C, unless oth er wise stated.

▫ Pulse-by-pulse drain overcurrent limiting

▫ Overvoltage protection (bias winding voltage sensing),

with latch

▫ Overload protection with latch

▫ Maximum on-time limit

Absolute Maximum Ratings at TA = 25°C

Parameter Symbol Conditions Rating Unit

Drain Current1IDpeak Single pulse 15 A

Maximum Switching Current2IDmax TA = –20°C to 125°C 15 A

Single Pulse Avalanche Energy3EAS Single pulse, VDD = 99 V, L = 20 mH, ILpeak = 5.1 A 292 mJ

Input Voltage for Controller (MIC) VCC 35 V

SS/OLP Terminal Voltage VSSOLP –0.5 to 6.0 V

FB Terminal Inflow Current IFB 10 mA

FB Terminal Voltage VFB IFB within the limits of IFB –0.5 to 9.0 V

OCP/BD Terminal Voltage VOCPBD –1.5 to 5.0 V

MOSFET Power Dissipation4PD1

With infinite heatsink 28 W

Without heatsink 1.3 W

Controller (MIC) Power Dissipation PD2 VCC × ICC 0.8 W

Operating Internal Leadframe Temperature TFRecommended operation temperature, see cautions –20 to 115 °C

Operating Ambient Temperature TOP –20 to 115 °C

Storage Temperature Tstg –40 to 125 °C

Channel Temperature Tch 150 °C

1Refer to figure 2

2IDMAX is the drain current determined by the drive voltage of the IC and the threshold voltage, Vth, of the MOSFET

3Refer to figure 3

4Refer to figure 5

SANKEN ELECTRIC CO., LTD.

28103.32

Quasi-Resonant Topology

Primary Switching Regulators

STR-W6754

S/GND

OCP/BD

Reg and

const

OVP

Drive Control IC

Reg

Protection

Latch

OCP

BSD

Bottom Select

Counter

SS/OLP

OLP

Delay

OSC

Max On

Soft Start

Burst

Control

Start

Stop

Burst

Control

Temperature, T

(°C)

Safe Operating Area

Temperature Derating Coefficient (%)

100

0 20 40 60 10080 120

Drain-to-Source Voltage, VDS (V)

Drain Current, ID (A)

10.00

1.00

0.10

100.00

100 100010

1 ms

0.1 ms

Refer to figure 1 for MOSFET SOA

temperature derating coefficient

Current limit

due to R

DS(on)

Figure 1 – MOSFET Safe Operating Area

Derating Curve Figure 2 – MOSFET Safe Operating Area

Drain Current versus Voltage

at TA = 25°C, Single Pulse

Terminal List Table

Number Name Description Functions

1 D Drain MOSFET drain

2 NC Clipped No connection

3 S/GND Source/ground terminal MOSFET source and ground

4 VCC Power supply terminal Input of power supply for control circuit

5 SS/OLP Soft Start/Overload Protection terminal Input to set delay for Overload protection and Soft Start operation

6 FB Feedback terminal Input for Constant Voltage Control and Burst (intermittent) Mode

oscillation control signals

7 OCP/BD Overcurrent Protection/Bottom Detection Input for overcurrent detection and bottom detection signals

SANKEN ELECTRIC CO., LTD.

28103.32

Quasi-Resonant Topology

Primary Switching Regulators

STR-W6754

Channel Junction Temperature, T

(°C)

Temperature Derating Coefficient (%)

100

25 50 75 100 125 150

Time, t (s)

Transient Thermal Resistance, RQJC (°C/W)

0.001

0.010

0.100

1.000

10.000

100μ10μ10m1m 100m1μ

Ambient Temperature, TA (°C)

Power Dissipation, PD1 (W)

0 20 40 60 80 100 120 140 160

= 1.3 W at T

≤ 25°C

Without heatsink

With infinite heatsink

= 28 W at T

≤ 25°C

Figure 3 – MOSFET Avalanche Energy Derating Curve

VDD = 99 V, L = 20 mH, IL = 3.6 A Figure 4 – Transient Thermal Resistance

Figure 5 – MOSFET Power Dissipation versus Temperature

SANKEN ELECTRIC CO., LTD.

28103.32

Quasi-Resonant Topology

Primary Switching Regulators

STR-W6754

ELECTRICAL CHARACTERISTICS

Characteristic Symbol Test Conditions Min. Typ. Max. Units

ELECTRICAL CHARACTERISTICS for Controller (MIC)1, valid at TA = 25°C, VCC = 20 V, unless otherwise specified

Power Supply Start-up Operation

Operation Start Voltage VCC(ON) VCC = 0→20 V 16.3 18.2 19.9 V

Operation Stop Voltage VCC(OFF) VCC = 20→8.8 V 8.8 9.7 10.6 V

Circuit Current In Operation ICC(ON) ––6mA

Circuit Current In Non-Operation ICC(OFF) VCC = 15 V – – 100 μA

Oscillation Frequency fosc 19 22 25 kHz

Soft Start Operation Stop Voltage VSSOLP(SS) VSS/OLP increasing 1.1 1.2 1.4 V

Soft Start Operation Charging Current ISSOLP(SS) VSS/OLP = 0 V –710 –550 –390 μA

Normal Operation

Bottom-Skip Operation Threshold Voltage 1 VOCPBD(BS1) –0.720 –0.665 –0.605 V

Bottom-Skip Operation Threshold Voltage 2 VOCPBD(BS2) –0.485 –0.435 –0.385 V

Overcurrent Detection Threshold Voltage VOCPBD(LIM) VOCP/BD falling –0.995 –0.940 –0.895 V

OCP/BD Terminal Outflow Current IOCPBD VOCP/BD = –0.95 V –250 –100 –40 μA

Quasi-Resonant Operation Threshold Voltage 1 VOCPBD(TH1) VOCP/BD falling 0.28 0.40 0.52 V

Quasi-Resonant Operation Threshold Voltage 2 VOCPBD(TH2) VOCP/BD rising 0.67 0.80 0.93 V

FB Terminal Threshold Voltage VFB(OFF) VFB rising 1.32 1.45 1.58 V

FB Terminal Inflow Current (Normal Operation) IFB(ON) VFB = 1.6 V 600 1000 1400 μA

Standby Operation

Standby Operation Start Voltage VCC(S) VCC = 0→15 V, VFB = 1.6 V 10.3 11.1 12.1 V

Standby Operation Start Voltage Interval VCC(SK) VCC(SK) = VCC(S) – VCC(OFF) 1.10 1.35 1.65 V

Standby Non-Operation Circuit Current ICC(S) VCC = 10.2 V, VFB = 1.6 V –2056μA

FB Terminal Inflow Current, Standby Operation IFB(S) VCC = 10.2 V, VFB = 1.6 V –414μA

FB Terminal Threshold Voltage, Standby Operation VFB(S) VCC = 15 V, VFB rising 0.55 1.10 1.50 V

Minimum On Time tON(MIN) 0.4 0.8 1.2 μs

Protection Operation

Maximum On Time tON(MAX) 27.5 32.5 39.0 μs

Overload Protection Operation Threshold Voltage VSSOLP(OLP) 4.0 4.9 5.8 V

Overload Protection Operation Charging Current ISSOLP(OLP) VSS/OLP = 2.5 V –16 –11 –6 μA

Overvoltage Protection Operation Voltage VCC(OVP) VCC = 0→30 V 25.5 27.7 29.9 V

Latch Circuit Holding Current2ICC(H) VCC(OFF)

– 0.3 V – 45 140 μA

Latch Circuit Release Voltage2VCC(La.OFF) VCC = 30→6 V, OVP operating 6.0 7.2 8.5 V

ELECTRICAL CHARACTERISTICS for MOSFET, valid at TA = 25°C, unless otherwise specified

Drain-to-Source Breakdown Voltage VDSS ID = 300 μA 650 – – V

Drain Leakage Current IDSS VDS = 650 V – – 300 μA

On Resistance RDS(on) ID = 1.9 A – – 0.96 Ω

Switching Time tf– – 400 ns

Thermal Resistance Rθch-F Channel to internal frame – – 1.6 °C/W

1Current polarity with respect to the IC: positive current indicates current sink at the terminal named, negative current indicates source at the

terminal named.

2The latch circuit means a circuit operated OVP and OLP.

SANKEN ELECTRIC CO., LTD.

28103.32

Quasi-Resonant Topology

Primary Switching Regulators

STR-W6754

PACKAGE DIMENSIONS, TO-220

10.0 ±0.2 4.2 ±0.2

2.8 ±0.2

Ø3.2 ±0.2

2.6 ±0.1

(2×R1)

Terminal dimension at case surface

5.08 ±0.6

0.65 +0.2

–0.1

0.74±0.15

0.45 +0.2

–0.1

16.9 ±0.3

10.4 ±0.5

5.0 ±0.5

7.9 ±0.2

4 ±0.2

0.5

2.8

(5.4)

Gate Burr

Branding

XXXXXXXX

XX XX

Gate burr: 0.3 mm (max.)

Terminal core material: Cu

Terminal treatment: Ni plating and solder dip

Leadform: 2003

Weight (approximate): 2.3 g

Dimensions in millimeters

Drawing for reference only

Branding codes (exact appearance at manufacturer discretion):

1st line, type: STR

2nd line, subtype: W6754

3rd line, lot: YM DD

Where: Y is the last digit of the year of manufacture

M is the month (1 to 9, O, N, D)

DD is the 2-digit date

1234567

Terminal dimensions at case surface

6×P1.27 ±0.15 = 7.62 ±0.15

Terminal dimension at lead tips

View B

0.5

View A

0.5

Leadframe plating Pb-free. Device composition

includes high-temperature solder (Pb >85%),

which is exempted from the RoHS directive.

SANKEN ELECTRIC CO., LTD.

28103.32

Quasi-Resonant Topology

Primary Switching Regulators

STR-W6754

Because reliability can be affected adversely by improper

storage environments and handling methods, please observe

the following cautions.

Cautions for Storage

• Ensure that storage conditions comply with the standard

temperature (5°C to 35°C) and the standard relative

humidity (around 40% to 75%); avoid storage locations

that experience extreme changes in temperature or

humidity.

• Avoid locations where dust or harmful gases are present

and avoid direct sunlight.

• Reinspect for rust on leads and solderability of the

products that have been stored for a long time.

Cautions for Testing and Handling

When tests are carried out during inspection testing and

other standard test periods, protect the products from

power surges from the testing device, shorts between

the product pins, and wrong connections. Ensure all test

parameters are within the ratings specified by Sanken for

the products.

Remarks About Using Silicone Grease with a Heatsink

• When silicone grease is used in mounting the products on

a heatsink, it shall be applied evenly and thinly. If more

silicone grease than required is applied, it may produce

excess stress.

• Volatile-type silicone greases may crack after long periods

of time, resulting in reduced heat radiation effect. Silicone

greases with low consistency (hard grease) may cause

cracks in the mold resin when screwing the products to a

heatsink.

Our recommended silicone greases for heat radiation

purposes, which will not cause any adverse effect on the

product life, are indicated below:

Type Suppliers

G746 Shin-Etsu Chemical Co., Ltd.

YG6260 Momentive Performance Materials Inc.

SC102 Dow Corning Toray Co., Ltd.

Cautions for Mounting to a Heatsink

• When the flatness around the screw hole is insufficient, such

as when mounting the products to a heatsink that has an

extruded (burred) screw hole, the products can be damaged,

even with a lower than recommended screw torque. For

mounting the products, the mounting surface flatness should

be 0.05 mm or less.

• Please select suitable screws for the product shape. Do not

use a flat-head machine screw because of the stress to the

products. Self-tapping screws are not recommended. When

using self-tapping screws, the screw may enter the hole

diagonally, not vertically, depending on the conditions of hole

before threading or the work situation. That may stress the

products and may cause failures.

• Recommended screw torque: 0.588 to 0.785 N●m (6 to 8

kgf●cm).

• For tightening screws, if a tightening tool (such as a driver)

hits the products, the package may crack, and internal

stress fractures may occur, which shorten the lifetime of

the electrical elements and can cause catastrophic failure.

Tightening with an air driver makes a substantial impact.

In addition, a screw torque higher than the set torque can

be applied and the package may be damaged. Therefore, an

electric driver is recommended.

When the package is tightened at two or more places, first

pre-tighten with a lower torque at all places, then tighten

with the specified torque. When using a power driver, torque

control is mandatory.

Soldering

• When soldering the products, please be sure to minimize

the working time, within the following limits:

260±5°C 10±1 s (Flow, 2 times)

380±10°C 3.5±0.5 s (Soldering iron, 1 time)

• Soldering should be at a distance of at least 2.0 mm from

the body of the products.

Electrostatic Discharge

• When handling the products, the operator must be

grounded. Grounded wrist straps worn should have at

least 1 MΩ of resistance from the operator to ground to

prevent shock hazard, and it should be placed near the

operator.

• Workbenches where the products are handled should be

grounded and be provided with conductive table and floor

mats.

• When using measuring equipment such as a curve tracer,

the equipment should be grounded.

• When soldering the products, the head of soldering irons

or the solder bath must be grounded in order to prevent

leak voltages generated by them from being applied to the

products.

• The products should always be stored and transported in

Sanken shipping containers or conductive containers, or

be wrapped in aluminum foil.

SANKEN ELECTRIC CO., LTD.

28103.32

Quasi-Resonant Topology

Primary Switching Regulators

STR-W6754

• The contents in this document are subject to changes, for improvement and other purposes, without notice. Make sure that this is the

latest revision of the document before use.

• Application and operation examples described in this document are quoted for the sole purpose of reference for the use of the prod-

ucts herein and Sanken can assume no responsibility for any infringement of industrial property rights, intellectual property rights or

any other rights of Sanken or any third party which may result from its use.

• Although Sanken undertakes to enhance the quality and reliability of its products, the occurrence of failure and defect of semicon-

ductor products at a certain rate is inevitable. Users of Sanken products are requested to take, at their own risk, preventative measures

including safety design of the equipment or systems against any possible injury, death, fires or damages to the society due to device

failure or malfunction.

• Sanken products listed in this document are designed and intended for the use as components in general purpose electronic equip-

ment or apparatus (home appliances, office equipment, telecommunication equipment, measuring equipment, etc.).

When considering the use of Sanken products in the applications where higher reliability is required (transportation equipment and

its control systems, traffic signal control systems or equipment, fire/crime alarm systems, various safety devices, etc.), and whenever

long life expectancy is required even in general purpose electronic equipment or apparatus, please contact your nearest Sanken sales

representative to discuss, prior to the use of the products herein.

The use of Sanken products without the written consent of Sanken in the applications where extremely high reliability is required

(aerospace equipment, nuclear power control systems, life support systems, etc.) is strictly prohibited.

• In the case that you use Sanken products or design your products by using Sanken products, the reliability largely depends on the

degree of derating to be made to the rated values. Derating may be interpreted as a case that an operation range is set by derating the

load from each rated value or surge voltage or noise is considered for derating in order to assure or improve the reliability. In general,

derating factors include electric stresses such as electric voltage, electric current, electric power etc., environmental stresses such

as ambient temperature, humidity etc. and thermal stress caused due to self-heating of semiconductor products. For these stresses,

instantaneous values, maximum values and minimum values must be taken into consideration.

In addition, it should be noted that since power devices or IC's including power devices have large self-heating value, the degree of

derating of junction temperature affects the reliability significantly.

• When using the products specified herein by either (i) combining other products or materials therewith or (ii) physically, chemically

or otherwise processing or treating the products, please duly consider all possible risks that may result from all such uses in advance

and proceed therewith at your own responsibility.

• Anti radioactive ray design is not considered for the products listed herein.

• Sanken assumes no responsibility for any troubles, such as dropping products caused during transportation out of Sanken's distribu-

tion network.

• The contents in this document must not be transcribed or copied without Sanken's written consent.