〇Product structure : Silicon integrated circuit 〇This product has no designed protection against radioactive rays.

1/32

19.May.2022 Rev.001

TSZ22111 • 14 • 001

www.rohm.com

TSZ02201-0F1F0A200880-1-2

Isolated DC/DC Converter IC

Isolated Type Fly-back Converter IC

with Integrated Switching MOSFET

for Automotive

BD7F205EFJ-C

General Description

BD7F205EFJ-C is an opto-coupler-less isolated flyback

converter. Feedback circuit by optocouplers or the

auxiliary winding of transformers becomes unnecessary,

contributing to reduction of set parts. Furthermore, the

adoption of original adapted ON-time control technology

enables fast load response. In addition, the various

protection function realizes the designs of isolated power

supply application for high reliability.

Features

◼ AEC-Q100 Qualified

(Note 1)

◼ No Need for Optocoupler and Third Winding of

Transformer

◼ Set Output Voltage with Two External Resistors and

Ratio of Transformer Turns

◼ Adopt of Original Adapted ON-Time Control Technology

Fast Load Response

◼ High Efficiency at Light Load Mode (PFM Operation)

◼ Shutdown Function / Enable Control

◼ Built-in 60 V Switching MOSFET

◼ Frequency Spectrum Spread

◼ Soft Start Function

◼ Load Compensation Function

◼ Various Protection Function

Input Low Voltage Lockout (UVLO)

Over Current Protection (OCP)

Thermal Shutdown (TSD)

REF Pin Open Protection (REFOPEN)

Short Circuit Protection (SCP)

Battery Short Protection (BSP)

◼ HTSOP-J8 Package

(Note 1) Grade 1

Key Specifications

◼ Input Voltage Range:

VIN Pin 3.4 V to 42.0 V

SW Pin 60 V (Max)

◼ Switching Frequency: 363 kHz (Typ)

◼ Reference Voltage Precision: ± 2.8 % (Typ)

◼ Shutdown Current: 0 μA (Typ)

◼ Operating Ambient Temperature Range

-40 °C to +125 °C

Package W (Typ) x D (Typ) x H (Max)

HTSOP-J8 4.9 mm x 6.0 mm x 1.0 mm

Applications

◼ Automotive Isolated Power Supplies

(E-Comp, Inverter etc)

◼ Industrial Isolated Power Supplies

Typical Application Circuit

VIN

VOUT+

VOUT-

SDX/EN

L_COMP

REF GND

VIN

RFB

RREF

Datashee

2/32

BD7F205EFJ-C

19.May.2022 Rev.001

www.rohm.com

TSZ22111 • 15 • 001

TSZ02201-0F1F0A200880-1-2

Contents

General Description ........................................................................................................................................................................ 1

Features.......................................................................................................................................................................................... 1

Key Specifications .......................................................................................................................................................................... 1

Package .......................................................................................................................................................................................... 1

Applications .................................................................................................................................................................................... 1

Typical Application Circuit ............................................................................................................................................................... 1

Contents ......................................................................................................................................................................................... 2

Pin Configuration ............................................................................................................................................................................ 3

Pin Descriptions .............................................................................................................................................................................. 3

Block Diagram ................................................................................................................................................................................ 3

Description of Blocks ...................................................................................................................................................................... 4

1 INTERNAL REGULATOR ................................................................................................................................................. 4

2 Input Low Voltage Lock Out (UVLO) ................................................................................................................................. 4

3 Thermal Shutdown (TSD) ................................................................................................................................................. 5

4 SW VOLTAGE DETECTION ............................................................................................................................................. 5

5 SOFT START.................................................................................................................................................................... 5

6 PWM COMPARATOR ....................................................................................................................................................... 5

7 ADAPTIVE ON TIME CONTROLLER .............................................................................................................................. 5

8 Maximum Frequency Limit Function (MAX FREQ) ........................................................................................................... 5

9 DRIVER ............................................................................................................................................................................ 5

10 Nch MOSFET ................................................................................................................................................................... 5

11 LOAD COMPENSATION .................................................................................................................................................. 6

12 Frequency Spectrum Spread (SPECTRUM SPREAD) ..................................................................................................... 6

13 Over Current Protection (OCP), Battery Short Protection (BSP) ...................................................................................... 6

14 Short Circuit Protection (SCP), REF Pin Open Protection (REFOPEN) ........................................................................... 7

Absolute Maximum Ratings ............................................................................................................................................................ 8

Thermal Resistance ........................................................................................................................................................................ 8

Recommended Operating Conditions ............................................................................................................................................. 8

Electrical Characteristics................................................................................................................................................................. 9

Typical Performance Curves ......................................................................................................................................................... 10

Application Examples ................................................................................................................................................................... 18

1 Output Voltage ................................................................................................................................................................ 18

2 Transformer .................................................................................................................................................................... 20

3 Output Capacitor ............................................................................................................................................................ 22

4 Input Capacitor ............................................................................................................................................................... 22

5 Secondary Output Diode ................................................................................................................................................ 23

6 Output Resistor and Output Zener Diode (Minimum Load Current)................................................................................ 23

7 Snubber Circuit ............................................................................................................................................................... 24

8 Setting of SDX/EN Pin Resistor ...................................................................................................................................... 24

9 The Output Voltage Compensation Function by L_COMP Pin Resistor ......................................................................... 25

10 The Influence on Frequency and Output Voltage for Each Load .................................................................................... 26

I/O Equivalence Circuits................................................................................................................................................................ 27

Operational Notes ......................................................................................................................................................................... 28

Ordering Information ..................................................................................................................................................................... 30

Marking Diagram .......................................................................................................................................................................... 30

Physical Dimension and Packing Information ............................................................................................................................... 31

Revision History ............................................................................................................................................................................ 32