Rohm BD7F105EFJ-EVK-001 User manual

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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
Figure 1. BD7F105EFJ-EVK-001
Isolated DC/DC Converters ICs
Built-in Automotive Switching MOSFET
Isolated Flyback Converter ICs
BD7F105EFJ-C Evaluation Board
BD7F105EFJ-EVK-001
Overview
This evaluation board outputs an isolated 16.5 V voltage from an input of 8 V to 32 V, and can output a maximum output current
of 0.25 A.
BD7F105EFJ-C is an isolated flyback converter that does not require a photocoupler.
Feedback circuit by the transformer’s tertiary winding or photocouplers becomes unnecessary, contributing to reduction of set
parts.
It also has a number of built-in protection functions that enable the design of isolated power supply applications for high reliability.
Performance Specifications
This is a typical value and does not guarantee the characteristics.
Unless otherwise specified, VIN = 12 V, IOUT = 0.2 A, Ta = 25 °C
Parameter
Symbol
Min
Typ
Max
Units
Conditions
Input voltage range
VIN
8
12
32
V
Output voltage
VOUT
14.8
16.5
18.2
V
Output current
IOUT
0
0.25
A
Maximum output power
POUT
-
-
4
W
Standby power
PINSTBY
-
40
100
mW
IOUT = 0 A VIN = 12 V
Power Supply Efficiency
η
65
80
-
%
POUT = 2 W
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 2. Connection Diagram
Operating Procedure
1. Necessary equipment
(1) DC power supply with an output voltage of 32 V or more and an output power of 10 W / 5 A or more
(2) Load device of 5 W or more
(3) DC voltmeter
2. Connecting the Equipment
(1) Preset the DC power supply to 8 V to 32 V and turn off the power output.
For power supplies with slow response, connect a large capacitor to the output of the power supply.
(2) Set the load to less than or equal to the rated current of each output and disable the load.
(3) Connect the positive terminal of the power supply to the VIN terminal and the negative terminal to the GND
terminal with a pair of wires.
(4) Connect the positive terminal of the load to VOUT1 terminal and the negative terminal to GND1 terminal with a
pair of wires.
(5) When connecting a wattmeter, connect as shown below. (Refer to your power meter User's Manual for more
information)
(6) Connect the positive terminal of the DC voltmeter to VOUT1 terminal and the negative terminal to GND1
terminal for measuring the output voltage.
(7) Turn on the output of the DC power supply.
(8) Check that the DC voltmeter display is at the set voltage (16.5 V).
(9) Activates the load.
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 3. Circuit diagram
Application circuit
The evaluation board operates with an average frequency 363 kHz.
Monitoring the flyback voltage due to the voltage at the output (16.5 V) provides primary-side feedback control that eliminates
the need for photocouplers and auxiliary windings.
Operation starts when the VIN pin voltage exceeds UVLO detect voltage of 3.4 V (Typ) and SDXEN pin Enable pin voltage of
2.0 V (Typ).
The circuit diagram of the demonstration board is shown in the figure below, and the parts list is shown on page 9.
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
1
2
3
4
8
7
6
5
GND
SDX/EN
L_COMP
REF
VIN
SW
N.C.
FB
EXP-PAD
(TOP VIEW)
Figure 4. Pin layout drawing
Outline of BD7F105EFJ-C
Features
◼AEC-Q100 (Grade-1)
◼No Need for Optocoupler and Third Winding of
Transformer
◼Output voltage is set by two external resistors and
transformer winding ratio.
◼Uses proprietary adaptive ON-time control
technology
◼Highly efficient light load mode (PFM operation)
◼Shutdown and Enable control
◼Burst voltage design possible
◼60 Built-in V-switching MOSFET
◼Spread frequency spectrum
◼Soft start function
◼Load current compensation function
◼Various protection functions
Undervoltage protection (UVLO)
Overcurrent protection (OCP)
Overheat protection (TSD)
REF pin open protection (REFOPEN)
Short-circuit protection (SCP)
Battery short-circuit protection (BSP)
Critical Characteristics
◼Input voltage range :
VIN terminal 3.4 V to 42.0 V
SW pin to 60 V
◼Switching frequency : 363 kHz (Typ)
◼Reference voltage accuracy: ±2.8 % (Typ)
◼Shutdown current 0 μA (Typ)
◼Operating 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
Insulated power supply for automotive use (E-Comp, Inverter
etc)
Insulated power supply for industrial equipment
Pin Layout
PIN ASSIGNMENT
No.
Pin name
Function
1
GND
GND terminal
2
SDX/EN
Shutdown/Enable control pin
3
L_COMP
Load current compensation value setting pin
4
REF
Output voltage setting pin
5
FB
Output voltage setting pin
6
N.C.
No Connect
7
SW
Switching output pin
8
VIN
Power input terminal
-
EXP-PAD
Rear heat dissipation pin
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 5. Output Voltage vs Output Current
Figure 6 Efficiency vs Output Current
Figure 8. Efficiency vs Input Voltage
Figure 8. Frequency vs Input Voltage
Figure 7. Output Voltage vs Input Voltage
Measurement data
1. Load regulation
2. Line regulation
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 9. MOSFET Waveform
Vin = 12 V, IO = 0.1 A
Figure 10. MOSFET Waveform
Vin = 12 V, IO = 0.2 A
Figure 11. Load response
Vin = 12 V, IO = 50 mA to 200 mA
Figure 12. Output Voltage ripple
VIN = 12 V / IO = 250 mA
Figure 13. Output Voltage ripple
VIN = 12 V / IO = 250 mA
Measured data-continued
3. Switching waveform
4. Load response waveform
5. Output voltage ripple waveform
VSW (20V/div)
VOUT (10V/div)
VSW (20V/div)
VOUT (10V/div)
VSW (20V/div)
VOUT (1Vac/div)
IOUT (200mA/div)
VOUT (50mVac/div)
VOUT (50mVac/div)
IOUT (200mA/div)
IOUT (200mA/div)
*This ripple is due to spread spectrum.
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 14. Start Up Waveform
Figure 15. Shut Down Waveform
Figure 16. VOUT Short Waveform
Vin = 8 V
Figure 17. VOUT Short Waveform (ZOOM)
Vin = 8 V
Figure 18. VOUT Short Waveform
Vin = 15 V
Figure 19. VOUT Short Waveform (ZOOM)
Vin = 15 V
Measured data-continued
6. Startup/stop waveform
7. Output short waveform
VSW (20V/div)
VSW (20V/div)
VOUT (10V/div)
VSW (20V/div)
VOUT (10V/div)
VIN (5V/div)
VIN (5V/div)
VIN (10V/div)
VSW (20V/div)
ISW (2A/div)
VOUT (20V/div)
VSW (20V/div)
VOUT (20V/div)
VIN (10V/div)
ISW (2A/div)
10ms/div
500us/div
VIN (10V/div)
VSW (20V/div)
ISW (2A/div)
VOUT (20V/div)
VOUT (20V/div)
ISW (2A/div)
VSW (20V/div)
VIN (10V/div)
10ms/div
500us/div
VOUT (20V/div)
ISW (2A/div)
VSW (20V/div)
VIN (10V/div)
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 20. Surface Temperature
Vin = 8 V, IO = 250 mA (Ta = 23.3℃)
Figure 21. Surface Temperature Reference
Figure 22. Peak Current Waveform
Vin = 8 V, IO = 250 mA
Table 1. Tj Calculation
Measured data-continued
8. Component surface temperature
Tj calculation of IC is calculated using the above table.
Loss of IC is divided into 1: Turn on loss, 2: conduction loss, 3: Turn off loss, and 4: ICC.
Calculate the loss according to Table1 from the actual current waveform and power supply spec.
In this case, Tj is estimated to be 37.73 °C because Tc = 30.3 °C and ΔTj = 7.07 °C.
Tj should be designed to be 150 °C or less.
In this case, when Ta = 125 °C, Tj = 137.4 °C, and Tj = 150 °C is not reached, so it can be judged that there is no problem in the
whole temperature range.
VIN (10V/div)
VSW (20V/div)
ISW (2A/div)
VOUT (20V/div)
30.3℃
VSW (10V/div)
IOUT (500mA/div)
①
②
③
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Figure 23. BD7F105EFJ-EVK-001 Schematic
Circuit diagrams
(Condition) VIN = 8 V to 32 V, VOUT = 16.5 V, 0.2 A
Bill of Materials
*Parts are subject to change without notice.
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© 2022 ROHM Co., Ltd.
No. 65UG016E Rev.001
2022.7
User's Guide
BD7F105EFJ-EVK-001
Transformer specifications
Manufacturer : Sumida Electric Co., Ltd.
https://job.mynavi.jp/conts/n/sp/23/54430_23sumida/
Product name: CEFD2010_00399_T379
◼External Dimensions
◼Recommended Land
■Terminal connection diagram
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