Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET

Product catalog summary

General Description
The BM2SC12xFP2-LBZ series is a quasi-resonant AC/DC converter designed for industrial applications, featuring a built-in 1700 V SiC-MOSFET. It supports long-term use in the industrial market and offers low EMI through quasi-resonant operation. The IC is designed for flexibility with external current detection resistors and includes various protection functions such as soft start, burst operation, and overcurrent protection.

Features

Long-term support for industrial applications
TO263-7L package
Built-in 1700 V SiC-MOSFET
Low EMI quasi-resonant type
Frequency reduction function
Low standby current consumption (19 µA)
Burst operation at light load
Multiple protection functions including overcurrent and overvoltage protection

Key Specifications

Operating power supply voltage range: VCC: 15.0 V to 27.5 V, DRAIN: 1700 V (Max)
Normal operating current: 800 µA (Typ)
Burst operating current: 500 µA (Typ)
Maximum operating frequency: 120 kHz (Typ)
Operating temperature: -40 °C to +105 °C

Applications
Suitable for industrial equipment, AC adaptors, and household appliances.

Startup Sequences
The startup sequence involves applying input voltage, releasing the VCC UVLO function, and starting the switching operation. The IC includes a soft start function to regulate voltage and prevent excessive rise in voltage and current.

VCC Pin Protection Function
The IC includes VCC low voltage protection (UVLO) and overvoltage protection (OVP) to prevent voltage-related failures in MOSFETs. The UVLO function is auto-restart type, while the OVP function can be latch or auto-restart mode.

DC/DC Converter Function
The BM2SC12xFP2-LBZ uses PFM mode control, monitoring the FB, ZT, and SOURCE pins to optimize the DC/DC system. The ON width is controlled by the FB and SOURCE pins, while the OFF width is controlled by the ZT pin. The IC includes a leading edge blanking function to prevent detection errors in the overcurrent limiter circuit.

Conclusion
The BM2SC12xFP2-LBZ series offers a robust solution for industrial applications requiring efficient AC/DC conversion with integrated protection features and low EMI operation.

Specifications
The document outlines the electrical characteristics of the BM2SC12xFP2-LBZ Series, focusing on parameters such as over current detection voltage, switching frequencies, and protection functions. Key specifications include:

Over Current Detection Voltage for SOURCE Pin: VLIM2A ranges from 0.200 to 0.400 V, and VLIM2B ranges from 0.140 to 0.280 V.
Maximum Operating Frequency: fSW1 is 106 to 134 kHz, and fSW2 is 20 to 40 kHz.
Soft Start Times: tSS1 is 0.600 to 1.400 ms, and tSS2 is 2.400 to 5.600 ms.

Procedures and Recommendations
The document provides operational notes and recommendations for using the IC:

Reverse Connection of Power Supply: Use an external diode to prevent damage from reverse polarity.
Power Supply Lines: Ensure low impedance and connect capacitors to ground at all power supply pins.
Ground Wiring: Separate small-signal and large-current ground traces, connecting them at a single reference point.
Inrush Current: Consider power coupling capacitance and ground wiring to manage inrush current during power-up.
Testing: Discharge capacitors completely after each test and ensure proper grounding to prevent static discharge damage.

Performance Curves
The document includes various performance curves showing the relationship between operating parameters and temperature. Key observations include:

Standby, Normal, Burst, and Protection Circuit Operating Currents vary with temperature.
VCC UVLO and OVP Voltages are temperature-dependent.
FB Pin Frequency Reduction Start and End Voltages change with temperature.

Critical Information
Ensure operation within recommended conditions to guarantee IC functionality. Pay attention to inter-pin shorts and mounting errors to avoid damage. Unused input pins should not be left unconnected to prevent unintended charging.

Operational Notes
1. Unused Input Pins: Connect unused input pins to the power supply or ground to prevent unexpected IC operation.
2. Input Pin Isolation: The IC uses P+ isolation and P substrate layers to prevent interference. Avoid applying voltage lower than GND to input pins to prevent parasitic diode operation.
3. Ceramic Capacitor: Consider temperature and DC bias effects on capacitance when selecting ceramic capacitors.
4. Thermal Shutdown Circuit (TSD): Protects the IC from heat damage by shutting down power output when maximum junction temperature is exceeded.
5. Over Current Protection Circuit (OCP): Activates during load shorting to prevent damage, but not suitable for continuous operation.

Ordering Information
Details the part numbers, package types, and features such as Auto Restart and Latch modes for the BM2SC12xFP2-LBZ series.

Precautions
1. High-Reliability Applications: Consult ROHM for use in critical applications like medical or aerospace.
2. Safety Measures: Implement fail-safe designs and protection circuits.
3. Environmental Conditions: Avoid using products in extreme conditions such as exposure to corrosive gases or static electricity.
4. Electrostatic Sensitivity: Handle with care to prevent damage from electrostatic discharge.
5. Storage and Transportation: Follow recommended conditions to maintain product integrity.

Intellectual Property and Usage Rights
ROHM provides information for reference only and does not guarantee non-infringement of third-party rights. Products should not be used for military purposes without consent.

Catalog excerpts

Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-1

Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET BM2SC12xFP2-LBZ Series General Description This is the product guarantees long time support in industrial market. BM2SC12xFP2-LBZ series is a quasi-resonant AC/DC converter that provides an optimum system for all products which has an electrical outlet. Quasi-resonant operation enables soft switching and helps to keep the EMI low. This IC can be designed easily because it includes the 1700 V SiC (Silicon-Carbide) MOSFET. Design with a high degree of flexibility is achieved with current detection resistors as external devices. The burst operation reduces an electric power at light load. BM2SC12xFP2-LBZ series includes various protection functions, such as soft start function, burst operation function, over current limiter per cycle, over voltage protection, overload protection. ◼ Operating Power Supply Voltage Range: VCC: 15.0 V to 27.5 V DRAIN: 1700 V (Max) ◼ Normal Operating Current: 800 µA (Typ) ◼ Burst Operating Current: 500 µA (Typ) ◼ Maximum Operating Frequency: 120 kHz (Typ) ◼ Operating Temperature: -40 °C to +105 °C Long Time Support Product for Industrial Applications TO263-7L Package Built-in 1700 V SiC-MOSFET Quasi-resonant Type (Low EMI) Frequency Reduction Function Low Current Consumption (19 µA) during Standby Burst Operation at Light Load SOURCE Pin Leading Edge Blanking VCC UVLO (Under Voltage Lock Out) VCC OVP (Over Voltage Protection) Over Current Protection Circuit per Cycle Soft Start Function ZT Pin Trigger Mask Function ZT OVP (Over Voltage Protection) BR UVLO (Under Voltage Lock Out) FB OLP Auto Restart Latch Auto Restart Latch VCC OVP Latch Latch Auto Restart Auto Restart Applications Industrial Equipment, AC Adaptor, Household Appliances Typical Application Circuit FUSE Filter Diode Bridge SOURCE SOURCE 〇Product structure : Silicon integrated circuit www.rohm.com © 2020 ROHM Co., Ltd. All rights reserved. TSZ22111 • 14 • 001 〇This product has no designed protection against radioactive rays.

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-2

BM2SC12xFP2-LBZ Series Pin Configuration (TOP VIEW) ZT VCC GND FB BR SOURCE SOURCE DRAIN www.rohm.com © 2020 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001 Function Zero current detection pin Power supply input pin GND pin Feedback signal input pin AC voltage detect pin MOSFET SOURCE pin MOSFET SOURCE pin MOSFET DRAIN pin

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-3

BM2SC12xFP2-LBZ Series Block Diagram VOUT Diode Bridge Internal Supply Gate Clamper Internal Supply Maximum Blanking Frequency Burst Comp. Soft Start CURRENT SENSE (V-V Change) Leading Edge Blanking www.rohm.com © 2020 ROHM Co., Ltd. All rights reserved. TSZ22111 • 15 • 001

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-4

BM2SC12xFP2-LBZ Series Description of Blocks 1 Startup Sequences (FB OLP: Auto Restart Mode) The BM2SC12xFP2-LBZ’s startup sequence is shown in Figure 1. See the sections below for the detailed descriptions. Over Load Normal Load Light Load Burst Mode Switching Soft Start Figure 1. Startup Sequence Timing Chart A: B: C: The input voltage VH is applied. The VCC pin voltage rises due to start resistor RSTART. This IC starts operating when the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V). When the protection functions are judged as normal status, the switching operation starts. At that...

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-5

Startup Sequences (FB OLP: Auto Restart Mode) – continued Start resistance RSTART is the resistance required to start the IC. If the start resistance RSTART value is set to low, the standby power becomes high and the startup time becomes short. Conversely, if the start resistance R START value is set to high, standby power becomes low and the startup time becomes long. The standby current I OFF of BM2SC12xFP2LBZ is 30 µA (Max). However, this is the minimum current required to start the IC. It is necessary to set the appropriate current value for the set target. e.g. Start Resistance RSTART Setting...

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-6

BM2SC12xFP2-LBZ Series Description of Blocks – continued 2 VCC Pin Protection Function BM2SC12xFP2-LBZ includes the VCC low voltage protection function VCC UVLO and the VCC over voltage protection function VCC OVP. These functions prevent the abnormal voltage-related break in MOSFETs used for switching. The VCC UVLO function is an auto restart type comparator with voltage hysteresis and the VCC OVP function is the comparator uses latch mode or auto restart mode. After latch function is detected by VCC OVP, latching is released (reset) when the condition the VCC pin voltage < VLATCH (Typ = VUVLO2...

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-7

VCC Pin Protection Function – continued Figure 3. VCC UVLO/OVP (Auto Restart Mode) A: B: VH is applied, the VCC pin voltage rises. When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), the VCC UVLO function is released and the switching operation starts. C: When the VCC pin voltage becomes lower than VUVLO2 (Typ = 14.0 V), the switching operation stops by the VCC UVLO function. D: When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), the VCC UVLO function is released and the switching operation starts. E: The VCC pin voltage drops until the output voltage is stabilized....

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-8

BM2SC12xFP2-LBZ Series Description of Blocks – continued 3 DC/DC Converter Function BM2SC12xFP2-LBZ uses PFM (Pulse Frequency Modulation) mode control. The FB pin, the ZT pin, and the SOURCE pin are monitored to provide a system optimized as DC/DC. The switching MOSFET ON width (turn OFF) is controlled by the FB pin and the SOURCE pin, and the OFF width (turn ON) is controlled by the ZT pin. By setting maximum frequency, PFM mode will control it to meet noise regulation. A detailed description is below. (Refer to Figure 4) Internal Supply Gate Clamper NOUT FBOLP_OH OR Maximum Blanking Frequency...

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Quasi-resonant AC/DC Converter Built-in 1700 V SiC-MOSFET-9

DC/DC Converter Function – continued 3.1 Determination of ON Width (Turn OFF) ON width is controlled by the FB pin and the SOURCE pin. The ON width is determined by comparing the FB pin voltage at 1/AV (Typ = 1/2) with the SOURCE pin voltage. In addition, the comparator level is changed by comparing with the IC's internally generated VLIM1A (Typ = 1.0 V), as is shown in Figure 5. The SOURCE pin is also used for the over current limiter circuit per pulse. Changes at the FB pin changes in the maximum blanking frequency and over current limiter level. mode 1: Burst operation mode 2: Frequency reduction...

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