LM25183

Part: LM25183 — Texas Instruments

Type: Primary-Side Regulated (PSR) Flyback DC/DC Converter

Description: The LM25183 is a 4.5–42 V input, primary-side regulated flyback converter with an integrated 65-V, 2.5-A power MOSFET, providing up to 10 W output power with ±1.5% total output regulation accuracy.

Operating Conditions:

• Supply voltage: 4.5–42 V (operation down to 3.5 V after start-up)
• Operating junction temperature: -40 to 150 °C
• SW voltage: 65 V

Absolute Maximum Ratings:

• Max supply voltage (VIN to GND): 45 V
• Max SW to GND voltage: 70 V
• Max operating junction temperature: 150 °C
• Max storage temperature: 150 °C

Key Specs:

• VIN shutdown current (V EN/UVLO = 0 V): 1.8 μA (Typ)
• VIN active current (V EN/UVLO = 2.5 V, V RSET = 1.8): 260 μA (Typ)
• Enable threshold (V EN/UVLO rising): 1.45 V (Min), 1.5 V (Typ), 1.53 V (Max)
• RSET regulation voltage (R RSET = 12.1 kΩ): 1.194 V (Min), 1.21 V (Typ), 1.22 V (Max)
• Minimum switching frequency: 12 kHz (Typ)
• Maximum switching frequency: 350 kHz (Typ)
• MOSFET on-state resistance (I SW = 100 mA, T J = 25°C): 0.11 Ω (Typ), 0.135 Ω (Max)
• Peak current limit threshold: 2.2 A (Min), 2.5 A (Typ), 2.65 A (Max)
• Thermal shutdown threshold (T J rising): 175 °C (Typ)

Features:

• Wide input voltage range of 4.5 V to 42 V
• Integrated 65-V, 0.11-Ω power MOSFET
• No optocoupler or transformer auxiliary winding required for VOUT regulation
• Internal loop compensation
• Quasi-resonant MOSFET turnoff in BCM
• Hiccup-mode overcurrent fault protection
• Input UVLO and thermal shutdown protection
• Optional VOUT temperature compensation

Applications:

• Motor drives: IGBT and SiC gate driver supplies
• Isolated field transmitters and field actuators
• Isolated bias power rails

Package:

• WSON (8) 4.00 mm × 4.00 mm

• Functional Safety-Capable
• -Documentation available to aid functional safety system design
• Designed for reliable and rugged applications
• -Wide input voltage range of 4.5 V to 42 V with operation down to 3.5 V after start-up
• -Robust solution with only one component crossing the isolation barrier
• -±1.5% total output regulation accuracy
• -Optional VOUT temperature compensation
• -Input UVLO and thermal shutdown protection
• -Hiccup-mode overcurrent fault protection
• --40°C to +150°C junction temperature range
• Integration reduces solution size and cost
• -Integrated 65-V, 0.11-Ω power MOSFET
• -No optocoupler or transformer auxiliary winding required for V OUT regulation
• -Internal loop compensation
• High-efficiency PSR flyback operation
• -Quasi-resonant MOSFET turnoff in BCM
• -External bias option for improved efficiency
• -Single- and multi-output implementations
• Ultra-low conducted and radiated EMI signatures
• -Soft switching avoids diode reverse recovery
• -Optimized for CISPR 32 EMI requirements
• Create a custom flyback regulator design using WEBENCH ® Power Designer

• Motor drives: IGBT and SiC gate driver supplies
• Isolated field transmitters and field actuators
• Isolated bias power rails

Figure 5-1. 8-Pin WSON NGU Package With Wettable Flanks (Top View)

Typical values correspond to TJ = 25°C. Minimum and maximum limits aaply over the full -40°C to 150°C junction temperature range unless otherwise indicated. VIN = 12 V and VEN/UVLO = 2 V unless otherwise stated.

Over the recommended operating junction temperature range of -40°C to 150°C (unless otherwise noted) (1)

Over the recommended operating junction temperature range of -40°C to 150°C (unless otherwise noted)

The LM25183 requires only a few external components to convert from a wide range of supply voltages to one or more isolated output rails. To expedite and streamline the process of designing of a LM25183-based converter, a comprehensive LM25183 quick-start calculator is available for download to assist the designer with component selection for a given application. WEBENCH ® online software is also available to generate complete designs, leveraging iterative design procedures and access to comprehensive component databases. The following sections discuss the design procedure for both single- and dual-output implementations using specific circuit design examples.

As mentioned previously, the LM25183 also integrates several optional features to meet system design requirements, including precision enable, input UVLO, programmable soft start, output voltage thermal compensation, and external bias supply connection. Each application incorporates these features as needed for a more comprehensive design.

The application circuits detailed in Section 8.2 show LM25183 configuration options suitable for several application use cases. Refer to the LM25184EVM-S12 EVM user's guide for more detail.