PRODUCT DATA SHEET PLANAR POWER TRANSFORMER Features Applications ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ ∗ Planar windings 4mm height above PCB Low leakage inductance High frequency operation Externally configurable 18–70V input capability Auxiliary winding Lead-free (Pb-free) P6140 DC-DC converters Flyback converters 48V or 24V systems 15V @ 1A output 5V @ 3A output DESCRIPTION P6140 is a planar power transformer using multilayer PCB technology. It is intended for low profile high frequency discontinuous flyback DC-DC converters up to 500kHz. With careful design, output power exceeding 20W is achievable. P6140 has split primaries that can be configured in series or parallel for nominal 48V and 24V systems respectively, with nominal 15V output. The recommended input voltage range is 18V to 70V. Additionally, an auxiliary winding is provided on the primary side. ETALDOC 855/2 Page 1 of 4 The contacts to the host circuit board are made by solder connection to large plated-through holes in the P6140 PCB, thus ensuring low resistance connection. The ferrite is intended to sit within a PCB cut-out, giving a height above board of 4mm. P6140 is lead-free (Pb-free) and suitable for conventional and lead-free processing. August 2004 P6140 SPECIFICATIONS Electrical Typical values at T = 25ºC, unless otherwise stated. Parameter Conditions Min Typ Max Units Primary Inductance 100kHz, 100mV Each primary winding 3-8, 4-7 P6140-1 2.0 2.25 2.50 µH P6140-2 2.4 2.8 3.25 µH - - 100 nH 500 - - Vrms Leakage Inductance 500kHz, 100mV (3, 4)-(7, 8); link 1, 2, 9, 10; link 5, 6 Primary/Secondary voltage isolation (3+4+5):2 Interwinding capacitance 100kHz, 1V - 325 - pF Total transformer losses Vout = 15V at Iout = 1A 400kHz - 0.6 - W DCR Primaries 3-8, 4-7 12 16 20 mΩ Auxiliary 53 70 87 mΩ Secondary: each section 2-1, 1-10, 10-9 3.4 4.5 5.6 mΩ - 1.0 1.0 1.0 1.0 1.0 - - -40 -40 - +85 +85 ºC ºC Turns Ratio (3-8):(4-7) (3-8):(5-6) (3-8):(9-2) (9-10):(10-1) (9-10):(1-2) Operating range: Functional Storage Ambient temperature Transformer sc hematic Typical Magnetic Core Coefficients C1 Core factor Ve Effective volume le Effective length Ae Effective area µe Effective permeability m Mass ETALDOC 855/2 Fig 1 -1 0.514mm 3 PRIMARY 3 800mm 20.3mm 3T 8 4 PRIMARY 2 39.5mm 123 (P6140-1) 154 (P6140-2) 4.1g Page 2 of 4 2 1T 1 1T SECONDARY 10 3T 1T 7 5 9 AUXILIARY 3T 6 August 2004 P6140 APPLICATION SCHEMATICS In the flyback converter topology, the transformer operates as an energy storage element, and the ferrite core of P6140 is gapped to avoid saturation. The variants P6140-1 and P6140-2 differ in their gap sizes to suit particular applications and switching frequencies. P6140-1 is recommended for frequencies from 100kHz to 350kHz; P6140-2 is recommended for frequencies from 350kHz to 500kHz Note that in the discontinuous conduction flyback mode, the output load current flows when the switch is open. Observe winding polarities. The auxiliary winding may be used to provide a power rail for switching and control circuits. In the schematics below, switch drive circuitry and feedback components are omitted for simplicity. 48V operation (38–70V) For 48V operation the transformer primaries are connected in series, giving nominal primary inductance of 9µH (P6140-1) and 11.3µH (P6140-2), and primary DCR of 33mΩ. Fig 2 shows a typical schematic with a 15V @ 1A output. For a 5V output, use the output tap as shown in fig 3. 48V Operation Fig 2 3 2 1A + 8 + 38-70V – 15V 4 7 SWITCH – 9 For 5V output see fig 3 24V operation (18–38V) For 24V operation the transformer primaries are connected in parallel, giving nominal primary inductance of 2.25µH (P6140-1) and 2.84µH (P6140-2), and primary DCR of 8mΩ. Fig 3 shows a typical schematic with a 5V @ 3A output. For a 15V output, use the output tap as shown in fig 2. 24V Operation Fig 3 3 3A + 8 + 18-38V – 4 7 SWITCH 10 5V – 9 For 15V outp ut see fig 2 Multiple output Following the examples given in figs 2 and 3, the secondary taps can be utilized to provide multiple output voltages. For example, fig 4 shows a 48V input flyback converter with +10V and ±5V outputs. Other combinations are possible. Multiple output Fig 4 + 10V 3 8 + 48V – 4 2 1 0V + 5V 10 0V 7 SWITCH 9 -5V ETALDOC 855/2 Page 3 of 4 August 2004 P6140 CONSTRUCTION Dimensions Connections Fig 6 25.0 12.0 9.8 5 19.2 3 4.2 PCB c utout 4 CORE Mounting pads: plated through holes ø1.5 11.7 10.0 2.1 7.0 7.9 1 2 9.8 Pin 1 ident 9.8 7.0 6 CYYMM 7.7 18.0 12.0 7 7.9 8 P6140 - X 10 9 Cu PADS 2.0 x 2.4 (10x) R1 . 4.2 Fig 5 20 6.0 RECOMMENDED PCB LAYOUT (TOP VIEW) Dimensions shown are in millimetres. Terminal finish is 0.1µm max gold (Au) over nickel (Ni). ORDERING CODE ABSOLUTE MAXIMUM RATINGS (Ratings of components independent of circuit). P6140- T Tape and Reel (400 parts per 13” reel) Gap variant: 1= 2.25µH (nominal), frequency 100—350kHz Short term isolation voltage (1s) 500Vrms Peak primary Current 8A (primaries in series) 2= 2.84µH (nominal), frequency 350—500kHz 16A (primaries in parallel; 8A per primary winding) Type code V.µs per primary winding 24V.µs (for B=200mT) Storage temperature +85ºC Magnetic Core temperature 120ºC Reflow temperature (10s) 260ºC ISO 9001 FM 25326 ETAL Group Oy, Kuormatie 14, FIN-03101, Nummela Telephone: +358 (0)20 7500 330 Fax: +358 (0)20 7500 333 Website: www.etalgroup.com Email: [email protected] ETALDOC 855/2 Page 4 of 4 August 2004