L6743Q STMicroelectronics, L6743Q Datasheet
L6743Q
Specifications of L6743Q
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L6743Q Summary of contents
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... Applications ■ High current VRM / VRD for desktop / server / workstation CPUs ■ High current and high efficiency converters Description L6743, L6743Q is a flexible, high-frequency dual- driver specifically designed to drive N-channel MOSFETs connected in synchronous-rectified buck topology. Table 1. Device summary Order code L6743 ...
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... Electrical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Device description and operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1 High-impedance (HiZ) management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.2 Preliminary OV protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.3 Internal BOOT diode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.4 Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 5.5 Layout guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 7 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 2/17 L6743, L6743Q ...
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... L6743, L6743Q 1 Typical application circuit and block diagram 1.1 Application circuit Figure 1. Typical application circuit 12V CC C PWM Input EN Input L6743 Reference Schematic 1.2 Block diagram Figure 2. Block diagram VCC EN PWM Typical application circuit and block diagram DEC VCC BOOT PWM ...
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... PCB. Connect to the PGND plane. (DFN10 only) 4/17 UGATE 1 8 PHASE 2 7 L6743 3 6 GND 4 5 LGATE for guidance in designing the capacitor value. Section 5.1 Section 5.1 for details about HiZ. L6743, L6743Q BOOT 1 10 PWM L6743Q 8 VCC 4 7 VCC 5 6 Function BOOT for details about HiZ ...
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... L6743, L6743Q 3 Thermal data Table 3. Thermal data Symbol Thermal resistance junction to ambient R thJA (Device soldered on 2s2p board) R Thermal resistance junction to case thJC T Maximum junction temperature MAX T Storage temperature range STG T Junction temperature range J Maximum power dissipation at 25°C P TOT (Device soldered on 2s2p PC board) ...
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... VCC rising VCC falling PWM rising PWM falling EN rising EN falling to GND BOOT - PHASE = 12 V; 100 mA BOOT - PHASE = PHASE = 3.3 nF UGATE BOOT - PHASE = 12 V; 100 mA 100 mA ( GND = 5.6 nF LGATE 100 mA PHASE rising L6743, L6743Q Min. Typ. Max. Unit 4 0.8 V 150 ...
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... This mechanism allows the system to regulate even if the current is negative. Before VCC to overcome the UVLO threshold, L6743, L6743Q keeps firmly-OFF both high- side and low-side MOSFETS then, after the UVLO has been crossed, the EN and PWM inputs take the control over driver’ ...
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... Preliminary OV protection After VCC has overcome its UVLO threshold and while in HiZ, L6743, L6743Q activates the Preliminary-OV protection. The intent of this protection is to protect the load especially from high-side MOSFET failures during the system start-up. In fact, VRM, and more in general PWM controllers, have bus compatible turn-on threshold and results to be non-operative if VCC is below that turn- on thresholds (that results being in the range of about 10 V) ...
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... L6743, L6743Q 5.3 Internal BOOT diode L6743, L6743Q embeds a boot diode to supply the high-side driver saving the use of an external component. Simply connecting an external capacitor between BOOT and PHASE complete the high-side supply connections. To prevent bootstrap capacitor to extra-charge as a consequence of large negative spikes, an external series resistance R BOOT pin ...
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... Device description and operation When designing an application based on L6743, L6743Q it is recommended to take into consideration the effect of external gate resistors on the power dissipated by the driver. External gate resistors helps the device to dissipate the switching power since the same power P will be shared between the internal driver impedance and the external resistor SW resulting in a general cooling of the device ...
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... L6743, L6743Q 5.5 Layout guidelines L6743, L6743Q provides driving capability to implement high-current step-down DC-DC converters. The first priority when placing components for these applications has to be reserved to the power section, minimizing the length of each connection and loop as much as possible. To minimize noise and voltage spikes (also EMI and losses) power connections must be a part of a power plane and anyway realized by wide and thick copper traces: loop must be anyway minimized ...
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... Device description and operation Figure 8. External components placement example BOOT PWM EN VCC 12/17 Rboot Cboot UGATE PHASE 3 6 GND L6743 4 5 LGATE L6743, L6743Q Rboot Cboot BOOT UGATE 1 10 PWM PHASE GND 3 8 L6743Q VCC GND 4 7 VCC LGATE 5 6 ...
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... L6743, L6743Q 6 Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label ...
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... L6743, L6743Q mils Min Typ Max 53.1 68.9 3.9 9.8 43.3 65.0 13.0 20.1 7.5 9.8 189.0 196.9 149.6 157.5 50 ...
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... L6743, L6743Q Table 7. DFN10 mechanical data Dim Figure 10. Package dimensions mm Min Typ Max 0.80 0.90 1.00 0.02 0.05 0.70 0.20 0.18 0.23 0.30 3.00 2.21 2.26 2.31 3.00 1.49 1.64 1.74 0.50 0.3 0.4 0.5 0.75 0.25 Package mechanical data mils ...
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... Revision history 7 Revision history Table 8. Document revision history Date 20-Aug-2007 05-Jun-2008 16/17 Revision 1 Initial release 2 Updated: Table 6 on page 15 L6743, L6743Q Changes ...
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... L6743, L6743Q Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...