L5983 1.5 A step-down switching regulator Datasheet - production data Industrial: chargers, PLD, PLA, FPGA Networking: XDSL, modems, DC-DC modules Computer: optical storage, hard disk drive, printers, audio/graphic cards VFQFPN8 3 x 3 mm LED driving Description Features The L5983 is a step-down switching regulator 1.5 A DC output current with a 2.0 A (min.) current limited embedded 2.9 V to 18 V input voltage Power MOSFET, so it is able to deliver an output Output voltage adjustable from 0.6 V current in excess of 1.5 A DC to the load. 250 kHz switching frequency, programmable The input voltage can range from 2.9 V to 18 V, up to 1 MHz while the output voltage can be set starting from 0.6 V to V . Having a minimum input voltage of Internal soft-start and inhibit IN 2.9 V, the device is suitable also for a 3.3 V bus. Low dropout operation: 100% duty cycle Requiring a minimum set of external components, Voltage feedforward the device includes an internal 250 kHz switching Zero load current operation frequency oscillator that can be externally Overcurrent and thermal protection adjusted up to 1 MHz. VFQFPN8 3 x 3 mm package The VFQFPN package with an exposed pad allows reducing the R down to approximately thJA 60 C/W. Applications Consumer: STB, DVD, DVD recorder, car audio, LCD TV and monitors Figure 1. Application circuit May 2014 DocID13005 Rev 8 1/41 This is information on a product in full production. www.st.comContents L5983 Contents 1 Pin settings 3 1.1 Pin connection 3 1.2 Pin description 3 2 Maximum ratings 4 2.1 Absolute maximum ratings . 4 2.2 Thermal data . 4 3 Electrical characteristics . 5 4 Functional description . 7 4.1 Oscillator and synchronization 8 4.2 Soft-start 10 4.3 Error amplifier and compensation .11 4.4 Overcurrent protection . 12 4.5 Inhibit function . 13 4.6 Hysteretic thermal shutdown 13 5 Application information . 14 5.1 Input capacitor selection 14 5.2 Inductor selection . 15 5.3 Output capacitor selection 16 5.4 Compensation network . 17 5.4.1 Type III compensation network . 18 5.4.2 Type II compensation network 22 5.5 Thermal considerations 26 5.6 Layout considerations . 27 5.7 Application circuit . 29 6 Application ideas . 33 6.1 Positive buck-boost . 33 6.2 Inverting buck-boost . 35 2/41 DocID13005 Rev 8