DC-DC converters High performance switching regulators for industrial Up to 3 A and up to 61 V input voltage range step down ideal for fail safe systems ST’s L7985, L7986, L7987 and ST1S14, are perfect solutions for industrial applications and fail safe systems. These devices are able to provide up to 3 A of continuous output current and with a wide input voltage range from 4.5 V up to 61 V, accordingly to the part number chosen. High flexibility is given by several adjustable parameters, like output voltage, switching frequency, current limit and soft start to name a few. KEY FEATURES • High switching frequency up to 1.5 MHz • Wide input voltage range up to 61 V • Full set of embedded protection functions • Extended operation junction temperature KEY BENEFITS • High safety margin KEY APPLICATIONS • Industrial application • Fail safe systems • Factory automation • Building automation • PLCs • 24 V bus applications • High robustness and reliability • High design flexibility • Low BOM cost www.st.com BLOCK DIAGRAM Digital I/O Sensors Power supply line 12 V - 24 V Vin DC-DC Analog output modules 1.. Analog output modules # DEVICE SUMMARY Part Number Package Input voltage range (V) L7985, L7985A L7986, L7986A DFN3x3 10L/ HSOP 8 DFN3x3 10L/ HSOP 8 L7986TA ST1S14 L7987(*) L7987L(*) HSOP 8 HSOP 8 HTSSOP 16 HTSSOP 16 4.5 to 38 4.5 to 38 4.5 to 38 5.5 to 48 4.5 to 61 4.5 to 61 2 3 3 3 Up to 3 Up to 2 0.6 to Vin 0.6 to Vin 0.6 to Vin 0.8 to 97% Vin 0.8 to 97% Vin 0.8 to 97% Vin Switching frequency (kHz) 250 to 1000 250 to 1000 250 to 1000 850 250 to 1500 250 to 1500 External synchronization frequency (kHz) Up to 1000 Up to 1000 Up to 1000 N.A Up to 1500 Up to 1500 Adjustable current limit, Adjustable soft start, Enable pin, PGood Adjustable current limit, Adjustable soft start, Enable pin, PGood Output current (A) Output voltage range (V) Additional features Enable pin, Soft start Enable pin, Soft start Enable pin, Soft start Enable/Inhibit pin, PGood, Soft start Operating junction temperature (Tj °C) -40, 150 -40, 150 -40, 150 -40, 150 -40, 150 -40, 150 25 25 -40, 125 25 25 25 Parameters tested and guaranteed over the temperature Tj (°C) (*) Coming soon © STMicroelectronics - April 2014 - Printed in United Kingdom - All rights reserved The STMicroelectronics corporate logo is a registered trademark of the STMicroelectronics group of companies All other names are the property of their respective owners Order code: FLL798x0414 For more information on ST products and solutions, visit www.st.com