DATASHEET ISL85012 FN8677 Rev.2.00 12A, 3.8V to 18V Input, Synchronous Buck Regulator Mar 17, 2017 The ISL85012 is a highly efficient, monolithic, synchronous Features buck regulator that can deliver 12A of continuous output Power input voltage range variable 3.8V to 18V current from a 3.8V to 18V input supply. The device uses current mode control architecture with a fast transient PWM output voltage adjustable from 0.6V response and excellent loop stability. Up to 12A output load The ISL85012 integrates very low ON-resistance high-side and Prebias start-up, fixed 3ms soft-start low-side FETs to maximize efficiency and minimize external Selectable f of 300kHz, 600kHz, and external SW component count. The minimum BOM and easy layout synchronization up to 1MHz footprint are extremely friendly to space constraint systems. Peak current mode control The operation frequency of this device can be set using the - DCM/CCM FREQ pin: 600kHz (FREQ = float) and 300kHz (FREQ = GND). - Thermally compensated current limit The device can also be synchronized to an external clock up to 1MHz. - Internal/external compensation Both high-side and low-side MOSFET current limit along with Open-drain, PG window comparator reverse current limit, fully protects the regulator in an Output overvoltage and thermal protection overcurrent event. Selectable OCP schemes can fit various Input overvoltage protection applications. Other protections, such as input/output overvoltage and over-temperature, are also integrated into the Integrated boot diode with undervoltage detection device which give required system level safety in the event of Selectable OCP schemes fault conditions. -Hiccup OCP The ISL85012 is offered in a space saving 15 Ld 3.5mmx3.5mm -Latch-off Pb-free TQFN package with great thermal performance and Compact size 3.5mmx3.5mm 0.8mm maximum height. Applications Related Literature Servers and cloud infrastructure POLs For a full list of related documents please visit our web page - ISL85012 product page IPCs, factory automation, PLCs Telecom and networking systems Storage systems Test measurement R 200k 1 R 2 100k C 5 C R 1 1F 3 200 4.7pF 15 14 13 12 11 10 FB VIN EN DNC DNC COMP VIN L1 PVIN 9 0.68H 3x22F V OUT 4.5-18V PHASE 8 C in C OUT 3x100F GND 1.8V/12A GND 7 C 4 CERAMIC 100nF GND SYNC MODE FREQ PG VDD BOOT 12 3 4 5 6 C3 2.2F FIGURE 1. TYPICAL APPLICATION SCHEMATIC FOR INTERNAL COMPENSATION FN8677 Rev.2.00 Page 1 of 19 Mar 17, 2017ISL85012 Typical Application Schematic 330pF R 20k 1 80.6k C 5 C 2 R 3 1F C 1 47pF 15 14 13 12 11 10 R 2 FB VIN EN DNC DNC COMP 10k VIN L1 PVIPVINN 99 0.68H V OUT 4.5-18V 3x22F C PHASE 8 in PHASE 8 3x100F C GND OUT 1.8V/12A GND 7 C CERAMIC 4 7 GND 100nF GND SYNC MODE FREQ PG VDD BOOT 12 34 5 6 C 3 2.2F FIGURE 2. TYPICAL APPLICATION SCHEMATIC FOR EXTERNAL COMPENSATION TABLE 1. DESIGN TABLE FOR DIFFERENT OUTPUT VOLTAGE V (V) 0.9 1 1.2 1.5 1.8 2.5 3.3 5 OUT V (V) 4.5 to 18 4.5 to 18 4.5 to 18 4.5 to 18 4.5 to 18 4.5 to 18 4.5 to 18 6 to 18 IN FREQ (kHz) 300 300 300 600 600 600 600 600 Compensation Internal Internal Internal Internal Internal Internal Internal Internal C (F) 3x22 3x22 3x22 3x22 3x22 3x22 3x22 3x22 in C (F) 2x560 + 4x100 2x330 + 3x100 2x330 + 3x100 4x100 3x100 4x47 4x47 4x47 out L (H) 0.68 0.68 1 0.68 0.68 1 1 1.5 1 R (k ) 100 100 147 150 200 301 365 365 1 R (k ) 200 150 147 100 100 95.3 80.6 49.9 2 C (pF) DNP DNP DNP 10 4.7 4.7 3.3 3.3 1 NOTES: 1. The design table is referencing the schematic shown in Figure 1. 2. Ceramic capacitors are selected for 22F and 100F in the table. 3. 560F (14m ) and 330F (10m ) are selected low ESR conductive polymer aluminum solid capacitors. 4. Inductor 7443340068 (0.68H), 7443340100 (1H) and 7443340150 (1.5H) from Wurth Electronics are selected for the above applications. 5. Recommend to keep the inductor peak-to-peak current less than 5A. TABLE 2. KEY DIFFERENCES BETWEEN FAMILY OF PARTS INTERNAL/EXTERNAL EXTERNAL FREQUENCY PROGRAMMABLE SWITCHING CURRENT PART NUMBER COMPENSATION SYNC SOFT-START FREQUENCY (kHz) RATING (A) ISL85003 Yes Yes No 500 3 ISL85003A Yes No Yes 500 3 ISL85005 Yes Yes No 500 5 ISL85005A Yes No Yes 500 5 ISL85012 Yes Yes No 300 or 600 selectable 12 FN8677 Rev.2.00 Page 2 of 19 Mar 17, 2017