DATASHEET ISL85009 FN8918 Rev.1.00 9A, 3.8V to 18V Input, Synchronous Buck Regulator Mar 28, 2017 The ISL85009 is a highly efficient, monolithic, synchronous Features buck regulator that can deliver 9A of continuous output current Power input voltage range variable 3.8V to 18V from a 3.8V to 18V input supply. The device uses current mode control architecture with a fast transient response and PWM output voltage adjustable from 0.6V excellent loop stability. Up to 9A output load The ISL85009 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 protect 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 ISL85009 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, 15 Ld TQFN 0.8mm maximum height. Applications Related Literature Servers and cloud infrastructure POLs For a full list of related documents please visit our web page - ISL85009 product page IPCs, factory automation, and PLCs Telecom and networking systems Storage systems Test measurement R 2 C 1 C VIN R 3 100 90 R 1 15 14 13 12 11 10 80 VIN EN DNC DNC COMP FB VIN 9 L PVIN 1 VOUT 70 4.5V TO 8 PHASE 18V C 60 IN 7 GND C OUT SYNCMODE FREQ PG VDD BOOT 50 1 2 34 56 Vout = 5V, fsw = 600kHz 40 C VDD Vout = 3.3V, fsw = 600kHz C 2.2F BOOT 30 100nF 0 123 456 78 9 OUTPUT CURRENT (A) FIGURE 1. TYPICAL APPLICATION SCHEMATIC FOR INTERNAL COMPENSATION FIGURE 2. EFFICIENCY (V = 12V) IN FN8918 Rev.1.00 Page 1 of 20 Mar 28, 2017 EFFICIENCY (%)ISL85009 Typical Application Schematic C 1 C 2 C VIN R 3 R 1 R 2 15 14 13 12 11 10 VIN VIN EN DNC DNC COMP FB 9 PVIN L 1 VOUT 4.5 TO 8 PHASE 18V C IN 7 GND C OUT SYNCMODE FREQ PG VDD BOOT 1 2 34 56 C VDD 2.2F C BOOT 100nF FIGURE 3. TYPICAL APPLICATION SCHEMATIC FOR EXTERNAL COMPENSATION TABLE 1. DESIGN TABLE FOR DIFFERENT OUTPUT VOLTAGE USING INTERNAL COMPENSATION (See Figure 1) V (V) 1 1.2 1.8 3.3 5 OUT V (V) 4.5 to 18 4.5 to 18 4.5 to 18 4.5 to 18 6 to 18 IN FREQ (kHz) 300 300 600 600 600 Compensation Internal Internal Internal Internal Internal C (F) 3x22 3x22 3x22 3x22 3x22 IN C (F) 560 + 3x100 560 + 3x100 3x100 4x47 4x47 OUT L (H) 1 1 1 1.5 1.5 1 R (k ) 100 147 200 365 365 1 R (k ) 150 147 100 80.6 49.9 2 C (pF) DNP DNP 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, 47F, and 100F in the table. 3. 560F (4.5m ) low ESR conductive polymer aluminum solid capacitors are selected. 4. Recommend to keep the inductor peak-to-peak current to less than 5A. Ordering Information PART NUMBER PART TEMP. RANGE TAPE AND REEL PACKAGE PKG. (Notes 5, 6, 7) MARKING (C) (UNITS) (RoHS COMPLIANT) DWG. ISL85009FRZ-T 5009 -40 to +125 6k 15 Ld 3.5mmx3.5mm TQFN L15.3.5x3.5 ISL85009FRZ-T7A 5008 250 ISL85009EVAL1Z Evaluation Board NOTES: 5. Refer to TB347 for details on reel specifications. 6. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 7. For Moisture Sensitivity Level (MSL), please see product information page for ISL85009. For more information on MSL, see tech brief TB363. FN8918 Rev.1.00 Page 2 of 20 Mar 28, 2017