DATASHEET ISL78233, ISL78234 FN8359 Rev.10.00 3A and 4A Compact Synchronous Buck Regulators Jan 12, 2021 The ISL78233 and ISL78234 are highly efficient, monolithic, Features synchronous step-down DC/DC converters that can deliver 3A 2.7V to 5.5V input voltage range (ISL78233), or 4A (ISL78234) of continuous output current from a 2.7V to 5.5V input supply. The devices use current mode control Very low ON-resistance FETs - P-channel 35m and architecture to deliver a very low duty cycle operation at high N-channel 11m typical values frequency with fast transient response and excellent loop stability. High efficiency synchronous buck regulator with up to 95% The ISL78233 and ISL78234 integrate a very low efficiency ON-resistance P-channel (35m ) high-side FET and N-channel -1.2%/1% reference accuracy over temperature/load/line (11m ) low-side FET to maximize efficiency and minimize Complete BOM with as few as 3 external parts external component count. The 100% duty-cycle operation allows less than 200mV dropout voltage at 4A output current. Internal soft-start - 1ms or adjustable The operation frequency of the Pulse-Width Modulator (PWM) Soft-stop output discharge during disable is adjustable from 500kHz to 4MHz. The default switching Adjustable frequency from 500kHz to 4MHz - default at frequency of 2MHz is set by connecting the FS pin high. 2MHz The ISL78233 and ISL78234 can be configured for External synchronization up to 4MHz discontinuous or forced continuous operation at light load. Forced continuous operation reduces noise and RF Over-temperature, overcurrent, overvoltage, and negative interference, while discontinuous mode provides higher overcurrent protection efficiency by reducing switching losses at light loads. Shared common device pinout allows simplified output power upgrades over time Fault protection is provided by internal Hiccup mode current limiting during short-circuit and overcurrent conditions. Other Tiny 3mmx3mm TQFN package protection, such as overvoltage and over-temperature are also AEC-Q100 qualified integrated into the device. A power-good output voltage monitor indicates when the output is in regulation. Applications The ISL78233 and ISL78234 offer a 1ms Power-Good (PG) DC/DC POL modules timer at power-up. When in shutdown, the ISL78233 and ISL78234 discharge the output capacitor through an internal C/P, FPGA, and DSP power soft-stop switch. Other features include internal fixed or Video processor/SOC power adjustable soft-start and internal/external compensation. Li-ion battery powered devices The ISL78233 and ISL78234 are available in a 3mmx3mm 16 Automotive infotainment power Ld Thin Quad Flat (TQFN) Pb-free package and in a 5mmx5mm 16 Ld Wettable Flank Quad Flat No-Lead (WFQFN) package Related Literature with an exposed pad for improved thermal performance. The For a full list of related documents, visit our website: ISL78233 and ISL78234 are rated to operate across the temperature range of -40C to +125C. ISL78233, ISL78234 device pages 100 3.3V OUT 90 1.5V 80 OUT 1.2V OUT 1.8V OUT 70 2.5V OUT 60 50 40 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 OUTPUT LOAD (A) FIGURE 1. EFFICIENCY vs LOAD (2MHz 5V PFM, T = +25C) IN A FN8359 Rev.10.00 Page 1 of 20 Jan 12, 2021 EFFICIENCY (%)ISL78233, ISL78234 Typical Application Diagram L 1 +1.8V/4A V OUT 1.0H C 2 2x22F GND +2.7V +5.5V 1 VIN PGND V ISL78233, ISL78234 IN R C 2 1 C * 3 2x22F 200k 22pF GND 2 R 1 VDD PGND 100k R 3 3 PG SGND PG 100k 4 SYNC FB *C IS OPTIONAL. IT IS 3 RECOMMENDED TO PUT A PLACEHOLDER FOR IT AND CHECK LOOP ANALYSIS BEFORE USE. FIGURE 2. TYPICAL APPLICATION DIAGRAM TABLE 1. COMPONENT SELECTION TABLE V 1.2V 1.5V 1.8V 2.5V 3.3V 3.6V OUT C 2 x 22F 2 x 22F 2 x 22F 2 x 22F 2 x 22F 2 x 22F 1 C 2 x 22F 2 x 22F 2 x 22F 2 x 22F 2 x 22F 2 x 22F 2 C 22pF 22pF 22pF 22pF 22pF 22pF 3 L 0.33-0.68H 0.33-0.68H 0.33-0.68H 0.47-0.78H 0.47-0.78H 0.47-0.78H 1 R 100k 150k 200k 316k 450k 500k 2 R 100k 100k 100k 100k 100k 100k 3 FN8359 Rev.10.00 Page 2 of 20 Jan 12, 2021 5 16 EN EN VIN 6 15 FS PHASE 7 14 SS PHASE 8 13 COMP PHASE PAD 17