DATASHEET ISL8026, ISL8026A FN8736 Rev 2.00 Compact Synchronous Buck Regulators October 28, 2016 The ISL8026, ISL8026A are highly efficient, monolithic, Features synchronous step-down DC/DC converters that can deliver 6A of 2.5V to 5.5V input voltage range continuous output current from a 2.5V to 5.5V input supply. The devices use current mode control architecture to deliver a very low Very low ON-resistance FETs - P-channel 36m and duty cycle operation at high frequency with fast transient N-channel 13m typical values response and excellent loop stability. High efficiency synchronous buck regulator with up to 95% The ISL8026, ISL8026A integrate a very low ON-resistance efficiency P-channel (36m ) high-side FET and N-channel (13m) 1.0% reference accuracy over load/line/temperature (-40C low-side FET to maximize efficiency and minimize external to +85C) component count. The 100% duty-cycle operation allows less 1.5% reference accuracy over load/line/temperature (-40C than 180mV dropout voltage at 6A output current. The to +125C) operation frequency of the Pulse-width Modulator (PWM) is adjustable from 500kHz to 4MHz. The default switching Internal soft-start: 1ms or adjustable frequency, which is set by connecting the FS pin high, is 1MHz Soft-stop output discharge during disable for the ISL8026 and 2MHz for the ISL8026A. Adjustable frequency from 500kHz to 4MHz - default at The ISL8026, ISL8026A can be configured for discontinuous or 1MHz (ISL8026) or 2MHz (ISL8026A) forced continuous operation at light load. Forced continuous External synchronization up to 4MHz operation reduces noise and RF interference, while discontinuous mode provides higher efficiency by reducing Over-temperature, overcurrent, overvoltage and negative switching losses at light loads. overcurrent protection Fault protection is provided by internal hiccup mode current Applications limiting during short-circuit and overcurrent conditions. Other DC/DC POL modules protection, such as overvoltage and over-temperature, are also integrated into the device. A power-good output voltage C/P, FPGA and DSP power monitor indicates when the output is in regulation. Video processor/SOC power The ISL8026, ISL8026A offer a 1ms Power-Good (PG) timer at Li-ion battery powered devices power-up. When in shutdown, the ISL8026, ISL8026A Routers and switchers discharge the output capacitor through an internal soft-stop switch. Other features include internal fixed or adjustable Portable instruments soft-start and internal/external compensation. Test and measurement systems The ISL8026, ISL8026A are offered in a space saving 16 Ld Industrial PCs 3x3 Pb-free TQFN package with an exposed pad for improved thermal performance and 0.8mm maximum height. The Related Literature 2 complete converter occupies less than 142mm . UG033, ISL8026xEVAL3Z Evaluation Board User Guide L1 100 +1.8V/6A VOUT 1.0H C2 2 x 22F 90 3.3V PFM GND OUT +2.5V +5.5V 1 PGND VIN VIN ISL8026 R2 C1 C3* 200k 2 x 22F 22pF 80 GND 2 R1 VIN PGND 100k 3.3V PWM OUT R3 3 PGND/ 70 PG PG SGND 100k 4 SYNC FB 60 *C3 IS OPTIONAL. IT IS 50 RECOMMENDED TO PUT A PLACEHOLDER FOR IT AND CHECK LOOP ANALYSIS BEFORE USE. 40 V O 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 ------------ R = R 1 (EQ. 1) 2 3 VFB OUTPUT LOAD (A) FIGURE 1. TYPICAL APPLICATION CIRCUIT CONFIGURATION (INTERNAL FIGURE 2. EFFICIENCY vs LOAD 1MHz 5V IN COMPENSATION OPTION) FN8736 Rev 2.00 Page 1 of 23 October 28, 2016 5 16 EN VIN EN 6 15 FS PHASE 7 14 SS PHASE 8 13 COMP PHASE PAD 17 EFFICIENCY (%)ISL8026, ISL8026A Table of Contents Pin Configuration 3 Pin Descriptions . 3 Ordering Information 4 Block Diagram 5 Absolute Maximum Ratings . 6 Thermal Information . 6 Recommended Operating Conditions 6 Electrical Specifications . 6 Typical Operating Performance 8 Theory of Operation . 17 PWM Control Scheme 17 SKIP Mode . 17 Frequency Adjust 18 Overcurrent Protection . 18 Negative Current Protection . 18 PG 18 UVLO 18 Soft Start-Up 18 Enable . 18 Discharge Mode (Soft-Stop) . 18 Power MOSFETs . 18 100% Duty Cycle 18 Thermal Shutdown 18 Power Derating Characteristics 19 Application Information . 19 Output Inductor and Capacitor Selection 19 Output Voltage Selection . 19 Input Capacitor Selection . 19 Loop Compensation Design . 19 PCB Layout Recommendation 21 Revision History 22 About Intersil 22 Package Outline Drawing 23 FN8736 Rev 2.00 Page 2 of 23 October 28, 2016