DATASHEET ISL8022 FN7650 Rev 3.00 Dual 2A/1.7A Low Quiescent Current 2.25MHz High Efficiency Synchronous Buck March 14, 2013 Regulator The ISL8022 is a high efficiency, dual synchronous step-down Features DC/DC regulator that can deliver up to 2A/1.7A continuous Dual 2A/1.7A high efficiency synchronous buck regulator output current per channel. The channels are 180 out-of- with up to 97% efficiency, low iq (40A) phase for input RMS current and EMI reduction. The supply voltage range of 2.8V to 5.5V allows for the use of a single Li+ 180 out-of-phase cell, three NiMH cells or a regulated 5V input. The current Start-up with pre-biased output mode control architecture enables very low duty cycle Selectable forced PWM mode and PFM mode operation at high frequency with fast transient response and excellent loop stability. The ISL8022 operates at 2.25MHz External synchronization up to 8MHz switching frequency allowing for the use of small, low cost Negative current detection and protection inductors and capacitors. Each channel is optimized for generating an output voltage as low as 0.6V. 100% maximum duty cycle for lowest dropout Internal current mode compensation The ISL8022 has a user configurable mode of operation-forced PWM mode and PFM/PWM mode. The forced PWM mode Peak current limiting, hiccup mode short circuit protection operation reduces noise and RF interference while the PFM and over-temperature protection mode operation provides high efficiency by reducing switching Pb-free (RoHs compliant) losses at light loads. In PFM mode of operation, both channels draw a total quiescent current of only 40A, hence enabling Applications high light load efficiency in order to maximize battery life. DC/DC POL modules The ISL8022 offers a 1ms Power-Good (PG) to monitor both C/P, FPGA and DSP power outputs at power-up. When shutdown, ISL8022 discharges the Plug-in DC/DC modules for routers and switchers outputs capacitor. Other features include internal digital soft-start, enable for power sequence, overcurrent protection, Test and measurement systems and thermal shutdown. The ISL8022 is offered in a Li-ion battery powered devices 4mmx3mm 12 Ld DFN package with 1mm maximum height. 2 The complete converter occupies less than 1.8cm area. Bar code readers Related Literature AN1554 ISL8022EVAL1Z Dual 2A/1.7A Low Quiescent Current 2.25MHz High Efficiency Synchronous Buck Regulator AN1587 ISL8022EVAL2Z Dual 2A/1.7A Low Quiescent Current 2.25MHz High Efficiency Synchronous Buck Regulator 100 90 80 2.5V OUT1PFM 2.5V OUT1PWM 3.3V OUT2PFM 70 60 50 3.3V OUT2 PWM 2.25MHz 5V AT +25C IN 40 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 OUTPUT LOAD (A) FIGURE 1. CHARACTERISTIC CURVE FN7650 Rev 3.00 Page 1 of 18 March 14, 2013 EFFICIENCY (%)ISL8022 Typical Applications L1 OUTPUT1 1.2H 2.5V/2A LX1 C2 22F C3 PGND R2 10pF 316k IN P U T 2.8V TO 5.5V FB1 VIN R3 EN1 C1 100k 2 x 10F ISL8022 L2 EN2 OUTPUT2 1.2H 1.8V /1.7A LX2 PG C4 22F PGND C5 SYNC R5 10pF 200k FB2 R6 100k FIGURE 2. TYPICAL APPLICATION DIAGRAM - DUAL INDEPENDENT OUTPUTS TABLE 1. COMPONENT VALUE SELECTION V 0.8V 1.2V 1.5V 1.8V 2.5V 3.3V OUT C1 2x10F 2x10F 2x10F 2x10F 2x10F 2x10F C2 (or C4) 22F 22F 22F 22F 22F 22F C3 (or C5) 10pF 10pF 10pF 10pF 10pF 10pF L1 (or L2) 1.0~2.2H 1.0~2.2H 1.0~2.2H 1.2~3.3H 1.2~3.3H 1.5~4.7H R2 (or R5) 33k 100k 150k 200k 316k 450k R3 (or R6) 100k 100k 100k 100k 100k 100k In Table 1, the minimum output capacitor value is given for different output voltage to make sure the whole converter system is stable. Output capacitance should increase to support faster load transient requirement. FN7650 Rev 3.00 Page 2 of 18 March 14, 2013