ISL8012IRZ-T Renesas

DATASHEET ISL8012 FN6616 Rev 2.00 2A Low Quiescent Current 1MHz High Efficiency Synchronous Buck Regulator December 1, 2011 The ISL8012 is a high efficiency, monolithic, synchronous Features step-down DC/DC converter that can deliver up to 2A High Efficiency Synchronous Buck Regulator with up to 95% continuous output current from a 2.7V to 5.5V input supply. It Efficiency uses a current control architecture to deliver very low duty cycle operation at high frequency with fast transient response Power-Good (PG) Output with a 1ms Delay and excellent loop stability. 2.7V to 5.5V Supply Voltage The ISL8012 integrates a pair of low ON-resistance P-Channel 3% Output Accuracy Over-Temperature/Load/Line and N-Channel internal MOSFETs to maximize efficiency and 2A Guaranteed Output Current minimize external component count. The 100% duty-cycle operation allows less than 240mV dropout voltage at 2A Start-up with Pre-Biased Output output current. High 1MHz pulse width modulation (PWM) Internal Soft-Start - 1ms switching frequency allows the use of small external Soft-Stop Output Discharge During Disabled components. 40A Quiescent Supply Current in PFM Mode The ISL8012 can be configured for discontinuous or forced continuous operation at light load. Forced continuous Selectable Forced PWM Mode and PFM Mode operation reduces noise and RF interference while Less than 1A Logic Controlled Shutdown Current discontinuous mode provides high efficiency by reducing 100% Maximum Duty Cycle switching losses at light loads. Internal Current Mode Compensation Fault protection is provided by internal current limiting during Peak Current Limiting and Hiccup Mode Short Circuit short circuit and overcurrent conditions, an output overvoltage Protection comparator and over-temperature monitor circuit. A power- good output voltage monitor indicates when the output is in Over-Temperature Protection regulation. Small 10 Ld 3mmx3mm DFN The ISL8012 offers a 1ms Power-good (PG) timer at power-up. Pb-Free (RoHS Compliant) When shutdown, ISL8012 discharges the output capacitor. Other features include internal soft-start, internal Applications compensation, overcurrent protection, and thermal shutdown. DC/DC POL Modules The ISL8012 is offered in a space saving 3mmx3mm 10 Ld C/P, FPGA and DSP Power DFN package lead free package with exposed pad lead frames for low thermal. The complete converter occupies less than Plug-in DC/DC Modules for Routers and Switchers 2 0.35in area. Portable Instruments Test and Measurement Systems Li-ion Battery Powered Devices Small Form Factor (SFP) Modules Bar Code Readers Related Literature See AN1360 for ISL8012EVAL1Z: 2A Synchronous Buck Regulator with Integrated MOSFETs FN6616 Rev 2.00 Page 1 of 17 December 1, 2011ISL8012 Pin Configuration ISL8012 (10 LD DFN) TOP VIEW VIN 1 10 LX VCC 2 9 PGND EN 8 3 SGND PD PG 4 7 VFB 6 MODE 5 RSI Pin Descriptions SYMBOL PIN NUMBER DESCRIPTION VIN 1 Input supply voltage. Connect a 10F ceramic capacitor to power ground. VCC 2 Input supply for the logic. Connect to VIN. EN 3 Regulator enable pin. Enable the output when driven to high. Shutdown the chip and discharge output capacitor when driven to low. Do not leave this pin floating. PG 4 1ms timer output. At power-up or EN HI, this output is a 1ms delayed Power-Good signal for the output voltage. This output can be reset by a low RSI signal. 1ms starts when RSI goes to high. MODE 5 Mode Selection pin. Connect to logic high or input voltage VIN for PFM mode connect to logic low or ground for forced PWM mode. Do not leave this pin floating. RSI 6 This input resets the 1ms timer. When the output voltage is within the PGOOD window, an internal timer is started and generates a PG signal 1ms later when RSI is low. A high RSI resets PG and RSI high to low transition restarts the internal counter if the output voltage is within the window, otherwise the counter is reset by the output voltage condition. VFB 7 Buck regulator output feedback. Connect to the output through a resistor divider for adjustable output voltage (ISL8012-ADJ). For preset output voltage, connect this pin to the output. SGND 8 System ground for the control logic. All voltage levels are measured with respect to this pin. PGND 9 Ground connect for the IC and thermal relief for the package. The exposed pad must be connected to PGND and soldered to the PCB. LX 10 Switching node connection. Connect to one terminal of inductor. Exposed Pad PD The exposed pad must be connected to the PGND and SGND pin for proper electrical performance. The exposed pad must also be connected to as much as possible for optimal thermal performance. FN6616 Rev 2.00 Page 2 of 17 December 1, 2011