DATASHEET ISL9021A FN7845 Rev 3.00 250mA Single LDO with Low I , Low Noise and High PSRR LDO Q December 20, 2012 The ISL9021A is a single LDO, which provides high Features performance, low input voltage and high PSRR. It delivers High performance LDO with 250mA guaranteed continuous guaranteed continuous 250mA load current and is stable with output current 1F to 4.7F of output capacitance (30%) with an ESR range of 5m to 400m. Input voltage range: 1.5V to 5.5V The input voltage range for the ISL9021A is between 1.5V to Output voltage range: 1.2V to 3.3V 5.5V and the output voltage comes in many fixed voltage High PSRR: 75dB 10kHz, 50dB 1MHz options with 1.8% accuracy over-temperature, line and load Low quiescent current: 35A ranges. The ISL9021A has typical PSRR of 75dB 10kHz and 50dB 1MHz. Dropout voltage: <150mV 250mA Stable with 1F to 4.7F output capacitance (30%) with an The reverse current protection feature prevents current from ESR range of 5m to 400m flowing back to the power source when the output voltage is pulled higher than the input. 1.8% output accuracy over-temperature/load/line The ISL9021A is offered in tiny 4-bump 0.975mmx1.155mm Soft-start limits input current surge during enable WLCSP and 1.6mmx1.6mm 6 Ld TDFN packages. Current limit and overheat protection -40C to +85C operating temperature range Related Literature Available in 0.975mmx1.155mm 4-bump WLCSP package See FN6867, ISL9021 250mA Single LDO with Low IQ, Low and 1.6mmx1.6mm 6 Ld TDFN Noise and High PSRR LDO Pb-free (RoHS compliant) Applications PDAs, cell phones and smart phones Portable instruments, MP3 players Handheld devices including medical handheld ISL9021A VIN (1.5V TO 5.5V) VIN VO VOUT ON ENABLE EN GND OFF C1 C2 C1, C2: 1F X5R CERAMIC CAPACITOR FIGURE 1. TYPICAL APPLICATION FN7845 Rev 3.00 Page 1 of 12 December 20, 2012ISL9021A Block Diagram PASS ELEMENT VIN VOUT EN SHORT-CIRCUIT TEMP CONTROL PROTECTION SENSOR LOGIC THERMAL PROTECTION SOFT-START VOLTAGE AND + REFERENCE GENERATOR BANDGAP GND Pin Configurations Pin Descriptions ISL9021A PIN TDFN WLCSP (6 LD 1.6x1.6 TDFN) NAME PIN PIN DESCRIPTION TOP VIEW VIN 1 B1 IC Supply/LDO Input. Connect a 1F VIN 1 6 capacitor to GND. VO NC 2, 5 - No Connect. NC 2 5 NC GND 4 A2 System ground pin. EN 3 4 GND EN 3 A1 LDO Enable. When this signal goes high, the LDO is turned on. ISL9021A VO, 6 B2 LDO Output. Connect a 1F to 4.7F (4 BALL 0.975x1.155 WLCSP) VOUT capacitor to GND. TOP VIEW PAD - - For TDFN package option only. Connect it to the system ground. GND VOUT A2 B2 EN A1 B1 VIN FN7845 Rev 3.00 Page 2 of 12 December 20, 2012