The ISL9021 is a single-channel low dropout linear regulator from Intersil that offers low quiescent current, low noise, and high PSRR. It delivers a guaranteed continuous 250mA load current with an input voltage range of 1.5V to 5.5V and an output voltage range of 0.9V to 3.3V. The ISL9021 has typical PSRR of 75dB@10kHz and 50dB@1MHz. It is available in tiny 4-bump 1.155mmx0.975mm WLCSP and 1.6mmx1.6mm 6 LD µTDFN packages.
The ISL9021 is a single LDO providing 250 mA continuous output current, stable with 1 pF‑4.7 µF output capacitors and an ESR range of 5 mΩ‑400 mΩ. It operates from 1.5 V to 5.5 V input and offers fixed output voltages from 0.9 V to 3.3 V with ±1.8 % accuracy.
The device includes reverse‑current protection, over‑current limit, short‑circuit protection, thermal shutdown and soft‑start. It is supplied in a 4‑ball WLCSP (1.155 mm × 0.975 mm) and a 6‑lead UTDFN (1.6 mm × 1.6 mm) package, both RoHS‑compliant.
| Input Voltage Range | 1.5 V to 5.5 V |
|---|---|
| Output Voltage Range | 0.9 V to 3.3 V |
| Continuous Output Current | 250 mA |
| Dropout Voltage | <150 mV @ 250 mA |
| Quiescent Current | 35 µA |
| Power‑Supply Rejection (PSRR) | 75 dB @ 10 kHz, 50 dB @ 1 MHz |
| Operating Temperature Range | -40 °C to +85 °C |
The ISL9021 provides reverse‑current protection, over‑current limit, short‑circuit protection, thermal shutdown and soft‑start.
The typical quiescent current is about 35 µA.
A ceramic capacitor of 1 pF to 4.7 µF with an ESR up to 400 mΩ is suitable.