SQ24390VLQ

Application Note: SQ24390 Negative Charge Pump and Adjustable Regulator General Description Features • • • • • • Low Quiescent Current: 1.2mA Wide Input Voltage Range from 2.3V to 5.5V Up to 200mA Output Current No Inrush Current during Startup Over and Short Circuit Protection Dual Output: ✓ -1× Charge Pump ✓ Regulated Output Between 0V and -VIN • Small QFN 1.4mm ×1.8mm Package for Space Saving The SQ24390 is a charge pump with wide input voltage range from 2.3V to 5.5V that provides an unregulated negative voltage which equal to VIN, and also affords an adjustable negative voltage regulator between 0V and negative input voltage. Without inductor, just 4 ceramic capacitors as the external component and compacted QFN 1.4mm× 1.8mm package make PCB size small and BOM cost low. Ordering Information Applications • Optical Module • Bias for RF Amplifier • Sensor Supply in Portable Instrument SQ24390 □(□□ □) Package Code Optional Spec Code Ordering Number SQ24390VLQ Package type QFN1.4×1.8-10 Note ---- Typical Application C2 2.2µF CP CN -3.3V +3.3V OUT1 IN C1 4.7µF C3 2.2µF SQ24390 CTL OUT2 EN TM GND 0V to -3.3V Equal to -CTL C4 2.2µF Figure1. Schematic Diagram AN_SQ24390 Rev.0.9 ©2020 Silergy Corp. Silergy Corp. Confidential- Prepared for Customer Use Only 1 All Rights Reserved. SQ24390 Pinout (top view) GND EN IN CP CN 10 9 8 1 2 7 OUT1 6 GND 3 4 5 CTL TM OUT2 (QFN1.4×1.8-10) Top Mark: 6Gxyz for SQ24390VLQ (Device code: 6G; x=year code, y=week code, z= lot number code) Pin Name GND EN CTL Pin number 1 2 3 TM 4 OUT2 5 GND OUT1 CN CP 6 7 8 9 IN 10 AN_ SQ24390 Rev.0.9 © 2020 Silergy Corp. Pin Description Power ground. ON/OFF Control. Internal integrated a 1MΩ to GND. Analog input voltage. The OUT2 voltage will be -1× CTL pin voltage. Test mode pin, this pin is for entering the IC test mode. Connected to GND when customer use. Negative linear regulator output. A decouple capacitor is needed. The VOUT2 follow the -VCTL. Power ground. Negative charge pump output. A decouple capacitor is needed. Negative terminal of fly capacitor. Positive terminal of fly capacitor. Power supply pin for charge pump and internal control circuit. A 4.7μF ceramic cap to GND is recommended to decouple potential voltage spikes. Silergy Corp. Confidential- Prepared for Customer Use Only 2 All Rights Reserved. SQ24390 Block Diagram CN CP M1 M2 IN OUT1 M3 M4 OUT2 M5 EN CTL VOUT1 TM Control Circuit GND Absolute Maximum Ratings (Note 1) IN ----------------------------------------------------------------------------------------------- ------------------------ -0.3V to 6.5V CP ---------------------------------------------------------------------------- -0.3V/-0.7V(