DATASHEET RAA212422 FN9326 Rev.1.00 Dual channel 40V 1.1A and 5.5V 1.5A synchronous buck regulators Jul 8, 2019 The RAA212422 is a dual output regulator combining a Features 1.1A synchronous buck regulator with an input range of Wide V buck regulator IN 3V to 40V with a 1.5A synchronous buck regulator with Input voltage: 3V to 40V with 1.1A output current an input voltage range of 2.7V to 5.5V. Because both high-side and low-side MOSFETs are integrated for both Internal fixed frequency (500kHz) or adjustable regulators, the RAA212422 provides an easy-to-use, switching frequencies (300kHz to 2MHz) high-efficiency, and low BOM-count solution for a Selectable PFM or PWM mode at light loads variety of applications. Internal or external soft-start Both regulators feature internal and external compensation, thermal shutdown, and power-good Low V buck regulator IN functions. The wide V buck regulator features a PFM IN Input voltage: 2.7V to 5.5V, with 1.5A output mode for improved efficiency at light load. This feature current can be disabled if forced PWM mode is desired. It V range: 0.6V to V switches at a default frequency of 500kHz however, it OUT IN can also be programmed using an external resistor from Fixed 1MHz switching frequency 300kHz to 2MHz. Other features include programmable Synchronous operation for high efficiency soft-start and hiccup overcurrent protection. Integrated high-side and low-side MOS devices The low V buck regulator operates at 1MHz switching IN frequency, which provides fast load transient response Internal or external compensation option allowing the use of small inductors. Because the Power-good and enable functions high-side MOSFET of the low V buck regulator is a IN Thermal shutdown PMOS, a boot capacitor is not needed, reducing the external component count. They operate at 100% duty Applications cycle and in PWM mode only, reducing noise Industrial control, medical devices, portable susceptibility and RF interference. instrumentation, distributed power supplies, and The RAA212422 is available in a small RoHS compliant cloud infrastructure 3mmx6mm TDFN plastic package with a full-range General purpose point of load DC/DC, set-top boxes industrial temperature of -40C to +125C. and cable modems, FPGA power, DVD, HDD drives, Related Literature LCD panels, and TV For a full list of related documents, visit our website: RAA212422 device page L 1 VIN1 LX1 + 100 EN1 + C BOOT SYNC1 95 R 1 FS1 BOOT1 C FF1 COMP1 90 C V V FB1 OUT1 OUT1 IN1 SS1 85 PG1 VCC1 R 2 - 80 - C VCC GND1 75 L 2 RAA212422 70 LX2 VIN2 VIN1 = 12V 65 + + VIN3 EN2 R 60 VIN1 = 24V C 3 FF2 COMP2 C OUT2 V 55 V OUT2 VIN1 = 33V IN2 FB2 PG2 50 R GND2 4 - - 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 Output Load (A) Figure 2. Efficiency vs Load, V = 5V, L = 22H Figure 1. Typical Application OUT1 1 FN9326 Rev.1.00 Page 1 of 35 Jul 8, 2019 Efficiency (%)RAA212422 Contents 1. Overview . 3 1.1 Typical Application Circuits 3 1.2 Block Diagram 5 1.3 Ordering Information . 6 1.4 Pin Configurations . 6 1.5 Pin Descriptions . 6 2. Specifications . 8 2.1 Absolute Maximum Ratings 8 2.2 Thermal Information 8 2.3 Recommended Operating Conditions 9 2.4 Electrical Specifications . 9 3. Typical Performance Curves 12 3.1 Efficiency Curves . 12 3.2 Measurements . 15 4. Detailed Description 21 4.1 Power-On Reset /UVLO . 21 4.2 Soft-Start (Wide V and Low V Buck) . 21 IN IN 4.3 Power-Good . 21 4.4 PWM Control Scheme (Wide V and Low V Buck) . 22 IN IN 4.5 Light Load Operation 22 4.6 Output Voltage Selection . 23 4.7 Protection Features . 24 4.8 Discharge Mode/Soft-Stop (Low V Buck) . 25 IN 4.9 100% Duty Cycle (Low V Buck) 25 IN 4.10 Power Derating Characteristics 25 5. Application Guidelines 26 5.1 Simplifying the Design . 26 5.2 Operating Frequency (Wide V Buck) 26 IN 5.3 Minimum On/Off-Time Limitation . 26 5.4 Synchronization Control (Wide V Buck) 27 IN 5.5 Output Inductor Selection 27 5.6 Input Capacitor Selection . 27 5.7 Output Capacitor Selection . 27 5.8 Loop Compensation Design 28 6. Layout Suggestions . 32 7. Revision History 33 8. Package Outline Drawing 34 FN9326 Rev.1.00 Page 2 of 35 Jul 8, 2019