PM8908TR STMicroelectronics

PM8908 Monolithic buck converter for DDR memory termination Datasheet - production data Applications Memory termination regulator for DDR3, DDR4 and low power DDR3/DDR4 Notebook/desktop/server Low voltage application for 1 V to 3.5 V input QFN20 3.5 x 4.0 mm rails Description Features The PM8908 is a high efficiency monolithic step- down switching regulator designed mainly for the Integrated MOSFETs for high efficiency DDR termination. Current COT architecture The IC operates from 1 V to 3.5 V input voltage 1 V to 3.5 V input voltage (V ) IN (V ). IN 5.0 V supply voltage (V ) CC The device uses a COT control loop that provides Constant frequency mode very good performances in terms of load and line 1% output voltage accuracy transients. The current sense is internally thermally compensated for optimum precision. Two programmable switching frequencies (0.6 MHz or 1 MHz) The output voltage is adjusted from 0.5 V to 2 V with 1% accuracy overtemperature variations. ADJ output voltage from 0.5 V to 2 V Embedded bootstrap diode The PM8908 also provides external tracking support. OV/UV/OC and overtemperature protection The PM8908 provides positive and negative Soft-off with integrated discharge resistor overcurrent protection as well as External tracking over/undervoltage and overtemperature Power Good output protection. PGOOD output easily provides real- time information on the output voltage. QFN20 3.5 x 4.0 mm compact package The PM8908 is available in a QFN20 3.5 x 4.0 mm package. Table 1. Device summary Order code Package Packaging PM8908TR QFN20 (3.5 x 4.0 mm) Tape and reel July 2017 DocID027688 Rev 4 1/28 This is information on a product in full production. www.st.comContents PM8908 Contents 1 Typical application circuit and block diagram 4 1.1 Application circuit 4 1.2 Block diagram . 5 2 Pin description and connection diagrams . 6 Pin description 6 3 Thermal data . 8 4 Electrical specifications 9 4.1 Absolute maximum ratings . 9 4.2 Electrical characteristics 10 5 Device description . 13 5.1 Power section 13 5.2 Device configuration . 14 5.3 Startup and shutdown management . 14 Soft-off 16 5.4 Output voltage monitoring and protection 16 5.4.1 Overvoltage protection 16 5.4.2 Undervoltage protection . 17 5.4.3 Power Good (PGOOD) . 17 5.4.4 Overcurrent protection 17 5.4.5 Overtemperature protection 18 6 Application information . 19 6.1 Output voltage setting . 19 6.2 Droop setting 19 6.3 Non-droop setting . 20 6.4 Inductor design . 20 6.5 Output capacitors . 21 6.6 Input capacitors 21 6.7 Compensation network . 22 2/28 DocID027688 Rev 4