RT7237BHGSP Richtek

RT7237B 2A, 18V, 1.2MHz Synchronous Step-Down Converter General Description Features 1.5% High Accuracy Reference Voltage The RT7237B is a high efficiency, monolithic synchronous 4.5V to 18V Input Voltage Range step-down DC/DC converter that can deliver up to 2A 2A Output Current output current from a 4.5V to 18V input supply. The Integrated N-MOSFET Switches RT7237B s current mode architecture and external Current Mode Control compensation allow the transient response to be Fixed Frequency Operation : 1.2MHz optimized over a wide input range and loads. Cycle-by- Output Adjustable from 0.8V to 12V cycle current limit provides protection against shorted Stable with Low ESR Ceramic Output Capacitors outputs, and soft-start eliminates input current surge during Up to 95% Efficiency start-up. The RT7237B also provides under voltage Programmable Soft-Start protection and thermal shutdown protection. The low Cycle-by-Cycle Over Current Limit current (<3A) shutdown mode provides output Input Under Voltage Lockout disconnection, enabling easy power management in Output Under Voltage Protection battery-powered systems. The RT7237B is available in Thermal Shutdown Protection an SOP-8 (Exposed Pad) package. RoHS Compliant and Halogen Free Marking Information Applications RT7237BxGSP : Product Number RT7237Bx Wireless AP/Router x : H or L GSPYMDNN Set-Top-Box YMDNN : Date Code Industrial and Commercial Low Power Systems LCD Monitors and TVs Green Electronics/Appliances Point of Load Regulation of High-Performance DSPs Simplified Application Circuit V VIN BOOT IN C BOOT C IN RT7237B L SW V OUT Chip Enable R1 EN C OUT SS FB C C SS R2 C R C COMP GND Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS7237B-01 September 2012 www.richtek.com 1RT7237B Ordering Information Pin Configurations RT7237B (TOP VIEW) Package Type 8 BOOT SS SP : SOP-8 (Exposed Pad-Option 2) 2 7 VIN EN GND 3 6 SW COMP Lead Plating System 9 4 5 GND FB G : Green (Halogen Free and Pb Free) H : UVP Hiccup SOP-8 (Exposed Pad) L : UVP Latch-Off Note : Richtek products are : RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. Functional Pin Description Pin No. Pin Name Pin Function Bootstrap for High Side Gate Driver. Connect a 0.1F or greater ceramic 1 BOOT capacitor from BOOT to SW pins. Input Supply Voltage, 4.5V to 18V. Must bypass with a suitable large ceramic 2 VIN capacitor. 3 SW Switch Node. Connect this pin to an external L-C filter. 4, Ground. The exposed pad must be soldered to a large PCB and connected to GND 9 (Exposed Pad) GND for maximum power dissipation. Feedback Input. It is used to regulate the output of the converter to a set value 5 FB via an external resistive voltage divider. Compensation Node. COMP is used to compensate the regulation control 6 COMP loop. Connect a series RC network from COMP to GND. In some cases, an additional capacitor from COMP to GND is required. Enable Input. A logic high enables the converter a logic low forces the IC into 7 EN shutdown mode reducing the supply current to less than 3A. Attach this pin to VIN with a 100k pull-up resistor for automatic startup. Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor 8 SS from SS to GND to set the soft-start period. A 0.1F capacitor sets the soft-start period to 13.5ms. Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS7237B-01 September 2012 2