RT8296AHGSP Richtek

RT8296A 3A, 23V, 340kHz Synchronous Step-Down Converter General Description Features 1.5% High Accuracy Feedback Voltage The RT8296A is a high efficiency, monolithic synchronous 4.5V to 23V Input Voltage Range step-down DC/DC converter that can deliver up to 3A 3A Output Current output current from a 4.5V to 23V input supply. The Integrated N-MOSFET Switches RT8296A s current mode architecture and external Current Mode Control compensation allow the transient response to be Fixed Frequency Operation : 340kHz optimized over a wide range of loads and output capacitors. Output Adjustable from 0.8V to 20V Cycle-by-cycle current limit provides protection against Up to 95% Efficiency shorted outputs and soft-start eliminates input current Programmable Soft-Start surge during start up. Fault conditions also include output Stable with Low ESR Ceramic Output Capacitors under voltage protection and thermal shutdown. The low Cycle-by-Cycle Over Current Protection current (<3A) shutdown mode provides output Input Under Voltage Lockout disconnect, enabling easy power management in battery Output Under Voltage Protection powered systems. The RT8296A is available in a Thermal Shutdown Protection SOP-8 (Exposed Pad) package. RoHS Compliant and Halogen Free Ordering Information Applications RT8296A Package Type Industrial and Commercial Low Power Systems SP : SOP-8 (Exposed Pad-Option 1) Set Top Box Lead Plating System LCD Monitors and TVs G : Green (Halogen Free and Pb Free) Green Electronics/Appliances Z : ECO (Ecological Element with Point of Load Regulation of High Performance DSPs Halogen Free and Pb free) Wireless AP/Router H : UVP Hiccup L : UVP Latch-Off Pin Configurations Note : Richtek products are : (TOP VIEW) RoHS compliant and compatible with the current require- 8 BOOT SS ments of IPC/JEDEC J-STD-020. 2 7 VIN EN GND 3 Suitable for use in SnPb or Pb-free soldering processes. 6 SW COMP 9 4 GND 5 FB SOP-8 (Exposed Pad) Marking Information RT8296AxZSP RT8296AxGSP RT8296AxZSP : Product Number RT8296AxGSP : Product Number RT8296Ax RT8296Ax x : H or L x : H or L ZSPYMDNN GSPYMDNN YMDNN : Date Code YMDNN : Date Code Copyright 2015 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. DS8296A-05 October 2015 www.richtek.com 1RT8296A Typical Application Circuit 1 V 2 IN VIN BOOT 4.5V to 23V C C IN BOOT L RT8296A 10F x 2 100nF 10H V 3 OUT SW 3.3V/3A R EN 100k R1 7 EN 75k C OUT 8 5 SS FB 22F x 2 C C C R SS C R2 3.3nF 0.1F 13k 4, 9 (Exposed Pad) 24k 6 COMP GND C P Open Table 1. Recommended Component Selection V (V) R1 (k) R2 (k) R (k) C (nF) L ( H) C ( F) OUT C C OUT 8 27 3 33 3.3 22 22 x 2 5 62 11.8 20 3.3 15 22 x 2 3.3 75 24 13 3.3 10 22 x 2 2.5 25.5 12 9.1 3.3 6.8 22 x 2 1.5 10.5 12 5.6 3.3 3.6 22 x 2 1.2 12 24 4.3 3.3 3.6 22 x 2 1 3 12 3.6 3.3 2 22 x 2 Functional Pin Description Pin No. Pin Name Pin Function Bootstrap for High Side Gate Driver. Connect 0.1 F or greater ceramic 1 BOOT capacitor from BOOT to SW pins. 2 VIN Input Supply Voltage. Must bypass with a suitably large ceramic capacitor. 3 SW Phase Node. Connect to 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 Pin. This pin is connected to the converter output. It is used to set the output of the converter to regulate to the desired value via an internal 5 FB resistive divider. For an adjustable output, an external resistive divider is connected to this pin. 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 Pin. A logic high enables the converter a logic low forces the 7 EN RT8296A into shutdown mode reducing the supply current to less than 3 A. 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 0.1 F capacitor sets the soft-start period to 13.5ms. Copyright 2015 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. www.richtek.com DS8296A-05 October 2015 2