RICHTEK RT6254BHGJ6F

The RT6254A/B is a high-performance, synchronous stepdown DC-DC converter that can deliver up to 4A output current from a 4.5V to 18V input supply. The device integrates low RDS(ON) power MOSFETs, accurate 0.6V reference and an integrated diode of bootstrap circuit to offer a very compact solution. The RT6254A/B adopts Advanced Constant On-Time (ACOT*) control architecture that provides ultrafast transient response and further reduces the externalcomponent count. In steady states, the ACOT operates in nearly constant switching frequency over line, load and output voltage ranges and makes the EMI filter design easier. The device offers Independent enable control input pin and power good indicator (TSOT-23-8 only) for easily sequence control. To control the inrush current during the startup, the device provides a fixed 1.5ms soft-start up. Fully protection features are also integrated in the device including the cycle-by-cycle current limit control, UVP, input UVLO and OTP. The RT6254A/B is available in the TSOT-23-6 (FC) and TSOT-23-8 (FC) package.

• 4.5V to 18V Input Voltage Range
• 4A Output Current
• Constant-on-Time Mode to Enables Fast Transient Response
• Low Output Ripple and Allows Ceramic Output Capacitor
• 500kHz Switching Frequency
• High Efficient Internal Power MOSFET Switch Optimized for Lower Duty Cycle Applications
• Integrated 48mΩ/25mΩ MOSFETs
• Internal Soft-Start (1.5ms typ.)
• Built-In UVP/OTP
• Power Good Indicator (90%)
• Input Under Voltage Lockout
• TSOT-23-6 (FC) and TSOT-23-8 (FC) Packages

• Set Top Box
• Portable TV
• Access Point Router
• DSL Modem
• LCD TV