RT5711BHGQW

RT5711B 1.5A, 1MHz, 6V CMCOT Synchronous Step-Down Converter General Description Features The RT5711B is a high efficiency synchronous step-down DC-DC converter. Its input voltage range is from 2.5V to 6V and provides an adjustable regulated output voltage from 0.6V to 3.4V while delivering up to 1.5A of output current.      for Best Transient Response, Robust Loop Stability with Low-ESR (MLCC) COUT The internal synchronous low on-resistance power switches increase efficiency and eliminate the need for an external Schottky diode. The Current Mode Constant-On-time (CMCOT) operation with internal    compensation allows the transient response to be optimized over a wide range of loads and output capacitors.   Fixed Soft-Start 1.2ms Cycle-by-Cycle Over-Current Protection Input Under-Voltage Lockout Output Under-Voltage Protection (UVP Hiccup) Thermal Shutdown Protection Marking Information Applications  STB, Cable Modem, & xDSL Platforms LCD TV Power Supply & Metering Platforms  General Purpose Point of Load (POL)  Efficiency Up to 95% RDSON 160m HS / 110m LS VIN Range 2.5V to 6V VREF 0.6V with 2% Accuracy CMCOT ™ Control Loop Design 2Y : Product Code W : Date Code 2YW Ordering Information Pin Configuration (TOP VIEW) Package Type QW : WDFN-6L 2x2 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) NC 1 EN VIN 2 GND RT5711B 3 7 UVP Option H : Hiccup 6 FB 5 GND LX 4 WDFN-6L 2x2 Note : Richtek products are :  RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.  Suitable for use in SnPb or Pb-free soldering processes. Simplified Application Circuit L VIN VIN CIN LX RT5711B EN DS5711B-04 December 2019 R1 FB GND Copyright © 2019 Richtek Technology Corporation. All rights reserved. VOUT COUT R2 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT5711B Functional Pin Description Pin No. Pin Name Pin Function 1 NC No internal connection. 2 EN Enable control input. 3 VIN Supply voltage input. The RT5711B operates from a 2.5V to 6V input. 4 LX Switch node. Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum thermal dissipation. 5, 7 (Exposed Pad) GND 6 FB Feedback. Functional Block Diagram EN VIN UVLO Shut Down Control OTP - FB VREF Error Amplifier Ton Comparator + RC CCOMP + - Logic Control LX VIN Driver Current Limit Detector Current Sense LX GND LX Operation The RT5711B is a synchronous low voltage step-down converter that can support the input voltage range from 2.5V to 6V and the output current can be up to 1.5A. The RT5711B uses a constant on-time, current mode architecture. In normal operation, the high side P-MOSFET is turned on when the switch controller is set by the comparator and is turned off when the Ton UV Comparator comparator resets the switch controller. Enable Comparator Low side MOSFET peak current is measured by internal RSENSE. The error amplifier EA adjusts COMP voltage by comparing the feedback signal (VFB) from the output voltage with the internal 0.6V reference. When the load current increases, it causes a drop in the feedback voltage relative to the reference, then the COMP voltage rises to allow higher inductor current to match the load current. A logic-high enables the converter; a logic-low forces the IC into shutdown mode. Copyright © 2019 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 If the feedback voltage (VFB) is lower than threshold voltage 0.2V, the UV comparator's output will go high and the switch controller will turn off the high side MOSFET. The output under voltage protection is designed to operate in Hiccup mode. Soft-Start (SS) An internal current source charges an internal capacitor to build the soft-start ramp voltage. The VFB voltage will track the internal ramp voltage during soft-start interval. The typical soft-start time is 1.2ms. is a registered trademark of Richtek Technology Corporation. DS5711B-04 December 2019 RT5711B Over-Current Protection (OCP) The RT5711B provides over-current protection by detecting low side MOSFET valley inductor current. If the sensed valley inductor current is over the current limit threshold (1.8A typ.), the OCP will be triggered. When OCP is tripped, the RT5711B will keep the over current threshold level until the over current condition is removed. Thermal Shutdown (OTP) The device implements an internal thermal shutdown function when the junction temperature exceeds 150°C. The thermal shutdown forces the device to stop switching when the junction temperature exceeds the thermal shutdown threshold. Once the die temperature decreases below the hysteresis of 20°C, the device reinstates the power up sequence. Copyright © 2019 Richtek Technology Corporation. All rights reserved. DS5711B-04 December 2019 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT5711B Absolute Maximum Ratings (Note 1)  Supply Input Voltage -------------------------------------------------------------------------------------------0.3V to 6.5V  LX Pin Switch Voltage----------------------------------------------------------------------------------------- 0.3V to (VIN + 0.3V)