DatasheetsPDF.com

RT8240A Dataheets PDF



Part Number RT8240A
Manufacturers Richtek
Logo Richtek
Description High Efficiency Single Synchronous Buck PWM Controller
Datasheet RT8240A DatasheetRT8240A Datasheet (PDF)

® RT8240A/B/C High Efficiency Single Synchronous Buck PWM Controller General Description Features The RT8240A/B/C PWM controller provides high efficiency, excellent transient response, and high DC output accuracy needed for stepping down high voltage batteries to generate low voltage CPU core, I/O, and chipset RAM supplies in notebook computers. The RT8240A/B/C supports on chip voltage programming function between 1V and 1.05V by controlling G0 digital inputs. The constant on-time PWM contro.

  RT8240A   RT8240A


Document
® RT8240A/B/C High Efficiency Single Synchronous Buck PWM Controller General Description Features The RT8240A/B/C PWM controller provides high efficiency, excellent transient response, and high DC output accuracy needed for stepping down high voltage batteries to generate low voltage CPU core, I/O, and chipset RAM supplies in notebook computers. The RT8240A/B/C supports on chip voltage programming function between 1V and 1.05V by controlling G0 digital inputs. The constant on-time PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns “instant-on” response to load transients while maintaining a relatively constant switching frequency. The RT8240A/B/C achieves high efficiency at a reduced cost by eliminating the current sense resistor found in traditional current mode PWMs. Efficiency is further enhanced by its ability to drive very large synchronous rectifier MOSFETs and enter diode emulation mode at light load condition. The buck conversion allows this device to directly step down high voltage batteries at the highest possible efficiency. The RT8240A/B/C is intended for CPU core, chipset, DRAM, or other low voltage supplies as low as 1V. The RT8240A/B/C is available in a WQFN -12L 2x2 package. Ordering Information RT8240A/B/C z Built-in 0.5% Reference Voltage z 1 Bit Programmable Output Voltage Between 1V and 1.05V with Integrated Transition Support z Output Voltage Range from 1V to 3.6V z Quick Load-Step Response within 100ns z Support Pure MLCC Output Capacitor z 4700ppm/°C Programmable Current Limit by Low Side RDS(ON) Sensing z 4.5V to 26V Battery Input Range z Internal Ramp Current Limit Soft-Start Control z Drives Large Synchronous Rectifier FETs z Integrated Boost Switch z Over/Under Voltage Protection z Thermal Shutdown z Power Good Indicator z RoHS Compliant and Halogen Free Applications z Notebook Computers z CPU/GPU Core Supply z Chipset/RAM Supply z Generic DC/DC Power Regulator Pin Configurations (TOP VIEW) GND G0 CS Package Type QW : WQFN-12L 2x2 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) Z : ECO (Ecological Element with Halogen Free and Pb free) Note : Switching Frequency Operation A : 300kHz B : 400kHz C : 500kHz 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. 12 11 10 LGATE 1 PHASE 2 UGATE 3 GND 13 9 PGOOD 8 EN 7 RGND 4 56 BOOT VCC VOUT WQFN-12L 2x2 Copyright ©2014 Richtek Technology Corporation. All rights reserved. DS8240A/B/C-04 January 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT8240A/B/C Marking Information RT8240AGQW 45: Product Code 45W YMDNN : Date Code RT8240AZQW 45: Product Code 45W YMDNN : Date Code RT8240BGQW 29 : Product Code 29W YMDNN : Date Code RT8240BZQW 29 : Product Code 29W YMDNN : Date Code RT8240CGQW 43 : Product Code 43W YMDNN : Date Code RT8240CZQW 43 : Product Code 43W YMDNN : Date Code Typical Application Circuit (1) Remote Sense RT8240A/B/C VCC 5 VCC BOOT 4 Chip Enable UGATE 3 9 PGOOD PHASE 2 8 EN 11 G0 LGATE 1 12, 13 (Exposed Pad) GND 10 CS VOUT 6 RGND 7 Remote (+) Remote (-) VIN VOUT Copyright ©2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS8240A/B/C-04 January 2014 (2) Local Sense RT8240A/B/C VCC 5 VCC BOOT 4 9 PGOOD Chip Enable 8 EN 11 G0 12, 13 (Exposed Pad) GND 10 CS UGATE 3 PHASE 2 LGATE 1 VOUT 6 RGND 7 VID Table G0 VOUT 0 1V 1 1.05V RT8240A/B/C VIN VOUT Copyright ©2014 Richtek Technology Corporation. All rights reserved. DS8240A/B/C-04 January 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT8240A/B/C Functional Pin Description Pin No. 1 2 3 4 Pin Name LGATE PHASE UGATE BOOT 5 VCC 6 VOUT 7 RGND 8 EN 9 PGOOD 10 CS 11 G0 12, 13 (Exposed Pad) GND Pin Function Gate Drive Output for Low Side External MOSFET. External Inductor Connection Pin for PWM Converter. It behaves as the current sense comparator input for low side MOSFET RDS(ON) sensing and reference voltage for on time generation. Gate Drive Output for the High Side External MOSFET. Supply Input for High Side Driver. Connect a capacitor to the floating node (PHASE) pin. Control Voltage Input. Provides the power for the buck controller, the low side driver and the bootstrap circuit for high side driver. Bypass to GND with a 4.7μF ceramic capacitor. Output Voltage Feedback Input. Connect VOUT to converter output node. Remote Voltage Sense Ground Pin. PWM Enable Pin. Pull low to GND to disable the PWM. Open Drain Power Good Indicator. High impedance indicates power is good. Current Limit Threshold Setting Input. Connect a setting resistor to GND and the current limit threshold is equal to 1/8 of the voltage at this pin. Input Pin for Programming the Output Voltage Betw.


SN11220APF RT8240A RT8240B


@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site.
(Privacy Policy & Contact)