900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




  Richtek Technology Electronic Components Datasheet  

RT8237E Datasheet

High Efficiency Single Synchronous Buck PWM Controller

No Preview Available !

®
RT8237E
High Efficiency Single Synchronous Buck PWM Controller
General Description
The RT8237E 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 constant on-time PWM control scheme handles wide
input/output voltage ratios with ease and provides 100ns
instant-onresponse to load transients while maintaining
a relatively constant switching frequency.
The RT8237E 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 pre-set frequency selections
minimize design effort required for new designs. The
RT8237E is intended for CPU core, chipset, DRAM, or
other low voltage supplies as low as 0.7V. The RT8237E
is available in the WDFN-10L 3x3 package.
Features
z Wide Input Voltage Range : 4.5V to 26V
z Output Voltage Range : 0.7V to 3.3V
z Built-in 0.5% 0.7V Reference Voltage
z Quick Load-Step Response within 100ns
z 4700ppm/°C Current Source for Current Limit
RDS(ON)
z Adjustable Current Limit with Low Side MOSFET
z 4 Selectable Frequency Setting
z Soft-Start Control
z Drives Large Synchronous-Rectifier FETs
z Integrated Boot Switch
z Built-in OVP/OCP/UVP
z Thermal Shutdown
z Power Good Indicator
z RoHS Compliant and Halogen Free
Applications
z Notebook Computers
z CPU Core Supply
z Chipset/RAM Supply as Low as 0.7V
z Generic DC/DC Power Regulator
Simplified Application Circuit
RT8237E
VCC VCC
BOOT
PGOOD
EN
RF
CS
UGATE
PHASE
LGATE
GND
FB
VIN
VOUT
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
DS8237E-00 December 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1


  Richtek Technology Electronic Components Datasheet  

RT8237E Datasheet

High Efficiency Single Synchronous Buck PWM Controller

No Preview Available !

RT8237E
Ordering Information
RT8237E (2)
Pin 1 Orientation
(2) : Quadrant 2, Follow EIA-481-D
Package Type
QW : WDFN-10L 3x3 (W-Type)
Lead Plating System
Z : ECO (Ecological Element with
Halogen Free and Pb free)
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.
Pin Configurations
(TOP VIEW)
PGOOD 1
CS 2
EN 3
FB 4
RF 5
10 BOOT
9 UGATE
8 PHASE
7 VCC
11 6 LGATE
WDFN-10L 3x3
Marking Information
88 : Product Code
88 DF
A26
DFA26 : Date Code
Functional Pin Description
Pin No.
Pin Name
Pin Function
1
PGOOD
Open Drain Power Good Indicator. High impedance indicates power is good.
2 CS
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.
3 EN
Enable Control Input. Pull low to GND to disable the PWM.
4 FB
5 RF
VOUT Feedback Input. Connect FB to a resistor voltage divider from VOUT to GND
to adjust the output from 0.7V to 3.3V
Switching Frequency Selection. Connect a resistance to select switching
frequency as shown in Electrical Characteristics. The switching frequency is
detected and latched after startup. This pin also controls diode emulation mode or
forced CCM selection.
Pull down to GND with resistor : Diode Emulation Mode.
Connect to PGOOD with resistor : forced CCM after PGOOD becomes high.
6
LGATE
Gate Drive Output for Low Side External MOSFET.
7 VCC
Supply Voltage Input. This pin provides the power for the Buck controller, the low
side driver and the bootstrap circuit for high side driver. Bypass to GND with a 1μF
ceramic capacitor.
External Inductor Connection Pin for PWM Converter. It behaves as the current
8
PHASE
sense comparator input for low side MOSFET RDS(ON) sensing and reference
voltage for on time generation.
9
UGATE
Gate Drive Output for High Side External MOSFET.
10 BOOT
11
(Exposed Pad)
GND
Bootstrap Supply for High Side Gate Driver. Connect through a capacitor to the
floating node (PHASE).
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS8237E-00 December 2012


Part Number RT8237E
Description High Efficiency Single Synchronous Buck PWM Controller
Maker RICHTEK
Total Page 18 Pages
PDF Download

RT8237E Datasheet PDF

View PDF for Mobile








Similar Datasheet

1 RT8237A (RT8237A/B) High Efficiency Single Synchronous Buck PWM Controller
RICHTEK
2 RT8237B (RT8237A/B) High Efficiency Single Synchronous Buck PWM Controller
RICHTEK
3 RT8237C (RT8237C/D) High Efficiency Single Synchronous Buck PWM Controller
RICHTEK
4 RT8237D (RT8237C/D) High Efficiency Single Synchronous Buck PWM Controller
RICHTEK
5 RT8237E High Efficiency Single Synchronous Buck PWM Controller
RICHTEK





Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

Site map

Webmaste! click here

Contact us

Buy Components

Privacy Policy