OMNI-VISION WS4667E Ultra-low Ron Load Switch User Manual

WS4667E
4.5A, 22mΩ, Ultra-low Ron Load Switch
with Quick Output Discharge

Descriptions
The WS4667E is a small, ultra-low Ron, single channel load switch with a controlled turn-on. The device contains an N-channel MOSFET that can operate over an input voltage range of 0.8V to 3.5V and supports a maximum continuous current of 4.5A.

http://www.ovt.com 

This device is suitable for driving processor power rails with very strict voltage dropout tolerances. Quick rise time of the device allows for power rails to come up quickly when the device is enabled, thereby reducing response time for power distribution. The ON terminal can be directly connected with the low-voltage control signals generated by microcontrollers or low-voltage discrete logic circuits.
Pin configuration (Top view)
The WS4667E is available in the SOT23-6L package. The standard product is Pb- free and Halogen-free.

Features

• Input Voltage Range: 0.8V to 3.5V
• Ultra-Low On Resistance (RON) RON = 22mΩ at VBIAS = 5V
• 4.5 A Maximum Continuous Switch Current
• Low Control Input Threshold Enables Use of 1.2V, 1.8V, 2.5V and 3.3V Logic
• Quick Output Discharge (QOD)
• SOT23-6L Package
• ESD Performance Tested per JESD 22 2kV HBM and 1kV CDM

For detailed order information, please see page 2.

Applications

• Ultrabook™
• Notebooks/Netbooks
• Tablet PC
• Consumer Electronics
• Set-top Boxes/Residential Gateways
• Telecom Systems

Order Information

Ordering No.| Continuous
Current| Rise
Time| Enable| Output
Discharge
Resistor| Package| Operating
Temperature| Marking| Shipping
---|---|---|---|---|---|---|---|---
WS4667EAA-
6/TR| 4.5A| 3.4us| Active
High| Yes| SOT23-6L| -40-85°C| 4667
EEYW| 3000/Reel&
Tape

Marking Information
4667 = Device code
EE = Special code
Y = Year code
W = Week code
Marking

Typical Application

Pin Description

terminal and GND.
3| NC| —| Not connected.
4| VOUT| 0| Switch output. Place ceramic bypass capacitor(s) between this terminal and GND.
5| VBIAS| —| Bias voltage. Power supply to the device.
6| ON| I| Active high switch control input. Do not leave floating.

Block Diagram

Absolute Maximum Ratings

Thermal Information

Thermal Resistance| WS4667E
SOT23-6L| Unit
---|---|---
Thermal Resistance, RθJA（Junction-to-Ambient）Without Copper Pour| 198| °C/W
Thermal Resistance, RθJA（Junction-to-Ambient）With Copper Pour*| 133| °C/W

: Surface mounted on FR-4 Board using 2 oz, 1 square inch Cu area, PCB board size 1.51.5 square inches.

Recommended Operating Conditions

Electrical Characteristics

VBIAS=5.0V, Cin=1uF, TA=25°C, unless otherwise noted.

Electrical Characteristics (Continued)
VBIAS=3.0V, Cin=1uF, TA=25°C, unless otherwise noted.

Parameter| Symbol| Test Conditions| Min| Typ| Max| Unit
---|---|---|---|---|---|---
VBIAS Quiescent Current| lo.vms| louT =0mA,VIN = 1.0V| | 12| 25| μA
VBIAS Shutdown Current| ISD.VBIAS| VON = OV , VOUT = OV| | 0.1| 1| μA
VIN Shutdown Current| Iso.viN| VON = OV ,
VOUT = OV| VIN = 1.05V| | 0.001| 0.3| μA
VIN = 0.8V| | 0.001| 0.3
ON Pin Input Leakage Current| ION| VON = 5.5V| | 0.1| 1| μA
ON Logic High Input Voltage| VON.H| VIN = 0.8V to 1.0V| 1.| | | V
ON Logic Low Input Voltage| VON.L| VIN = 0.8V to 1.0V| | | 0.4| V
ON-state resistance| RON| IOUT = -1.0A| MN = 1.0V| | 22| 40| mΩ
VIN = 0.8V| | 22| 40
Output pull-down resistance| RPD| VIN = VOUT=1.0V, VON = OV| | 260| | Ω

Switching Characteristics Measurement Information

Switching Characteristics

VIN = 2.5V, VON = VBIAS = 5V, TA = 25 °C (unless otherwise noted)
tON Turn-on time| RL= 10Ω, CL= 0.1uF| 4.1| μs
toFF Turn-off time| 1.2
tR VOUT rise time| 3.4
2
tF VOUT fall time
to ON delay time| 3.1
VIN = 1.05V, VON = VBIAS = 5V, TA = 25 °C (unless otherwise noted)
toN Turn-on time| RL= 10Ω, CL= 0.1uF| 4| μs
toFF Turn-off time| 1.3
tR VOUT rise time| 1.5
tF Vou-r fall time| 1.8
to ON delay time| 3.4
VIN = 1.05V, VON = 5V, VBIAS = 3.3V, TA = 25 °C (unless otherwise noted)
tON Turn-on time| RL= 10Ω, CL.= 0.1uF| 7| μs
toFF Turn-off time| 2
tR VOUT rise time| 5
2
tF Vou-r fall time
to ON delay time| 5.5

Typical Characteristics

|
---|---
|
|
|

Working Waveforms

Detailed Description

Overview

The WS4667E device is a 3.5V, 4.5A load switch in a DFN3x2-8L package. To reduce voltage drop for low voltage and high current rails, the device implements an ultra-low resistance N-channel MOSFET. The device has a controlled, fixed slew rate for applications that require a specific rise- time. During the shutdown, the device has very low leakage currents, thereby reducing unnecessary leakages for downstream modules during standby. The integrated control logic, driver, and output discharge FET eliminate the need for ny external components, which reduces solution size and bill of materials (BOM) count.

ON and OFF Control
The ON pin controls the state of the load switch. ON is active high and has a 1.2 V ON pin enable threshold, making it capable of interfacing with low- voltage signals. The ON pin is compatible with standard GPIO logic thresholds. It can be used with any microcontroller with 1.2 V or higher GPIO voltage. This pin cannot be left floating and must be driven either high or low for proper functionality.

Input Capacitor (CIN) (Optional)
To limit the voltage drop on the input supply caused by transient inrush currents when the switch turns on into a discharged load capacitor or short- circuit, a capacitor needs to be placed between VIN and GND. A 1µF ceramic capacitor, CIN, placed close to the pins, is usually sufficient. Higher values of CIN can be used to further reduce the voltage drop in high-current applications. When switching heavy loads, it is recommended to have an input capacitor about 10 times higher than the output capacitor (CL) to avoid excessive voltage drop.

Output Capacitor (CL) (Optional)
Because of the integrated body diode in the NMOS switch, a CIN greater than CL is highly recommended. A CL greater than CIN can cause VOUT to exceed VIN when the system supply is removed. This could result in current flow through the body diode from VOUT to VIN. A CIN to CL ratio of 10 to 1 is recommended for minimizing VIN dip caused by inrush currents during startup; however, a 10 to 1 ratio for capacitance is not required for the proper functionality of the device. A ratio smaller than 10 to 1 (such as 1) could cause slightly more VIN dip upon turn-on because of inrush currents.

Quick-Output Discharge
When the switch is disabled， an internal discharge resistance is connected between VOUT and GND to remove the remaining charge from the output. This resistance has a typical value of 260 Ω and prevents the output from floating while the switch is disabled. For best results, it is recommended that the device gets disabled before VBIAS falls below the minimum recommended voltage.

Layout guide
For best performance, all traces should be as short as possible. To be most effective, the input and output capacitors should be placed close to the device to minimize the effect that parasitic trace inductance may have on normal and short-circuit operation. Using wide traces for VIN, VOUT, GND helps minimize parasitic electrical effects along with minimizing the case-to- ambient thermal impedance.

PACKAGE OUTLINE DIMENSIONS

TAPE AND REEL INFORMATION

RD| Reel Dimension|
---|---|---
 W| Overall width of the carrier tape
P1| Pitch between successive cavity centers
Pin1| Pin1 Quadrant

OmniVision reserves the right to make changes to its products or to discontinue any product or service without further notice. OmniVision and the OmniVision logo are trademarks or registered trademarks of OmniVision Technologies, Inc. All other trademarks are the property of their respective owners.

4275 Burton Drive
Santa Clara, CA 95054
USA
Tel: + 1 408 567 3000
Fax: + 1 408 567 3001
www.ovt.com
2022/1/4 – Rev. 0.5

Read User Manual Online (PDF format)

Download This Manual (PDF format)

Download this manual  >>