Richtek RT9728CHGE, RT9728CHGQW Schematic [ru]

RT9728C

120m

ΩΩ

Ω, 1.3A Power Switch with Programmable Current Limit

ΩΩ

General Description

The RT9728C is a cost effective, low voltage, single

P-MOSFET high-side power switch IC for USB application

with a programmable current limit feature. Low switch-on

resistance (typ.120mΩ) and low supply current (typ.

120μA) are realized in this IC.The RT9728C can offer a

programmable current limit threshold between 75mA and

1.3A (typ.) via an external resistor. The ±10% current limit

accuracy can be realized for all current limit settings. In

addition, a flag output is available to indicate fault

conditions to the local USB controller. Furthermore, the

chip also integrates an embedded delay function to prevent

mis-operation from happening due to high inrush current.

The RT9728C is an ideal solution for USB power supply

and can support flexible applications since it is functional

for various current limit requirements. It is available in

SOT-23-6 and WDFN-6L 2x2 packages.

Features

±±





±10% Current Limit Accuracy @ 1.3A



±±



 Adjustable Current Limit : 75mA to 1.3A (typ.)



 Meets USB Current Limiting Requirements



 Operating Voltage Range : 2.5V to 5.5V



 Reverse Input



 Built-in Soft-Start



 120m



 120



 RoHS Compliant and Halogen Free



ΩΩ

Ω High-Side MOSFET

ΩΩ

μμ

μA Supply Current

μμ

−−

−Output Voltage Protection

−−

Applications

 USB Bus/Self Powered Hubs

 USB Peripheral Ports

 ACPI Power Distribution

 Battery Power Equipment

 3G/3.5G Data Card, Set-Top Boxes

Ordering Information

RT9728C

Package Type E : SOT-23-6 QW : WDFN-6L 2x2

Lead Plating System G : Green (Halogen Free and Pb Free)

H : Chip Enable High

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)

ILIM

VOUT

GND

VIN

SOT-23-6

VOUT

ILIM

WDFN-6L 2x2

FAULT

GND

VIN

GND ENFAULT

DS9728C-00 October 2015 www.richtek.com

RT9728C

Marking Information

RT9728CHGE

42= : Product Code

42=DNN

Typical Application Circuit

DNN : Date Code

RT9728CHGQW

3WW

3W : Product Code

W : Date Code

FAULT Signal

Chip Enable

FAULT

100k

10µF

VIN

FAULT

VOUT

RT9728C

Functional Pin Description

Pin No.

SOT-23-6 WDFN-6L 2x2

1 6 VIN Input Voltage.

7 (Exposed Pad)

3 4 EN Chip Enable.

4 3

5 2 ILIM

6 1

Pin Name Pin Function

GND

FAULT

Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation.

Active-Low Open-Drain Output. Asserted during over current, over temperature, or reverse-voltage conditions.

Current Limit Set Pin. External resistor used to set current limit threshold. Recommend 19.1k  R

VOUT Power Switch Output.

ILIM

GND

OUT

150µF

ILIM

 232k.

ILIM

DS9728C-00 October 2015www.richtek.com

Function Block Diagram

VIN

Switch

well

Current

Sense

RT9728C

Reverse Voltage

Comparator

VOUT

UVLO

Drive

Thermal

Sense

Operation

The RT9728C are current-limited, power-distribution

switches using P-channel MOSFETs for applications

where short circuits or heavy capacitive loads will be

encountered. These devices allow the user to program

the current-limit threshold between 75mA and 1.3A (typ)

via an external resistor. Additional device shutdown features

include over temperature protection and reverse-voltage

protection.

Current

Limit

ILIM

4ms

Deglitch

7.5ms

Deglitch

≒60

FAULT

GND

The driver controls the gate voltage of the power switch.

The driver incorporates circuitry that controls the rise and

fall times of the output voltage to limit large current and

voltage surges and provides built-in soft-start functionality.

The RT9728C enters the constant-current mode when the

load exceeds the current-limit threshold.

DS9728C-00 October 2015 www.richtek.com

RT9728C

Absolute Maximum Ratings (Note 1)

 Supply Input Voltage ------------------------------------------------------------------------------------------------------ −0.3V to 6V

 Other Pin Voltage --------------------------------------------------------------------------------------------------------- −0.3V to 6V

 Power Dissipation, P

SOT-23-6 -------------------------------------------------------------------------------------------------------------------- 0.4W

WDFN-6L 2x2 -------------------------------------------------------------------------------------------------------------- 0.606W

 Package Thermal Resistance (Note 2)

SOT-23-6, θJA--------------------------------------------------------------------------------------------------------------- 250°C/W

WDFN-6L 2x2, θJA--------------------------------------------------------------------------------------------------------- 165°C/W

WDFN-6L 2x2, θJC-------------------------------------------------------------------------------------------------------- 7°C/W

 Lead Temperature (Soldering, 10 sec.)------------------------------------------------------------------------------- 260°C

 Junction Temperature ----------------------------------------------------------------------------------------------------- 150°C

 Storage Temperature Range -------------------------------------------------------------------------------------------- −65°C to 150°C

 ESD Susceptibility (Note 3)

HBM (Human Body Model)---------------------------------------------------------------------------------------------- 2kV

Recommended Operating Conditions (Note 4)

@ T

= 25°C

 Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------- 2.5V to 5.5V

 Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C

 Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C

Electrical Characteristics

(VIN = 3.6V, 19.1kΩ ≤ R

Parameter Symbol Test Conditions Min Typ Max Unit

EN Input Voltage

Current Limit Threshold Resistor Range

Under Voltage Lockout Threshold

Shutdown Current I

Quiescent Current IQ

Reverse Leakage Current I

Thermal Shutdown Temperature Static Drain-Source On-State Resistance

Current Limit I

≤ 232kΩ, T

ILIM

Logic-High V

= 25°C, unless otherwise specified)

1.1 -- --

Logic- Low VIL -- -- 0.66

(nominal 1%) from I

ILIM

Rising -- 2.3 --

UVLO

SHDN

REV

-- 160 -- °C

DS(ON)

LIM

VIN Falling -- 2.1 --

VIN = 5.5V, No Load on V

= 5.5V,

No Load on V

= 5.5V, VIN = 0V -- 1 3 A

OUT

ISW = 0.2A -- 120 -- m

= 20k 1190 1295 1400

ILIM

= 49.9k 468 520 572

ILIM

= 210k 110 130 150

ILIM

to GND 19.1 -- 232 k

LIM

, VEN = 0V -- 1 3 A

OUT

= 20k -- 120 170

ILIM

= 210k -- 120 170

ILIM

A

ILIM Shorted to VIN 50 75 100

DS9728C-00 October 2015www.richtek.com

RT9728C

Parameter Symbol Test Conditions Min Typ Max Unit

Reverse Voltage Comparator Trip Point (V

OUT

VIN)

FAULT Output Low Voltage

FAULT Off State Leakage

FAULT Deglitch

Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are

stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in

the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may

affect device reliability.

Note 2. θ

Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions.

is measured at T

measured at the exposed pad of the package.

-- 135 -- mV

= 1mA

= 25°C on a low effective thermal conductivity single-layer test board per JEDEC 51-3. θJC is

FAULT

= 5.5V

FAULT assertion or de-assertion due to over current condition

FAULT assertion or de-assertion due to reverse voltage condition

-- 180 -- mV

-- 1 -- A

5 7.5 10

2 4 6

DS9728C-00 October 2015 www.richtek.com

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