RS2599

Precision Adjustable Current Limited Power Distribution
Switches
1 FEATURES

3 DESCRIPTION•

Up to 3A Maximum Load Current

The RS2599 is an integrated power switch for self-•

Typical 100μA Low Quiescent Current

powered and bus-powered Universal Serial Bus (USB)•

Typical 0.1μA Shutdown Current

applications.

•

No Reversed Leakage Current When PowerOffThe RS2599 is a cost-effective, low voltage, single P-•

Meets USB Current Limiting Requirements

channel MOSFET load switch with 50mΩ RDS(ON), which•

Adjustable Current Limit: 500mA to 3A

is free of parasitic body diode to eliminate any reversed•

Fast Over-Current Response: 2μs

current flow across the switch when it is powered off.

•

50mΩ High-side MOSFET•

Reverse Input-Output Voltage Protection•

Under Voltage Lockout•

Thermal Shutdown Protection•

Operating Range: 2.5V to 5.5V•

Built-In Soft-Start Function•

Available in the Green DFN3X3-8 Package

2 APPLICATIONS•

USB Host and Self-Powered Bubs•

USB Bus-Powered Hubs•

USB Power Management•

General Purpose Power Switch (High Side)•

Hot Plug-in Power Supplies•

Battery-Charger Circuits

When the output voltage is higher than input voltage,
the power switch is turned off by internal output
reverse-voltage protector.
Several Protection features include current limiting andthermal shutdown to prevent catastrophic switch failurecausedbyincreasing

power

dissipation

when

continuous heavy loads or short circuit occurs.
FLAG is an open-drain output report over-current orover-temperature event and has typical 13ms deglitch
timeout period. In addition, FLAG also reports output
reverse-voltage condition with typical 5ms deglitch
timeout period.
RS2599 is available in the Green DFN3X3-8 package. It
is rated over the -40°C to +85°C temperature range.

Device Information (1)REV A.3.1

PART NUMBER

PACKAGEBODY SIZE (NOM)

RS2599DFN3X3-8

3.00mm×3.00mm(1)

For all available packages, see the orderable addendum at theend of the data sheet.

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RS2599
4 Functional Block Diagram
VIN
SwitchWell
1:K

ReverseUVLO
Driver

ThermalShutdown

Reference
Voltage

AMP

OCP

OUT
EN

OSC

EN

FLAG
Diglitch

GND

SET

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RS2599
Table of Contents
1 FEATURES ............................................................................................................................................................................... 1
2 APPLICATIONS ...................................................................................................................................................................... 1
3 DESCRIPTION ........................................................................................................................................................................ 1
4 Functional Block Diagram .................................................................................................................................................... 2
5 Revision History ..................................................................................................................................................................... 4
6 PACKAGE/ORDERING INFORMATION ......................................................................................................................... 5
7 PIN CONFIGURATIONS ...................................................................................................................................................... 6
8 Specifications .......................................................................................................................................................................... 7
8.1 Absolute Maximum Ratings (1) ...................................................................................................................................... 7
8.2 ESD Ratings ...................................................................................................................................................................... 7
8.3 Recommended Operating Rating ................................................................................................................................. 7
8.4 ELECTRICAL CHARACTERISTICS ............................................................................................................................... 8
8.5 PARAMETER MEASUREMENT INFORMATION ..................................................................................................... 9
8.6 TYPICAL PERFORMANCE CHARACTERISTICS ....................................................................................................10
9 DETAILED DESCRIPTION .................................................................................................................................................12
9.1 Input and Output ...........................................................................................................................................................12
9.2 Thermal Shutdown ........................................................................................................................................................12
9.3 Soft-Start.........................................................................................................................................................................12
9.4 Under-Voltage Lockout (UVLO) .................................................................................................................................12
9.5 Current Limiting and Short-Circuit Protection ........................................................................................................12
9.6 Reverse-Voltage Protection ........................................................................................................................................12
9.7 Fault Flag (FLAG) ...........................................................................................................................................................12
9.8 Power Dissipation .........................................................................................................................................................12
9.9 Supply Filter Capacitor .................................................................................................................................................13
9.10 Output Filter Capacitor .............................................................................................................................................13
9.11 PCB Layout Guide.......................................................................................................................................................13
10 PACKAGE OUTLINE DIMENSIONS .............................................................................................................................14
11 TAPE AND REEL INFORMATION .................................................................................................................................15

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RS2599
5 Revision History
Note: Page numbers for previous revisions may different from page numbers in the current version.
VERSION

Change Date

Change Item

A.0

2021/11/26

Initial version completed

A.1

2022/05/05

A.2

2022/08/29

A.3

2023/08/31

Official version completed
1. Update ILIMIT、ISHORT PARAMETER on Page 8@RevA.1
2. Update Current Limiting and Short-Circuit Protection on Page 12@RevA.1
Update ESD Ratings

A.3.1

2024/02/23

Modify packaging naming

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RS2599
6 PACKAGE/ORDERING INFORMATION (1)PRODUCT

ORDERING
NUMBERTEMPERATURE
RANGE

PACKAGELEAD

PACKAGEMARKING (2)PACKAGE OPTION

RS2599RS2599YTDC8-40°C ~+85°C

DFN3X3-8

RS2599Tape and Reel,5000

NOTE:(1) This information is the most current data available for the designated devices. This data is subject to change without notice and revisionof this document. For browser-based versions of this data sheet, refer to the right-hand navigation.
(2) There may be additional marking, which relates to the lot trace code information(data code and vendor code)，the logo or theenvironmental category on the device.

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RS2599
7 PIN CONFIGURATIONSTOP VIEW

VIN

1

8

OUT

VIN

2

7

OUT

EN

3

6

FLAG

GND

4

5

SET

DFN3X3-8

PIN DESCRIPTIONPIN
DFN3X3-8
1NAME

DESCRIPTION

VINPower Supply Input. The P-Channel Source of Switch, Which also supplies IC’s internal
circuitry. Connect to Positive Supply.

3

EN

Enable Input. Logic Level Enable Input, Active high available.

4

GND

5

SET

6

FLAG

Ground.
Current limit set pin. Connect a resistor between this pin and ground to program the desired
current limit set point.
Fault Flag. Active low, open-drain output. Indicates over-current or thermal shutdown
conditions. Over-current condition must last longer than td in order to assert FLAG

2

7
8

OUT

Switch Output. The P-Channel Drain of Switch, Which Typically Connects to Load.

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RS2599
8 Specifications
8.1 Absolute Maximum Ratings (1)over operating free-air temperature range (unless otherwise noted) (1)

(1)

(2)
(3)

MIN

MAX

UNIT

VIN

Supply voltage range

-0.3

6.0

V

VOUT

Output voltage range

-0.3

6.0

V

VEN

EN Input Voltage

-0.3

6.0

V

VFLAG

FLAG Output Voltage

-0.3

6.0

V

VSET

SET Output Voltage

-0.3

6.0

V

θJA

Package thermal impedance (2)

45

°C/W

TJ

Junction temperature (3)

-40

150

°C

Tstg

Storage temperature

-65

150

°C

TL

Lead Temperature (Soldering,10secs)

260

°C

DFN3X3-8

Stresses beyond those listed under 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 under Recommended Operating
Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
The package thermal impedance is calculated in accordance with JESD-51.
The maximum power dissipation is a function of TJ(MAX), RθJA, and TA. The maximum allowable power dissipation at any ambient
temperature is PD = (T J(MAX) - TA) / RθJA. All numbers apply for packages soldered directly onto a PCB.

8.2 ESD Ratings
The following ESD information is provided for handling of ESD-sensitive devices in an ESD protected area only.
VALUE
V(ESD)

Electrostatic discharge

Human-body model (HBM), JEDEC EIA/ JESD22 - A114

±2000

Charged-device model (CDM), ANSI/ESDA/JEDEC JS-002-2018

±1000

UNIT
V

ESD SENSITIVITY CAUTION
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be
more susceptible to damage because very small parametric changes could cause the device not to meet its publishedspecifications.

8.3 Recommended Operating Rating
MIN

MAX

UNIT

VIN

Supply voltage range

2.5

5.5

V

VOUT

Output voltage range

0

5.5

V

VEN

EN Input Voltage

0

5.5

V

VFLAG

FLAG Output Voltage

0

5.5

V

VSET

SET Output Voltage

0

5.5

V

TA

Operating Temperature

85

°C

-40

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RS2599
8.4 ELECTRICAL CHARACTERISTICS(VIN=5.0V, TA = +25°C, unless otherwise noted.) (1)
PARAMETERSYMBOLTEST CONDITIONSMIN (2)TYP (3) MAX (2) UNIT

Power Input Voltage Range

VIN

5.5

V

Power Supply Current

IQ

Switch on, VOUT=Open

100

200

μA

Shutdown Supply Current

ISD

Switch off, VOUT=Open

0.1

1.0

μA

Under-Voltage Lockout Threshold
Under-Voltage Lockout Threshold
Hysteresis
High-side MOSFET On Resistance

VUVLO

CIN=10μF

1.9

2.4

V

VUVLO_HY

CIN=10μF

0.1

0.2

V

RDS(ON)IOUT=500mA

50

60

mΩ

VIH

VIN=2.5V to 5.5V, CIN=10μF

Enable Input Threshold

2.5

1.6

V

VIL

VIN=2.5V to 5.5V, CIN=10μF

0.4

V

Enable Input Current

IEN

VEN= 5V

10

20

μA

Output Turn-On Delay TimetON

CIN=10μF, RL=10Ω, CL=1μF

2.0

3.0

ms

Output Turn-Off Delay Time

tOFF

CIN=10μF, RL=10Ω, CL=1μF

20

30

μs

Response Time to Short CircuittSCR

CIN=470μF to 1000μF

2.0

Current Limit Threshold

Short-Circuit Current Threshold

μs

CIN=10μF, CL=1μF, RSET=22kΩ

0.44

0.56

0.67

CIN=10μF, CL=1μF, RSET=12.3kΩ

0.80

1.0

1.20

CIN=10μF, CL=1μF, RSET=4.12kΩ

2.40

3.0

3.60

CIN=10μF, CL=1μF, RSET=22kΩ

0.33

0.42

0.51

ISHORT

CIN=10μF, CL=1μF, RSET=12.3kΩ

0.60

0.75

0.90

1.80

2.25

2.70

tD

13

20

ms

200

mV

0.1

1.0

μA

350

ILIMIT

Over-Current FLAG Response Delay
Time
FLAG Output Low Voltage

VFLAG_L

CIN=10μF, CL=1μF, RSET=4.12kΩ
CIN=10μF, CL=1μF, VOUT=0 until
FLAG is low
CIN=10μF, ISINK=2mA

FLAG Output Leakage Current

IFLAG_L

CIN=10μF, VFLAG=5.0V

Discharge Resistor

RDischarge

A

A

CIN=10μF, Switch off

300

Thermal Shutdown Temperature

TSD

CIN=10μF

150

°C

Ω

Thermal Shutdown Hysteresis

TSD_HY

CIN=10μF

20°C(1) Electrical table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very
limited self-heating of the device.
(2) Limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlations using statisticalquality control (SQC) method.
(3) Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may varyover time and will also depend on the application and configuration.

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RS2599
8.5 PARAMETER MEASUREMENT INFORMATION

VEN

tON

tOFF

VOUT

Figure 1. Switch Turn-On and Turn-Off Delay TimeISHORTIOUTtSCR

Figure 2. Short-Circuit Response Time

2.5V~5.5V

IOUT

Power
SupplyVIN

RS2599CIN
10μF

Enable

OUT

EN

FLAG

Load

10kΩ

CL
1μF

SET

GND

RSET

Figure 3. Typical Application Circuit

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RS2599
8.6 TYPICAL PERFORMANCE CHARACTERISTICS
NOTE: The graphs and tables provided following this note are a statistical summary based on a limited number of samples
and are provided for informational purposes only.
130
120

85℃
25℃
-40℃

100

25℃
-40℃

Rdson(mΩ)

110

IQ(μA)

120

85℃

100
90
80

80
60

40
20

70
60

0
2.5

3

3.5

4

4.5

5

5.5

2.5

3

3.5

4

4.5

5

5.5

Figure 4. Quiescent Current vs Supply Voltage

Figure 5. High-side MOSFET On Resistance vs
Supply Voltage

EN

VOUT
FLAG
IOUT

VIN=5V,RL=10Ω

EN
VOUT
FLAG

IOUT

2ms/div

500mA /di v 5V /div 5V /div 5V /div

VIN(V)

500mA /di v 5V /div 5V /div 5V /div

VIN(V)

Figure 6. Turn-On Delay Time

VIN=5V,RL=10Ω

50us/div
Figure 7. Turn-Off Delay Time

FLAG
IOUT

VOUT
FLAG
IOUT

500mA /di v 5V /div 5V /div

VOUT

500mA /di v 5V /div 5V /div

VIN=5V,RSET=10KΩ,RL=1KΩ

5ms/div

1ms/div

Figure 8. Exit Over Temperature Protection

Figure 9. Enter Over Temperature Protection

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FLAG

IOUT

EN

VOUT
FLAG

IOUT

10ms/div
Figure 10. No Load into Short-Circuit

VIN=5V,RSET=10KΩ,RL=10Ω

10ms/div
Figure 11. Device Enabled into Short-Circuit

FLAG
VOUT
VIN

IOUT

2A/div

500mA /di v 5V /div 5V /div 5V /div

VOUT

VIN=5V

IOUT

1A/div 100mV/div 2V/div

VIN

500mA /di v 5V /div 5V /div 5V /div

RS2599tSCR

5ms/div

2us/div

Figure 12. Short-Circuit Response Time

Figure 13. Reverse Input-Output Voltage
Protection

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RS2599
9 DETAILED DESCRIPTION
9.1 Input and Output
VIN is the power supply connection to the logic circuitry and the source of the P-channel MOSFET. OUT is thedrain of the P-channel MOSFET. In a typical circuit, current flows from VIN to OUT toward the load. The output
P-channel MOSFET and driver circuit are also designed to allow the MOSFET drain to be externally forced to ahigher voltage than the source (VOUT>VIN) when the switch is disabled.

9.2 Thermal Shutdown
Thermal shutdown is employed to protect device and load from damage because of excessive power dissipation.
It shuts off the output MOSFET and asserts the FLAG output, if the die temperature exceeds 150°C until the dietemperature drops to 130°C.

9.3 Soft-Start
In order to eliminate the upstream voltage sag caused by the large inrush current during hot-plug events, thesoft-start feature effectively isolates power supplies from such highly capacitive loads.

9.4 Under-Voltage Lockout (UVLO)
UVLO prevents the MOSFET switch from turning on until input voltage exceeds 1.9 (Typical). If input voltage
drops below 1.8V (Typical), UVLO shuts off the MOSFET switch. Under-voltage detection functions only when
the switch is enabled.

9.5 Current Limiting and Short-Circuit Protection
The current limit circuit is designed to limit the output current to protect the upstream power supply. Current
limit threshold is programmed with a resistor from SET to ground marked as R SET. It can be estimated by thefollowing equation:
12320
12320
ILIMIT =, ISHORT = 0.75 ∗，R SET ≤24kΩ
RSET

RSET

Under output short-circuit condition; the typical current limit folded back 75%. If the RS2599 keeps at overcurrent condition for a long time, the junction temperature may exceed 150°C, and over- temperature protection
will shut down the output until temperature drops 130°C or limit (short-circuit) condition is removed.

9.6 Reverse-Voltage Protection
The reverse-voltage protection feature turns off the MOSFET switch whenever the output voltage exceeds the
input voltage by 50mV (Typical). Its hysteresis voltage is 20mV (Typical). The Output reverse-voltage deglitch
time is 13ms (Typical).

9.7 Fault Flag (FLAG)
The signal is an open-drain N-MOSFET output. FLAG is asserted (active low) when an over-current, short-circuitor thermal shutdown condition occurs.
In the case of an over-current condition, FLAG will be asserted only after the response delay time (tD) has elapsed.
This ensures that FLAG is asserted only upon valid over-current condition and that erroneous error reporting iseliminated.
False over-current condition can occur during hot-plug events when a highly capacitive load is connected andcauses a high transient inrush current that exceeds the current limit threshold for up to 1ms. The FLAG responsedelay time tD is 13ms (Typical).

9.8 Power Dissipation
The device’s junction temperature depends on several factors such as the load, PCB layout, ambient temperature,and package type. Equations that can be used to calculate power dissipation and junction temperature are foundbelow:PD = RDS(ON) × IOUT2
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RS2599
To relate this to junction temperature, the following equation can be used:
TJ = PD × θJA + TA
Where:
TJ = junction temperature
TA = ambient temperature
θJA = the thermal resistance of the package

9.9 Supply Filter Capacitor
In order to prevent the input voltage drooping during hot-plug events, connect a ceramic capacitor (CIN) from
VIN to GND. The CIN is positioned close to VIN and GND of the device. However, higher capacitor values could
reduce the voltage sag on the input further. Furthermore, an output short will cause ringing on the input without
the input capacitor. It could destroy the internal circuitry when the input transient exceeds 6.0V which is theabsolute maximum supply voltage even for a short duration.
If the upstream supply cable is long or the VIN transient exceeds 6.0V during the V OUT short, recommend adding
a second filter capacitor (not less than 47μF) at the upstream supply output terminal.

9.10 Output Filter Capacitor
A low-ESR 10uF ceramic capacitor between OUT and GND is strongly recommended to reduce the voltage
droop during hot-attachment of downstream peripheral. Higher value output capacitor is better when the output
load is heavy. Additionally, bypassing the output with a 0.1uF ceramic capacitor improves the immunity of thedevice to short-circuit transients.

9.11 PCB Layout Guide
For best performance of the RS2599, the following guidelines must be strictly followed:
1.Please place the input capacitors near the VIN pin as close as possible.
2.Keep VIN and OUT traces as wide and short as possible.
3.Locate RS2599 and output capacitors near the load to reduce parasitic resistance and inductance for excellent
load transient performance.
4.Input and output capacitors should be placed closed to the IC and connected to ground plane to reduce noise
coupling. Place a ground plane under all circuitry to lower both resistance and inductance and improve DC andtransient performance
5.The traces routing the RILIM resistor to the RS2599 should be as short as possible to reduce parasitic effects on
the current limit accuracy.

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RS2599
10 PACKAGE OUTLINE DIMENSIONSDFN3X3-8 (2)
E

e

D

E1

L

b

D1

TOP VIEW

BOTTOM VIEW
0.65

1.70

A1

2.86

A2

A

0.70

0.30

SIDE VIEW
2.40
RECOMMENDED LANDPATTERN (Unit: mm)

Dimensions In Millimeters

Dimensions In Inches

Min

Max

Min

Max

A (1)

0.700

0.800

0.028

0.031

A1

0.000

0.050

0.000

0.002

Symbol

A2

0.203

0.008

b

0.250

0.350

0.010

0.014

D (1)

2.900

3.100

0.114

0.122

D1

2.350

2.450

0.093

0.096

E (1)

2.900

3.100

0.114

0.122

E1

1.650

1.750

0.065

0.069

e
L

0.650 TYP
0.370

0.026 TYP
0.470

0.015

0.019

NOTE:
1. Plastic or metal protrusions of 0.075mm maximum per side are not included.
2. This drawing is subject to change without notice.

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RS2599
11 TAPE AND REEL INFORMATIONREEL DIMENSIONSTAPE DIMENSION

Reel
DiameterReel Width(W1)

DIRECTION OF FEEDNOTE: The picture is only for reference. Please make the object as the standard.

KEY PARAMETER LIST OF TAPE AND REEL
PackageType

Reel
Diameter

DFN3X3-8

13’’

Reel
Width
(mm)
12.4

A0
(mm)

B0
(mm)

K0
(mm)

P0
(mm)

P1
(mm)

P2
(mm)

W
(mm)

Pin1
Quadrant

3.35

3.35

1.13

4.0

8.0

2.0

12.0

Q1

NOTE:
1. All dimensions are nominal.
2. Plastic or metal protrusions of 0.15mm maximum per side are not included.

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RS2599
IMPORTANT NOTICE AND DISCLAIMER
Jiangsu RUNIC Technology Co., Ltd. will accurately and reliably provide technical and reliability data (including
data sheets), design resources (including reference designs), application or other design advice, WEB tools, safety
information and other resources, without warranty of any defect, and will not make any express or implied
warranty, including but not limited to the warranty of merchantability Implied warranty that it is suitable for a
specific purpose or does not infringe the intellectual property rights of any third party.
These resources are intended for skilled developers designing with RUNIC products You will be solely
responsible for: (1) Selecting the appropriate products for your application; (2) Designing, validating and testing
your application; (3) Ensuring your application meets applicable standards and any other safety, security or otherrequirements; (4) RUNIC and the RUNIC logo are registered trademarks of RUNIC INCORPORATED. All
trademarks are the property of their respective owners; (5) For change details, review the revision history
included in any revised document. The resources are subject to change without notice. Our company will not beliable for the use of this product and the infringement of patents or third-party intellectual property rights due
to its use.

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