USB Power-Distribution Switches
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General Description
Features
The XZ2416/XZ2417/XZ2418/XZ2419 series of power
switches are designed for USB applications. The
Datasheet
62mN-channel MOSFET power switch satisfies the voltage
drop requirements of USB specification.
The protection features include current-limit protection,
short-circuit protection, and over-temperature
protection.The device limits the output current at current
limit threshold level. When VOUT drops below 1.5V, the devices
limit the current to a lower and safe level. The
over-temperature protection limits the junction temperature
below 140oC in case of short circuit or over load
conditions.Other features include a deglitched OCB output to
indicate the fault condition and an enable input to enable or
disable the device.
62mΩ High Side MOSFET
Wide Supply Voltage Range: 2.7V to 5.5V
Current-Limit and Short-Circuit Protections
Over-Temperature Protection
Fault Indication Output
Enable Input
Lead Free and Green Devices Available
Applications
Notebook and Desktop Computers
USB Ports
High-Side Power Protection Switches
Pin Configurations
SOT-23-5(Top View)
SOT-23-5(Top View)
XZ2416A/XZ2417A
XZ2418A/XZ2419A
SOT-23-5(Top View)
SOT-23-5(Top View)
XZ2416B/XZ2417B
XZ2418B/XZ2419B
Figure Pin Configuration of XZ2416/XZ2417/XZ2418/XZ2419(Top View)
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Datasheet
USB Power-Distribution Switches
Pin Description
Pin Number
XZ2418/
XZ2419
XZ2416/
XZ2417
Pin
Name
Description
1
5
VOUT
Output Voltage Pin. The output voltage follows the input voltage. When ENB is
high or EN is low, the output voltage is discharged by an internal resistor.
2
2
GND
Ground.
3
1
OCB
Fault Indication Pin. This pin goes low when a current limit or an
over-temperature condition is detected after a 12ms deglitch time.
EN
Enable Input. Pulling this pin to high will enable the device and pulling this pin to
low will disable device. The EN pin cannot be left floating.
ENB
Enable Input. Pulling this pin to high will enable the device and pulling this pin to
low will disable device. The EN pin cannot be left floating.
VIN
Power Supply Input. Connect this pin to external DC supply.
4
5
3
4
Ordering Information
XZ241X □
Circuit Type
A/B:
A- Enable High
B- Enable Low
□
□
Packing:
Blank：Tube
R:Type and Reel
T:SOT-23
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Datasheet
USB Power-Distribution Switches
Functional Block Diagram
Absolute Maximum Ratings
Symbol
Parameter
VIN
VOUT
VOUT to GND Voltage
VENB, VEN
EN, ENB to GND Voltage
VOCB
OCB to GND Voltage
TJ
TSTG
TSDR
Rating
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
-0.3 ~ 7
150
-65 ~ 150
260
VIN Input Voltage (VIN to GND)
Maximum Junction Temperature
Storage Temperature
Maximum Soldering Temperature, 10 Seconds
Unit
V
V
V
V
o
C
o
C
o
C
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Exposure to absolute maximum rating conditions
for extended periods may affect device reliability.
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Datasheet
Recommended Operating Conditions
Symbol
Parameter
VIN
VIN Input Voltage
VCC
VCC Supply Voltage
IOUT
TA
TJ
OUT Output Current
(XZ2416/XZ2418)
OUT Output Current
Range
2.7~5.5
4.5 ~ 5.5
0~1
0~ 2.4
-40 ~ 85
-40 ~ 125
(XZ2417/XZ2419)
Ambient Temperature
Junction Temperature
Unit
V
V
A
A
o
C
o
C
Note: Refer to the typical application circuit.
Thermal Characteristics
Symbol
JA
Parameter
Typical Value
235
Junction-to-Ambient Resistance in Free Air
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Unit
°C/W
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Datasheet
Electrical Characteristics
Unless otherwise specified, these specifications apply over V IN=5V, VEN =5V or VENB=0V and TA= -40 ~ 85 oC. Typical values are at TA=25oC.
Symbol
Parameter
Test Conditions
Unit
Min.
Typ.
Max.
SUPPLY CURRENT
VIN Supply Current
-
-
-
62
No load, VEN=0V or VENB=5V
VOUT=GND, VEN=0V or VENB=5V
Reverse Leakage Current
VIN=GND, VOUT=5V, VEN=0V or VENB=5V
A
60
No load, VEN=5V or VENB=0V
Leakage Current
1
100
A
-
1
A
1
A
78
m
POWER SWITCH
RDS(ON)
Power Switch On Resistance
IOUT=1A, TA= 25 oC
UNDER-VOLTAGE LOCKOUT (UVLO)
VIN UVLO Threshold Voltage
VIN rising, TA= -40 ~ 85 oC
1.7
VIN UVLO Hysteresis
2.65
0.2
V
V
CURRENT-LIMIT AND SHORT-CIRCUIT PROTECTIONS
Current Limit Threshold
XZ2417/XZ2419 VIN=2.7V to 5.5V, TA= -40 ~ 85 oC
2.5
2.8
3.1
A
XZ2416/XZ2418 VIN=2.7V to 5.5V, TA= -40 ~ 85 oC
ILIM
1.1
1.3
1.5
A
XZ2417/XZ2419 VIN=2.7V to 5.5V
1.5
A
XZ2416/XZ2418 VIN=2.7V to 5.5V
0.8
A
OCB Output Low Voltage
IOCB=5mA
0.2
OCB Leakage Current
ISHORT
VOCB=5V
OCB Deglitch Time
OCB assertion, TA= -40 ~ 85 oC
5
2
Short-Circuit Output Current
OCB OUTPUT PIN
tD(OCB)
0.4
V
1
12
20
uA
mS
EN OR ENB INPUT PIN
VIH
Input Logic HIGH
VIN=2.7V to 5V
VIL
Input Logic LOW
VIN=2.7V to 5V
V
0.8
1
Input Current
VOUT Discharge Resistance
VEN=0V or VENB=5V, VOUT=1V
V
uA
40
tD(ON)
Turn On Delay Time
30
uS
tD(OFF)
Turn Off Delay Time
30
uS
tSS
Soft-Start Time
No load, COUT=1F, VIN=5V
400
uS
TJ rising
140
C
20
C
OVER-TEMPERATURE PROTECTION (OTP)
TOTP
Over-Temperature Threshold
Over-Temperature Hysteresis
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Datasheet
Typical Operating Characteristics
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Typical Operating Characteristics(Cont.)
XZ2417/XZ2419
XZ2417/XZ2419
XZ2416/XZ2418
XZ2416/XZ2418
XZ2416/XZ2418
XZ2417/XZ2419
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Typical Operating Characteristics(Cont.)
XZ2417/XZ2419
XZ2416/XZ2418
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Datasheet
Typical Operating Characteristics(Cont.)
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Datasheet
Typical Operating Characteristics(Cont.)
XZ2416/XZ2418
XZ2417/XZ2419
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Operating Waveforms
VIN =5V, RLOAD =30, CIN =33F/Electrolytic,
VIN =5V, RLOAD =30, CIN =33F/Electrolytic,
COUT =1F/Electrolytic
COUT =1F/Electrolytic
CH1: VENB, 5V/Div, DC
CH1: VENB, 5V/Div, DC
CH2: VOUT, 2V/Div, DC
CH2: VOUT, 2V/Div, DC
TIME: 200s/Div
TIME: 100s/Div
VIN =5V, RLOAD =30, CIN =33F/Electrolytic,
VIN =5V, RLOAD =30, CIN =33F/Electrolytic,
COUT =1F/Electrolytic
COUT =1F/Electrolytic
CH1: VIN, 1V/Div, DC
CH2: VOUT, 1V/Div, DC
TIME: 2ms/Div
October, 20, 2011.
CH1: VIN, 1V/Div, DC
CH2: VOUT, 1V/Div, DC
TIME: 2ms/Div
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Operating Waveforms(Cont.)
XZ2416A , VIN =5V, OUT short to GND,
XZ2416A , VIN =5V, CIN =COUT=33F/Electrolytic
CIN =COUT=33F/Electrolytic
CH1: VOCB, 5V/Div, DC
CH1: VEN, 5V/Div, DC
CH2: VOUT, 2V/Div, DC
CH2: VOCB, 5V/Div, DC
CH3: IOUT, 1A/Div, DC
CH3: IOUT, 1A/Div, DC
TIME: 5ms/Div
TIME: 5ms/Div
XZ2416A , VIN =5V, OUT Short to GND,
XZ2417A , VIN =5V, RLOAD =1k 2.2
CIN =33F/Electrolytic, No COUT
CIN =COUT=33F/Electrolytic
CH1: VIN, 2V/Div, DC
CH1: VOUT, 1V/Div, DC
CH2: VOUT, 2V/Div, DC
CH2: IOUT, 1A/Div, DC
CH3: IOUT, 5A/Div, DC
TIME: 1ms/Div
TIME: 50s/Div
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Type Application Circuit
XZ2416/XZ2418
XZ2417/XZ2419
Function Description
VIN Under-Voltage Lockout (UVLO)
OCB Output
The XZ241X series of power switches have a built-in
under-voltage lockout circuit to keep the output shutting off
until internal circuitry is operating properly. The UVLO circuit
has hysteresis and a de-glitch feature so that it will typically
ignore undershoot transients on the input. When input
voltage exceeds the UVLO threshold, the output voltage
starts a soft-start to reduce the inrush current.
The XZ241X series of power switches provide an open-drain
Power Switch
Pull the ENB above 2V or EN below 0.8V will disable the device,
The power switch is an N-channel MOSFET with a low RDS(ON). The
and pull ENB pin below 0.8V or EN above 2V will enable the
internal power MOSFET does not have the body diode. When IC is
device. When the IC is disabled, the supply current is reduced to
off, the MOSFET prevents a current flowing from the VOUT back
less than 1A. The enable input is compatible with both TTL and
to VIN and VIN to VOUT.
CMOS logic levels. The EN/ENB pin cannot be left floating.
output to indicate that a fault has occurred. When any of
current-limit or over-temperature protection occurs for a deglitch
time of tD(OCB), the OCB goes low. Since the OCB pin is an
open-drain output, connecting a resistor to a pull high voltage is
necessary.
Enable/Disable
Current-Limit Protection
Over-Temperature Protection
The XZ241X series of power switches provide the current- limit
When the junction temperature exceeds 140oC, the internal
protection function. During current-limit, the devices limit output
thermal sense circuit turns off the power FET and allows the
current at current limit threshold. For reliable operation, the device
device to cool down. When the device’s junction temperature cools
should not be operated in current-limit for extended period.
by 20oC, the internal thermal sense circuit will enable the device,
Short-Circuit Protection
resulting in a pulsed output during continuous thermal protection.
When the output voltage drops below 1.5V, which is caused by an
Thermal protection is designed to protect the IC in the event of
over-load or a short-circuit, the devices limit the output current
over temperature conditions. For normal operation, the junction
down to a safe level. The short-circuit current limit is used to
temperature cannot exceed TJ=+125oC.
reduce the power dissipation during short-circuit conditions. If the
junction temperature reaches over-temperature threshold, the
device will enter the thermal shutdown.
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Application Information
Layout Consideration
The PCB layout should be carefully performed to maximize
thermal dissipation and to minimize voltage drop, droop and
EMI. The following guidelines must be considered:
1. Please place the input capacitors near the VIN pin as close
as possible.
2. Output decoupling capacitors for load must be placed near
the load as close as possible for decoupling highfrequency
ripples.
3. Locate XZ241X and output capacitors near the load to
reduce parasitic resistance and inductance for excellent load
transient performance.
4. The negative pins of the input and output capacitors and
the GND pin must be connected to the ground plane of the
load.
5. Keep VIN and VOUT traces as wide and short as possible.
Input Capacitor
A 1F ceramic bypass capacitor from VIN to GND, located near
the XZ241X , is strongly recommended to suppress the ringing
during short circuit fault event. Without the bypass capacitor,
the output short may cause sufficient ringing on the input
(from supply lead inductance) to damage internal control
circuitry.
Output Capacitor
A low-ESR 10F aluminum electrolytic or tantalum between
VOUT and GND is strongly recommended to reduce the voltage
drop during hot-attachment of downstream peripheral. (Per
USB 2.0, output ports must have a minimum 120F of
low-ESR bulk capacitance per hub).
Higher-value output capacitor is better when the output load
is heavy. Additionally, bypassing the output with a 0.1F
ceramic capacitor improves the immunity of the device to
short-circuit transients.
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Datasheet
Package Information
TSOT23-5
Package Outline Dimensions
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Design Notes
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