Document
POLYSWITCH® Resettable PTCs
Surface Mount > LoRho Series
LoRho SMD PTC for Charging Cable Protection
Description
The Littelfuse LoRho SMD PTC for Charging Cables provides protection from heat generated due to faults within the connector such as USB-C, microUSB, and many others.
As connectors get smaller, their pin-to-pin spacings are shrinking which increases the opportunity for debris such as dust, dirt, or water to collect causing a fault. These faults can generate heat which may damage charging cables, the devices they charge, or the people using them.
Agency Approvals
AGENCY
AGENCY FILE NUMBER
AMPERE RANGE
E74889*
4.5A
J 50313999*
4.5A
* See Electrical Characteristic Table for approved part numbers.
Applications
• Over temperature (OT) protection for USB connectors and cables including:
– USB Type-C
– USB Micro-B
– USB-A
• Fast charging standards and protocols including:
– USB Power Delivery (PD) †
– Qualcomm Quick Charge (QC) †
– Mediatek Pump Express (PE) †
– Samsung Adaptive Fast Charging (AFC) †
– Huawei/HiSilicon Fast Charging Protocol (FCP) †
† These charging protocols are the property of their respective owners.
Features
• SMD compatible with reflow soldering process
• Available in small 1206 and 1210 sizes
• Up to 21Vdc and 4.5A Ihold
Benefits
• Surface mount design reduces assembly time and cost compared to leaded/strapped models
• Saves PCB space in the USB-C connector and ensures that the USB-C plug meets USB-IF dimension specifications
• Ultra low internal resistance
• Reset automatically • Halogen-free, lead-free
and RoHS compliant
• Well-suited for fastcharging applications up to 21Vdc and 4.5A Ihold
Electrical Characteristics
Part Number
Marking
I1
hold
(A)
nanoSMD350LR-C
P 3.50
nanoSMD400LR-C
S 4.00
microSMD450LR-C S 4.50
400CC1206LR-C
Y 4.00
450CC1210LR-C
K 4.50
V2 max
(Vdc)
12 12 12 21 21
Thermal Cut Off (TCO) - ºC @ 2A
Min Max
Thermal Cut Off (TCO) - ºC @ 3A
Min Max
Pd3 typ. (W)
75 100 60 85 1.0 85 110 70 95 1.0 90 115 75 100 1.0 85 110 70 95 1.0 90 115 75 100 1.3
Resistance
R4 min (Ω)
0.004 0.004 0.002 0.004 0.002
R5 1max (Ω)
0.018 0.010 0.0085 0.010 0.008
Agency Approvals
-- --- --
XX
-- --- --
Notes: 1. Ihold = Hold current: maximum current device will pass without tripping in 20°C still air 2. Vmax = Maximum voltage device can withstand without damage at rated current (Imax) 3. Pd = Power dissipated from device when in the tripped state at 20°C still air 4. Rmin = Minimum resistance of device in initial (un-soldered) state 5. R1max = Maximum resistance of device at 20°C measured one hour after tripping or
reflow Soldering of 260°C for 20 seconds (Values specified were determined using PCBs with 0.115in x 1.0in ounce copper traces) Caution: Operation beyond the specified rating may result in damage and possible arcing
and flame
TCO and Pd Testing Method: Thermal Cut-Off Test– 1. Put the device into the thermostatic chamber controlled at room temperature or 25°C. 2. Apply the specified current to the device, and increase the chamber temperature at the
rate of 2°C per minute. 3. Measure the device ambient temperature when the applied current has reduced to less
than 20% of initial value. Power Dissipation– 1. Conduct thermal cut-off test at rated current/voltage. 2. After device trip, decrease the chamber temperature with keeping trip state. 3. Measure the tripped-state power dissipation when the device ambient temperature has
reduced to 30°C or less.
© 2019 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 03/15/19
POLYSWITCH® Resettable PTCs
Surface Mount > LoRho Series
Temperature Rerating
Ambient OperatingTemperature
-20°C
0°C
20°C
60°C
Part Number
Hold Current (A)
nanoSMD350LR-C
4.80 4.00 3.50 1.90
nanoSMD400LR-C
5.20 4.60 4.00 2.82
microSMD450LR-C
6.20 5.50 4.50 3.30
400CC1206LR-C
5.20 4.60 4.00 2.82
450CC1210LR-C
6.20 5.50 4.50 3.30
Note: The temperature rerating data is for reference only. Please contact Littelfuse technical support for detail temperature rerating information.
85°C
1.30 2.10 2.30 2.10 2.30
Temperature Derating Curve
Environmental Specifications
Operating Temperature
-20°C to +85°C
Maximum Device Surface Temperature in Tripped State
125°C
Passive Aging Humidity Aging Thermal Shock
+85°C, 1000 hours -/+10% typical resistance change
+85°C, 85% R.H.,100 hours -/+15% typical resistance change
MIL–STD–202, Method 215 No change
Vibration Moisture Sensitivity Level
MIL–STD–883, Method 2007, Condition A No change
Level 2a, J–STD–020
Physical Specifications
Terminal Materials
Lead Solderability
Solder-Plated Copper (Solder Material: Matte Tin (Sn))
Meets EIA Specification RS186-9E, ANSI/JSTD-002, Category 3
© 2019 Littelfuse, Inc. Specifications are subject to change without notice.
Revised: 03/15/19
POLYSWITCH® Resettable PTCs
Surface Mount > LoRho Series
.