1.5KE11CA - 1500W Bidirectional TVS, 9.4V VRWM | Littelfuse
MPN: 1.5KE11CA ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.72 | $0.72 |
| 10 | $0.61 | $6.10 |
| 100 | $0.47 | $47.00 |
| 500 | $0.39 | $195.00 |
| 1,000 | $0.32 | $320.00 |
1.5KE11CA Overview
A TVS diode is a solid-state avalanche device engineered to shunt large transient currents away from downstream circuitry in microseconds, providing far faster response than MOVs or PTC fuses. TVS diodes sit at the bottom of the protection hierarchy as discrete semiconductors, fall under the surge-protector family, and serve as the first-line defense on DC power rails, signal lines, and automotive bus networks where predictable clamping behavior is mandatory.
Key differentiating specifications include 1500W peak pulse power dissipation at a 10/1000 microsecond waveform, a peak pulse current (IPPM) of 97.4A, glass-passivated chip junction construction for long-term reliability, low Zener impedance, and a maximum clamping voltage of 15.6V that keeps downstream 12V logic rails well within their absolute-maximum ratings during surge events. The bidirectional (CA suffix) variant conducts transients of either polarity, eliminating orientation errors during PCB assembly.
Architecturally, the 1.5KE11CA is a silicon PN-junction avalanche suppressor with a glass-passivated surface that suppresses leakage and stabilizes breakdown characteristics across the -55C to +175C operating range. The avalanche breakdown mechanism provides sub-microsecond response, ensuring that fast-rise transients such as those defined by IEC 61000-4-2 are clamped before sensitive ICs see the overvoltage.
Typical applications include 12V automotive load-dump protection per ISO 7637-2, industrial PLC 24V rail transient suppression, telecom -48V battery backplane protection, USB and HDMI port ESD/lightning protection on consumer devices, and protection of SMPS auxiliary windings from flyback spikes. The wide standoff-voltage range and 1500W rating also suit PoE PSE input protection.
When designing with this part, derate surge power for temperatures above 75C using the derating curve in the datasheet, ensure lead bend radius exceeds 1.5mm to avoid axial-package cracking, and place the TVS within 50mm of the protected connector for maximum effectiveness. For multi-stage protection, pair the 1.5KE11CA with an upstream GDT or PTC to coordinate energy dissipation.
This page synthesizes current distributor pricing, drop-in cross-brand equivalents, parametric comparison tables, and practical design notes not found in the manufacturer datasheet alone - giving the engineer a one-stop reference for sourcing and qualifying the 1.5KE11CA in new or existing designs.
Drop-in alternatives for 1.5KE11CA — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with 1.5KE11CA (same form factor and footprint) — differing in Lead Finish, Mounting Type, Package, Peak Pulse Power (PPP).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
1.5KE11CA
✅ Drop-In✓ In Stock
$0.32 / Unit
View Datasheet →1.5KE11A
✅ Drop-In📋 Reference alternative (not in catalog)
1.5KE11CA/TR13
✅ Drop-In📋 Reference alternative (not in catalog)
1.5KE11CA
✅ Drop-In✓ In Stock
$0.32 / Unit
View Datasheet →1.5KE11CA
✅ Drop-In✓ In Stock
$0.32 / Unit
View Datasheet →1.5KE11CA
✅ Drop-In✓ In Stock
$0.32 / Unit
View Datasheet →1.5KE11CA
✅ Drop-In✓ In Stock
$0.32 / Unit
View Datasheet →1.5KE11CA Specifications
| Series | 1.5KE |
| Reverse Working Standoff Voltage (VRWM) | 9.4 V |
| Breakdown Voltage (VBR) Min | 10.5 V |
| Breakdown Voltage (VBR) Max | 11.6 V |
| Maximum Clamping Voltage (VC) | 15.6 V at IPPM = 97.4 A |
| Peak Pulse Current (IPPM) | 97.4 A (10/1000 us waveform) |
| Peak Pulse Power (PPP) | 1500 W (10/1000 us waveform) |
| Diode Configuration | Bidirectional (single die, two anti-series junctions) |
| Package | DO-201 (axial through-hole) |
| Mounting Type | Through Hole (axial leaded) |
| Operating Temperature | -55 C to +175 C |
| Construction | Glass-passivated chip junction in molded plastic |
| Response Time | < 1 ns (avalanche breakdown) |
| Leakage Current | Typically < 1 uA at VRWM |
| RoHS Status | Compliant |
| Lead Finish | Tin-plated (lead-free) |
1.5KE11CA Pin Configuration
| Pin 1 | Anode/K Cathode/K — Terminal 1 - bidirectional, electrically equivalent to pin 2 |
| Pin 2 | Anode/K Cathode/K — Terminal 2 - bidirectional, electrically equivalent to pin 1 |
Peak Pulse Power vs Pulse Duration (10/1000 us waveform)
Typical Applications
1.5KE11CA is suitable for 7 applications: 12V Automotive Load-Dump Protection, Industrial 24V PLC Transient Suppression, Telecom -48V Battery Backplane Protection, USB / HDMI Port ESD Protection, SMPS Flyback Spike Clamping, PoE PSE Input Protection, Test and Measurement Front-End Protection.
12V Automotive Load-Dump Protection
The 1.5KE11CA's 1500W peak pulse rating and 15.6V clamping voltage make it a strong fit for 12V automotive load-dump transient suppression per ISO 7637-2 pulse 5a. Its 9.4V working standoff keeps the part invisible during normal 12V operation, while the bidirectional construction eliminates orientation errors on board-assembly lines. Compared with the smaller 600W P6KE11CA, the 1.5KE11CA absorbs approximately 2.5x more energy before failing, giving extra margin for severe cold-crank or alternator-field-collapse events. Designers typically place it within 50mm of the battery feed-through connector on the PCB, parallel with a series PTC or current-limiting resistor for coordinated protection.
Recommended
Industrial 24V PLC Transient Suppression
On 24V industrial PLC and sensor-trunk lines, the 1.5KE11CA clamps motor back-EMF and inductive-switching transients that frequently exceed 40V. Although the VRWM is 9.4V and the part is optimized for 12V rails, design houses commonly use two 1.5KE11CA in anti-series on true 24V differential pairs (effective VRWM 18.8V), gaining the 1500W surge capability that standard 24V TVS parts cannot match. The DO-201 axial package suits through-hole industrial backplanes where conformal coating and field-serviceability are priorities.
Recommended
Telecom -48V Battery Backplane Protection
In -48V telecom rectifier backplanes, the 1.5KE11CA in anti-series with a matching unit (effective VRWM near 9.4V) clamps ringing transients from hot-swap events and protects downstream DC-DC converter input pins. The 15.6V clamp voltage stays well below the 100V typical isolation rating of telecom converter front ends, while the 1500W rating survives the worst-case battery-cable discharge events. Glass-passivated construction and a 175C junction rating ensure long-term reliability in fan-less outdoor enclosures.
Recommended
USB / HDMI Port ESD Protection
For USB 2.0, USB 3.0, and HDMI consumer-electronics ports, the 1.5KE11CA provides secondary protection after a smaller GDT or polymer TVS, absorbing the residual energy from cable discharge events (CDE) and indirect lightning strikes. Its bidirectional operation suits polarity-agnostic data lines such as D+/D- and TMDS pairs, and the 15.6V clamp stays within the absolute-maximum ratings of common USB-PHY ICs. The DO-201 axial footprint suits chassis-mounted jack assemblies where the TVS lives behind the connector.
Recommended
SMPS Flyback Spike Clamping
Across the auxiliary windings of flyback switch-mode power supplies, the 1.5KE11CA clamps the high-voltage ringing that occurs when the main MOSFET turns off. Its sub-nanosecond avalanche response suppresses the spike before it reaches the opto-coupler or synchronous-rectifier controller, reducing EMI and improving converter efficiency. The 1500W peak rating comfortably handles the rare but energetic spikes seen during output short-circuit recovery, while the DO-201 package supports the high-voltage clearance requirements of offline SMPS designs.
Recommended
PoE PSE Input Protection
On Power-over-Ethernet Power-Sourcing-Equipment (PSE) input rails, the 1.5KE11CA clamps the cable-discharge and ESD transients that propagate from outdoor Ethernet runs into the PSE controller. Its 9.4V VRWM and 15.6V clamp suit the 12V PSE auxiliary rail and the protected Ethernet PHY supply, while the bidirectional construction handles the polarity-reversal that occurs when a PD is unplugged under load. The 1500W rating exceeds IEEE 802.3 surge requirements, supporting PSE designs in industrial and outdoor installations.
Recommended
Test and Measurement Front-End Protection
In oscilloscope and bench-multimeter front ends, the 1.5KE11CA serves as a clamp on the input attenuator node, protecting the downstream op-amp or ADC from over-voltage transients caused by accidental probe misconnection. Its 9.4V VRWM keeps insertion loss negligible on 1x-attenuator paths, while the 15.6V clamp prevents damage to low-voltage front-end ICs when a user accidentally connects a 50V probe reference. The axial DO-201 package supports hand-reworkable lab instrumentation where field-serviceability is essential.
Recommended
Recommended Products Summary
Engineering reference data for 1.5KE11CA — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 1.5KE11A | 1.5KE11CA/TR13 | 1.5KE11CA | 1.5KE11CA | 1.5KE11CA |
|---|---|---|---|---|---|---|
| Brand | Littelfuse | Littelfuse | YAGEO | Diodes Incorporated | Multicomp | Taiwan Semiconductor |
| Package | DO-201 (axial) | DO-201 (axial) | DO-201 (axial) | DO-201 (axial) | DO-201 (axial) | DO-201 (axial) |
| Polarity | Bidirectional (CA) | Unidirectional (A) | Bidirectional (CA) | Bidirectional (CA) | Bidirectional (CA) | Bidirectional (CA) |
| Reverse Working Standoff (VRWM) | 9.4 V | 9.4 V | 9.4 V | 9.4 V | 9.4 V | 9.4 V |
| Breakdown Voltage (VBR) | 10.5 V - 11.6 V | 10.5 V - 11.6 V | 10.5 V - 11.6 V | 10.5 V - 11.6 V | 10.5 V - 11.6 V | 10.5 V - 11.6 V |
| Maximum Clamping Voltage (VC) | 15.6 V | 15.6 V | 15.6 V | 15.6 V | 15.6 V | 15.6 V |
| Peak Pulse Current (IPPM) | 97.4 A | 97.4 A | 97.4 A | 97.4 A | 97.4 A | 97.4 A |
| Peak Pulse Power (10/1000us) | 1500 W | 1500 W | 1500 W | 1500 W | 1500 W | 1500 W |
Key Differentiators
- Bidirectional operation with single-die construction (vs 1.5KE11A)
- Industry-standard 1.5KE series form factor (vs P6KE11CA)
- Glass-passivated junction construction (vs Generic unbranded 1.5KE11CA)
Design Notes
The 1500W peak pulse rating is specified at 25C and derates linearly to zero at 175C Tj. For continuous-operation designs, junction temperature should remain below 150C; at 100C ambient the derated pulse power is roughly 1500 * (175-100)/150 = 750W. Estimated: using a 50C ambient with natural convection, derated PPP drops to approximately 1250W, still adequate for ISO 7637-2 pulse 5a load-dump.
Place the 1.5KE11CA within 50mm of the connector or terminal it protects. Keep trace length short and use 2oz or heavier copper to minimize parasitic inductance - every 10nH of trace adds approximately 1V of overshoot per 100A/us edge. For bidirectional signal-line applications, place the TVS in parallel with the line and provide a low-impedance ground return directly to the connector shield.
Do not use the 1.5KE11CA in circuits where the continuous DC voltage exceeds 9.4V - the part will conduct continuously and overheat. The bidirectional CA variant is not a replacement for a unidirectional A part on DC rails where forward conduction at -9.4V is undesirable. Also avoid bending the axial leads at a radius smaller than 1.5mm, which can crack the glass package and cause latent failures.
For multi-stage protection, coordinate the 1.5KE11CA with an upstream GDT or PTC. The TVS handles fast-rise residual energy while the GDT absorbs the bulk of the lightning current. Ensure the GDT triggers before the TVS reaches its maximum clamping voltage - typical coordination requires a 2-5 ohm series impedance or a GDT with a DC sparkover above the TVS VRWM.
Compliance Information
RoHS and REACH compliant per Littelfuse product page. Not formally AEC-Q100 qualified - for automotive-grade designs consult dedicated AEC-Q TVS parts.
