www.bourns.com

3/23 • e/KLM2215

Bourns® Mini-Breaker Thermal Cutoff Device (TCO)

Model SD and AD Series

NEW PRODUCT BRIEF

5 3 1

2 2 A

1 0

S D 90

A B B

M

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2 2 A

0 0

A D 90

A B B

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With the introduction of the its new Model

SD and AD Series Thermal Cutoff devices

(TCOs), Bourns is pushing the boundaries of

overtemperature protection compared to

traditional devices that have come before it.

These series deliver several industry FIRSTs:

• First TCO series that can be either surface-

mountable (SD Series) or axial leaded/

weldable (AD Series)

• First TCO series with trip temperature

ranges from 55 ˚C up to 150 ˚C

(previous models only supported from

72 ˚C up to 85 ˚C or 90 ˚C)

• First TCO series offering non-automatically

resettable (self-hold function) or

automatically resettable (non self-hold)

function options

• First TCO series tested to AEC-Q200

equivalent test standards

The advanced technology and features in

these versatile series significantly broaden

their use in a new and wider range of markets

and applications.

Bourns’ existing TCO products provide accurate

overtemperature protection, but are best

suited for lower temperature lithium-ion

battery packs. In applications where a trip

temperature greater than 90 ˚C is required, the

Bourns® Model SD and AD Series help meet this

requirement with a trip temperature range of

55 ˚C up to 150 ˚C. This capability is particularly

useful in a variety of heater device applications

that require either low trip temperatures or

high trip temperatures .

Until now, protection in heater devices either

did not exist and relied on the control circuitry,

or, if a protection device was specified, it

typically was a single-blow device or a very

large traditional bimetal device.

The Bourns® Model SD Series can be surface

mounted either directly onto commonly-

used flexible film heaters or onto the PCB

of the heater control unit. For wired heater

assemblies, designers are able to attach wires

directly to the Bourns® Model AD series making

this series an optimal solution. An added

value for these applications is that both series

give designers a resettable overtemperature

protection option they didn’t have before.

The versatility of the new Model SD and AD Series

TCOs means the devices can be used in traditional

notebook and tablet PC, smartphone and

wearable device applications.

In addition, the Bourns® Model SD and AD series

provide extended temperature operation support

for a broad range of additional designs such as:

• Cosmetic and medical* diagnostic

equipment heaters

INTRODUCTION

APPLICATIONS

FEATURES

PRODUCT FIT

BENEFITS

• Resettable overtemperature and

overcurrent protection

• Can be used as a resettable

overtemperature sensor

• Trip temperature range of 55 ˚C up to 150 ˚C

• High trip temperature accuracy of just ±5 ˚C

• Highly repeatable with ratings of up to

10,000 cycles

• Surface mount (SD Series) or axial leaded/

weldable (AD Series)

• Option for either non-automatically

resettable (self-hold function)

or automatically resettable

(non self-hold function)

• Very low resistance values of just 4 mΩ max.

• Tested to AEC-Q200 equivalent

test standards

• RoHS compliant**

• Meets extended temperature

protection requirements

• Highly accurate resettable protection

overcomes nuisance tripping circuit issues

• Ease of mounting directly onto the

flexible film heater or on a PCB, enabling

protection for FET devices

• Welded option for protection in non-

SMD locations (e.g., battery packs or

wired heaters)

• AEC-Q200 compliant

• Small package size for

space-constrained designs

*Bourns® products have not been designed for and are not

intended for use in "lifesaving," "life-critical" or "life-sustaining"

applications nor any other applications where failure or

malfunction of the Bourns® product may result in personal

injury or death. See Legal Disclaimer Notice:

www.bourns.com/docs/legal/disclaimer.pdf

**RoHS Directive 2015/863, Mar 31, 2015 and Annex.

HOW TO ORDER

Series Designator

AD = Axial Leaded/Weldable

SD = Surface Mount

Trip Temperature (±5 °C)

(See Data Sheet Temp. Options Chart)

Function

A = Self-hold

W = No Self-hold

Reset Temperature

B = 20 °C or 40 °C min.

(See Data Sheet Temp. Options Chart)

Special Specification Code

Resin Type, Mfg. Internal Code,

Design Mark, etc.

SD 90 A B B