BT137S-600E,118
WeEn Semiconductors
MOQ 1 · Tape & Reel (TR); Cut Tape (CT) · RoHS · EIA-481 · DAP/DDP · T/T
Technical specifications
| Parameter / Attribute | Specification / Value |
|---|---|
| Triac type | Logic - Sensitive Gate |
| Mounting | Surface Mount |
| Voltage - off state | 600 V |
| Voltage - gate trigger (Vgt) | 1.5 V |
| Current - hold (Ih) | 20 mA |
| Current - gate trigger (Igt) | 10 mA |
| Current - on state (It (RMS)) | 8 A |
| Current - non rep. surge 50, 60Hz | 65A, 71A |
| Operating temperature | 125°C(TJ) |
| Package | Tape & Reel (TR); Cut Tape (CT) |
| Configuration | Single |
| Case | TO-252-3, DPak (2 Leads + Tab), SC-63 |
Need Stock or a Drop-in Second-Source for BT137S-600E,118?
Package: TO-220AB · Pin-compatible replacements with immediate Shenzhen spot stock
This is the triac row behind dimmers, speed controllers, heater regulators and every mains switch built in the last forty years: the BT13x series from 4A to 16A and the BTA/BTB 16-40A generation, all in TO-220 bodies that differ in ways the eye cannot see. Two laws govern the family. The prefix encodes the tab: BTA is the isolated-tab part that bolts straight to a grounded heatsink, BTB is the non-isolated one that needs an insulating pad. And the suffix encodes drive class and voltage: sensitive-gate D/E grades trigger from logic-level currents where the snubberless B/A grades demand tens of milliamps. Every substitution along this row is one of those two letters read wrong.
Verified Pin-Compatible Replacements (3 verified alternatives)
The Next Rung Up, Same Family, Same Letters
Shenzhen Spot Stock (24-48h Dispatch)
The 8A member of the same ladder (BT136 4A, BT137 8A, BT138 12A, BT139 16A) with the same gate-grade suffixes - substitute within the family by keeping the suffix letters intact.
Same non-isolated TO-220AB; voltage class in the trailing digits (4 = 400V, 6 = 600V, 8 = 800V).
The Isolated-Tab Upgrade
Shenzhen Spot Stock (24-48h Dispatch)
The 16A isolated-tab generation: about 2500V RMS case-to-tab insulation means direct mounting on a grounded chassis - but standard gate classes (suffix B about 50mA, A about 100mA), an order of magnitude heavier than the BT13x sensitive grades.
Voltage in the trailing digits by the same rule; 600V and 800V common.
The 40A Top of the Row
Shenzhen Spot Stock (24-48h Dispatch)
The 40A isolated member: for heater banks, big motors and mains switching where the whole row below runs out of current.
Same naming laws: isolated tab, snubberless classes, voltage in the trailing digits.
Buyer & Quality Checklist for Sourcing Alternatives
- Read the prefix first: BTA = isolated tab (direct mounting on grounded chassis), BTB = non-isolated (insulator required). On shared heatsinks, this letter decides whether the case shorts the mains to the chassis.
- Read the suffix second: gate class and dv/dt are a package deal - D/E grades are the sensitive, logic-drivable, lower-dv/dt parts; B/A snubberless grades need tens of milliamps and tolerate fast commutation. Substituting a sensitive gate into a snubberless role (or the reverse) changes both the drive budget and the false-trigger margin.
- Current reads in the name: BT136 4A, BT137 8A, BT138 12A, BT139 16A; BTA16 16A, BTA41 40A. Voltage in the trailing digits: 4/6/8 for 400/600/800V. Grade up freely; grade down only with the transient arithmetic done.
- The trigger network is half the repair: gate resistor, optotriac or pulse transformer, and the RC snubber around the triac. A triac replaced into a tired snubber fails again at the next inductive event - bench-test with the actual load class.
- Sensitive gates and snubberless parts exchange dv/dt margin for trigger convenience: on motor and transformer loads, resist the convenient substitution and match the class to the commutation environment.
- Thermal mounting is part of the electrical design here: insulator pads (or the isolated tab) and heatsink compound decide the junction temperature, and these parts run hot by nature.
Frequently Asked Technical Questions
Q: What is the difference between BTA and BTB triacs?
A: The tab: BTA has an isolated tab (about 2500V RMS insulation), BTB does not. BTA mounts directly to a grounded chassis; BTB needs an insulating pad. Same function otherwise - the letter is a mechanical-safety specification.
Q: Can a BT137 replace a BT136?
A: Yes - same ladder, more current margin, same gate-grade suffixes. Keep the suffix letters intact (a D-grade circuit expects a sensitive gate) and the voltage digit equal or higher.
Q: Why does my replacement triac not trigger?
A: Usually a gate-class mismatch: the circuit triggers a sensitive (D/E, about 5-10mA) gate and the replacement needs 50-100mA. The letters after the number are the drive specification - match them, or rework the trigger network.