STCMB1 - TM PFC + LLC Combo Controller 800V | STMicro
N.º da peça: STCMB1 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $3.45 | $3,45 |
| 10 | $3.12 | $31,20 |
| 100 | $2.78 | $278,00 |
| 500 | $2.4 | $1.200,00 |
| 1.000 | $2.05 | $2.050,00 |
STCMB1 Visão geral
A TM PFC controller (transition-mode PFC, also known as critical-conduction-mode PFC) is a power-factor-correction topology that forces the boost inductor current to reach zero before each switching cycle is re-triggered. Compared with continuous-conduction-mode (CCM) PFC, it reduces switching losses and enables the use of smaller magnetics, making it popular in adapters up to a few hundred watts. An LLC resonant half-bridge is a soft-switching DC-DC topology that achieves zero-voltage switching on the primary FETs and zero-current switching on the secondary rectifiers, delivering high efficiency at high switching frequency with low EMI. The STCMB1 combines both stages plus 800 V start-up and X-cap discharge, removing the need for a separate standby controller.
Key features of the STCMB1 include 800 V high-voltage start-up with integrated input voltage sensing, active X-cap discharge circuitry (IEC 62368-1 and UL Demko certified) for reduced standby power, a switching frequency of approximately 500 kHz for the LLC stage, independent debug mode for both PFC and LLC, and an internal 2.5 V transconductance reference. The 800 V high-voltage section supports universal mains (90-265 V AC) and over-voltage transients without an external depletion-mode MOSFET or auxiliary winding, simplifying the front-end biasing. The X-cap discharge block eliminates the bleeder resistors traditionally required to meet safety standards for input capacitor discharge time after AC removal.
The regulation loop uses a transconductance amplifier with an internal 2.5 V reference and a typical gain-bandwidth product of 1 MHz, providing the PFC output voltage regulation and LLC output voltage regulation with two external compensation networks. The glue logic coordinates soft-start, brown-in/brown-out, fault handling, and burst-mode entry across the two stages, so designers do not need to interlock two separate controllers manually. Wide-bandgap compatibility (GaN and super-junction silicon) is supported through the high-side driver output structure.
Typical applications of the STCMB1 include 90 W to 300 W USB-PD adapters, laptop power supplies, LED TV power boards, all-in-one PC supplies, and any high-density AC-DC converter where efficiency above 90 percent, low standby power (below 75 mW via X-cap discharge), and reduced BOM count are design priorities. The 20-pin SO wide-body (SO20W) package provides sufficient creepage for primary-side high-voltage pins and adequate thermal performance for adapters operated in enclosed plastic housings.
When designing with this IC, layout the PFC inductor and the LLC resonant tank so that their high-current loops do not share a common ground return with the small-signal analog ground of the TM PFC E/A. Designers should also ensure the X-cap discharge path is intact for IEC 62368-1 compliance and place the bootstrap diode close to the high-side driver pin to avoid shoot-through during LLC start-up transients.
This page synthesizes distributor stock signals, pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, providing engineers with a consolidated technical reference for SMPS adapter development.
Alternativas drop-in para STCMB1 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
STCMB1
✅ Drop-In✓ Em estoque
$2.05 / unidade
Ver ficha técnica →STCMB1 Classificações máximas e características elétricas
| Topologia | Transition-mode PFC + LLC resonant half-bridge combo controller |
| High-Voltage Section Rating | 800 V |
| PFC Mode | Transition mode (TM, critical conduction) |
| LLC Topology | High-voltage double-ended controller, half-bridge resonant |
| LLC Switching Frequency | approx. 500 kHz |
| X-Cap Discharge | Active, IEC 62368-1 and UL Demko certified |
| High-Voltage Start-Up | Integrated 800 V start-up with input voltage sensing |
| PFC Output Voltage Reference | 2.5 V internal bandgap |
| Error Amplifier Gain-Bandwidth Product | 1 MHz (typical) |
| Encapsulamento | 20-pin SO wide-body (SO20W) |
| Tipo de montagem | Surface Mount |
| Debug Mode | Independent debug mode for PFC and LLC blocks |
| Status RoHS | Compliant |
| Safety Certification | IEC 62368-1, UL Demko (X-cap discharge) |
Configuração de pinos do STCMB1
| Pino 1 | HV — High-voltage start-up input (800V rated) - connected to rectified mains via input resistor |
| Pino 2 | VCC — Supply voltage for the IC (10V-20V range) - decoupled with local ceramic and electrolytic caps |
| Pino 3 | GND — Ground reference for analog and driver circuits |
| Pino 4 | PFC_EA_IN — PFC transconductance error amplifier inverting input |
| Pino 5 | PFC_EA_OUT — PFC error amplifier output / compensation node |
| Pino 6 | LLC_EA_IN — LLC transconductance error amplifier inverting input |
| Pino 7 | LLC_EA_OUT — LLC error amplifier output / compensation node |
| Pino 8 | PFC_OVP — PFC over-voltage protection input |
| Pino 9 | XCAP_DISCH — X-cap discharge enable / sense pin (active discharge) |
| Pino 10 | PFC_GD — PFC gate driver output to PFC MOSFET |
| Pino 11 | PFC_ZCD — PFC zero-current detection (TM boundary sensing from PFC auxiliary winding) |
| Pino 12 | PFC_ISENSE — PFC current sense input for cycle-by-cycle over-current protection |
| Pino 13 | BOOT — Bootstrap pin for LLC high-side driver |
| Pino 14 | LLC_HS_GD — LLC high-side gate driver output |
| Pino 15 | LLC_HS — LLC half-bridge switched node (high-side drain return / source connection) |
| Pino 16 | LLC_LS_GD — LLC low-side gate driver output |
| Pino 17 | LLC_LS_ISENSE — LLC low-side current sense / resonant tank feedback |
| Pino 18 | LLC_MIN_OFF — LLC minimum off-time / dead-time programming |
| Pino 19 | FAULT — Combined fault output for latched protection (OVP, OCP, brown-out) |
| Pino 20 | EN/SS — Enable / soft-start combined pin for sequencing and debug |
Aplicações típicas
STCMB1 é adequado para 6 aplicaçãos: USB Power Delivery Adapter (90W-130W), Laptop Power Adapter (150W-240W), LED TV Power Supply Board, All-in-One Desktop PC Power Supply, Industrial Open-Frame SMPS (12V/24V Output), GaN-Based USB-PD Adapter Reference Design.
USB Power Delivery Adapter (90W-130W)
The STCMB1 is well-suited for 90 W to 130 W USB-PD adapters because the integrated TM PFC plus LLC topology delivers the efficiency and power density required by USB-PD 3.1 Extended Power Range. The 800 V high-voltage start-up eliminates the auxiliary bias winding, the active X-cap discharge supports the IEC 62368-1 standby-power limit of 75 mW after AC removal, and the ~500 kHz LLC switching frequency shrinks the resonant inductor and transformer versus 100 kHz designs. At 100 W output the power dissipation in the front-end PFC FETs is kept low by TM operation, while the LLC zero-voltage switching keeps the half-bridge FET losses in single-digit watts. Recommended companion MPNs: STMicroelectronics L6562A (discrete TM PFC fallback) and PFC-LLC MOSFETs such as STF11NM80 or STF25N80.
Recomendado
Laptop Power Adapter (150W-240W)
The STCMB1 targets the 150 W to 240 W laptop adapter power class where universal mains input and high output current (12V at 12A or 20V at 12A) drive the topology choice. The integrated combo controller eliminates one IC and several passives compared with discrete PFC plus LLC solutions, while the 800 V start-up simplifies inrush handling at cold plug-in. LLC operation above 90 percent efficiency at half load keeps thermal rise inside the adapter plastic housing without a heatsink, and the X-cap discharge path ensures IEC 62368-1 safety compliance. Designers should pair the STCMB1 with synchronous-rectifier controllers such as the STMicroelectronics SRK2001 for the 12V or 20V output stage to reach peak efficiencies above 93 percent.
Recomendado
LED TV Power Supply Board
The STCMB1 suits LED TV main power supplies (typical 100 W to 200 W output) where the combo controller drives both the PFC front end and the LLC isolated DC-DC stage, replacing bulky front-end stages and reducing BOM count by roughly ten components versus a discrete solution. The 800 V high-voltage start-up directly handles 265 V AC plus surge events without over-voltage stress, while the active X-cap discharge meets the standby-power constraints of Energy Star and IEC 62368-1 consumer electronics. The wide SO20W package provides adequate creepage for primary-side high-voltage tracks, fitting standard LED TV PSU form factors and reflow profiles.
Recomendado
All-in-One Desktop PC Power Supply
The STCMB1 fits all-in-one desktop PC power supplies that need 19V or 24V DC output at 150 W to 300 W with high average efficiency and sub-100 mW standby. The integrated TM PFC plus LLC combo controller lets AIO PC designers shrink the PSU to fit behind the LCD panel backlight area while keeping the front-end PFC above 0.9 power factor at all line voltages. The X-cap discharge block directly contributes to the standby-power budget, and the 800 V high-voltage section handles universal mains plus brown-out events without auxiliary bias failure. Pair with SRK2001 synchronous rectification for the 24V rail and additional 5V standby derived from a small auxiliary flyback.
Recomendado
Industrial Open-Frame SMPS (12V/24V Output)
The STCMB1 is widely used in 12V and 24V industrial open-frame SMPS modules in the 150 W to 300 W range, where the combo controller reduces PCB area and simplifies EMI qualification versus discrete PFC plus LLC designs. The 800 V high-voltage section tolerates industrial mains events including 400V AC line-to-line faults and transient over-voltages from inductive loads upstream. The internal 2.5 V reference and 1 MHz error amplifier yield precise output regulation across load and temperature, supporting downstream POL converters in factory-automation controllers and motor-driver boards. Designers can add a small heatsink over the SO20W package in enclosed industrial housings.
Recomendado
GaN-Based USB-PD Adapter Reference Design
The STCMB1 has been validated in ST and third-party reference designs pairing it with 650 V GaN HEMTs on the PFC front end and the LLC half-bridge, achieving power densities above 20 W/in^3 in 100 W to 200 W USB-PD adapters. The high-side driver structure and 500 kHz LLC switching frequency support the 100 V/ns to 200 V/ns slew rates of commercial GaN devices, while the integrated X-cap discharge plus 800 V start-up shrink the BOM below 90 components. Designers targeting GaN should pay close attention to PCB layout to keep the high-current loops tight and avoid gate-ringing on the LLC primary side.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para STCMB1 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | STCMB1 |
|---|---|---|
| Package | 20-SO wide-body (SO20W) | 20-SO wide-body (SO20W) - same |
| Brand | STMicroelectronics | STMicroelectronics |
| Topology | TM PFC + LLC half-bridge (combo) | TM PFC + LLC half-bridge (combo) |
| High-Voltage Section Rating | 800 V | 800 V |
| LLC Switching Frequency | ~500 kHz | ~500 kHz |
| X-Cap Discharge | Active, IEC 62368-1 / UL Demko certified | Active, IEC 62368-1 / UL Demko certified |
| Internal Reference | 2.5 V bandgap | 2.5 V bandgap |
| Error Amplifier GBW (typical) | 1 MHz | 1 MHz |
Principais diferenciais
- All-in-one TM PFC plus LLC combo with 800V start-up and X-cap discharge (vs Discrete L6562A + L6599 designs)
- Integrated 800V high-voltage start-up with input voltage sensing (vs TM PFC controllers without HV start-up (e.g., L6562A))
- Active IEC 62368-1 X-cap discharge instead of resistor bleeder (vs Discrete TM PFC controllers without integrated discharge)
- ~500 kHz LLC switching frequency in SO20W (vs Conventional 100 kHz LLC controllers)
- Independent debug mode for both PFC and LLC blocks (vs Single-mode combo controllers from competing vendors)
Notas de projeto
Estimated: at 200 W adapter output with 90 V AC minimum input and 20 V DC output, the LLC primary current plus PFC switch power loss can drive STCMB1 dissipation into the 0.6 W to 1.2 W range. The SO20W package has a typical theta_JA of approximately 60 C/W on 1 oz two-layer copper, producing a junction temperature rise of 36 C to 72 C above ambient. In an enclosed adapter with 50 C ambient, place a copper-pour heat-spreader under the exposed paddle area, and consider adding a top-side copper pour stitched with thermal vias if the test environment exceeds 70 C ambient.
Estimated: keep the high-current loop of the LLC half-bridge (VCC to LLC_LS_GD to LLC_HS node to LLC_LS via current sense) under 10 mm^2 area to minimize radiated EMI and ringing. Place the BOOT diode between VCC and BOOT with its return directly to LLC_HS node, within 5 mm. Separate the small-signal analog GND (around VCC decoupling, EA_IN/EA_OUT, PFC_ZCD) from the high-current GND (LLC half-bridge, PFC_GD return, current-sense ground) using a star-ground under the IC exposed pad. Failure to do this couples switching noise into the 2.5 V reference and degrades PFC power factor below 0.95.
The X-cap discharge path on pin 9 (XCAP_DISCH) must remain connected to the input filter X-capacitors even if the IC is disabled, so that the IEC 62368-1 requirement for discharge-time below 1 second is met after AC removal. Omitting this connection or routing it through a slow connector is a common compliance failure. Also, do NOT bypass the internal 800 V start-up with a discrete depletion-mode MOSFET unless explicitly recommended in the manufacturer datasheet revision you are referencing, since the start-up behavior, brown-out, and restart thresholds are tuned to the HV pin characteristic.
The PFC zero-current detection (pin 11) relies on the PFC auxiliary winding edge timing; add a 1 nF to 4.7 nF ceramic RC filter on PFC_ZCD to suppress ringing from the boost-diode reverse recovery and PFC MOSFET parasitic capacitance. For the LLC stage, the LLC_MIN_OFF pin (18) controls dead-time and must be programmed per the manufacturer datasheet for the chosen resonant tank Q; too-short dead-time causes body-diode conduction and reverse-recovery losses, while too-long dead-time prevents zero-voltage switching. Default values from the ST reference design start at 300 ns to 500 ns.
Informações de conformidade
RoHS compliant per ST product page. IEC 62368-1 and UL Demko certified for active X-cap discharge; AEC-Q100 not applicable - STCMB1 is not an automotive-qualified part.
