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STMicroelectronics VIPER37HD
- Part No.:
- VIPER37HD
- Manufacturer:
- STMicroelectronics
- Category:
- AC DC Converters, Offline Switches
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
VIPER37HD.pdf
- Description:
- IC OFFLINE SWITCH FLYBACK 16SO
- Quantity:
- Payment:
- Shipping:
Inventory:824
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Product details
Overview
VIPER37HD from STMicroelectronics is a fixed-frequency offline AC-DC converter IC integrating an 800 V avalanche-rugged N-channel power MOSFET, current-mode PWM controller, dual overcurrent protection (OCP), output overvoltage protection (OVP), brownout detection, and burst-mode operation for <30 mW standby power at 265 Vac. It delivers up to 15 W in open-frame designs and targets auxiliary power supplies in consumer electronics.
For engineers reviewing the VIPER37HD datasheet, VIPER37HD pinout, VIPER37HD application, or VIPER37HD equivalent, key selection criteria include its 115 kHz switching frequency (H-type), SO16 narrow package thermal resistance (RthJA = 80 °C/W on FR4), adjustable current limit via CONT pin, and integrated high-voltage startup circuit eliminating external bias windings.
Technical Context
The VIPER37HD implements a current-mode flyback controller with a built-in 800 V SenseFET enabling direct rectified-line connection without external HV startup components. Its oscillator features ±8 kHz frequency jittering at 250 Hz to reduce EMI filter cost and size.
Brownout protection triggers at 0.45 V (falling) on the BR pin with 50 mV hysteresis, while OVP activates at 3.0 V (typ.) on the FB pin with 2.2 µs strobe timing and digital filtering for noise immunity. The device enters burst mode when FB voltage falls below 0.6 V, reducing no-load consumption to ≤30 mW.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 115 kHz (typ.) - enables compact transformer and EMI filter design for medium-power adapters. |
| Drain-Source Breakdown | 800 V min. - supports universal input (85–265 Vac) without external HV clamping. |
| Standby Power | ≤30 mW at 265 Vac - meets Energy Star® and EU CoC Tier 2 standby requirements. |
| RDS(on) | 4.5 Ω (25 °C), 9 Ω (125 °C) - defines conduction loss and thermal derating in flyback primary side. |
| Current Limit Set Point | Adjustable via external resistor on CONT pin - enables precise peak primary current tuning across line/load conditions. |
| Oscillator Jitter | ±8 kHz modulation depth at 250 Hz - spreads spectral energy to lower peak EMI emissions. |
| Thermal Shutdown | 155 °C (typ.) with 30 °C hysteresis - prevents latch-up during sustained overload or poor heatsinking. |
Pinout & Package
VIPER37HD is housed in a SO16 narrow (SOIC-16) surface-mount package with exposed DRAIN pins (13–16) connected to the metal frame for enhanced thermal dissipation. Pin 4 (N.A.) must be tied to GND for optimal noise immunity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1–2 GND | Power ground / source reference | Common return for control logic and power section source; must be low-inductance connection. |
| 3 N.C. | No connection | Not bonded; leave unconnected and unrouted. |
| 4 N.A. | Controller die pad tie | Mechanically connected to die paddle; tie to GND to improve EMI immunity and thermal path. |
| 5 VDD | Control supply input | Receives charging current from HV startup circuit; powers internal logic until auxiliary winding takes over. |
| 6 CONT | Current limit / OVP control | Configurable: sets cycle-by-cycle current threshold or enables digital OVP shutdown with strobe filtering. |
| 7 FB | Feedback / regulation input | Sources 200 µA; voltage below 0.6 V triggers burst mode; above 3.5 V approaches OCP limit. |
| 8 BR | Brownout detection input | Monitors scaled bulk voltage; shuts down non-latching when input drops below 0.45 V (with 50 mV hysteresis). |
| 9–12 N.C. | No connection | Not bonded; leave unconnected and unrouted. |
| 13–16 DRAIN | High-voltage power switch drain | Carries full primary current and HV startup current; requires large copper pour for thermal management. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 800 V SenseFET | Eliminates external HV startup circuit and sense resistor, reducing BOM count and board space. |
| Adjustable current limit | Set via single resistor on CONT pin - enables precise optimization of transformer turns ratio and peak stress. |
| Hysteretic thermal shutdown | 155 °C trip with 30 °C hysteresis - ensures safe recovery after fault without manual reset or external latching. |
| Dual OCP protection | Primary cycle-by-cycle limit + secondary 1.7 A hiccup-mode OCP - protects against short-circuit and winding faults. |
| Burst-mode operation | Activates below 0.6 V on FB - reduces switching losses and maintains <30 mW standby at full input range. |
Applications
| ATX Auxiliary Power Supply | White Goods Control Board |
|---|---|
Use Scenario: Providing +5 VSB rail in desktop PC power supplies to maintain USB wake-on-LAN and motherboard RTC during system sleep. IC Role / Device Role / Timing Role: Primary-side flyback controller managing isolated 5 V output with tight regulation under variable load (10 mA–3 A). Use Value: Integrated HV startup and 30 mW standby meet ATX 2.31 specification without auxiliary winding or startup resistor. | Use Scenario: Powering microcontroller, display, and sensor interfaces in washing machines and refrigerators operating across global mains voltages. IC Role / Device Role / Timing Role: Standalone offline converter delivering regulated 12 V/5 V rails from 85–265 Vac input with brownout immunity. Use Value: 0.45 V brownout threshold prevents erratic MCU resets during grid sags common in residential environments. |
| DVD Player Power Module | Set-Top Box SMPS |
Use Scenario: Generating isolated 12 V and 5 V outputs for servo motors, laser diodes, and digital logic in DVD/Blu-ray players. IC Role / Device Role / Timing Role: Fixed-frequency current-mode controller with soft-start limiting inrush into electrolytic capacitors during cold start. Use Value: 8.5 ms soft-start time prevents transformer saturation and secondary diode overstress during initial power-up. | Use Scenario: Delivering stable 3.3 V and 12 V rails to SoC, tuner, and HDMI interface in cable/satellite set-top boxes. IC Role / Device Role / Timing Role: Primary-side regulated flyback IC with OVP strobe timing (2.2 µs) rejecting transient noise on feedback loop. Use Value: Digitally filtered OVP prevents false shutdown during RF interference from tuner front-end circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar offline converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ICE3B0565J | 650 V MOSFET, fixed 65 kHz frequency, no built-in HV startup - requires external startup resistor. | Limited to 230 Vac max input; higher no-load power due to lack of burst mode. | Select when lower BVDSS suffices and board space allows external startup network. |
| LNK364PG | 725 V MOSFET, variable frequency (up to 132 kHz), integrated X-cap discharge - no CONT pin adjustability. | Superior light-load efficiency but lacks programmable current limit and brownout hysteresis. | Select for ultra-low standby (<15 mW) where precise current limit tuning is not required. |
Compared with ICE3B0565J and LNK364PG, VIPER37HD uniquely combines 800 V ruggedness, adjustable current limit, and brownout hysteresis in a single SO16 package - making it optimal for universal-input auxiliary supplies requiring robust line-sag immunity and design flexibility.
Availability
VIPER37HD is available at Aetrix Electronics and suitable for ATX auxiliary power supplies, white goods control boards, and set-top box SMPS requiring stable component supply across industrial temperature ranges and long production lifecycles.
Supply support for VIPER37HD includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and automotive ICs with vertical fabrication capability.
VIPER37HD belongs to the VIPerPlus family of integrated offline converters engineered specifically for cost-sensitive, high-reliability AC-DC power supplies in consumer and home appliance markets.
FAQ
What is the purpose of the N.A. pin (Pin 4) on VIPER37HD?
Pin 4 is mechanically connected to the controller die paddle and serves as a thermal and noise-immunity enhancement point. Though not electrically functional as an I/O, STMicroelectronics strongly recommends tying it directly to GND to improve EMI rejection and provide a low-impedance thermal path to the PCB ground plane.
How does the burst-mode operation reduce standby power?
Burst mode activates when FB voltage falls below 0.6 V, causing the IC to enter intermittent switching cycles - delivering just enough energy to sustain regulation while minimizing average switching and gate drive losses. This achieves ≤30 mW input power at 265 Vac, complying with stringent global energy standards.
Can VIPER37HD operate without an auxiliary winding?
Yes. Its integrated high-voltage startup circuit draws charging current directly from the DRAIN pin, allowing full operation from initial power-up through steady state without an auxiliary winding - simplifying transformer design and reducing component count in cost-sensitive applications.
What triggers the second-level overcurrent protection (2nd OCP)?
The 2nd OCP activates when drain current exceeds 1.7 A, independent of the primary cycle-by-cycle limit. It forces the IC into hiccup-mode auto-restart with low repetition rate, preventing thermal runaway during sustained overload or short-circuit conditions on the secondary side.
VIPER37HD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- VIPer™ plus
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Output Isolation:
- Isolated
- Internal Switch(s):
- Yes
- Voltage - Breakdown:
- 800V
- Topology:
- Flyback
- Voltage - Start Up:
- 14 V
- Voltage - Supply (Vcc/Vdd):
- 8.5V ~ 23.5V
- Duty Cycle:
- 80%
- Frequency - Switching:
- 115kHz
- Power (Watts):
- 20 W
- Fault Protection:
- Current Limiting, Over Temperature, Over Voltage
- Control Features:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 16-SO
- Mounting Type:
- Surface Mount
VIPER37HD FAQ
1.How can I place an order for VIPER37HD through Aetrix?
Please submit a Request for Quotation (RFQ) for VIPER37HD on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for VIPER37HD reliable?
The price and inventory of VIPER37HD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VIPER37HD is usually 5 days.
3.What payment methods are accepted for VIPER37HD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VIPER37HD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for VIPER37HD?
VIPER37HD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your VIPER37HD order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for VIPER37HD?
For technical support, including VIPER37HD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VIPER37HD requirements.
6.How does Aetrix verify that VIPER37HD is sourced from the original manufacturer or authorized distributors?
All VIPER37HD products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that VIPER37HD meets industry standards.
7.What is the process for return or replacement of VIPER37HD?
All VIPER37HD units undergo pre-shipment inspection (PSI). If there is an issue with VIPER37HD, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The VIPER37HD part is unused and in its original packaging.
Return procedure for VIPER37HD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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