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STMicroelectronics VIPER37LE
- Part No.:
- VIPER37LE
- Manufacturer:
- STMicroelectronics
- Category:
- AC DC Converters, Offline Switches
- Package:
- 10-SDIP (0.300", 7.62mm)
- Datasheet:
-
VIPER37LE.pdf
- Description:
- IC OFFLINE SWITCH FLYBACK 10DIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,533
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Product details
Overview
VIPER37LE from STMicroelectronics is a fixed-frequency offline AC-DC converter IC integrating an 800 V avalanche-rugged power MOSFET, PWM controller, dual overcurrent protection (OCP), output overvoltage protection (OVP), brownout detection, hysteretic thermal shutdown, and onboard soft-start. It delivers up to 20 W in open-frame designs at 50 °C ambient and achieves 30 mW standby power at 265 Vac. Used in auxiliary supplies for ATX systems and low-power adapters.
For engineers reviewing the VIPER37LE datasheet, VIPER37LE pinout, VIPER37LE application, or VIPER37LE equivalent, this page provides verified technical context, SDIP10 package mapping, confirmed 60 kHz operating frequency (L-type), validated burst-mode behavior at light load, and real-world design meaning of brownout hysteresis (50 mV) and second-level OCP (1.7 A).
Technical Context
The VIPER37LE implements current-mode PWM control with adjustable cycle-by-cycle current limit via the CONT pin and a secondary hiccup-mode OCP triggered at 1.7 A drain current. Its oscillator operates at 60 kHz ±4 kHz with 250 Hz frequency jittering to reduce EMI peak emissions.
Brownout protection uses a dedicated BR pin with 0.45 V threshold (±40 mV) and 50 mV hysteresis to disable switching when rectified input falls below specification; restart occurs only after voltage exceeds threshold + hysteresis. The high-voltage startup circuit draws charging current directly from the DRAIN pin above 80 V, eliminating external startup resistors.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Operating frequency | 60 kHz ±4 kHz - fixed frequency with jittering reduces EMI filter cost and size |
| Drain-source breakdown voltage | 800 V min - enables universal AC input (85–265 Vac) without external HV components |
| Standby power consumption | 30 mW at 265 Vac - meets Energy Star and EU CoC Tier 2 no-load requirements |
| Brownout threshold | 0.45 V (falling), 50 mV hysteresis - prevents erratic operation during AC sags; BR pin connects to voltage divider from bulk capacitor |
| Second-level OCP threshold | 1.7 A - triggers hiccup-mode restart after sustained overload, limiting average power dissipation |
| Soft-start time | 8.5 ms - ramps up current limit gradually to avoid transformer saturation and secondary diode stress |
| Thermal shutdown | 155 °C typical, 30 °C hysteresis - ensures safe recovery after overheating without manual reset |
Pinout & Package
VIPER37LE is housed in a SDIP10 (Small Outline Dual In-line Package, 10-pin) with exposed DRAIN pads for enhanced thermal dissipation. The package features integrated heat-sinking via pins 9–12 (DRAIN) connected to the metal frame.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (pins 1–2) | Power ground & MOSFET source reference | Common return for control logic and power section; must be low-inductance connection to minimize noise coupling |
| VDD (pin 5) | Control supply input | Receives startup current from DRAIN pin; powers internal circuitry once ≥14 V reached; clamped at 23.5 V |
| CONT (pin 6) | Current limit adjustment & OVP monitoring | Reduces default OCP threshold via external resistor to ground; also accepts strobed OVP signal for digital noise immunity |
| FB (pin 7) | Feedback input for duty cycle regulation | Sourced current (−200 µA typ.) enables optocoupler-based loop control; <0.6 V activates burst mode |
| BR (pin 8) | Brownout detection input | Monitors scaled bulk voltage; shuts down IC if input <0.45 V (with 50 mV hysteresis); connect to GND if unused |
| DRAIN (pins 9–12) | High-voltage MOSFET drain terminals | Four paralleled pins carry primary switching current and conduct heat to PCB copper; require ≥100 mm² Cu area underneath |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 800 V power MOSFET | Eliminates external HV switch and gate driver; supports direct rectified AC input up to 375 VDC |
| Adjustable current limit via CONT pin | Enables precise OCP tuning across production tolerances without changing sense resistor value |
| Burst-mode operation at light load | Reduces average switching frequency to <1 kHz under 10% load, cutting standby losses to 30 mW |
| Hysteretic thermal shutdown | Prevents thermal cycling by requiring 30 °C temperature drop before auto-restart, protecting transformer and magnetics |
| On-chip soft-start | 8.5 ms ramp prevents inrush current into output capacitors and avoids core saturation during cold start |
Applications
| ATX Auxiliary Power Supply | White Goods Control Board Supply |
|---|---|
|
Use Scenario: Providing +5 VSB (standby) rail in desktop PC power supplies during S5 sleep state. IC Role / Device Role / Timing Role: Offline flyback controller managing primary-side regulation and ultra-low standby consumption. Use Value: Achieves 30 mW no-load input power-meeting Intel ATX12V 2.51 spec-without auxiliary winding or external bias circuitry. |
Use Scenario: Generating isolated 12 V/5 V for microcontroller, display, and sensor interfaces in washing machines and refrigerators. IC Role / Device Role / Timing Role: Primary-side regulated flyback controller with brownout protection for unstable mains conditions. Use Value: Brownout hysteresis (50 mV) prevents nuisance shutdowns during brief AC dips common in residential grids. |
| DVD Player Main SMPS | Set-Top Box Standby Converter |
|
Use Scenario: Delivering 12 V and 5 V rails for servo motors, laser diodes, and digital logic in optical disc drives. IC Role / Device Role / Timing Role: Fixed-frequency current-mode controller with dual OCP for robust operation under variable mechanical loads. Use Value: Second-level OCP (1.7 A) limits fault energy during motor stall, preventing MOSFET failure without external current sensing. |
Use Scenario: Powering IR receiver, real-time clock, and network interface in always-on entertainment devices. IC Role / Device Role / Timing Role: Burst-mode flyback controller maintaining regulation while minimizing idle power draw. Use Value: Burst-mode activation at FB <0.6 V ensures stable 5 V output even at 1 mA load, with <30 mW total input power. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar offline AC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| VIPER27LN | Lower 700 V BVDSS, 1.2 A max OCP, no BR pin, 50 kHz operation | Limited to 230 Vac-only inputs; lacks brownout protection and second-level OCP | Select only for cost-sensitive, non-universal-input designs where brownout immunity is not required |
| ICE3B0565J | 650 V BVDSS, external MOSFET, higher 1.5 W dissipation, no integrated startup | Requires external HV startup resistor and sense resistor; better thermal headroom but larger BOM | Choose when >25 W output or discrete layout control is needed; not drop-in compatible |
Compared with VIPER27LN, VIPER37LE adds universal input support and system-level reliability features (brownout, 2nd OCP); versus ICE3B0565J, it trades external flexibility for integration density and lower component count in sub-20 W designs.
Availability
VIPER37LE is available at Aetrix Electronics and suitable for ATX auxiliary supplies, white goods control boards, DVD player SMPS, and set-top box standby converters requiring stable component supply across industrial and consumer production programs.
Supply support for VIPER37LE 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, MCU, power, and sensor solutions for automotive, industrial, and consumer markets.
VIPER37LE belongs to the VIPerPlus family of integrated offline converters, engineered specifically for compact, low-BOM-cost AC-DC power supplies in consumer and home appliance applications demanding high integration and regulatory compliance.
FAQ
What is the purpose of the BR pin on VIPER37LE?
The BR (Brownout) pin monitors a scaled version of the rectified input voltage. When the voltage drops below 0.45 V (typical), the IC disables switching to prevent unstable operation during AC line sags. A 50 mV hysteresis ensures clean re-enablement only after voltage recovers sufficiently-critical for appliances on weak grids.
Can VIPER37LE operate without an auxiliary winding?
Yes-VIPER37LE integrates a high-voltage startup circuit that draws initial current directly from the DRAIN pin above 80 V, eliminating the need for an auxiliary winding during startup. However, an auxiliary winding is still required for continuous operation to sustain VDD after startup, as the internal HV generator turns off once VDD reaches 14 V.
How does burst mode reduce standby power in VIPER37LE?
Burst mode activates when FB voltage falls below 0.6 V, causing the IC to skip switching cycles until FB rises above 0.7 V (100 mV hysteresis). This reduces average switching frequency to ~500 Hz at no load, cutting dynamic losses and enabling 30 mW input power at 265 Vac-well below Energy Star v6.0 limits.
What thermal derating applies to VIPER37LE in SDIP10 package?
In SDIP10 on a standard FR4 board with 100 mm² copper pour, VIPER37LE has RthJA = 85 °C/W. At 50 °C ambient, maximum continuous power is limited to ~15 W before junction temperature exceeds 150 °C. Derating is linear: every 10 °C ambient rise reduces usable power by ~1.8 W.
VIPER37LE Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- VIPer™ plus
- Package/Case:
- 10-SDIP (0.300", 7.62mm)
- 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:
- 60kHz
- 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:
- 10-SDIP
- Mounting Type:
- Through Hole
VIPER37LE FAQ
1.How can I place an order for VIPER37LE through Aetrix?
Please submit a Request for Quotation (RFQ) for VIPER37LE 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 VIPER37LE reliable?
The price and inventory of VIPER37LE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VIPER37LE is usually 5 days.
3.What payment methods are accepted for VIPER37LE?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VIPER37LE transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for VIPER37LE?
VIPER37LE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your VIPER37LE 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 VIPER37LE?
For technical support, including VIPER37LE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VIPER37LE requirements.
6.How does Aetrix verify that VIPER37LE is sourced from the original manufacturer or authorized distributors?
All VIPER37LE 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 VIPER37LE meets industry standards.
7.What is the process for return or replacement of VIPER37LE?
All VIPER37LE units undergo pre-shipment inspection (PSI). If there is an issue with VIPER37LE, 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 VIPER37LE part is unused and in its original packaging.
Return procedure for VIPER37LE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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