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STMicroelectronics VIPER22ASTR-E
- Part No.:
- VIPER22ASTR-E
- Manufacturer:
- STMicroelectronics
- Category:
- AC DC Converters, Offline Switches
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
VIPER22ASTR-E.pdf
- Description:
- IC OFFLINE SWITCH FLYBACK 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,068
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Product details
Overview
VIPER22ASTR-E from STMicroelectronics is a high-voltage, current-mode PWM controller integrated with a 730 V avalanche-rated power MOSFET in a single SO-8 package. It delivers up to 12 W output power (European mains) and features fixed 60 kHz switching, 9–38 V VDD operating range, and built-in overtemperature, overcurrent, and overvoltage protection with auto-restart - designed for off-line SMPS in battery charger adapters and standby supplies.
For engineers reviewing the VIPER22ASTR-E datasheet, VIPER22ASTR-E pinout, VIPER22ASTR-E application, or VIPER22ASTR-E equivalent, key selection criteria include its integrated HV start-up current source, FB pin current-sensing architecture, burst-mode operation at light load, and thermal shutdown at 140–170 °C - all critical for reliable low-power AC/DC converter design.
Technical Context
The device implements a current-mode control loop where peak drain current is directly regulated by feedback current (IFB) into the FB pin, with gain GID = 560 and internal blanking time of 500 ns. The 0.23 V current-sense reference and 200 ns current-sense delay enable precise cycle-by-cycle current limiting.
Startup relies on an internal high-voltage current source connected to the DRAIN pin, charging the external VDD capacitor until VDD reaches 14.5 V (VDDon), then disabling itself. Protection includes hysteresis-based UVLO (8 V VDDoff / 14.5 V VDDon), 42 V VDD overvoltage latch, and thermal shutdown with 40 °C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching frequency | Fixed 60 kHz ±10% - enables predictable EMI filtering and transformer design without external timing components. |
| VDD operating range | 9 V to 38 V - supports wide auxiliary supply variation and simplifies bias winding design across input voltage ranges. |
| Drain-source voltage (BVDSS) | 730 V - enables direct connection to universal AC inputs (85–265 Vac) without external HV startup network. |
| Peak current limit (IDlim) | 0.56–0.84 A - sets maximum primary current for safe operation under overload and short-circuit conditions. |
| FB pin current sensitivity | 0.9 mA shutdown threshold (IFBsd) - provides fast fault response when secondary-side regulation fails. |
| Thermal shutdown | 140–170 °C with 40 °C hysteresis - prevents permanent damage during sustained overload or poor heatsinking. |
| Start-up current (IDDch) | −1 mA (sourced from DRAIN) - eliminates need for external high-voltage resistor, reducing component count and no-load losses. |
Pinout & Package
Package: SO-8 (ECOPACK® compliant, RoHS-compliant surface-mount package with exposed thermal pad).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| DRAIN (Pins 1, 2, 3, 4, 5, 6, 7, 8) | Power MOSFET drain terminal and HV start-up current source input | Carries full primary-side switching current; also sources −1 mA start-up current to charge VDD capacitor before regulation begins. |
| VDD (Pin 7) | Control circuit supply and UVLO monitoring node | Accepts 9–38 V; triggers start-up at 14.5 V and shuts down at 8 V with 6.5 V hysteresis - ensures stable brown-out recovery. |
| SOURCE (Pin 8) | MOSFET source and control ground reference | Provides common return for internal current sense amplifier and FB comparator - must be low-inductance connection to PCB ground plane. |
| FB (Pin 6) | Current-mode feedback input | Accepts 0–0.9 mA; regulates peak drain current via internal 0.23 V reference - enables optocoupler-based secondary-side voltage/current regulation. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 730 V power MOSFET | Eliminates external HV switch and gate driver, reducing BOM count and layout complexity in <12 W flyback designs. |
| Current-mode PWM control | Enables inherent cycle-by-cycle current limiting and stable operation across wide input/output variations without slope compensation. |
| Burst-mode operation below 85 mA ID | Reduces no-load power consumption to <300 mW - meets Energy Star and EU CoC Tier 2 standby efficiency requirements. |
| HICCUP-mode overvoltage protection | Auto-restarts after VDD falls below 8 V post-overvoltage event - avoids latch-off failure and enables self-recovery during transient surges. |
| Internal thermal shutdown with hysteresis | Prevents thermal runaway during prolonged overload while allowing automatic recovery once junction cools by ≥40 °C. |
Applications
| Smartphone Charger Adapter | TV Standby Power Supply |
|---|---|
Use Scenario: Compact 5 V/1 A offline flyback converter powering USB charging ports in wall adapters. IC Role / Device Role / Timing Role: Primary-side SMPS controller and power switch - handles AC rectification, isolation, regulation, and protection in single-chip solution. Use Value: Enables <12 mm × 12 mm board area with <300 mW no-load consumption and full short-circuit/auto-restart safety compliance. |
Use Scenario: 3.3 V/0.5 A auxiliary supply powering microcontroller and IR receiver in TV mainboard standby mode. IC Role / Device Role / Timing Role: Always-on offline regulator - maintains stable output during main power-off state using minimal auxiliary winding energy. Use Value: Supports <100 mW total system standby power with guaranteed start-up even after extended AC removal and reapplication. |
| Motor Control Auxiliary Supply | IoT Gateway Power Module |
Use Scenario: Isolated 12 V/0.3 A supply for gate drivers and logic in BLDC motor inverters. IC Role / Device Role / Timing Role: Primary-side regulated supply - decouples control electronics from high-power switching noise and transients. Use Value: Delivers clean, ripple-free 12 V with <±3% regulation across −40 °C to +105 °C ambient - immune to motor bus voltage spikes. |
Use Scenario: Dual-output (5 V + 3.3 V) flyback supply for Wi-Fi/BLE modules in smart home hubs. IC Role / Device Role / Timing Role: Single-chip primary controller managing both outputs via optocoupler feedback and synchronous rectification support. Use Value: Achieves >75% full-load efficiency and <0.5 W no-load draw - extends battery backup runtime and reduces thermal derating needs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar primary-side SMPS controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ICE2QS03G | Fixed 65 kHz frequency; requires external HV start-up resistor; no integrated MOSFET - discrete gate driver + 650 V MOSFET needed. | Lacks integrated power switch - increases BOM, layout area, and thermal management complexity for <10 W designs. | Preferred only when higher frequency or discrete MOSFET selection (e.g., SiC) is required for specific EMI or efficiency targets. |
| LNK304P | 700 V MOSFET; 66 kHz; uses frequency jittering for EMI reduction; no VDD hysteresis - simpler UVLO but less robust brown-out recovery. | Lower max power (6.5 W @ 85–265 Vac); lacks burst-mode optimization - no-load consumption ~450 mW vs. VIPER22ASTR-E's ~250 mW. | Valid for cost-sensitive, ultra-low-power (<5 W) applications where tighter no-load spec is not mandatory. |
Compared with ICE2QS03G and LNK304P, VIPER22ASTR-E offers superior integration (HV start-up + MOSFET), lower no-load loss, and more robust UVLO hysteresis - making it optimal for compact, high-reliability 7–12 W AC/DC adapters requiring minimal external components and certified safety margins.
Availability
VIPER22ASTR-E is available at Aetrix Electronics and suitable for smartphone charger adapters, TV standby power supplies, and motor control auxiliary supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.
Supply support for VIPER22ASTR-E 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 silicon solutions for automotive, industrial, and consumer markets since 1987.
VIPER series ICs are ST's dedicated family of high-voltage offline SMPS controllers targeting cost-sensitive, space-constrained AC/DC power conversion - optimized for battery chargers, auxiliary supplies, and IoT edge devices.
FAQ
What is the minimum recommended VDD capacitor value for reliable startup?
A 100 nF ceramic capacitor is sufficient when using forward-bias auxiliary winding configuration, as specified in Figure 4 of the datasheet. Lower values risk premature VDD collapse before auxiliary supply engages, causing startup failure - especially under low-line (85 Vac) or high-temperature conditions.
Can VIPER22ASTR-E operate without an optocoupler in the feedback path?
No - the FB pin requires controlled current injection (0–0.9 mA) for regulation; open-loop operation results in uncontrolled peak current and immediate overcurrent shutdown. Basic voltage regulation requires at minimum an optocoupler or TL431-based shunt regulator with current-limiting resistor.
How does the device behave during output short-circuit conditions?
Under sustained short-circuit, the device enters HICCUP mode: it cycles between 16% duty-cycle bursts and shutdown periods until VDD drops below 8 V, then auto-restarts. This limits average power dissipation to <1 W and prevents thermal damage without external intervention.
Is the SO-8 package thermally enhanced compared to DIP-8?
Yes - SO-8 has RthJA = 55 °C/W (vs. DIP-8's 45 °C/W) on standard FR4, but its smaller footprint and surface-mount construction allow better PCB copper pour integration. With 200 mm² of 35 µm Cu connected to DRAIN pins, SO-8 achieves effective thermal performance suitable for 12 W European mains operation.
VIPER22ASTR-E Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- VIPER™
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Isolation:
- Isolated
- Internal Switch(s):
- Yes
- Voltage - Breakdown:
- 730V
- Topology:
- Flyback
- Voltage - Start Up:
- 14.5 V
- Voltage - Supply (Vcc/Vdd):
- 8V ~ 38V
- Duty Cycle:
- -
- Frequency - Switching:
- 60kHz
- Power (Watts):
- 7 W
- Fault Protection:
- Current Limiting, Over Temperature, Over Voltage
- Control Features:
- -
- Operating Temperature:
- -40°C ~ 150°C (TC)
- Grade:
- -
- Qualification:
- -
- Supplier Device Package:
- 8-SOIC
- Mounting Type:
- Surface Mount
VIPER22ASTR-E FAQ
1.How can I place an order for VIPER22ASTR-E through Aetrix?
Please submit a Request for Quotation (RFQ) for VIPER22ASTR-E 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 VIPER22ASTR-E reliable?
The price and inventory of VIPER22ASTR-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VIPER22ASTR-E is usually 5 days.
3.What payment methods are accepted for VIPER22ASTR-E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VIPER22ASTR-E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for VIPER22ASTR-E?
VIPER22ASTR-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your VIPER22ASTR-E 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 VIPER22ASTR-E?
For technical support, including VIPER22ASTR-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VIPER22ASTR-E requirements.
6.How does Aetrix verify that VIPER22ASTR-E is sourced from the original manufacturer or authorized distributors?
All VIPER22ASTR-E 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 VIPER22ASTR-E meets industry standards.
7.What is the process for return or replacement of VIPER22ASTR-E?
All VIPER22ASTR-E units undergo pre-shipment inspection (PSI). If there is an issue with VIPER22ASTR-E, 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 VIPER22ASTR-E part is unused and in its original packaging.
Return procedure for VIPER22ASTR-E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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