TOP221PN Offline PWM Switch 5.7V 1.2mA IC DIP-8
The TOP221PN is part of the TOPS witch family of integrated offline PWM switchers, designed to simplify AC-DC power supply circuits. It integrates a high-voltage power MOSFET, PWM controller, oscillator, and protection circuitry into a single DIP-8 package, significantly reducing external component count and design complexity.
This IC is typically used in Flyback converter topologies operating directly from rectified AC mains. It offers high efficiency, low standby power consumption, and reliable operation through built-in protection features such as thermal shutdown, current limiting, and auto-restart. The TOP221PN is widely used in low to medium power applications, making it ideal for consumer electronics and industrial power supplies.
Features:
- Integrated high-voltage power MOSFET.
- Built-in PWM controller.
- Internal oscillator.
- Minimal external components required.
- Auto-restart protection.
- Thermal shutdown protection.
- Current limiting protection.
- High efficiency operation.
- Compact DIP-8 package.
- Reliable and robust design.
Specifications:
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Drain breakdown voltage | ID = 250 µA | 700 | – | – | V |
| Output frequency | IC = 4 mA, 25 °C | 90 | 100 | 110 | kHz |
| Maximum duty cycle | IC = ICD1+0.4 mA | 64 | 67 | 70 | % |
| Minimum duty cycle | IC = 10 mA | 0.7 | 1.7 | 2.7 | % |
| Shunt regulator voltage | IC = 4 mA | 5.5 | 5.7 | 6.0 | V |
| Control supply current (ICD1) | Output MOSFET enabled, TOP221 | 0.6 | 1.2 | 1.6 | mA |
| Control discharge current (ICD2) | Output MOSFET disabled | 0.5 | 0.8 | 1.1 | mA |
| Dynamic impedance (ZC) | IC= 4 mA, 25 °C | 10 | 15 | 22 | Ω |
| RDS(on) (TOP221) | ID= 25 mA, 25 °C | – | 31.2 | 36.0 | Ω |
| Thermal shutdown temp. | IC = 4 mA | 125 | 135 | – | °C |
| Power‑up reset threshold | – | 2.0 | 3.3 | 4.3 | V |
Pinout:
| Pin Number | Name | Description |
|---|---|---|
| 1 | S (SOURCE) | Primary‑side control circuit common / reference |
| 2 | S (SOURCE) | Primary‑side control circuit common / reference |
| 3 | S (SOURCE) | Primary‑side control circuit common / reference |
| 4 | C (CONTROL) | Feedback input; bypass capacitor connection |
| 5 | D (DRAIN) | Internal power MOSFET drain |
| 6 | S (HV RTN) | High‑voltage power return (source) |
| 7 | S (HV RTN) | High‑voltage power return (source) |
| 8 | S (HV RTN) | High‑voltage power return (source) |
Applications:
- AC-DC adapters.
- Battery chargers.
- Standby power supplies.
- Consumer electronics power supplies.
- Industrial SMPS systems.
Packages Included:
- 1x TOP221PN Offline PWM Switch 5.7V 1.2mA IC DIP-8.