PN8106 CHIPOWN | Alldatasheet
Document overview
- Manufacturer or author: Provided By alldatasheet.com(free datasheet download site)
- PDF pages: 8
Technical content
Features
■ Internal 730 V avalanche-rugged power MOSFET ■ Operating Frequency(60kHz) ■ Frequency modulation for low EMI ■ Burst-mode Operation ■ No-load consumption power < 40 mW @220VAC ■ Built-in Soft Start ■ Internal HV Start-up Circuit ■ Open frame output power >18W @230VAC ■ Excellent Protection Coverage: Over Temperature Protection (OTP) Adjustable and accurate Over Voltage Protection (OVP) Adjustable Pulse-by-Pulse Over Current Protection (OCP) Over Load Protection (OLP) Auto- recovery protection Mode
Applications
■ Switch AC/DC Adaptor and Battery Charger ■ Auxiliary Power for White Goods, PC,Audio ■ LCD /PDP TV Power ■ LED Drivers Pin Assignments GND VDD COMP CTRL SW SW (NC) NC DIP8/DIP7 Typical Application Schematic CTRL GND COMP SnubberAC 85~265V DC Output FB Block Control Block OTP Block HV Start Block PWM Switch &Gate Driver SUPPLY &UVLO VDD SW PN8106
Table 1. Pin Definitions 2 VDD Positive Supply voltage Input..
3 CTRL
and output voltage monitoring.
4 COMP
control loop and achieve the regulation. Table 2. Typical power
230 VAC 16W 18 / 23W
- Typical continuous power in a non-ventilated enclosed adapter measured at 55°C ambient temperature.
- Maximum practical continuous power in an open-frame design at 55°C and 25°C ambient.
Electrical Characteristics
(TJ =25°C, VDD = 14 V; unless otherwise specified) Table 3. Power section Table 4. Supply section
Table 5. Controller section (TJ = 25°C, VDD = 14 V; unless otherwise specified)
- Startup At start up, the internal high-voltage current source supplies the internal bias and charges the external VDD capacitor. When VDD reaches 13V, the device starts switching and the internal high-voltage current source stops charging the capacitor. The device is in normal operation provided VDD does not drop below 8V. After start up, the bias is supplied from the auxiliary transformer winding. When high voltage current source is turned on, the charge current of the VDD capacitance is 3mA. If a fault happen, the circuit enter auto- recovery mode and IDD charge current is turned to 0.6mA. 2. Soft-start up In the process of start up, the current of drain increases to maximum limitation step by step. As a result, it can reduce the stress of secondary diode greatly and is propity to prevent the transformer turning into the saturation states. Typically, the duration of soft-start is 8.5ms. 3. Gate driver The internal power MOSFET in PN8106 is driven by a dedicated gate driver for power switch control. Too weak the gate driver strength results in higher conduction and switch loss of MOSFET while too strong gate drive results in worse EMI. A good tradeoff is achieved through the built-in totem pole gate design with proper output strength and dead time. The good EMI system design and low idle loss is easier to achieve with this dedicated control scheme. 4. Oscillator The switching frequency of PN8106 is internally fixed at 60 kHz. No external frequency setting components are required for PCB design. The frequency modulation is implemented in PN8106. So that, it minimizes the conduction band EMI and therefore eases the system design because the tone energy could be spread out. 5. Feed-back The PN8106 is a current mode controlled device. The feedback voltage is compared with an internally generated saw-tooth waveform. This controls the duty cycle directly. 6. Over load protection (OLP) Overload is defined as the load current exceeding a pre-set level due to an accident event as a fault. In this case, the protection circuit should be activated to protect the SMPS. If VCOMP exceeds 3.4V, the feedback input diode is blocked and the 3uA current source starts to charge CCOMP slowly up. In this case, VCOMP increases until it reaches 4.8V, when the switching operation is terminated. The delay time from the overload detection to the device shutdown required to charge CCOMP from 3.4V to 4.8V with a 3uA current source. 7. Burst-mode operation PN8106 enters burst-mode operation in order to minimize the power dissipation in standby mode. As the load decreases, the feedback voltage decreases. When the voltage on COMP pin falls below 0.45V typ, VCOMPbm, the device enters
50mV over VCOMPbm. The switching frequency control also eliminates the audio noise at any loading condition.
- Adjustable current limit of over current protection (OCP)
through changing the Rlim value. see Figure 3. Figure 3. Current limit vs Rlim.
- Over voltage protection(OVP)
enable. As a result, the device shut down and system enters auto- recovery mode operation.
- Over temperature protection (OTP)
MOSFET. If the temperature exceeds about 160℃，OTP fault is activated.
Table 7. DIP8 mechanical data