Silan Microelectronics launches full-bridge drive single-phase brushless fan drive circuit

Silan Microelectronics launches full-bridge drive single-phase brushless fan drive circuit

Silan Microelectronics recently launched a full-bridge drive single-phase brushless fan drive circuit-SD1561, which integrates locked-rotation protection, automatic restart, speed detection (FG), lock detection (RD) and 6V regulated output modules; And can realize the automatic speed regulation function according to the external thermistor sensing ambient temperature. It has the characteristics of low noise, high efficiency and high reliability. It can be widely used in the driving of cooling fans such as computer CPU, graphics card and chassis.

SD1561 is based on the 0.8-micron fully complementary BCD process developed by Silan Microelectronics. The operating voltage range is 4.5V ~ 16V, and the maximum operating current is 1A. The circuit has a built-in synchronous rectification function and is driven by a DMOS tube. It has extremely low on-resistance and high driving efficiency. At the same power, the fan speed can be increased by more than 10% compared with other similar circuits; high efficiency and low surface temperature make the It is more energy efficient and more reliable.

The circuit is equipped with a PWM speed regulation function. One way can adjust the fan speed independently based on the temperature of the heat sink and the set temperature-speed characteristic curve measured by the temperature sensor, thermistor, etc. Another way can be through Direct PWM input to adjust the speed. The speed regulation function can achieve the balance of high performance and low noise, which can effectively protect the heat dissipation equipment and reduce power consumption and noise when the temperature is low. When there is no thermistor connection, the circuit can achieve full-speed operation. At the same time, the circuit has a built-in minimum speed limit, and the fan can also set its own minimum speed limit according to actual needs.

At the same time, SD1561 sets two monitoring methods: lock detection alarm RD and speed detection FG. With the lock detection alarm, an alarm signal can be given when the fan speed is below a certain threshold; the speed detection output can realize real-time monitoring of the fan speed.

In addition, SD1561 has a built-in fan stall protection and automatic restart circuit. When the rotor is locked for a period of T seconds, it automatically stops the fan for 10T seconds and then restarts for T seconds. This state will continue. Until the fan clears the fault and runs normally, this protection mode can prevent the fan motor from overheating and burning, which improves the safety of the system. Different fan designs can set T by changing the size of the external capacitor.

Benefiting from the high-efficiency design of the circuit, SD1561 can provide two packages of HTSSOP14 and TSSOP16, especially the small and compact TSSOP16 package. The plastic package is only 3/4 of HTSSOP14. The high integration level saves the system power consumption and reduces the circuit board size It is conducive to the development of products to miniaturization, reducing development costs and accelerating the development and listing of new products.