APX9292 datasheet(9/18 Pages) ANPEC

9 / 18 page

Rev. A.3 - Apr., 2017

www.anpec.com.tw

APX9292

Functional Descriptions

Lockup Protection and Automatic Restart

The APX9292 provides the lockup protection and auto-

matic restart functions for preventing the coil burnout while

the fan is locked. Connecting the capacitor from CT pin to

GND determines the shutdown time and restart time. As

the fan is locked, the charge/discharge circuit will charge

the CT capacitor to 3.6V by a 2

µA source current for a

locked detection time, and then the circuit will switch the

capacitor to discharge. During the discharging interval,

the output drivers are switched off until the CT voltage is

discharged to 1.4V by a 0.2

µA sink current, and the circuit

will switch the capacitor to charge. In the charging interval,

the IC enters the restart time; one output is high and

another is low, which makes a torque for fan rotation until

the CT voltage is charged to 3.6V by a 2

µA source current.

If the locked condition still remains, the charge/discharge

process will be recurred until the locked condition is

released (See Figure 2: Lock/Auto Restart Waveform).

Figure 1: Rotation Waveform

Figure 2: Lock/Auto Restart Waveform

The APX9292 has a variable speed controller, which is

operated by comparing the voltage of OSC, MIN and

SET. Fan

’s minimum speed is set by comparing the OSC

oscillating voltage and MIN pin voltage. PW M control

system works by comparing the voltage of SET and OSC.

When SET voltage is lower than OSC voltage, one OUT

pulled high and another OUT pulled low. On the contrary,

when SET voltage is higher than OSC voltage, upper side

transistors are OFF, meanwhile, the coil current re-circu-

lates lower side transistor. Therefore, with decreasing

SET voltage, the output ON-Duty will be increasing, which

results in the increasing of the coil current and motor

rotation speed. Rotation speed is able to feedback by FG

output. PWM basic frequency becomes 30 KHz, when

putting on C

OSC=100pF. (See Figure 1: Rotation Waveform).

Variable speed control

IN+

IN-

SET

OUT1

OUT2

OUT

MIN

OSC

Full

Speed

Lowest

Speed

IN+

IN-

Lock

Detection

Release

OUT2

OUT1

TOFF

TON

APX9292 Fiches technique(PDF) 9 Page - Anpec Electronics Coropration

APX9292 Fiches technique(HTML) 9 Page - Anpec Electronics Coropration

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Fiches technique Télécharger

Lien URL