Can you please tell me how to use the AMS 1117 5.0 voltage regulator chip?

王小明A

Can you please tell me how to use the AMS 1117 5.0 voltage regulator chip? [Copy link]

 

I want to use the AMS1117 5.0 voltage regulator chip to convert 12V voltage to 5V voltage, and then use the obtained 5V voltage directly to drive the air pump of the air pump with a rated voltage of 6V and a rated current of 450mA, but this makes the AMS1117 chip a little hot. I would like to ask you, is it because the current passing through the AMS1117 5.0 is too large? Is it beyond the use range of the AMS1117 5.0 chip? The description on the encyclopedia is as shown in the picture:

qwqwqw2088

It should be that the voltage difference is too large. Several people in the building suggested changing the switch power supply. You can try using 9V power supply now. It is still hot to the touch.

chunyang

Normal, the heat power can be calculated by yourself: (12-5)*0.45=3.15W. If you want to reduce the heat, use a switching power supply.

王小明A

chunyang posted on 2016-4-7 16:14 It is normal. You can calculate the power consumption by yourself: (12-5)*0.45=3.15W. If you want to reduce the heat, use a switching power supply.

With this amount of heat, the chip should not be burned.

chunyang

Wang Xiaoming A posted on 2016-4-7 16:19 With this kind of heat generation, the chip should not be burned.

As long as the temperature does not exceed the limit (it is stated in the manual, generally 125 degrees Celsius), it will be fine, but you must pay attention to heat dissipation and the temperature resistance of surrounding devices must also be considered.

风铃

The heat is caused by too large a voltage difference between input and output. Either lower the input voltage or use DC-DC.

王小明A

Feng Ling posted on 2016-4-7 16:49 The heat is caused by the voltage difference between input and output being too large. Either reduce the input voltage or use DC-DC

What does DC-DC mean? I don't know much about it. .

hfw9331

Have you ever referred to the corresponding circuit? If you are just imagining it yourself, there may be problems. Is the air pump drive considered an inductive load? Can 1117 carry an inductive load?

yayasoso

AMS1117 has no problem working continuously for 2 hours in an environment of 150℃, but we use 5-》3.3, and the current is less than 0.5A

yayasoso

LM2576 can be used for 12V input and 5V output. Maximum output current: 3A; ● Maximum input voltage: 45V for LM2576 and 60V for LM2576HV; ● Output voltage: 3.3V, 5V, 12V, 15V and ADJ (adjustable) are optional; ● Vibration frequency: 52kHz; ● Conversion efficiency: 75%~88% (different efficiency at different voltage outputs); ● Control method: PWM; ● Operating temperature range: -40℃ ~+125℃ ● Operating mode: Low power consumption/normal modes can be externally controlled; ● Operating mode control: TTL level compatible; ● Required external components: only four (non-adjustable) or six (adjustable); ● Device protection: thermal shutdown and current limiting;

风铃

Wang Xiaoming A posted on 2016-4-7 17:48 What does DC-DC mean? I don't know much about it. .

DC-DC is a switching power supply chip. This high voltage difference has high conversion efficiency and will not consume energy in itself to cause heat.

王小明A

hfw9331 posted on 2016-4-7 18:04 Have you ever referred to the corresponding circuit? If it is purely your own idea, there may be problems. Is the air pump drive considered an inductive load? Can 1117 be used with inductive...

I have made a simple reference to the circuit, but I haven't considered it that much.

王小明A

yayasoso posted on 2016-4-7 20:56 12V input 5V output can use LM2576. Maximum output current: 3A; ● Maximum input voltage: LM2576 is 45V, LM2576HV is 60V; ● Input...

Well, if 1117 doesn't work, I'll try another one

1071416541

The maximum current of ASM1117 seems to be 500ma, which is a bit dangerous...

王小明A

1071416541 posted on 2016-4-8 16:07 The maximum current of ASM1117 seems to be 500ma, which is a bit dangerous. . .

But the maximum output current in its parameters is 1A.

micjhon

It can be calculated that the input-output voltage difference = 12-5 = 7V, the current is 450mA, then the power consumption P on 1117 = 7*0.45 = 3.15W. It would be strange if such a large power consumption is not hot on this package. Suggestions: ① Replace the power supply with a larger heat dissipation area; ② If you still insist on this model of power supply, change the package type and add a heat sink

唐辉电子92

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gzswood

If the circuit is to be stable, some backup power must be left. If conditions permit, make an IC to drive the motor.