1 amp high side driver chip

Thread Starter

jonfarrugia

Joined Feb 19, 2010
71
I'm looking at designing a high side driver circuit, controlled by a TTL PWM signal, to drive a load with 12 or 24 vdc.
I've been searching for a chip to do everything I needed and I came a cross a Microchip TC4432
http://ww1.microchip.com/downloads/en/devicedoc/21424d.pdf
All the images I've seen of this chip has it driving a Mosfet. Is it possible to use this chip to drive a restive or inductive load directly?
 

Papabravo

Joined Feb 24, 2006
16,481
I'm looking at designing a high side driver circuit, controlled by a TTL PWM signal, to drive a load with 12 or 24 vdc.
I've been searching for a chip to do everything I needed and I came a cross a Microchip TC4432
http://ww1.microchip.com/downloads/en/devicedoc/21424d.pdf
All the images I've seen of this chip has it driving a Mosfet. Is it possible to use this chip to drive a restive or inductive load directly?
The dive is not symmetrical. It will sink more current than it can source. With an output resistance of 12Ω it will generate some heat while trying to source current into a grounded load. You don't want to use this part to switch a load connected to Vcc since you will be supplying power to the GND through the output resistance when the output is high. I think this might be a bad choice for driving a load directly.
 

ScottWang

Joined Aug 23, 2012
7,047
1. How much current does the load needed?
2. What's your load (motor or coil) and the resistance?
3. What it your TTL PWM signal looks like and the frequency?
4. What's purpose of this designation?
5. Why you want to choose TC4432?
 

Thread Starter

jonfarrugia

Joined Feb 19, 2010
71
1. How much current does the load needed?
2. What's your load (motor or coil) and the resistance?
3. What it your TTL PWM signal looks like and the frequency?
4. What's purpose of this designation?
5. Why you want to choose TC4432?
1. about 1 amp
2. outputs could be anything. This is more of a universal output controller capable of connecting to any load, requiring 1 amp or less.
3. The TTL signal will be from a Teensy. a 0 to 3.3 v signal, 15 bits resolution at 1831 Hz.
4. This will be used in a universal IO controller for 12v or 24v controls. Could be automotive or industrial applications.
5. I am just looking for a all in one driver between my Teensy and loads.

I looked further into drivers and perhaps found a better/cheaper load driver. TPS1H200AQDGNRQ1
http://www.ti.com/lit/ds/symlink/tps1h200a-q1.pdf
 

ScottWang

Joined Aug 23, 2012
7,047
TC4431/TC4432 -- High Peak Output Current – 1.5 A
TPS1H200A-Q1 -- 1.5A
If you need to output 1A current then you have to find the components can be output 5A current, at least 3A, the better is to use 5A parts, or adds the MOSFET to increase the current from the chip that you been have chosen.

The output voltage level of TTL is about 2.4V~5V, maybe you can use N MOSFET to drive the load, but the TTL voltage may not enough to drive the logic level Vgs as 4.5V or 5V, so you have to use the voltage shifter from 2.4V to 5V.

You could refer to -- N, P type MOSFET Components Simple Data.
You can choose a VDSS = Vcc * 1.5 or higher.
Id = Ids * 5 or higher. (At least Id=Ids*3, Ids is your real current flows through the Rds and load)
Rds = 2.0 ~ 20 mΩ
 

Thread Starter

jonfarrugia

Joined Feb 19, 2010
71
For TPS1H200A Chip

Capture.JPG
The Nominal operating current is 2.5 amps.

Capture.JPG
The internal Current limiter is 4.8 A
Does this not cover my 1 amp working current design?
 

ScottWang

Joined Aug 23, 2012
7,047
The package of TPS1H200AQDGNRQ1 is better than TC4432, but its internal resistance is 200-mΩ, 1A load, V_TPS = 1A * 0.2Ω = 0.2V, and that is as the Vce of bjt, do you know the heat problem of a bjt?

I was used the 2N3055 (15A) just only 2A in the power supply and it needs the heatsink, you can try it if you can accept the heat.

TPS1H200A-Q1.jpg
Source.
 

ScottWang

Joined Aug 23, 2012
7,047
I'm not sure why you don't want to use the simple components and circuit, but the circuit below usually used in many applications.

If you use the circuit below then you can choose a P MOSFET as Vdss ≥ 1.5*(V_load), Ids≥5A, Rds(on) ≤ 50mΩ, the Values of R1 will affecting the frequency of input signal, so if the frequency more higher then the values will be more lower.

TTL signal to MOSFET 12~24V 1A Load_ScottWang.png
 

Thread Starter

jonfarrugia

Joined Feb 19, 2010
71
I'm not sure why you don't want to use the simple components and circuit, but the circuit below usually used in many applications.

If you use the circuit below then you can choose a P MOSFET as Vdss ≥ 1.5*(V_load), Ids≥5A, Rds(on) ≤ 50mΩ, the Values of R1 will affecting the frequency of input signal, so if the frequency more higher then the values will be more lower.

View attachment 175357
I find that this will take up to much space on a board and doesn't contain current limiting and temp shutdown features.
 
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