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Single chip (IC) with adjustable constant current and PWM? July 15, 2016 11:28AM |
Hey,
I stumbled across the TLD5085EJ
in the LITIX series , it is a pretty awesome chip that offers to do it all up to 1800mA.
From the description:
• Wide Input Voltage Range from 4.75V to 45V
• Constant Current or Constant Voltage Regulation
• Drives LEDs in Buck Topology
• Very low shutdown current consumption (typ. 0.1µA)
• 370 kHz switching frequency
• PWM Dimming
• Integrated power-switch (output current up to 1.8A)
• Internal Soft-Start function
• ± 2% output current tolerance (± 4% for full load current range)
• Small thermally enhanced exposed heatslug package
• Over Temperature Shutdown
Sometimes a diagram says more then a 1000 words, so here is what I believe is a PWM controllable up-to 1.8A constant current circuit with that chip:
This chip uses about the same number of components as a LM317 just it offers Softstart, overtemp and what-not in the same.
Whoa? Bad part about it? Chip is discontinued from now in 2016. Still there is stock around. I will pick up some.
Infineon seem to have abandoned the integrated power control in favor of using MOSFETs outside.
The TLD5098 is today the head product I think. It has the advantage that it also can give analog dimming controlled via PWM also - However, it is getting a little too complicated for me to fully understand some of the concepts.
This is the first time I have seen full feature IC's in that power class. Is there other around?
Edited 1 time(s). Last edit at 07/15/2016 11:29AM by LarsK.
I stumbled across the TLD5085EJ
in the LITIX series , it is a pretty awesome chip that offers to do it all up to 1800mA.
From the description:
• Wide Input Voltage Range from 4.75V to 45V
• Constant Current or Constant Voltage Regulation
• Drives LEDs in Buck Topology
• Very low shutdown current consumption (typ. 0.1µA)
• 370 kHz switching frequency
• PWM Dimming
• Integrated power-switch (output current up to 1.8A)
• Internal Soft-Start function
• ± 2% output current tolerance (± 4% for full load current range)
• Small thermally enhanced exposed heatslug package
• Over Temperature Shutdown
Sometimes a diagram says more then a 1000 words, so here is what I believe is a PWM controllable up-to 1.8A constant current circuit with that chip:
This chip uses about the same number of components as a LM317 just it offers Softstart, overtemp and what-not in the same.
Whoa? Bad part about it? Chip is discontinued from now in 2016. Still there is stock around. I will pick up some.
Infineon seem to have abandoned the integrated power control in favor of using MOSFETs outside.
The TLD5098 is today the head product I think. It has the advantage that it also can give analog dimming controlled via PWM also - However, it is getting a little too complicated for me to fully understand some of the concepts.
This is the first time I have seen full feature IC's in that power class. Is there other around?
Edited 1 time(s). Last edit at 07/15/2016 11:29AM by LarsK.
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Re: Single chip (IC) with adjustable constant current and PWM? July 15, 2016 02:23PM |
The whole point of soft start would be not to have that. It is the exact reason why I am not just making a simple voltage regulator circuit.
On the drivers that let you down, how fast were those transients?
Would I be able to see them?
My scope can do:
●Model
SO1062B
●Bandwidth:60MHz
●Channel:2
●Real-Sample Rate:1GSa/s
●Equivalent Sample Rate:25GSa/s
●Record Length:1M
●Rish time:≤1.7ns/≤3.5ns/≤5.8ns
●Timebase Accuracy:±50ppm
●Time Base Range:2ns/div-40s/div / 4ns/div-40s/div / 4ns/div-40s/div
●Input Impandance:1MΩ
●VOLTS/DIV Range:2mV/div～5V/div
●A/D Converter:8bit
●Position Range:±50V(5V/div), ±40V(2V/div～500mV/div), ±2V(200mV/div～50mV/div), ±400mV(20mV/div～2mV/div)
●DC Gain Accuracy:
±3% for Normal or Average acquisition mode, 5V/div to 10mV/div;
±4% for Normal or Average acquisition mode, 5mV/div to 2mV/div
●Bandwidth Limit:20MHz
Edited 1 time(s). Last edit at 07/15/2016 02:24PM by LarsK.
On the drivers that let you down, how fast were those transients?
Would I be able to see them?
My scope can do:
●Model
SO1062B●Bandwidth:60MHz
●Channel:2
●Real-Sample Rate:1GSa/s
●Equivalent Sample Rate:25GSa/s
●Record Length:1M
●Rish time:≤1.7ns/≤3.5ns/≤5.8ns
●Timebase Accuracy:±50ppm
●Time Base Range:2ns/div-40s/div / 4ns/div-40s/div / 4ns/div-40s/div
●Input Impandance:1MΩ
●VOLTS/DIV Range:2mV/div～5V/div
●A/D Converter:8bit
●Position Range:±50V(5V/div), ±40V(2V/div～500mV/div), ±2V(200mV/div～50mV/div), ±400mV(20mV/div～2mV/div)
●DC Gain Accuracy:
±3% for Normal or Average acquisition mode, 5V/div to 10mV/div;
±4% for Normal or Average acquisition mode, 5mV/div to 2mV/div
●Bandwidth Limit:20MHz
Edited 1 time(s). Last edit at 07/15/2016 02:24PM by LarsK.
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Re: Single chip (IC) with adjustable constant current and PWM? July 15, 2016 05:10PM |
... I'm switching the currents with up to 2MHz bandwith and the spikes have some 10 nanoseconds duration.
The first image shows some 'typical' spikes and overshoots while switching OFF and ON - here is the current set to 3.6A and measured as voltage drop across the shunt resistor of 111 Milliohms - 0,4 V / 0,111 Ohm = 3,6 A:
And here current set to 10 Amps and the OFF-spike zoomed more in detail:
Edited 1 time(s). Last edit at 07/15/2016 05:17PM by VDX.
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
The first image shows some 'typical' spikes and overshoots while switching OFF and ON - here is the current set to 3.6A and measured as voltage drop across the shunt resistor of 111 Milliohms - 0,4 V / 0,111 Ohm = 3,6 A:
And here current set to 10 Amps and the OFF-spike zoomed more in detail:
Edited 1 time(s). Last edit at 07/15/2016 05:17PM by VDX.
Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]
Call for the project "garbage-free seas" - [reprap.org]
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