Hi,
I would like a confirmation that we can tie the pin MODE / Data pin directly to VIN on the TPS62420. According to the spec, this is an open-drain pin, but the "ACK" should be driven low only if an exact sequence of bits has been send. So I assume that it is OK to connect it directly to VIN if I want to disable the POWER SAVE mode.
Thanks,
Denis
Hi ,
We are using 1.2V Buck converter IC TLV62090,Switching frequency is 1.25MHz, And there is no compensation network available to tune the phase Margin.
We are facing problem to achieve the Cross over frequency as the desired frequency is 1/10 of 1.25Mhz i.e around 120Khz but we are getting 24Khz only by changing the feed back resistors R334=150kOHM'S and R335=75Kohm's.
Please find the Schematic for reference.
Please Suggest what needs to be done to achieve the desired cross over frequency.
Regards,
Utkarsh
HI we have been using the LM3671 series (4 pin BGA or 1.4mm Sq area) device to convert 5V nominal (+/- 5% USB input voltage to 1.2V/1.8V and 3.3V/2.5V outputs. This is a good low cost and space saving solution. The current requirement are maximum 240mA on any of the output voltages. Cost of that device is below 30c in 1K volume so even lower in high volume. Out target price in 100K volume is close to 10c per piece if possible as this is a reference design for high volume consumer electronics product
The problem is there is no mode control and for our noise sensitive application, we want the operate the device in fixed PWM mode.
Can you recommend a small low cost device (dual outputs of 1.2V/1.8V) and 2.5V/3.3V in one package would be O.K. as well as long as the price/area is smaller than 2 single voltage output devices.
Please let me know of your recommended solutions
Hi ,
I have a design requirement where i have to drive the module from 2 or 4 AAA batteries thats 3 or 6 Volts input .
The module has 3.3V Microcontroller and 9-12V Stepper motor with a driver circuit . I am searching for the Boost converter which can provide me these voltages and the total peak current output of around 1.2A. What is the most appropriate Boost converter that I can use for this design.
It would be of great help if this is provided with a reference design also which minimizes the back propagation of motor noise back to controller.
Thanks in Advance.
Naveen
All designers of ultra-low power systems are concerned about battery life. How much time will elapse before the battery in a fitness tracker will need recharging? Or, for primary cell systems, how long will it be before a technician must service the smart meter and change the battery? Clearly, the design goal is maximum battery runtime. But what do you need to consider in each of the various subsystems to achieve this?
In many systems, one or two voltage rails are always enabled. These power the system microcontroller (MCU), a critical sensor or maybe a communication bus. These always-on rails need to have very high efficiency to extend the battery runtime. A good subsystem design reduces the current drawn by each of the always-on subsystems to a minimum – many times this is less than 10µA total. As I discussed in this blog post, an ultra-low power supply is required to reap the benefits of these subsystem optimizations. In rails with very low current consumption, this translates to a power supply with ultra-low quiescent current (IQ), such as the TPS62743.
You might be tempted to think that it’s most important to minimize the current consumption of each of the power supplies while they are running. Reducing the IQ increases efficiency and thus extends the battery runtime by consuming less battery power. But is the efficiency increase always significant? For systems that operate at relatively higher load currents, such as displays and some sensors, the answer is clearly no; the output power is much greater than the IQ power. For example, if the display in a fitness tracker draws 12V at 5mA (60mW total), the 100µA IQ drawn from the 3.6V battery (0.36 mW total) is insignificant.
More important for these types of subsystems is the power consumption when disabled. An ultra-low power system turns off power-hungry subsystems most of the time in order to conserve the battery. Thus, the shutdown current becomes critical to the system’s battery life. This leakage current, as it is frequently called, may be so high that you will have to add a load switch to disconnect the subsystem from its power source to further reduce its shutdown current. The TPS62748, high efficiency buck converter, provides both a load switch and ultra-low IQ for such systems.
When a load switch is not used, you must consider both the leakage current into the device itself and its load if there is a path to the load through the device. This is frequently the case with a boost converter, so specific circuitry is sometimes added to break this path, such as the isolation switch in the TPS61046, boost converter. In other cases, this path is specifically optimized to allow bypass operation– powering the load with less than 50nA of shutdown current consumption in the disabled device.
It’s important to pick the right type of device – ultra-low IQ or ultra-low shutdown current – for your specific subsystem. These nuances are prevalent in every ultra-low power system, from a wearable to a smart meter to a medical device, so consider the requirements of your application wisely before choosing the optimal solution. Learn more about nuances in ultra-low power designs for wearable products in my ECN article.
For more information on this topic, check out my other blogs:
Hello,
I'm currently designing a board where I plan to use TPS62120. I have been examining the datasheet and I have some questions regarding it:
1) In table 7.5 current I_LIMF is defined only for V_in = 8V. I wonder how it changes depending on the input voltage? Are the values for 3.3V, 8V or 12V much different?
2) In equation (2) shouldn't there be [A] instead of [mA]?
3) I calculated C_ff according to equation (7) for R1=560k and obtained the value 11pF that is two times smaller than the one proposed in the table. I know it doesn't matter much, but is there a reason to go with 22uF?
4) In the Power Supply and Layout section there is nothing regarding bulk capacitor. Won't it hurt much if I will add a 100uF electrolytic capacitor before the input capacitor (main power source is couple of meters away)?
Excuse me for kind a pedantic questions, but I want to be very sure about each detail. Thanks in advance.
Power banks can be indispensable on a long flight or during a long meeting if you need to recharge your smartphone’s or tablet’s battery. Having previously charged up your power bank, you efficiently transfer its energy to your portable device to achieve a longer runtime. In order to give your device sufficient energy, the power bank should have a high-capacity battery – on an order of magnitude of your device’s battery. It should also keep nonbattery circuitry to a minimum so that its size is not much bigger than your phone. Finally, the power bank’s efficiency must be very high (over 95%) in order to not waste energy during power transfer and to not get too hot for the user.
Figure 1 shows a typical power-bank power scheme. Since the power source is almost always a single-cell lithium battery and the output voltage is almost always a 5V USB port, the power bank will also need:
Figure 1: Typical power-bank power architecture
The TPS61088 is a traditional boost converter that can deliver the 5V output at currents above 5A for very-high-power power banks. As opposed to most other boost converters operating at that power level, the TPS61088 incorporates both power MOSFETs to reduce the total solution size required by half, while still delivering 95% efficiency.
The load switch and detection circuit are extra circuits that will take up space and add losses to the system. Building them into the boost converter, however, reduces both solution size and power loss. Reduced power loss means a lower temperature rise, making higher power densities possible.
Figure 2 shows a power-bank solution using the TPS61235/6 boost converter. The TPS61235/6 has a constant output-current function and output-current monitor pin to fulfill the protection and detection needs in power-bank systems. Incorporating these two functions and using a much smaller 2.5mm-by-2.5mm package allows a maximum output power of 5V at 3A and 95% efficiency.
Figure 2: New power-bank power architecture with the TPS61235/6
What can you do with smaller solution sizes and higher output powers in your power-bank designs?
Read more blog on portable power:
Hi ,
We are using 1.2V Buck converter IC TLV62090,Switching frequency is 1.25MHz, And there is no compensation network available to tune the phase Margin.
We are facing problem to achieve the Cross over frequency as the desired frequency is 1/10 of 1.25Mhz i.e around 120Khz but we are getting 24Khz only by changing the feed back resistors R334=150kOHM'S and R335=75Kohm's.
Please find the Schematic for reference.
Please Suggest what needs to be done to achieve the desired cross over frequency.
Regards,
Utkarsh
All designers of ultra-low power systems are concerned about battery life. How much time will elapse before the battery in a fitness tracker will need recharging? Or, for primary cell systems, how long will it be before a technician must service the smart meter and change the battery? Clearly, the design goal is maximum battery runtime. But what do you need to consider in each of the various subsystems to achieve this?
In many systems, one or two voltage rails are always enabled. These power the system microcontroller (MCU), a critical sensor or maybe a communication bus. These always-on rails need to have very high efficiency to extend the battery runtime. A good subsystem design reduces the current drawn by each of the always-on subsystems to a minimum – many times this is less than 10µA total. As I discussed in this blog post, an ultra-low power supply is required to reap the benefits of these subsystem optimizations. In rails with very low current consumption, this translates to a power supply with ultra-low quiescent current (IQ), such as the TPS62743.
You might be tempted to think that it’s most important to minimize the current consumption of each of the power supplies while they are running. Reducing the IQ increases efficiency and thus extends the battery runtime by consuming less battery power. But is the efficiency increase always significant? For systems that operate at relatively higher load currents, such as displays and some sensors, the answer is clearly no; the output power is much greater than the IQ power. For example, if the display in a fitness tracker draws 12V at 5mA (60mW total), the 100µA IQ drawn from the 3.6V battery (0.36 mW total) is insignificant.
More important for these types of subsystems is the power consumption when disabled. An ultra-low power system turns off power-hungry subsystems most of the time in order to conserve the battery. Thus, the shutdown current becomes critical to the system’s battery life. This leakage current, as it is frequently called, may be so high that you will have to add a load switch to disconnect the subsystem from its power source to further reduce its shutdown current. The TPS62748, high efficiency buck converter, provides both a load switch and ultra-low IQ for such systems.
When a load switch is not used, you must consider both the leakage current into the device itself and its load if there is a path to the load through the device. This is frequently the case with a boost converter, so specific circuitry is sometimes added to break this path, such as the isolation switch in the TPS61046, boost converter. In other cases, this path is specifically optimized to allow bypass operation– powering the load with less than 50nA of shutdown current consumption in the disabled device.
It’s important to pick the right type of device – ultra-low IQ or ultra-low shutdown current – for your specific subsystem. These nuances are prevalent in every ultra-low power system, from a wearable to a smart meter to a medical device, so consider the requirements of your application wisely before choosing the optimal solution. Learn more about nuances in ultra-low power designs for wearable products in my ECN article.
For more information on this topic, check out my other blogs:
HI we have been using the LM3671 series (4 pin BGA or 1.4mm Sq area) device to convert 5V nominal (+/- 5% USB input voltage to 1.2V/1.8V and 3.3V/2.5V outputs. This is a good low cost and space saving solution. The current requirement are maximum 240mA on any of the output voltages. Cost of that device is below 30c in 1K volume so even lower in high volume. Out target price in 100K volume is close to 10c per piece if possible as this is a reference design for high volume consumer electronics product
The problem is there is no mode control and for our noise sensitive application, we want the operate the device in fixed PWM mode.
Can you recommend a small low cost device (dual outputs of 1.2V/1.8V) and 2.5V/3.3V in one package would be O.K. as well as long as the price/area is smaller than 2 single voltage output devices.
Please let me know of your recommended solutions
Hi ,
I have a design requirement where i have to drive the module from 2 or 4 AAA batteries thats 3 or 6 Volts input .
The module has 3.3V Microcontroller and 9-12V Stepper motor with a driver circuit . I am searching for the Boost converter which can provide me these voltages and the total peak current output of around 1.2A. What is the most appropriate Boost converter that I can use for this design.
It would be of great help if this is provided with a reference design also which minimizes the back propagation of motor noise back to controller.
Thanks in Advance.
Naveen
Hello,
I'm currently designing a board where I plan to use TPS62120. I have been examining the datasheet and I have some questions regarding it:
1) In table 7.5 current I_LIMF is defined only for V_in = 8V. I wonder how it changes depending on the input voltage? Are the values for 3.3V, 8V or 12V much different?
2) In equation (2) shouldn't there be [A] instead of [mA]?
3) I calculated C_ff according to equation (7) for R1=560k and obtained the value 11pF that is two times smaller than the one proposed in the table. I know it doesn't matter much, but is there a reason to go with 22uF?
4) In the Power Supply and Layout section there is nothing regarding bulk capacitor. Won't it hurt much if I will add a 100uF electrolytic capacitor before the input capacitor (main power source is couple of meters away)?
Excuse me for kind a pedantic questions, but I want to be very sure about each detail. Thanks in advance.
Hi,
We are looking for a DC-DC buck converter which will be used with a coin cell (3.6V down to about 2 Volts). The output voltage will be about 2.1 V.
In order to increase battery life, the maximum current drain from the battery should be around 2 mA for short periods only (some seconds). Coin cell battery capacity is reduced if exposed to high pulse currents.
During these seconds, the output storage capacitor should store enough energy to supply up to 20 to 40 mA for a short duration, typically 10 to 30 ms or thereabout. This ensures that the "high" pulse currents is not drawn from the battery itself.
I have found TS3310 from another manufacturer which have this capability. However, it is a boost converter. So, does TI have any DCDC converter which is designed to meet the criterion mentioned?
Regards,
HC
Hi,
If I calculate the Lmin using the formula in datasheet with Vout = 5V, Vin(max) = 10.5V, delta IL(max)=0.009 A (0.03A is load current), Efficiency = 0.9 (90%) and Fsw= 183856 Hz (Web bench simulation)
Thanks & Regards,
Hi ,
We are using 1.2V Buck converter IC TLV62090,Switching frequency is 1.25MHz, And there is no compensation network available to tune the phase Margin.
We are facing problem to achieve the Cross over frequency as the desired frequency is 1/10 of 1.25Mhz i.e around 120Khz but we are getting 24Khz only by changing the feed back resistors R334=150kOHM'S and R335=75Kohm's.
Please find the Schematic for reference.
Please Suggest what needs to be done to achieve the desired cross over frequency.
Regards,
Utkarsh
HI we have been using the LM3671 series (4 pin BGA or 1.4mm Sq area) device to convert 5V nominal (+/- 5% USB input voltage to 1.2V/1.8V and 3.3V/2.5V outputs. This is a good low cost and space saving solution. The current requirement are maximum 240mA on any of the output voltages. Cost of that device is below 30c in 1K volume so even lower in high volume. Out target price in 100K volume is close to 10c per piece if possible as this is a reference design for high volume consumer electronics product
The problem is there is no mode control and for our noise sensitive application, we want the operate the device in fixed PWM mode.
Can you recommend a small low cost device (dual outputs of 1.2V/1.8V) and 2.5V/3.3V in one package would be O.K. as well as long as the price/area is smaller than 2 single voltage output devices.
Please let me know of your recommended solutions
Hi ,
I have a design requirement where i have to drive the module from 2 or 4 AAA batteries thats 3 or 6 Volts input .
The module has 3.3V Microcontroller and 9-12V Stepper motor with a driver circuit . I am searching for the Boost converter which can provide me these voltages and the total peak current output of around 1.2A. What is the most appropriate Boost converter that I can use for this design.
It would be of great help if this is provided with a reference design also which minimizes the back propagation of motor noise back to controller.
Thanks in Advance.
Naveen
Hi,
Why in TPS62130 3 SW pins are used?Is it to support heat dissipation at higher load current?
Power banks can be indispensable on a long flight or during a long meeting if you need to recharge your smartphone’s or tablet’s battery. Having previously charged up your power bank, you efficiently transfer its energy to your portable device to achieve a longer runtime. In order to give your device sufficient energy, the power bank should have a high-capacity battery – on an order of magnitude of your device’s battery. It should also keep nonbattery circuitry to a minimum so that its size is not much bigger than your phone. Finally, the power bank’s efficiency must be very high (over 95%) in order to not waste energy during power transfer and to not get too hot for the user.
Figure 1 shows a typical power-bank power scheme. Since the power source is almost always a single-cell lithium battery and the output voltage is almost always a 5V USB port, the power bank will also need:
Figure 1: Typical power-bank power architecture
The TPS61088 is a traditional boost converter that can deliver the 5V output at currents above 5A for very-high-power power banks. As opposed to most other boost converters operating at that power level, the TPS61088 incorporates both power MOSFETs to reduce the total solution size required by half, while still delivering 95% efficiency.
The load switch and detection circuit are extra circuits that will take up space and add losses to the system. Building them into the boost converter, however, reduces both solution size and power loss. Reduced power loss means a lower temperature rise, making higher power densities possible.
Figure 2 shows a power-bank solution using the TPS61235/6 boost converter. The TPS61235/6 has a constant output-current function and output-current monitor pin to fulfill the protection and detection needs in power-bank systems. Incorporating these two functions and using a much smaller 2.5mm-by-2.5mm package allows a maximum output power of 5V at 3A and 95% efficiency.
Figure 2: New power-bank power architecture with the TPS61235/6
What can you do with smaller solution sizes and higher output powers in your power-bank designs?
Read more blog on portable power:
We're evaluating the TPS62120 buck converter. We'll ultimately fix the output voltage in our design, and I'm wondering if there's a fixed voltage output part (3.3V) I should look at.