Part Number:UCC27282
Hello,
Is there a minimum input turn-on or turn-off time for the UCC27282? For the UCC27712 there is a minimum turn-on time of 25ns and turn-off time of 35ns. However, I do not think the UCC27282 has this limitation and I would like to confirm.
I am looking at using one of these two controllers with a buck converter operating at 600kHz.
Thanks,
Kyle
Hi,
I have two solar panels which are not mounted on the same location, so they are not exposed to the same environmental conditions - illumination, ...
For a higher efficiency of MPPT would like to use a separate buck converter for each of this panels, but because of nature of application I would need to connect outputs of buck converters in a parallel. On the output side of a converters will be a battery, so in one mode, this two converters will charge a battery, in another mode there will be also a load connected in a parallel with a battery, so there is a plan to deliver from solar panels as maximal as possible part of electrical energy, so each solar panel will must work near to maximum power point as possible.
Because I would like to use a separate buck converter for each panel, I must use a separate duty cycle control for each converter (PWM will be generated with MCU). Additionaly, because output voltage is determined by voltage of a battery, I am planning to use a feedback from the input (solar panel), so with duty cycle I will changing an input and not output voltage.
Do you see any problems with parallel conection of buck converters in that example?
Many thanks!
Dejan.
Part Number:UCC28951
Part Number:LM5575
Hi,
I'm working on measuring the closed loop Bode plots for the following regulator. Using one of our production units, I have inserted a 1k resistor to create a high Z / Low Z impedance nodes. Then using the Frequency Response Analyzer, I inject a signal via CH1 (1k and R50 node), and measure the response on CH2 (1k and C226 node). See the picture below.
I'm getting unusual phase measurements. Can anyone recommend what I'm doing wrong? Do I need to move the insertion point before the OUT (Pin 11) connection?
How does TI measure the closed loop performance that it shows in the Webench simulations?
Any help would be appreciated.
Part Number:BQ51003
Hi,
I am using BQ51003 as power supply and following the circuit shown in Fig. 32 on Pg. 27 of the datasheet:
Two questions:
1. What are the values for Ros1 and Ros2? In Pg. 30 of datasheet, it is mentioned that "Default values of 20 kΩ for Ros1 (RECT to FOD). Ros2 (OUT to FOD) remains open". But Ros1 is connected between OUT and FOD according to the circuit. Does this mean that Ros1 remains open and Ros2 is 20 kΩ?
2. For Cout, it is mentioned on Pg. 30 to use 10 uF and 0.1 uF. However, in the circuit shown on Pg. 3 of bq51003EVM-764 datasheet (circuit attached below), 0.1 uF and 1uF (C6 and C7) have been used. Please let me know the right values of output capacitance to be used.
Thanks.
Part Number:BQ25606
Hi,
I was wondering if I need to control the impedance of the D+/D- lines of the BQ25606 as I would for high speed USB lines? I wasn't able to find the manipulations on D+/D- during detection. I'm assuming they are simple manipulations, thus D+/D- can be routed with a bit of freedom to the charger, but I'd like to make sure.
Thank you,
Fred
Part Number:BQ24780S
A question from my customer:
"I had a question about the (bq24780S) charger. Can the IC handle going through IR reflow twice. Our SMT line will populate the top side then reflow that side then populate the button side then reflow again. Is that okay for that IC?"
I think it is safe to say that the 1st side only 'sees' the IR reflow once (directly), and only minimally on the 2nd pass (because it is on the non-IR side).
Thanks!
Part Number:BQ27742-G1
Hi!
In the bq27741-G1"Protector Status register: 0x6D" (see reference on page 36 of the user guide ( http://www.ti.com/lit/pdf/sluuaa3 ), there's a bit called "CVM", for Cell voltage monitor threshold. The bit says:
1 = Cell voltage monitor threshold detected
0 = Cell voltage monitor threshold not detected
It would be awfully nice to know what the heck this means: there is no documentation that we can find that explains what CVM is. Could someone please explain this bit? Seems important, possibly even critical to cell performance, and yet.. we have no idea what this means?
Thanks!
Andrew
When the battery voltage is low, between 3V and 3.6V the charge current is normal, 800mA. But as battery voltage increase the charge current begins to drop from 800mA to 460mA, battery is well below 4.2V for the start of constant voltage.
What could be causing this problem?
Part Number:BQ27411-G1
Hello,
We are using the BQ27411-G1A to monitor the SOC of our batteries. We are manually setting all values in ROM. Everything is working fine except the current measured by the fuel gauge when it is charging the batteries.
When discharging, the fuell cell measures with great accuracy the current flowing trough the 10m Ohm resistor. Never the less, when the batteries are charging the fuell cell reports approximately double the current that's flowing through the resistor. We have measured voltage drop across the resistor and also measured the current flowing trough the resistor and comparing it with the value reported by the fuel gauge, yielding the following table:
We tried two different devices with the same results "Equipo A" and "Equipo B". V Bat Tester is the voltage of the batteries reported by a tester, V Bat FG is the Voltage reported by the Fuel Gauge (FG). V R14 is the voltage drop in the 10m Ohm resistor measured with a tester.
As you can see, the FG reports an incorrect value for positive values of current (batteries charging). We are also sure it is reading current incorrectly, because when charging the Remaining Capacity reported by the Fuel Gauge increases to approximately double the design capacity. In the file "serial_20181222_144052_carga.txt" we have monitored the FG behaviour when charging from a full discharge.
(Please visit the site to view this file)
We are using two Li-Ion 3.7V 680mAh batteries connected in parallel. Here are the schematics of our design regarding the Fuel Gauge:
Also, with this function we are writing the values configured in ROM:
void fg_write_data_memory2 (void) {
unsigned char uc;
int cs;
fg_write(0x00, 0x00); // UNSEAL
fg_write(0x01, 0x80);
fg_write(0x00, 0x00);
fg_write(0x01, 0x80);
fg_write(0x00, 0x13); // SET_CFGUPDATE
fg_write(0x01, 0x00);
uc = fg_read_unsigned_byte(0x06);
while ((uc & 0x10) == 0) {
_delay_ms(100);
uc = fg_read_unsigned_byte(0x06);
}
fg_write(FG_BLOCKDATACONTROL, 0x00); // BlockDataControl
cs = 0;
fg_class(2); // safety
fg_block(0);
cs = fg_write_data_word(0, 550, cs);
cs = fg_write_data_word(2, 0, cs);
cs = fg_write_data_byte(4, 50, cs);
fg_checksum_write(~cs);
//
fg_class(36); // charge termination
fg_block(0);
cs = fg_write_data_word(0, 25, cs);
cs = fg_write_data_byte(2, 40, cs);
cs = fg_write_data_byte(3, 99, cs);
cs = fg_write_data_byte(4, 95, cs);
cs = fg_write_data_byte(5, -1, cs);
cs = fg_write_data_byte(6, 98, cs);
cs = fg_write_data_word(7, 50, cs);
fg_checksum_write(~cs);
//
fg_class(48); // data
fg_block(0);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_byte(2, -13, cs); // not default
cs = fg_write_data_word(3, -500, cs); // not default
fg_checksum_write(~cs);
//
fg_class(49); // discharge
fg_block(0);
cs = fg_write_data_byte(0, 10, cs);
cs = fg_write_data_byte(1, 15, cs);
cs = fg_write_data_byte(2, 2, cs);
cs = fg_write_data_byte(3, 5, cs);
fg_checksum_write(~cs);
//
fg_class(64); // registers
fg_block(0);
cs = fg_write_data_word(0, 0x25F8, cs);
cs = fg_write_data_byte(2, 0x0F, cs);
cs = fg_write_data_byte(3, 0x80, cs);
fg_checksum_write(~cs);
//
fg_class(68); // power
fg_block(0);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_word(7, 3, cs);
cs = fg_write_data_word(9, 2800, cs);
cs = fg_write_data_byte(11, 1, cs);
fg_checksum_write(~cs);
//
fg_class(80); // IT cfg
fg_block(0);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_word(4, 30, cs);
cs = fg_write_data_byte(10, 8, cs);
cs = fg_write_data_byte(17, 70, cs);
cs = fg_write_data_byte(19, 20, cs);
cs = fg_write_data_byte(20, 5, cs);
cs = fg_write_data_word(22, 800, cs);
cs = fg_write_data_byte(28, 10, cs);
fg_checksum_write(~cs);
//
fg_block(1);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_byte(35, 92, cs);
cs = fg_write_data_byte(36, 96, cs);
cs = fg_write_data_word(37, 125, cs);
cs = fg_write_data_word(39, 4, cs);
cs = fg_write_data_byte(41, 3, cs);
cs = fg_write_data_byte(42, 25, cs);
cs = fg_write_data_byte(44, 15, cs);
cs = fg_write_data_byte(45, 20, cs);
cs = fg_write_data_word(48, 500, cs);
cs = fg_write_data_word(52, 0, cs);
cs = fg_write_data_word(54, 0, cs);
cs = fg_write_data_byte(59, 1, cs);
cs = fg_write_data_byte(60, 20, cs);
cs = fg_write_data_word(61, 11, cs);
fg_checksum_write(~cs);
//
fg_block(2);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_word(70, 0, cs);
cs = fg_write_data_word(72, 200, cs);
cs = fg_write_data_word(74, 100, cs);
cs = fg_write_data_byte(76, 2, cs);
fg_checksum_write(~cs);
//
fg_class(81); // Current Thresholds
fg_block(0);
cs = fg_write_data_word(0, 167, cs);
cs = fg_write_data_word(2, 100, cs);
cs = fg_write_data_word(4, 250, cs);
cs = fg_write_data_word(6, 60, cs);
cs = fg_write_data_byte(8, 60, cs);
cs = fg_write_data_byte(9, 1, cs);
cs = fg_write_data_byte(10, 179, cs);
cs = fg_write_data_byte(11, 179, cs);
cs = fg_write_data_word(12, 400, cs);
fg_checksum_write(~cs);
//
fg_class(82); // State
fg_block(0);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_word(0, 16384, cs); // error here
cs = fg_write_data_byte(2, 0x00, cs);
cs = fg_write_data_word(3, 0, cs); // ?
cs = fg_write_data_byte(5, 0x81, cs);
cs = fg_write_data_word(6, 3803, cs);
cs = fg_write_data_word(8, 3752, cs);
cs = fg_write_data_word(10, 1360, cs); // Design Capacity 680+680 mAh
cs = fg_write_data_word(12, 5032, cs); // Design Energy 1360 mAh * 3.7 V
cs = fg_write_data_word(14, 1340, cs);
cs = fg_write_data_word(16, 3200, cs); // Terminate Voltage 3200 mV
cs = fg_write_data_byte(26, 1, cs);
cs = fg_write_data_word(27, 25, cs); // Tapper rate = 10*1032/Charge_current
cs = fg_write_data_word(29, 4100, cs);
cs = fg_write_data_byte(31, 10, cs); // Sleep current
fg_checksum_write(~cs);
//
fg_block(1);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_word(33, 4190, cs); // error ?
cs = fg_write_data_word(35, -50, cs);
cs = fg_write_data_word(37, -50, cs);
cs = fg_write_data_word(39, 1, cs);
fg_checksum_write(~cs);
//
fg_class(104); // Data
fg_block(0);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_byte(0, 0, cs);
cs = fg_write_data_byte(1, 0, cs);
cs = fg_write_data_byte(2, 0, cs);
fg_checksum_write(~cs);
fg_class(107); // Current
fg_block(0);
cs = fg_write_data_byte_dummy();
cs = fg_write_data_byte(1, 5, cs);
fg_checksum_write(~cs);
fg_write(0x00, 0x42); // SOFT_RESET
fg_write(0x01, 0x00);
uc = fg_read_unsigned_byte(0x06);
serial_printf_P(PSTR("flags %02X\n"), uc);
while ((uc & 0x10) != 0) {
_delay_ms(100);
uc = fg_read_unsigned_byte(0x06);
}
uc = fg_read_unsigned_byte(0x06);
serial_printf_P(PSTR("flags %02X\n"), uc);
fg_write(0x00, 0x20); // SEAL
fg_write(0x01, 0x00);
return;
}Any ideas ?
Thanks, Tomás
Part Number:BQ76940EVM
Hello,
I am using a switch across keyin to turn the discharge fets on and off. When I use a power supply to charge my battery pack the discharge fets are turned on to allow it to charge and then are turned off when the charge completes. However, when I use a "smart" charger the charger does not see any voltage at the terminals and does not initiate a charge. Is there any way to allow a charger that senses voltage before initializing to work while keyin has discharge set off?
-Kyle
Part Number:TPS40304
Dear support member,
My customer used TPS40304.
My customer mass-produce products.
I have a question.
（Situation）
It was happening that the IC will not start up when the temperature reaches minus 10 ° C.
（Question)
Is there any reason for it?
（Specification condition）
Vin: 12 V
Vout: -5 V
Iout: 3A
fsw: 500 kHz
Best regard.
Bob Lee.
Many DCDC converters require 0.1uF ceramic capacitor for bootstrap capacitor.
How can I select capacitor? I would like to know judgement method of capacitor spec as voltage rating, DC bias, size etc...
What kind of capacitors can we use actually?
Best Regards,
Kohei Sasaki
Part Number:UCC28251
Hi TI Engineers,
I am a graduate student in school, want to use UCC28251 to make a full bridge hard switching module power supply, read the manual of the chip, there is a problem is when the light load inductance current interrupted, synchronous rectifier tube is still open, then there will be reverse current into the rectifier tube causing burnout, how is your company consider it in this regard?
The synchronous rectifier tube of the power supply is damaged when it is powered on.
Excuse me, is this the breakdown reason, how to solve it?
Regars
shaowei
Part Number:TPS23880
Hi,
When testing TPS23880 with Reg 0x29 as value 0x0F (4 pair 90W), our got detection result from Reg 0x0C as value 0x0B/0x0C/0x0D/0x0F which are not listed in Table 12 of datasheet.
But result is what we expected when test TPS23880 with Reg 0x29 as value 0x03 (2 pair 30W) or using TPS23880EVM
1. Could you please tell us what the values(0x0B/0x0C/0x0D/0x0F) stand for?
2. How and why we got these values?
Or anything needs to be provided?
Thank you,
C.T.
Part Number:LM2766
Hi E2E Team
I am not familiar with ANSI standards, so it’s hard for me to understand the symbols C1 and C2 on page 1.
if I look at the designation, this is a non-polar capacitor (ANSI Y32.2-1975, p.44), but by the description in the datasheet - polar.
Tell me what is right :)
Part Number:LM2623
Hello,
I'll still could not upload the pdf files.
Here is what we did according to LM2623 datasheet reference design of 5V output.
In our design we need to achieve 12V output. Due to absolute maximum rating of 10V for BOOT, EN and VDD,
we disconnect BOOT,EN and VDD from VOUT (12V), and connect to 5V input, but the output measured is 18V and not 12V.
We then leave VDD and EN connect to 5V input, and connect BOOT to VOUT 12V, we get 12V ouput, but BOOT max rating is 10V.
We then drop VOUT to 10V (by adjusting the resistor's value), it still works fine, and we get 10V ouput.
My question is why BOOT have to connect to VOUT in order to make the circuit work? If so, the BOOT maximum rating is 10V, we will never achieve 12V.
In addition your specs stated output adjustable from .124V to 14V? Could you please advise.
Thanks.
Teck