TPS61023: INPUT VOLTAGE 1V IOUT=?

Hi Kwon,

TPS61023 cannot output 0.8A Iout under 0.5Vin-5Vout condition. The output current capability can be calculated by equation(1) on datasheet page 9. 

If you're looking for a device that can output big current under 0.5V Vin, you can check TPS61022. But still, the device is not enough to output 5V/0.8A when input drops to 0.5V.

Outputting 0.8A Iout under 0.5Vin-5Vout condition means the input current will exceed 8A. AA battery has a big internal resistor of several ohm when the battery capacity is near depleted, which will cause a big voltage drop when trying to output current. So it's really rare that an AA battery needs to output that massive current under such a low input, I would like to know why you need this feature.

Best Regards,

Travis

Thank you for your answer.

Generally, main DC power is used. If there is no main power source, try to use the AA battery for a very short time.

I have more questions.

1. tps61022 data sheet 5 page Vin_UVLO (VOUT>2.2V) range is  MAX1.8V. Does it work when the VIN is continuous 1V to 1.5V?

9PAGE 7.3.1 Undervoltage Lockout is described as follows.

[The TPS61022 has a built-in undervoltage lockout (UVLO) circuit to ensure the device working properly. When
the input voltage is above the UVLO rising threshold of 1.8 V, the TPS61022 can be enabled to boost the output
voltage.]

2. VEN_H & VMODE_H : It says MAX = 1.2V. However, the slvubj7 (TPS61022EVM-034 Schematic) is supposed to connect to the VIN.

If the VIN is 5 V, a voltage higher than MAX1.2 V is applied. Shouldn't it be MIN 1.2V, not MAX 1.2V?

Best regard,

KWON

Hi Kwon,

1. The 1.8V rising Vin_UVLO means If the Vin is below 1.8V, the device cannot start up. After start-up, the Vin_UVLO will be 0.4V

2. The 1.2V VEN_H means when EN exceeds this threshold , the device will recognize it as high. This threshold's max value is 1.2V. So when a 5V Vin is applied, the EN will be high.

BR,

Travis

Thank you for your answer.

DATASHEET states Input voltage range=0.5V~5.5V, but AA(1.5V) 1EA has a small VIN, so TPS61022 is not able to generate an output?

Best regard,

KWON

Hi Kwon,

It depends on whether you are rebooting this device when the battery is discharged below 1.8V.

TPS61022 has a 1.8-V minimum input voltage for start-up. The input range 0.5V~5.5V is the voltage after start-up.(Datasheet page 1 'Features' line 1&2)

Best Regards,

Travis

Thank you.

Best regards,

KWON.