Using TPS61032 Step up ic

may i know why you want to use TPS61032? I would suggest TPS61232 for your application instead of the TPS61032 if no special reason. all of information about the boost IC can be found in the datasheet.

the maximum output current is approximate 1.2A when the input voltage is 3V and input current (battery output current) is 2.2A

My application consists of SIM800 GSM Module, which consumes around 2 Amps of current.  The only reason behind using TPS 61032 is because of GSM module. And then again i pull down the voltage at 4v.

Or else can you please suggest me one IC where i can have a output voltage of fixed 4v when input is 3v to 4.2 using my li-po or li-ion battery to power only my GSM module.

Thanks...

I am going to use This IC for basically powering my microcontroller SST89E516RD2 and also GSM module SIM800. SIM 800 consumes around 2Amp of current..

but the source voltage i have is from li-Io or Li-po battery (3v to 4.2v) and current about 2.2Amps, so i need to step up using this IC.

i have gone through the datasheet of the IC TPS61232 you recommended. I think the IC you recommended would be a better choice for me.

But again i would like to ask you one think. 

i need two different voltages. 4v to power my GSM module and 5v for my controller. so can i use two IC's TPS61232-5v to power my controller and TPS61230-ADJ to power my GSM module. or can you please suggest me any different IC where i can power both my controller and GSM module using one single IC.

We don't have one single IC to support both 4V and 5V. you can use two TPS6123x boost converter.

but i guess the output current for the controller is small, so you can use TPS61220 to power the controller if the IOUT is approx. 50mA or TPS61240 if the IOUT is not higher than 250mA

Thanks a Lot for your Help..
will use two 6123x for my application. but can you please help me to know what output current can i get while using 61320-ADj if the output voltage is 4v and input current is 2.2Amps, and input voltage is 3v to 4.2v. how can i calucute the output current with related to input current. do i need to rise the input current to get output current around 1.8Amps at 3v.
As i have fixed the output voltage to 4v and when the input voltage rises to 4.2v, will the output voltage too rise to 4.2v or higher, or will the output voltage remain constant to 4v even at input voltage of 4.2v.

I am still confused about HYS pin and EN pin.
As this HYS pin is used for Undervoltage Lockout, what if i keep this pin floating. as i dont need any undervoltage lockout.
I have already interfaced Undervoltage lockout with my Li-ion Battery in my protection circuit. so when the battery voltage drops below 2.8v the output voltage from the battery stops until and unless the battery voltage rises to 2.85V or higher.
and can i connect EN pin directly to the battery PWR or GND using transistor to ON/OFF the IC's.

As i have seen through the datasheet....
PIN 1 and PIN 2 are both SW pins and PIN 3 and PIN 4 are VOUT pins...
which pins out of PIN 3 AND PIN 4 should be considered for output and which PIN out of PIN 1 and PIN 2 should be considered as Switch Pin.

1. about the output current, IOUT=VIN*IIN*Eff/VOUT, where EFF is approximately 0.9. if VIN=3V, IIN=2.2A, VOUT=4V, IOUT would be 1.6A. you should increase the IIN to get 1.8A output current at VIN=3V
2. You can let HYS floating, the UVLO of the IC will be 2V, but your system UVLO is 2.8V as your setting. you can enable the boost with a voltage higher than 1.3V, or disable the boost with a voltage lower than 1.1V. the transistor circuit you proposed also works.
3. both pin 1, 2 are Switch and both pin 3, 4 are VOUT. because two pins are required to reduce the ESR and support the high current. and please following datasheet, user's guide and the application note "slva773" for your PCB layout