o/p of boost converter if the regulator is shutdown

[[email protected]]

I am usiing LMR64010 to convert 5V to 12V. Load current is approx 150ma. The schematic is as per the application circuit in the datasheet. If I pull the shutdown pin to ground the o/p is approx 4.6V. Looking at the circuit there is an i/p to o/p path through the inductor and diode giving me 5V minusdiode drop during shut down.

Is it normal for boost converters? is there a simple way to make the o/p to0V if the regulator is in shutdown mode?

-bhavj

 

[Tim Williams]

Use SEPIC instead.

Tim

--
Seven Transistor Labs
Electrical Engineering Consultation
Website: http://seventransistorlabs.com

I am usiing LMR64010 to convert 5V to 12V. Load current is approx 150ma.
The schematic is as per the application circuit in the datasheet. If I
pull the shutdown pin to ground the o/p is approx 4.6V. Looking at the
circuit there is an i/p to o/p path through the inductor and diode giving
me 5V minus diode drop during shut down.

Is it normal for boost converters? is there a simple way to make the o/p
to 0V if the regulator is in shutdown mode?

-bhavj

 

[[email protected]]

On Wednesday, November 6, 2013 6:59:18 AM UTC-5, [email protected] wrote:

This is a cheap fix:
Please view in a fixed-width font such as Courier.

..
..
..
.. .------------------------------------------.
.. | |
.. | G
.. | SD
.. 5V---+----+-------LLLLL-------+--|>|---+-------+---S D-->
.. | | | | |
.. | | ------------ | | | Si2347DS
.. | | | | | | | P-CH MOSFET
.. +| +---|Vin SW|--' | +|
.. === | | | | ===
.. | [51K] | LMR64010 | | |
.. | | | | ------- |
.. | | |____ | | FDBK | |
.. >--------+---|SHDN FB|-------| | |
.. | | | | DVDR | |
.. | | GND | ------- |
.. | ------------ | |
.. | | | |
.. ----+---------------+-----------------+-------+----------
.. |
.. ---
.. ///
..
..
..
.. - OR -
..
.. 1n
.. .-------------------------------+--||-.
.. | | |
.. | G ---
.. | SD ///
.. 5V---+----+-------LLLLL-------+--|>|----S D----+-------+->
.. | | | | |
.. | | ------------ | Si2347DS | |
.. | | | | | P-CH MOSFET | |
.. +| +---|Vin SW|--' | +|
.. === | | | | ===
.. | [51K] | LMR64010 | | |
.. | | | | ------- |
.. | | |____ | | FDBK | |
.. >--------+---|SHDN FB|-----------------| | |
.. | | | | DVDR | |
.. | | GND | ------- |
.. | ------------ | |
.. | | | |
.. ----+---------------+---------------------------+-------+-
.. |
.. ---
.. ///
..
..