o/p of boost converter if the regulator is shutdown

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I am usiing LMR64010 to convert 5V to 12V. Load current is approx 150ma. Th
e schematic is as per the application circuit in the datasheet. If I pull t
he shutdown pin to ground the o/p is approx 4.6V. Looking at the circuit th
ere 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  

Re: o/p of boost converter if the regulator is shutdown
On a sunny day (Wed, 6 Nov 2013 03:59:18 -0800 (PST)) it happened
snipped-for-privacy@gmail.com wrote in

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Yes.


Power MOSFET in series with input or output?


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Re: o/p of boost converter if the regulator is shutdown
Use SEPIC instead.

Tim

--  
Seven Transistor Labs
Electrical Engineering Consultation
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Re: o/p of boost converter if the regulator is shutdown
On Wed, 06 Nov 2013 08:19:47 -0600, Tim Williams wrote:

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I have done that, it works well in practice.  You lose a bit of  
efficiency, but it's a worthwhile price to pay if you want "off" to  
really be "off".

--  

Tim Wescott
Wescott Design Services
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Re: o/p of boost converter if the regulator is shutdown
On Wed, 6 Nov 2013 03:59:18 -0800 (PST), snipped-for-privacy@gmail.com wrote:

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Here's a boost-doubler circuit. It adds C6 and D1 to the usual boost converter.
I wanted to pre-charge the output cap, so I have R14; you'd probably want to
delete that.

https://dl.dropboxusercontent.com/u/53724080/Circuits/Power/Boost-Doubler.pdf


This is in production, boosting 9 volts to 48 in a tiny laser driver. Works
fine.



--  

John Larkin                  Highland Technology Inc
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

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Re: o/p of boost converter if the regulator is shutdown
On Wednesday, November 6, 2013 6:59:18 AM UTC-5, snipped-for-privacy@gmail.com 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    |                  -------    |
.          |         ------------                      |       |
.          |               |                           |       |
.      ----+---------------+---------------------------+-------+-
.                          |
.                         ---
.                         ///
.
.

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