[net.analog] DC-DC converter ICs

monta@cmu-cs-g.ARPA (Peter Monta) (08/16/85)

Are there ICs which convert +5V to +15V and -15V, at about 40mA each?
This would be very convenient for providing RS-232 signal levels;
often this is the only place such voltages are needed.  (1488s require
about 40mA at each voltage.)

Failing a one-chip solution, what about a voltage quadrupler plus
small 15V regulator (using a +5V to -5V converter for the -15V side)?
Any suggestions, references, etc. about low-power DC-DC conversion
welcome.

Peter Monta
monta@cmu-cs-g
..!rochester!cmu-cs-pt!cmu-cs-g!monta

mae@weitek.UUCP (Mike Ekberg) (08/23/85)

In article <301@cmu-cs-g.ARPA>, monta@cmu-cs-g.ARPA (Peter Monta) writes:
> Are there ICs which convert +5V to +15V and -15V, at about 40mA each?
> This would be very convenient for providing RS-232 signal levels;
> often this is the only place such voltages are needed.  (1488s require
> about 40mA at each voltage.)				  ------

You might be interested in a new part from Motorola, it's the MC145406. It's
a CMOS tranceiver that combines the functions of the 1488 and 1489. It
contains 3 drivers and 3 receivers. It runs on +-5 V. And it uses 1/10 the 
power of the 1488. Price is $1.59 in 100-unit quantities(see _Electronic
Design_, August 8,1985, pg. 149).

Mike

ken@turtlevax.UUCP (Ken Turkowski) (08/23/85)

In article <301@cmu-cs-g.ARPA>, monta@cmu-cs-g.ARPA (Peter Monta) writes:
> Are there ICs which convert +5V to +15V and -15V, at about 40mA each?
> This would be very convenient for providing RS-232 signal levels;
> often this is the only place such voltages are needed.  (1488s require
> about 40mA at each voltage.)				  ------

Intersil makes the ICL7660, which converts from +5V to -5V at 20mA.  I
think that you could run two in parallel for more oomph.
-- 
Ken Turkowski @ CADLINC, Menlo Park, CA
UUCP: {amd,decwrl,hplabs,seismo,spar}!turtlevax!ken
ARPA: turtlevax!ken@DECWRL.ARPA

rbc@houxu.UUCP (R.CONNAGHAN) (08/27/85)

Power General makes a 24-pin module that converts +5V to +/- 12V 
at 40 mA each. About $35-40.

-- 
Robert Connaghan
WE 32100 Microprocessor Group
AT&T Information System - Holmdel, N.J.
houxu!rbc