>
> What I'm looking for is a regulator for a 6V sealed lead app that will
> indicate when the cell has reached 5.5V so the cell can be disconnected.
> Failing that, any suggestions re a reproducible discrete circuit that can
> match the MAX666 specs, eg 12uA quiescent, settable output voltage, set-
> table low voltage detect [ oh, is that all ? ;) ]
>

We have a circuit which is similar.  The problem we have had over the past
few years is that these battery monitor IC's are both expensive and tend to
be unavailable or discontinued on a regular basis.  We use low current
regulator like the Telecom TC55 or one of the National regulators to get a 5
volt reference.  Divide it with 1 MOhm resistors and buffer it through half
an LM2904 to provide a reference to a comparator.  The second half of the
LM2904 is set up as a comparator with positive feedback to give hysteresis
(On about 6.0 and off at about 6.3 volts).  The reference on one input and
battery voltage divided through large resistors on the other input.  The
output of the comparator drives a small signal NPN which in turn controls
the PNP pass transistor.  The pass transistor varies from a 2N2907 in lower
charging current applications to a D-PAK MOSFET when we are pumping 5 or 6
Amps into the gel-cell.

IIRC the entire circuit draws under 500 uA.  But the LM2904 is only US$0.15
in quantity.  There are lower current op-amps around, but I doubt you'll get
them at that price.

Mark Walsh