LED backlight dimmer for battery operation

I am designing an LED backlight for a keypad and an LCD display that
will operate from a battery pack with a voltage range of 7 to 14 volts.
I have found few devices that will operate from an input voltage range
this high as most are actually boost circuits designed for driving
white LEDs from lower voltages.

I need the circuit to conserve as much power as possible, so I expect
to need a buck switcher. It also has to be very small and low cost.
There are 9 keypad LEDs, each about 2 volts. The LEDs built into the
LCD are not well known at this point. The manufacturer does not
provide info on the LEDs, they just say to drive it from 5 volts. So I
will have to characterize this before I can use it in the same circuit
for equivalent brightness.

I have a candidate circuit that uses a few transistors and a few
passives. This is driven by a PWM output on the exisisting MCU. Most
of the circuit is there to prevent damage if the software goes south.
It is a bit Rube Goldberg and will take some work with a simulator and
lab bench to get working correctly. I'd rather use a chip if I can
find one that will do the job.

Otherwise, I have found one device from Intersil IIRC, but I don't have
a price on it yet so I don't know if it will meet my $1 goal for the
chip.

Anyone know of higher voltage buck switchers that can be used in this
application? I also need a switching PSU for about 200 mA, but they
dont' seem to exist. At these input voltages they are all either high
current requiring a larger inductor or are otherwise a poor choice
requiring diodes/too large/expensive. BTW, what is it with Linear Tech
requiring a couple of external diodes on so many of their switchers?
These diodes can double the size of a small switching design.

.

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