Datasheet

LTM9011-14/
LTM9010-14/LTM9009-14
24
9009101114fa
V
REF
1.25V
REFH
SENSE
TIE TO V
DD
FOR 2V RANGE;
TIE TO GND FOR 1V RANGE;
RANGE = 1.6 • V
SENSE
FOR
0.65V < V
SENSE
< 1.300V
REFL
0.1µF2.2µF
INTERNAL ADC
HIGH REFERENCE
BUFFER
9009101114 F08
LTM9011-14
5Ω
0.8x
DIFF AMP
INTERNAL ADC
LOW REFERENCE
1.25V BANDGAP
REFERENCE
0.625V
RANGE
DETECT
AND
CONTROL
1µF
0.1µF
0.1µF
0.1µF
applicaTions inForMaTion
Figure 8. Reference Circuit
Figure 9. Using an External 1.25V Reference
Reference
The LTM9011-14/LTM9010-14/LTM9009-14 has an inter-
nal 1.25V voltage reference. For a 2V input range using
the internal reference, connect SENSE to V
DD
. For a 1V
input range using the internal reference, connect SENSE
to ground. For a 2V input range with an external reference,
apply a 1.25V reference voltage to SENSE (Figure 9).
SENSE
1.25V
EXTERNAL
REFERENCE
1µF
9009101114 F09
LTM9011-14
The input range can be adjusted by applying a voltage to
SENSE that is between 0.625V and 1.30V. The input range
will then be 1.6 • V
SENSE
. The reference is shared by all
eight ADC channels, so it is not possible to independently
adjust the input range of individual channels.
The V
REF
, SENSE, REFH and REFL pins are internally
bypassed, as shown in Figure 8.