Datasheet

ADN8831 Data Sheet
Rev. A | Page 14 of 20
The sink current is set by the resistor connected from FREQ
(Pin 13) to ground. The sink current is calculated using the
following equation:
FREQ
SINK
R
I
V25.1
=
where:
I
SINC
is the sink current at VLIM (Pin 31).
R
FREQ
is the resistor connected at FREQ (Pin 13).
The cooling and heating limits are calculated using the
following equations:
B
A
BREF
COOLVLIM
RR
RV
V
+
×
=
,
B
ASINKCOOLVLIM
HEATVLIM
RRIVV ×−=
,
,
MAXIMUM TEC CURRENT LIMIT
To protect the TEC, separate maximum TEC current limits in
cooling and heating directions are set by applying a voltage at
ILIMC (Pin 1) and ILIMH (Pin 32). Maximum TEC currents
are calculated using the following equations:
SENSE
ILIMC
COOLMAXTEC
R
V
I
×
−
=
25
V25.1
,,
SENSE
ILIMH
HEATMAXTEC
R
V
I
×
−
=
25
V25.1
,,