Datasheet

ADATE207
Rev. 0 | Page 17 of 36
TEMPERATURE DIODE
ADATE207
100µA
TDIODE
TEMPERATURE DIODE
FORCE I, MEASURE V
05557-017
Figure 12. Block Diagram of Temperature Diode
740
600
0
TEMPERATURE (°C)
POTENTIAL (mV)
120
720
700
680
660
640
620
20 40 60 80 100
05557-018
Figure 13. Characteristic of Temperature Diode
The block diagram of the temperature diode is shown in Figure 12,
and its Output Voltage V
S
temperature characteristic is shown
in
Figure 13. Note in Figure 12 that 100 μA is forced into the diode.
HIGH SPEED DIFFERENTIAL DCL INTERFACE
The ADATE207 uses a differential interface for connections to
the DCL. The comparator inputs have on-chip 50 Ω resistors for
termination, configured to support either 50 Ω parallel termi-
nation or 100 Ω differential termination. The comparator inputs
are compatible with LVPECL, LVDS, and most CML outputs.
For PECL termination, connect the termination pin to V
CC
− 2.0 V
or to an appropriate resistor to ground. For LVDS termination,
do not connect the termination pin. For CML termination,
either do not connect the termination pin or connect the
termination pin to an appropriate supply.
50
COMP_CH0_P
COMP_CH0_T
COMP_CH0_N
50
DIFFERENTIAL LVPECL INPUT
05557-006
Figure 14. Differential Input with Termination Resistors
8mA
ADATE207
VOP
VON
50
50
EXTERNAL
TERMINATION
REQUIRED
ESD
ESD
05557-019
Figure 15. Differential Open Drain Output
The driver outputs are differential open-drain outputs. The
outputs require termination through an external resistor to a
positive supply and can be configured to be compatible with
most PECL, and CML inputs.
Their output currents can be programmed with a bias resistor to
ground on the REF_1K pin. If the REF_1K pin is left open
(>100 kΩ) then the drive current is a nominal 8 mA. If a
resistor is tied from REF_1K to ground, then the drive current
is adjustable with the resistance value. A 1 kΩ resistor yields a
nominal 8 mA output current swing. Less resistance results in
greater current. The relationship of drive current to resistance is
given approximately by
Drive_Current = 8 V/R
EXT
Best practice suggests limiting the external resistance value
between 800 Ω and 2500 Ω.