MAX9972
Quad, Ultra-Low-Power, 300Mbps ATE
Drivers/Comparators
18
Maxim Integrated
Comparators
The MAX9972 provides two independent high-speed
comparators for each channel. Each comparator has
one input connected internally to DUT_ and the other
input connected to either CHV_ or CLV_ (see Figure 1).
Comparator outputs are a logical result of the input
conditions, as indicated in Table 2.
The comparator output voltages are easily interfaced to a
wide variety of logic standards. Use buffered inputs
COMPHI and COMPLO to set the high and low output
voltages. For correct operation, COMPHI should be
greater than or equal to COMPLO. The comparator 50Ω
output impedance provides source termination (Figure 3).
Passive Load
The MAX9972 channels each feature a passive load
consisting of a buffered input voltage, LDV_, connected
to DUT_ through two resistive paths (Figure 1). Each
path connects to DUT_ individually by a switch con-
trolled through the serial interface. Programming
options include none (load disconnected), either, or
both paths connected. The loads facilitate fast
open/short testing in conjunction with the comparator,
and pullup of open-drain DUT_ outputs.
Parametric Switches
Each of the four MAX9972 channels provides force-
and-sense paths for connection of a PMU or other DC
resource to the device-under-test (Figure 1). Each
force-and-sense switch is independently controlled
though the serial interface providing maximum applica-
tion flexibility. PMU_ and DUT_ are provided on sepa-
rate pins allowing designs that do not require the
parametric switch feature to avoid the added capaci-
tance of PMU_. It also allows PMU_ to connect to DUT_
either directly or with an impedance-matching network.
Low-Leakage Mode, LLEAK
Asserting LLEAK through the serial port places the
MAX9972 into a very-low-leakage state (see the
Electrical Characteristics
table). This mode is conve-
nient for making IDDQ and PMU measurements without
the need for an output disconnect relay. LLEAK control
is independent for each channel.
When DUT_ is driven with a high-speed signal while
LLEAK is asserted, the leakage current momentarily
increases beyond the limits specified for normal opera-
tion. The low-leakage recovery specification in the
Electrical Characteristics
table indicates device behav-
ior under this condition.
Temperature Monitor
Each device supplies a single temperature output sig-
nal, TEMP, that asserts a nominal 3.43V output voltage
at a +70°C (343K) die temperature. The output voltage
increases proportionately with temperature at a rate of
10mV/°C. The temperature sensor output impedance is
500Ω, typical.
Table 2. Comparator Logic
