Datasheet

default (0x00) and the MAX13036 enters scan mode.
Note that SD is compatible with both V
L
and BAT voltage
levels. Having SD compatible to V
BAT
allows the
MAX13036 to retain the settings in the command register
as well as input monitoring even when V
L
is missing, pro-
vided that SD = V
BAT
. To reduce current consumption,
connect SD to BAT through a 470kΩ resistor. Having SD
compatible with V
L
has the advantage of reducing input
leakage current into SD when SD = V
L
.
Applications Information
Automotive Considerations
Reverse-Battery Tolerance
The BATREF and IN0–IN7 inputs withstand voltages
down to -45V without damage so that reverse battery is
not an issue. The BAT pin should be protected with a
reverse-battery diode as shown in the Typical
Application Circuit . The shutdown input (SD) can be
controlled from a battery-level source but should be
protected against reverse battery in the application.
Wetting Currents and Power Dissipation
It is important to consider the effects of wetting currents
on the power dissipated by the MAX13036. For example,
assume all inputs are configured for a continuous wetting
current of 25mA, all external switches have an on-resis-
tance of 1Ω and the battery voltage is 16V. If all switches
are simultaneously closed, the corresponding power dis-
sipated by the MAX13036 is (16V - (25mA x 1Ω)) x 25mA
x 8 = 3.12W; this is higher than the absolute maximum
power dissipation of 2759mW at T
A
= +70°C.
ESD Protection
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The IN7–IN0 inputs have extra protection against static
electricity. Maxim’s engineers have developed state-of-
the-art structures to protect these pins against ESD of
±8kV without damage.
Human Body Model
The MAX13036 IN7–IN0 pins are characterized for
±8kV ESD protection using the Human Body Model.
Figure 7a shows the Human Body Model and Figure 7b
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the device through a
1.5kΩ resistor.
MAX13036
Automotive Contact Monitor
and Level Shifter
______________________________________________________________________________________ 15
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
C
s
100pF
R
C
1MΩ R
D
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
Figure 7a. Human Body ESD Test Model
Chip Information
PROCESS: BiCMOS
I
P
100%
90%
36.8%
t
RL
TIME
t
DL
CURRENT WAVEFORM
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
I
r
10%
0
0
AMPERES
Figure 7b. Human Body Model Current Waveform