General Description
The MAX13037/MAX13038 automotive contact monitor
and level shifters monitor and debounce eight remote
mechanical switches and assert an interrupt (INT) if a
switch changes state. The state of each switch is sam-
pled through an SPI™ interface by reading the status
register. Any switch can be prohibited from asserting an
interrupt by writing to the command register. Four of the
switch inputs are intended for ground-connected
switches (IN0–IN3) and the other four inputs (IN4–IN7)
are programmable in groups of two for either ground-
connected or battery-connected switches. Two switch
inputs (IN0, IN1) have direct level-shifted outputs (DO0,
DO1) to be used for PWM or other timing-based signals.
Switch input thresholds are set to 50% of the voltage
applied to BATREF. The threshold hysteresis is set by
connecting an external resistor from HYST to ground.
The MAX13037/MAX13038 supply an adjustable wet-
ting current to each closed switch to clean mechanical
switch contacts that are exposed to adverse conditions.
The MAX13037/MAX13038 feature a low dropout (LDO)
linear regulator capable of supplying up to 150mA of
current. The MAX13037 LDO has an output voltage of
+5V, whereas the MAX13038 has an output voltage of
+3.3V. The MAX13037/MAX13038 also feature a watch-
dog timer and an open-drain reset output with
adjustable timing.
The MAX13037/MAX13038 operate with a +6V to +26V
battery voltage applied to BAT. The MAX13037/
MAX13038 are available in a 6mm x 6mm, 36-pin TQFN
package and operate over the automotive -40°C to
+125°C temperature range.
Applications
Body Computers
Window Lifters
Seat Movers
Electric Sunroofs
Other Control ECUs
Features
o +6V to +26V Operating Voltage Range
o +42V Compatibility on BAT
o Switch Inputs Withstand Reverse Battery
o 150mA LDO, +5V (MAX13037) or +3.3V
(MAX13038)
o Ultra-Low Operating Current 28µA (typ) in 64ms
Scan Mode with LDO ON
o Resistor Adjustable Switching Hysteresis
o Watchdog and Reset
o Built-In Switch Debouncing
o Interrupt Output
o Immunity to Transients
o High Modularity
o Thermal Protection
o ±8kV HBM ESD Protection on IN0–IN7 Without
External Components
o Two Inputs (IN0, IN1) Programmable as Direct
Outputs
o Four Inputs (IN4–IN7) Programmable for BAT or
GND Related Switches
MAX13037/MAX13038
Automotive Contact Monitor and
Level Shifters with LDO Regulator
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
19-1084; Rev 0; 11/07
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
+
Denotes a lead-free package.
*
EP = Exposed paddle.
