MAX13037 Datasheet, PDF (10/22 Pages) Maxim Integrated Products – Automotive Contact Monitor and Level Shifters with LDO Regulator

Automotive Contact Monitor and
Level Shifters with LDO Regulator
PIN
19
20
21
22
23
24
25
26
27
28
29
30
32
33
35, 36
—
Pin Description (continued)
NAME
SD
REGON
REGOFF
CS
SDO
SDI
CLK
RST
DO1
DO0
THRESH
WDI
BATREF
V_LO
BAT
EP
FUNCTION
Shutdown Input. Drive SD low to place the MAX13037/MAX13038 into shutdown mode and disable
the linear regulator. Drive SD high for normal operation. SD is compatible with voltages up to V_BAT.
Linear Regulator Enable Input (Active Low). Connect REGON to INT to enable a wake-up when a
switch status change is detected. Drive REGON using an open-drain logic output to control the
regulator directly. REGON is internally pulled up to an internal bias voltage of approximately +4.8V.
Linear Regulator Disable Input (Active Low). REGOFF is used in conjunction with REGON when the
internal regulator is enabled by an interrupt (see the Low-Dropout Linear Regulator (V_LO) section).
SPI Chip-Select Input. Drive CS low to enable the clocking of data into and out of the
MAX13037/MAX13038. SPI data is latched into the MAX13037/MAX13038 on the rising edge of CS.
SPI Serial-Data Output. SPI data is output on SDO on the rising edges of CLK while CS is held low.
SDO is three-state when CS is high.
SPI Serial-Data Input. SPI data is latched into the internal shift register on the falling edges of CLK
while CS is held low. SDI has an internal 100kΩ pulldown resistor.
SPI Serial-Clock Input
Reset Output. RST is an open-drain output that asserts low when V_LO is below the threshold
determined by the THRESH input. RST also asserts low when the watchdog times out.
Data Output Channel 1. DO1 is the level-shifted output of IN1 when WEND = 0.
Data Output Channel 0. DO0 is the level-shifted output of IN0 when WEND = 0.
Reset Threshold Level Input. Connect THRESH to a resistor divider between V_LO and GND to set the
reset reference level.
Watchdog Timer Input. The watchdog timer is reset at every transition on the WDI input.
Battery Reference Input. Switch thresholds are set to 50% of the voltage applied to BATREF. Connect
BATREF to the system’s battery supply voltage.
Linear Regulator Output. V_LO is the output of an internal linear regulator and is the reference voltage
for all digital I/O. Bypass V_LO with a 2.2µF or greater ceramic capacitor. Alternatively, a 10µF
electrolytic capacitor can be used in parallel with a 0.1µF ceramic capacitor.
Battery Supply Input. Connect BAT to a positive +6V to +26V battery supply voltage. Bypass BAT to
ground with a 0.1µF ceramic capacitor and a 10µF electrolytic capacitor placed as close as possible
to BAT.
Exposed Paddle. Connect EP to GND.
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