MAXIM MAX13037, MAX13038 User Manual

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 sam­pled 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 ground­connected 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 wet­ting 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 watch­dog 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.

Pin Configuration and Typical Application Circuit at end of data sheet.

SPI is a trademark of Motorola, Inc.

M A X13 037 ATX+ +5V

M A X13 038 ATX+ +3.3V

PART

LDO

OUTPUT

VO L T A G E

TEMP

RANGE

-40°C to
+125°C

-40°C to
+125°C

PIN-

PACKAGE

36 TQFN - E P *

( 6m m x

6m m )

36 TQFN - E P *

( 6m m x

6m m )

PKG

CODE

T3666-3

T3666-3

MAX13037/MAX13038

Automotive Contact Monitor and
Level Shifters with LDO Regulator

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

(All voltages referenced to GND, unless otherwise noted.)

ELECTRICAL CHARACTERISTICS

(BAT = +6V to +26V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at BAT = +14V, TA= +25°C.) (Note 2)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

VLO........................................................................-0.3V to +6.0V

BAT.........................................................................-0.3V to +42V

IN_ , BATREF...........................................................-45V to +45V

IN_ to BAT ...............................................................-45V to +45V

SD, REGON. ...........................................................-0.3V to +45V

HYST, WET, TD, TDEB, THRESH, OT, INT, RST......-0.3V to 6.0V

CS, CLK, SDI, SDO, WDI,

DO0, DO1, REGOFF.......................................-0.3V to (V

LO

+ 0.3V)

Continuous Current (CS, CLK, SDI, SDO, WDI, DO0,

DO1, REGOFF) .............................................................±20mA

Continuous Power Dissipation (T

A

= +70°C)

36-Pin TQFN (derate 35.7mW/°C above +70°C) .......2857mW

Junction-to-Case Thermal Resistance (

θ

JC

) (Note 1)

36-Pin TQFN .............................................................. 1.4°C/W

Junction-to-Ambient Thermal Resistance (

θ

JA

) (Note 1)

36-Pin TQFN ............................................................... 28°C/W

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a 4-layer

board. For detailed information on package thermal considerations see

www.maxim-ic.com/thermal-tutorial

.

POWER SUPPLY

BAT Supply Range V

BAT Supply Current with
Regulator On

BAT Supply Current with
Regulator Off

BAT Supply Current in Scan
Mode with Regulator On

BAT Supply Current in Scan
Mode with Regulator Off

BAT Supply Current in Shutdown
Mode

BATREF Input Resistance R

BATREF Input Leakage Current in
Shutdown

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

BAT

V

= +14V, continuous scan (SC2 = 1,

BAT

SC1 = 1, SC0 = 0), programmable

I

SUP_REG

I

SUP

I

SCAN_REG

I

SCAN

I

SHDN

BATREFVBATREF

I

L_BATREFVSD

hysteresis off (M0 = M1 = 1),
IN0–IN7 = unconnected, regulator on
(REGON = REGOFF = GND).

V

= +14V, continuous scan (SC2 = 1,

BAT

SC1 = 1, SC0 = 0), programmable
hysteresis off (M0 = M1 = 1),
IN0–IN7 = unconnected, regulator off
(REGON = BAT, REGOFF = GND).

= +14V, scan mode (SC0 = 0,

V

BAT

SC1 = 0, SC2 = 0), regulator on
(REGON = REGOFF = GND).

V

= +14V, scan mode (SC0 = 0,

BAT

SC1 = 0, SC2 = 0), regulator off
(REGON = BAT, REGOFF = GND).

VSD = 0V, V
REGON = BAT

BAT

= +14V 1 2.7 MΩ

= 0V, V

BATREF

= +14V,

= +14V 1 µA

TA = +25°C 3 5

T

= +125°C 4 7

A

626V

57 110 µA

46 80 µA

28 48 µA

17 35 µA

µA

MAX13037/MAX13038

Automotive Contact Monitor and

Level Shifters with LDO Regulator

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(BAT = +6V to +26V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at BAT = +14V, TA= +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SWITCH INPUTS (IN0–IN7)

R

= ∞ or programmable hysteresis

HYST

Input Voltage Threshold Center
(Note 3)

V

TH_C

disabled

R

= 90kΩ

HYST

R

= ∞ or programmable hysteresis

HYST

disabled

Input Voltage Threshold
Hysteresis (Note 4)

Switch-State Sense Resistor R

Wetting Current Rise/Fall Time
(Note 5)

IN0–IN7 Input Impedance in
Shutdown

V

TH_HYS

SENSE

I

WET_RISE_

FALL

WET

R

= 90kΩ

HYST

R

= 0Ω

HYST

R

= 61kΩ

WET

R

= 61kΩ 22

WET

R

= 30kΩ 28 40 51Wetting Current I

WET

R

= 330kΩ 7.5

WET

= 0V, VIN_ = +14V 5.5 8.5 MΩ

V

SD

Rise 6

Fall 1

ESD Protection IN0–IN7 Human Body Model (HBM) 8 kV

LOGIC-LEVELS (CS, CLK, SDI , SDI, DO0, DO1, INT, OT, RST, SD, REGON, REGOFF)

SDO, DO1, DO2
Output Voltage High

SDO, DO1, DO2
Output Voltage Low

INT, OT, RST Output Voltage Low V
SD Input Leakage Current I
SD, REGON Input Voltage Low V
SD, REGON Input Voltage High V
REGON Pullup Current I

REGON

CS, CLK, SDI, REGOFF, WDI

Input Voltage Low

CS, CLK, SDI, REGOFF, WDI
Input Voltage High

CS, CLK, WDI, REGOFF Input
Leakage Current

INT, OT, RST Leakage Current I

SDI Pulldown Resistor R

V

OH

V

OL

INTL

L_SD

IL_SD

IH_SD

V

V

I

IL

OL

SDI

Source current = 2mA 0.8 x V

Sink current = 4mA 0.2 x V

Sink current = 4mA 0.4 V

VSD = V

= +14V 1 µA

BAT

REGON = 0 0.4 1 3.0 µA

IL

IH

0.425 x
V

BATRE F

0.4 x

V

BATRE F

0.133 x
V

BATRE F

0. 26 x

V

BATRE F

0.5 x

V

BATREF

0.5 x

V

BATREF

0.166 x
V

BATREF

0.361 x
V

BATREF

0.575 x

V

BATRE F

0.63 x

V

BATRE F

0.22 x

V

BATRE F

0. 48 x

V

BATRE F

0.5 x

V

BATREF

11 16 22 kΩ

LO

LO

0.8 V

2.4 V

0.33 x V

LO

0.66 x V

LO

-1 +1 µA

-1 +1 µA

65 100 145 kΩ

V

V

µs

mA

V

V

V

V

MAX13037/MAX13038

Automotive Contact Monitor and
Level Shifters with LDO Regulator

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(BAT = +6V to +26V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at BAT = +14V, TA= +25°C.) (Note 2)

TIMING CHARACTERISTICS

(BAT = +6V to +26V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at BAT = +14V, TA= +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

LINEAR REGULATOR

Output Voltage V

Load Regulation LOAD _REG

Line Regulation LINE_REG V

LO

DROP

Output Current Limit I

Power-Supply Rejection Ratio PSRR

Start-Up Time t

RESET, WATCHDOG

Reset Reference Voltage V

THERMAL SHUTDOWN

Thermal Shutdown Temperature T

Thermal Shutdown Temperature
for Wetting Currents Only

Thermal Shutdown Hysteresis T

LIM

START

RST

SHDN

T

WARN

HYST

MAX13037, V

MAX13038, V

I

LOAD

= +14V

V

BAT

I

LOAD

= +14V

V

BAT

= +6V to +26V -0.9 +0.9 mV/V

BAT

VLO = +5V, ILO = 50mA (MAX13037) 330

VLO = +5V, ILO = 150mA (MAX13037) 1000Dropout Voltage V

VLO = +3.3V, ILO = 150mA (MAX13038) 1300

V

= +14V 150 mA

BAT

I

= 10mA, f = 100Hz, 500mV

LO

AC-coupled into V

THRESH from high to low 1.20 1.24 1.28 V

(Note 6) 165 °C

(Note 7) 135 °C

= 1mA to 50mA,

= 1mA to 150mA,

= +14V, I

BAT

= +14V, I

BAT

BAT

= 1mA 4.92 5.00 5.08

LOAD

= 1mA 3.234 3.300 3.366

LOAD

VLO = +5V
(MAX13037)

= +3.3V

V

LO

(MAX13038)

VLO = +5V
(MAX13037)

= +3.3V

V

LO

(MAX13038)

,

P-P

0.53 1

0.53 1

1 1.85

1 1.85

68 dB

1ms

15 °C

V

%

mV

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

V

= +6V 22 35

IN0 to DO0 Propagation Delay,
IN1 to DO1 Propagation Delay

CLK Frequency f
Falling Edge of CS to Rising

Edge of CLK
Required Setup Time

Falling Edge of CLK to Rising
Edge of CS
Required Setup Time

t

PROP

CLK

t

LEAD

t

LAG

BAT

V

= +14V 22

BAT

Input rise/fall time < 2ns 5 MHz

Input rise/fall time < 2ns, Figure 1 110 ns

Input rise/fall time < 2ns, Figure 1 50 ns

µs

MAX13037/MAX13038

Automotive Contact Monitor and

Level Shifters with LDO Regulator

_______________________________________________________________________________________ 5

TIMING CHARACTERISTICS (continued)

(BAT = +6V to +26V, TA= -40°C to +125°C, unless otherwise noted. Typical values are at BAT = +14V, TA= +25°C.) (Note 2)

)

)

Note 2: All units are 100% production tested at TA= 125°C. Limits over the operating temperature range are guaranteed by design and

not production tested.

Note 3: V

TH_C

= (V

TH_HIGH

+ V

TH_LOW

) / 2.

Note 4: V

TH_HYS

= (V

TH_HIGH

- V

TH_LOW

).

Note 5: Wetting current rise/fall time is measured as the time it takes to go from 20% to 80% of the maximum wetting current.
Note 6: T

SHDN

is the temperature at which the wetting currents and LDO are disabled.

Note 7: T

WARN

is the temperature at which only the wetting currents are disabled.

Note 8: When exiting SCAN mode to enter Normal Mode (through SPI) any input change is ignored for 500µs (typ) to allow correct

wake-up of input comparators. After this time elapses, the inputs are monitored in continuous mode.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SDI to Falling Edge of CLK
Required Setup Time

Falling Edge of CLK to SDI
Required Hold Time

Time from Falling Edge of CS to
SDO Low Impedance

Time from Rising Edge of CS to
SDO High Impedance

Time from Rising Edge of CLK to
SDO Data Valid

Debounce Time t

Scanning Time Pulse t

Scanning Time Period t

Wetting Time Pulse t

Time from Shutdown to Normal
Operation

Time from SCAN Mode to Normal
Operation

Reset Output Pulse Width t

Watchdog Timeout Period 1 t

Watchdog Timeout Period 2 t

Minimum Watchdog Timeout
Reset on WDI

t

SI(HOLD

t

t

SI(SU)

t

SO(EN)

SO(DIS

t

VALID

DEB

SCAN

SCAN-P

WETT

t

SD

t

SM

RST

WD1

WD2

t

WDI

Input rise/fall time < 2ns, Figure 1 30 ns

Input rise/fall time < 2ns, Figure 1 20 ns

Input rise/fall time < 2ns, Figure 1 55 ns

Figures 1 and 2 55 ns

C

=15pF, Figure 1 70 ms

SDO

C

= 500pF 3.18 5.9 9.42 ms

TDEB

C

= 10nF 63 120 188 ms

TDEB

130 250 400 µs

SC0 = 0, SC1 = 1, SC2 = 1 4 8 14 ms

WTOFF = 0 10 21 35 ms
SD low-to-high transition to input monitoring

enabled

(Note 8) 500 µs

CTD = 10nF (Figure 3) 10 21 36 ms

CTD = 10nF, time before INT goes low
(Figure 3)

CTD = 10nF, time before RST goes low
(Figure 3)

40 84 144 ms

300 ns

200 µs

2 x t

WD1

ms

MAX13037/MAX13038

Automotive Contact Monitor and
Level Shifters with LDO Regulator

6 _______________________________________________________________________________________

Figure 1. SPI Timing Characteristics

Figure 2. SDO Enable/Disable Test Circuit and Timing Diagram

Figure 3. Watchdog Interrupt/Reset Timing Diagram

CS

t

LEAD

CLK

t

SI(SU)tSI(HOLD)

SDI MSB IN

t

SO(EN)

SDO

MSB OUT LSB OUT

V

L

1kΩ

MAX13037/

MAX13038

SDOCS

15pF

SDO

t

LAG

t

SO(DIS)

t

SO(DIS)

VOL + 0.1V

L

t

VALID

CS

t

SO(EN)

1/3V

L

WDI

INT

RST

NORMAL OPERATION
(NO SWITCHES ACTIVE)

t

WD1

t

WD1

t

WD2

t

RST

MAX13037/MAX13038

Automotive Contact Monitor and

Level Shifters with LDO Regulator

_______________________________________________________________________________________

7

,

Typical Operating Characteristics

(BAT = +14V, SD = V

BAT

, R

WET

= 61kΩ, R

HYST

= 90kΩ, C

TDEB

= 4700pF, CTD= 4700pF, TA= +25°C, unless otherwise noted.)

WETTING CURRENT vs. V

30

20

10

0

-10

WETTING CURRENT (mA)

-20

-30

GND-CONNECTED SWITCH

BAT-CONNECTED SWITCH

626

BAT CURRENT vs. TEMPERATURE

110

100

90

80

70

60

(μA)

BAT

50

I

40

30

20

10

0

ADJUSTABLE HYSTERESIS ON

ADJUSTABLE HYSTERESIS OFF

-40 125-10-25 5 3520 50 8065 95 110

1410 18 22

V

(V)

BAT

(NORMAL MODE)

TEMPERATURE (°C)

BAT

MAX13037/8toc01

WETTING CURRENT (mA)

MAX13037/8toc04

(μA)

BAT

I

WETTING CURRENT vs. R

50

40

30

20

10

0

-10

-20

-30

-40

-50

GND-CONNECTED SWITCH

BAT-CONNECTED SWITCH

30 330

R

(kΩ)

WET

BAT CURRENT vs. TEMPERATURE

(NORMAL MODE)

8

SD = LOW

7

6

5

4

3

2

1

0

-40 125-25 95 11020-10 5 35 8050 65
TEMPERATURE (°C)

WET

WETTING CURRENT PULSE (NORMAL MODE

WTOFF = 0, WEN = WEND = 1)

V

IN_

MAX13037/8toc02

10V/div

INT

2V/div

I

IN_

20mA/div

280180 23013080

20ms/div

BAT CURRENT vs. TEMPERATURE

(SCANNING MODE)

45

LDO = ON

MAX13037/8toc05

40

35

(μA)

BAT

I

30

25

20

-40 12595 1105035205-10-25 8065

SCANNING PERIOD = 2ms

SCANNING PERIOD = 64ms

TEMPERATURE (°C)

MAX13037/8toc03

MAX13037/8toc06

(NORMAL MODE, WTOFF = WEN = WEND = 0)

TYPICAL IN0 DRIVING

f = 5kHz

V

IN0

5V/div

V

DO0

2V/div

40μs/div

MAX13037/8toc07

(NORMAL MODE, WTOFF = WEN = WEND = 0)

TYPICAL IN0 DRIVING

f = 100Hz
ADJUSTABLE HYSTERESIS OFF

V

IN0

5V/div

V

DO0

2V/div

2ms/div

MAX13037/8 toc08

HYSTERESIS (V)

8

HYSTERESIS vs. R

ADJUSTABLE HYSTERESIS ON

7

6

5

4

3

2

1

0

0 400 1000200 600 800

R

(kΩ)

HYST

HYST

MAX13037/8toc09