33972 datasheet(11/32 Pages) FREESCALE

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Analog Integrated Circuit Device Data

Freescale Semiconductor

33972

FUNCTIONAL DESCRIPTION

FUNCTIONAL PIN DESCRIPTION

WAKE-UP (WAKE)

The WAKE pin is an open-drain output and a wake-up

input. The pin is designed to control a power supply Enable

pin. In the Normal mode, the WAKE pin is LOW. In the Sleep

mode, the WAKE pin is HIGH. The WAKE pin has a pull-up to

the internal +5.0 V supply.

In Sleep mode with the WAKE pin HIGH, the falling edge

of WAKE will place the 33972 in Normal mode. In Sleep mode

with VDD applied, the INT pin must be HIGH for negative edge

of WAKE to wake up the device. If VDD is not applied to the

device in Sleep mode, INT does not affect WAKE operation.

BATTERY INPUT (VPWR)

The VPWR pin is battery input and Power-ON Reset to the

33972 IC. The VPWR pin requires external reverse battery

and transient protection. Maximum input voltage on VPWR is

50 V. All wetting, sustain, and internal logic current is

provided from the VPWR pin.

VOLTAGE DRAIN SUPPLY (VDD)

The VDD input pin is used to determine logic levels on the

microprocessor interface (SPI) pins. Current from VDD is

used to drive SO output and the pull-up current for CS and

INT

pins. VDD must be applied for wake-up from negative

edge of CS or INT.

GROUND (GND)

The GND pin provides ground for the IC as well as ground

for inputs programmed as switch-to-battery inputs.

PROGRAMMABLE SWITCHES (SP0:SP7)

The 33972 device has 8 switch inputs capable of being

programmed to read switch-to-ground or switch-to-battery

contacts. The input is compared with a 4.0 V reference.

When programmed to be switch-to-battery, voltages greater

than 4.0 V are considered closed. Voltages less than 4.0 V

are considered open. The opposite holds true when inputs

are programmed as switch-to-ground. Programming features

are defined in Table 6 through Table 11 in the Functional

Device Operation section of this datasheet beginning on

page 13. Voltages greater than the VPWR supply voltage will

source current through the SP inputs to the VPWR pin.

Transient battery voltages greater than 38/40 V must be

clamped by an external device.

SWITCH-TO-GROUND INPUTS (SG0:SG13)

The SGn pins are switch-to-ground inputs only. The input

is compared with a 4.0 V reference. Voltages greater than

4.0 V are considered open. Voltages less than 4.0 V are

considered closed. Programming features are defined in

Table 6 through Table 11 in the Functional Device Operation

section of this datasheet beginning on page 13. Voltages

greater than the VPWR supply voltage will source current

through the SG inputs to the VPWR pin. Transient battery

voltages greater than 40 V must be clamped by an external

device.

33972 Datasheet(PDF) 11 Page - Freescale Semiconductor, Inc

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