33989 datasheet(20/66 Pages) FREESCALE

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Analog Integrated Circuit Device Data

Freescale Semiconductor

33989

FUNCTIONAL DEVICE OPERATION

OPERATIONAL MODES

FUNCTIONAL DEVICE OPERATION

DEVICE SUPPLY

The device is supplied from the battery line through the

VSUP pin. An external diode is required to protect against

negative transients and reverse battery. It can operate from

4.5 V and under the jump start condition at 27 Vdc. This pin

sustains standard automotive voltage conditions such as

load dump at 40 V. When VSUP falls below 3.0 V typical the

33989 detects it and stores the information into the SPI

all operation modes.

The device incorporates a battery early warning function,

providing a maskable interrupt when the VSUP voltage is

below 6.0 V typical. A hysteresis is included. Operation is

only in Normal and Standby modes. VSUP low is reported in

the Input/Output Register (IOR).

VDD1 VOLTAGE REGULATOR

The VDD1 Regulator is a 5.0 V output voltage with output

current capability up to 200 mA. It includes a voltage

monitoring circuitry associated with a reset function. The

VDD1 regulator is fully protected against overcurrent and

short-circuit. It has over- temperature detection warning flags

(bit VDDTEMP in MCR and interrupt registers), and

overtemperature shutdown with hysteresis.

V2 REGULATOR

V2 Regulator circuitry is designed to drive an external path

transistor increasing output current flexibility. Two pins are

used to achieve the flexibility. Those pins are V2 and V2

control. The output voltage is 5.0 V and is realized by a

tracking function of the VDD1 regulator. The recommended

ballast transistor is MJD32C. Other transistors can be used;

however, depending upon the PNP gain an external resistor-

capacitor network might be connected. The V2 is the supply

input for the CAN cell. The state of V2 is reported in the IOR

(bit V2LOW set to 1 if V2 is below 4.5 V typical).

HS1 VBAT SWITCH OUTPUT

The HS1 output is a 2.0

Ω typical switch from the VSUP

pin. It allows the supply of external switches and their

associated pull-up or pull down circuitry, in conjunction with

the wake-up input pins, for example. Output current is limited

to 200 mA and HS1 is protected against short-circuit and has

an overtemperature shutdown (bit HS1OT in IOR and bit

HS1OT-V2LOW in INT register). The HS1 output is controlled

from the internal register and the SPI. Because of an internal

timer, it can be activated at regular intervals in Sleep and

Stop modes. It can also be permanently turned on in Normal

or Standby modes to drive loads or supply peripheral

components. No internal clamping protection circuit is

implemented, thus a dedicated external protection circuit is

required in case of inductive load drive.

BATTERY FALL EARLY WARNING

Refer to the discussion under the heading: Device Supply.

INTERNAL CLOCK

The device has an internal clock used to generate all

timings (Reset, Watchdog, Cyclic Wake-up, Filtering Time,

etc.). Two oscillators are implemented. A high accuracy

(±12 percent) used in Normal Request, Normal and Standby

modes, and a low accuracy (±30 percent) used in Sleep and

Stop modes.

OPERATIONAL MODES

FUNCTIONAL MODES

The device has four primary operation modes:

1. Standby mode

2. Normal mode

3. Stop mode

4. Sleep mode

All modes are controlled by the SPI. An additional

temporary mode called Normal Request mode is

automatically accessed by the device after reset or wake-up

from Stop mode. A Reset (RST) mode is also implemented.

Special modes and configuration are possible for debug and

program MCU flash memory.

STANDBY MODE

Only regulator 1 is ON. Regulator 2 is turned OFF by

disabling the V2 control pin. Only the wake-up capability of

the CAN interface is available. Other functions available are

wake-up input reading through SPI and HS1 activation. The

Watchdog is running.

NORMAL MODE

In this mode both regulators are ON. This corresponds to

the normal application operation. All functions are available in

this mode (Watchdog, wake-up input reading through SPI,

HS1 activation, CAN communication). The software

Watchdog is running and must be periodically cleared

through SPI.

STOP MODE

Regulator 2 is turned OFF by disabling the V2 control pin.

The regulator 1 is activated in a special low power mode,

allowing to deliver few mA. The objective is to maintain the

MCU of the application supplied while it is turned into power

saving condition (i.e Stop or Wait modes). In Stop mode the

device supply current from VBAT is very low.

33989 Datasheet(PDF) 20 Page - Freescale Semiconductor, Inc

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