33810 datasheet(17/35 Pages) FREESCALE

17 / 35 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

33810

FUNCTIONAL DEVICE OPERATION

OPERATIONAL MODES

the MAXI shutdown signal for GD0 and GD2 and the new

NOMI input pin receives the MAXI shutdown signal for GD1

and GD3. Further information on V10 Mode is provided in the

V10 Application section.

Note: RSN and RSP must be grounded in V10 Mode.

OVER/UNDER-VOLTAGE SHUTDOWN/RETRY BIT

The Over/Under-voltage Shutdown/Retry bit allows the

user to select the global over and under-voltage fault strategy

for all the outputs. In an over-voltage or under-voltage

condition on the VPWR pin, all outputs are commanded off.

The Over/Under-voltage control bit sets the operation of the

outputs when returning from over/under- voltage. Setting the

Over/Under-voltage bit to logic [1] will force all outputs to

remain OFF when VPWR returns to normal level. To turn the

output on again, the corresponding input pin or SPI bit must

be reactivated. Setting the Over/Under-voltage bit to logic [0]

will command all outputs to resume their previous state when

VPWR returns to normal level. Table 6 below provides the

output state when returning from over or under-voltage.

Table 6.

GINx DINx

Input Pin

SPI

Bit

Over/

Under-

voltage

Control

Bit

OUTEN

Input pin

State When

Returning From

Over/Under-voltage

OFF

* Default Setting

Over-voltage/Under-voltage Truth Table

Note: The SPI bit does not control the Gate Driver outputs in

the Ignition Mode, only in the GPGD Mode.

An under-voltage condition on VDD results in the global

shutdown of all outputs and reset of all internal control

registers. The VDD under-voltage threshold is between 0.8V

and 2.8V

PWMX ENABLE BIT

Gate Driver outputs programmed as General Purpose

Gate Drivers may be used as low frequency PWM outputs.

The PWM generators are enabled via bits 0 through 3 in the

Mode Select Command. Bits 0 through 3 correspond to

outputs GD0 through GD3 respectively. Once the frequency

and duty cycle are programmed through the PWM Frequency

& DC command, the PWM output may be turned ON and

OFF through the PWM enable bit. Further information on

PWM control is provided in the General Purpose Gate Driver

Mode section of this data sheet.

IGNITION (IGBT) GATE DRIVER MODE

The MC33810 contains dedicated circuitry necessary for

automotive ignition control systems. Each gate driver may be

individually configured as an Ignition Gate Driver with the

following features:

• Spark duration signal

• Open secondary timer

• Soft shutdown control

• Low-voltage flyback clamp

• Ignition ignition coil current measurement

• MAXI output and control

• NOMI output

• Maximum dwell timer

In the Ignition Mode, several control strategies are in place

to control the IGBT for enhanced system performance.

Information acquired from the FBx pin allows the device to

produce a spark duration signal output (SPKDUR) and detect

open secondary ignition coils. Based on the FBx signal and

Spark Command register settings, the device performs the

appropriate gate control (Low-voltage Flyback Clamp, Soft

Shutdown) and produces the SPKDUR output.

The FBx pin is connected to the collector of the IGBT

through an external 9:1 resistor divider network. The

recommended values for the resistor divider network is 36K

and 4.02K, with the 36K resistor connected from the IGBT

collector to the FBx pin and the 4.02K resistor connected

from the FBx pin to ground.

Additional controls to the gate driver are achieved by

sensing the current through the external IGBT. The Resistor

Sense Positive (RSP) and Resistor Sense Negative (RSN)

inputs are use to measure the voltage across an external

20 m

Ω or 40 mΩ current sense resistor. A gain select bit in

the Spark Command SPI Command messages should be set

to 1 (gain of 2) when using a 20 m

Ω current sense resistor.

When using a 40 m

Ω current sense resistor, the gain select

bit should be set to 0 (gain of 1 is the default value).

The ignition coil current is compared with the output of the

DACs which have been programmed via the SPI Commands.

The comparison generates the Nominal Current signal

(NOMI) and the Maximum Current signal (MAXI). Both

signals have a low output when the ignition coil current is

below the programmed DAC value and a high output when

the current is above the programmed DAC value.

When the GDx output is shutdown because of the control

strategy, the output may be activated again by toggling the

input control.

SPARK COMMAND

The Spark Command is an ignition mode command used

to program the parameters for the ignition mode features

listed below:

• End spark threshold (EndSparkTh bits)

• Open secondary fault timer (OSFLT bits)

33810 Datasheet(PDF) 17 Page - Freescale Semiconductor, Inc

33810 Datasheet(HTML) 17 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35

Datasheet Download

Link URL