33099 datasheet(9/18 Pages) FREESCALE

9 / 18 page

Analog Integrated Circuit Device Data

Freescale Semiconductor

33099

TYPICAL APPLICATIONS

INTRODUCTION

TYPICAL APPLICATIONS

INTRODUCTION

The 33099 is an alternator voltage regulator designed with

internal level shifting resistors to control the voltage in a 12 V

automotive system that uses a three-phase alternator with a

rotating field winding. The system shown in Figure 4 includes

an alternator with its associated field coil, stator coils and

rectifiers, an automotive battery, a fault indicator lamp, an

ignition switch, a field flyback diode, and the 33099.

Figure 4. 33099 Simplified Application

The 12 V system voltage (VBAT) is connected to a

REMOTE input by a remote wire, which provides the IC

regulator with an external Kelvin connection directly to the

battery to provide REMOTE voltage, Vrem. The system

voltage at the BAT pin is also sensed by an internal Local IC

connection as Local voltage Vl. The Local connection is

provided in the event the remote wire or remote connection

becomes faulty such as being resistive, an open, or shorted

to ground.

The PHASE input is normally connected to a tap on one

corner of the alternator's stator winding, which provides an

AC phase voltage (Vph) for the IC to determine the rotational

frequency (fph) of the alternator rotor. Two frequency

comparators (F1 and F2) monitor voltage Vph to determine a

phase rotation detection frequency (f1) and a Low/High RPM

transition phase frequency (f2), respectively. A PHASE

FILTER pin is provided for externally providing a filter

capacitance for filtering phase input noise.

The regulated DC system set voltage (Vset) is achieved by

employing feedback to compare a ratioed value of Vset to an

internal IC bandgap voltage reference having a negative

temperature coefficient (TC). The GATE drive of an external

N-channel MOSFET is regulated by the IC to control the field

current in the alternator field coil as an alternating ON or OFF

state dependent on load current conditions affecting voltage

Vset. The external MOSFET receives GATE-to-source

voltage drive from between the GATE and SOURCE output

pins of the IC. The GATE-to-source voltage is a Pulse Width

Low

Pass

0.6 V

Over

Voltage

Detector

1.25 V

Bandgap

Reference

Regulator

VDD

Internal

V reg

and Bias

Current

Regulator

Charge

Pump

Regulator

Min Duty

Cycle

Generator

OR1

REMOTE

Local

Sense

PHASE

BATT

GATE

SOURCE

(5.0 V)

(2.0 V)

1.25 V

CB1

CB2

Css

VTssc

Vls

Ign

Delay

Circuit

Gate

Polling

Circuit

Local

4 LSB

4 MSB

8-Bit Counter

Digital

Duty Cycle

Generator

U/D

Counter

Control

Switch

Up/Down

MUX

1.25 V

DAC

1.25V

Battery

Polling

Lamp

Driver

Circuit

OR2

LCR1

LRC2

AGND

GND

LAMP

DRAIN

LAMP

GATE

IGN

Dtl

Logic

u/d

Drain

A/D Duty Cycle

Comparator

& Tracking

Circuit

Limit

Current

Detector

Limit

Thermal

Detector

Battery

ref

VTigm

Iign

VTdsc

(OTC)

Osc

101 kHz

LCR TEST

P16

P256

PHASE

FILTER

Circuit

Lamp

Polling

Circuit

Vrem

Vrs

Cph

Crs

Vhvl

Vfb

Cdc

Cuv

Cign

Cds

lpd

lpu

Vdac

33099 Datasheet(PDF) 9 Page - Freescale Semiconductor, Inc

33099 Datasheet(HTML) 9 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Datasheet Download

Link URL