Key Features

-

Programmable PWM DC Motor Driver / Controller with

µP Interface (Three Wire Interface)

-

Programmable Functions and Parameters for Motor

Current, Voltage and Speed Regulation

-

Single Voltage Supply in the range

Vbat = 6.0 V to 30 V (Vbat,max = 40 V)

-

Total Power Efficiency up to 96 %

-

Low RF Emission within the whole frequency range due

to an integrated special EMC compliant driver

-

No EMC Filters required

-

Driver fulfils EMC Level 5 (CISPR 25)

-

Dynamically self-adjusting slew rate regulated switching

technology

-

Fully protected by programmable failure handling

procedures via µP

-

Fast Over Current and Over / Under Voltage Detection

and Protection, Battery Voltage Monitoring

-

External and On Chip Temperature Detection and

Protection

-

Motor Current and Speed Measurement with a shunt

resistor and capability of trimming the chip for an

external shunt value

-

LIN Bus Interface

-

Programmable Parameters:

• EMC compliant Driver Functions

• Over Current, Over / Under Voltage

Threshold Values

• Motor Failure Threshold Levels

• Motor Current Measurement Range

• Trimming for the current measurement shunt

• PWM Frequency, Charge Pump Monitor

-

Charge Pump to control high side drivers

-

Integrated 5 V Power Supply for external components

(µP, etc.)

-

Standby and Wake-up capability

-

Sleep / Wake-up Mode system controlled by the

µP and

the LIN Bus

-

SOIC 28 Package

General Description

The AS8444 is a complete and fully protected PWM DC

motor driver/controller, which could be implemented by

interfacing a low cost 8-bit

µP and a high-side N-channel

power FET switch.

It is an advanced PWM DC motor controller subsystem with

an excellent EMC behavior targeted especially for high

current automotive applications. The optimization of the

EMC behavior of the entire module without external

components makes it easier to implement in harsh

environments.

The programmability of parameters and functions allows the

adaptation of the AS8444 to a wide range of applications.

So the system can act either as a motor current or motor

speed or motor voltage regulator. Also a full diagnosis of

motor failures and power FET failures, over temperature

and over/under voltage can be formed by programmable

failure handling procedures using the motor characteristic

and the real time measured motor current, motor speed and

battery voltage.

To simplify the application of this motor regulator in

complex systems (e.g. automotive environment) the circuit

is endowed with a LIN bus interface.

There are two versions of this chip AS8444 and AS8446.

The only difference between the AS8444 and the AS8446 is

the start up behavior after system wake up or battery

connection.

Applications

-

Fan cooler

-

Air conditioning

-

Fuel pumps

-

Water and oil pumps

-

General purpose DC Motor Regulators

Typical Application Diagram

Vbat

M

TP

LIN

Vbat

VSS

Iref

VDDctrl

VDD

CP2

CP1

Vpump

OUT

CS

CMP

DATAout

CMN

FAIL

PWM

25

26

24

23

22

21

20

19

18

17

16

CLK

DATAin

Tx

Rx1

27

28

RESET

1

D1

Cbat

Tr1

CP12

CP0

VDD = 5 V

Rref

R

NTC

R

T1

M+

M-

GND_P

Power part

Control part

Bus

15

2

3

4

5

6

7

8

9

10

11

12

13

14

VMO

ADC

WD

µP

Q1

OSC1

OSC2

PWMout

VDD

GND

(optional)

Rx2

n.c.

CLK

(optional)

CS

INR

ANA

Port1

Port2

SPIout

SPIin

RESET

Tout

GND_P

VSS

AS 8444 / AS 8446

Programmable PWM DC Motor Driver / Controller

FEATURES