Datasheet MLX90719S Datasheet (MELEXIS)

MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 1

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 1 Rev 1.0 30/Jul/00

Featur es an d Be n efi ts

1µm CMOS technology MLX8 core with 8 accumulators, 80 b

y

tes RAM and 6K ROM

1 hi

g

h voltage input (detection of mains-active)

Zero-crossin

g

detection input to detect the 50/60Hz

7 standard inputs of which 2 can be used as comparator inputs and 2 can be confi

g

ured as open-collector o utp uts . 15 confi

g

urable LCD outputs (segment/backplane)

3 rela

y

drivers which can also be used to drive a triac or LED’s without the need for external resistors. Buzzer driver with pro

g

ramm able frequency

On-chip 4MHz oscillator, cr

y

stal oscillator and low power RC oscillator

Low power mo de

(

battery or decoupling capacitor)

Hi

g

h supply voltage eliminates the need for high power resistors

Batter

y

backup

On-chip watchdo

g

Applications

24 hour timer for cooker applications, coffee maker, ...

Ordering Information

Part No. Temperature Suffix Package version Temperature Range MLX90719 S LS -x 0C to 85C The c ustom er sp ecifi c ver sion c ode

(

defining the RO M conten t) is i ndi cat ed wit h 1 cha rac ter at th e en d of th e

orderin

g

number.

Description

The ASIC consists of a dedicated microcontroller combined with on-chip analo

g

and digital blocks,

which can be confi

g

ured to a great extend. This

makes it ideal to adapt it to different applications b

y

means of an update in the software. The number of external components for the electronic module is minimized. A t

y

pical application mainly consists of the MLX90719 ASIC, a number of command buttons, a LCD, a rela

y

, some LED’s and a buzzer. The number of buttons and their function can be freel

y

chosen. The configuration of the LCD, the number of backplanes and its pinout is also under software control. Three outputs are available for a rela

y

and LED’s.

Functional Diagram

MLX90719

LX11

Interrupt

controller

RAM

1 x comp

CounterWatchdo

g

XT1

XT2

IN 1-8

ZCD

VDD4

BAT VSS

LCD 1-15

OUT A,B,C

BUZ

17bit timer

Controller

125kHz

oscillator

4MHz

PLL

LC

oscillator

POR

8 x input

Vre

g

Xtal

LCD

Output

A, B, C

Buzzer

Zero

cross

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General description

The MLX90719 is an ASIC which is ideally suited for timing control application, low cost as well as high end, such as clocks in coffee machines, cookers, baking eq uipm ent,...

The ASIC consists of a dedicated microcontroller combined with on-chip analog and digital blocks, which can be configured to a great extend. This makes it ideal to adapt it to different applications by means of an update in the software. The number of external components for the electronic module is minimized. A typical application mainly consists of the MLX90719 ASIC, a number of command buttons, a LCD, a relay, some LED’s and a buzzer. The number of buttons and their function can be freely chosen. The configuration of the LCD, the number of backplanes and its pinout is also under soft war e contr ol. Thr ee out puts ar e avail able f or a relay and LED’s.

Main functions:

General-purpose timer chip based on the 8-bit LX11 core, including 80 bytes RAM and 6 Kbytes ROM. Programming of the ROM and selection of all other options is done with one mask. An interrupt controller guarantees exact timings and a clean refresh rate of the LCD. High supply voltage eliminates the need for high power resistors. 6 digital inputs and 2 I/O pins (function is under software control). 1 comparator (uses 2 of the digital inputs) which can be used for analog measurements. 3 hig h cur rent out put dri ver s. Th ey are s uita bl e for driving low cost 12V relays, but other types can also be used. They can also be used to drive triac or LED’s without the need for external resistors. 1 bu zzer ou t pu t fo r piezo el ec t r ic b u zzer s, w it h pr o grammable frequency. The LCD interface consists of 15 outputs, each of them can be con figured as backpl ane or segm ent driver. The time base for the clock function is derived either f r om t he m ains fr eq uen c y o r f r om a cr y st a l o s cillator. The clock frequency for the microcontroller, relay drivers and buzzer output is derived from an on chip oscillator, which is calibrated under software control. For applications that are disconnected from the mains for longer times, a battery backup can be foreseen, so that the module always keeps track of the time.

For short mains interruptions (up to 5 minutes), the energy in a decoupling capacitor can be used to keep track of the time. An on-chip watchdog ensures the functioning of the chip under all environmental conditions. The package size can be adapted to the number of used pins (non-used I/O’s do not need to be bonded).

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General purpos e timer

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MLX90719 Electrical Specifications

DC Operating Parameters T

A

= 0oC to 85

o

C, VDD = 60V (unless otherwise specified)

Parameter

Symbol

Test Conditions

Min Typ Max Units

Ambient temperature

Tamb

0

85 °C

Maximum chip temperature

Tic

150 °C Maximum allowed source

supply current

Idd4m

Drivers off = all the current flows in the chip

6 mA

Analog features

Power supply

The MLX90719 suppl

y

pin (VDD4) must be connected

b

y

external series resistor and rectifier diode to the

mains. An internal Zener function limits the volta

g

e at

VDD4 to 70-80V. For proper operation, a decouplin

g

capacitor needs to be connected between VDD4 and VSS

(

see figure 1).

90719

Vdd4

Vss

line

R1

R2

C

6k*

22uF*

*for information onl

y

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The MLX90719 has several internal supply lines for both analog and digital blocks:

Parameter

Symbol

Test Conditions

Min Typ Max Units

Voltage applied at the supply pin

Vdd4 Idd4 = 5mA

DRAINB = Vss

63 73 77 V

Internal buzzer driver supply

Vbuz Option OBZ3 active

20 V

Internal 11V supply

Vdd2 10 15 12 V

Internal 5V for main oscillator

Vdd1 4.5 5.0 5.5 V Internal 5V for digital

Vdd Normal mode

4.0 5.0 6.0 V Low power mode

2.7

LCD driver supply

Vlcd Option OLCD1 active

3.0 V

Option OLCD2 active

3.25 V

Option OLCD3 active

3.5 V

Option OLCD4 active

3.75 V

Option OLCD5 active

4 V

Option OLCD6 active

4.25 V

Option OLCD7 active

4.5 V

Option OLCD8 active

4.75 V

Option OLCD9 active

5 V

Option OLCD10 active

5.25 V

Option OLCD11 active

5.5 V

Option OLCD12 active

5.75 V

Option OLCD13 active

6 V

Option OLCD14 active

6.25 V

1Vlcd/3

Vlcd1

Of Vlcd

30 33 36 %

2Vlcd/3

Vlcd2

Of Vlcd

64 67 70 % Idd4 For Vdd4<Vaporl (LPM)

3

uA For Vdd4 = 73V

5 mA

Voltage of backup battery

Vbat

2.7 3 3.3 V Supply for external circuitry

Vext At Iext = 2mA

3.9 5 V

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Parameter

Symbol

Test Conditions

Min Typ Max Units

High level threshold

Vdporh

3.4 V Low level threshold

Vdporl

2.2

2.6 V Hysteresis

Vdphyst

0.3 V

Notes:

The power on reset does not reset the s

y

stem when en tering low power mode with battery (Vdporl<Vbat).

The power on reset resets the s

y

stem if the RAM data may be corrupt due to undervoltage (Vdporl>RAM data

retention volta

ge)

.

Analog Power-On Reset

The MLX90719 includes a high voltage power-on reset that watches on VDD3. This block has two outputs APORL and APORH: APORL = 1 when VDD3 > Vaporl APORH = 1 when VDD3 > Vaporh

(

see table 4)

The states of APORH and APORL define the operation mode of the chip

(

see s ecti ons “S leep m anager” and

“Interrupt controller”

)

.

In low power mode the analo

g

power on reset operates in strobe mode. It is only enabled a few microseconds at

each risin

g

edge of th e signal ASTR generated by the digital core.

When Vdd3 > Vapo r l the ci rcuit

g

oes out of strobe mode.

Parameter

Symbol

Test Conditions

Min Typ Max Units

High level threshold

Vaporh

65 V Low level threshold

Vaporl

50 V Hysteresis

Vaphyst

10 V Strobe frequency

Fastr Slow rate of Vdd3>200V/s

25 Hz

Low power mode (LPM)

In low power mode (when the mains hav e been dis connec ted from the application) all supply lin es ar e di s abled except VDD, which is

g

enera ted by a low co nsum ing regulator. The current is taken from the external decou-

plin

g

capa cit or of V DD4 or f rom a ba ck up ba tt ery connected to pin BAT. This depends on the type of applica-

tion defined b

y

the mask option OXBAT implem ented within the chip:

OXBAT = 1 for application with batter

y

and crystal.

OXBAT = 0 for applications without batter

y

or crystal.

LCD operating voltage

The LCD operating voltage can have14 different values and can be chosen by mask options.

Supply for external components

If the mask option OVEXT is set the MLX90719 can supply some external circuitry from the internal Vdd1 throu

g

h pin IN5B (which can not be used as input anymore).

Power On Reset

This module ensures a correct start of the MLX90719 logic. The reset si

g

nal (DPORB) rises when VDD>Vdporh and falls when VDD<Vdporl

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General purpos e timer

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Zero crossing detector

The MLX90719 includes a zero crossing detector on pin ZCD. This detector contains two comparators with hysteresis. The first comparator has negative thresholds and the second one has positive thresholds (see table 5). Outputs ZOUT1 and ZOUT2 of those comparators are changing as follows: ZOUT1 rises wh en Vmains>Vz1h ZOUT1 fal ls when Vmains<V z1l ZOUT2 rises wh en Vmains>Vz2h ZOUT2 fal ls when Vmains<V z2l

A mask option defines the levels of those thresholds. Low levels (+/- 5V, option OZCD = 0) are suitable for zero crossing detection and high levels (+/- 20V, option OZCD = 1) for frequency detection with a better noise immunity. A 1MΩ resistor must be connected between pin ZCD and the mains.

Parameter

Symbol

Test Conditions

Min Typ Max Units

High level threshold 1

Vz1h Rzcd = 1Mohm

-5 V Rzc d = 1Mohm, OZCD = 1

-5 V Low level threshold 1

Vz1l Rzcd = 1Mohm

-9 V Rzcd = 1Mohm, OZCD = 1

-29 V High level threshold 2

Vz2h Rzcd = 1Mohm

9 V

Rzcd = 1Mohm, OZCD = 1

29 V

Low level threshold 2

Vz2l Rzcd = 1Mohm

5 V

Rzcd = 1Mohm, OZCD = 1

5 V

External resistor

Rzcd Vline = 230VAC typical

0.8 1 1.2 Mohm

Low voltage inputs

The MLX90719 has 7 CMOS Schmitt trigger inputs with internal pull-up.

Note:

the input signals are inverted in the digital core so these inputs are active low. Signal ENINB (active at 0) enables the pull-up current flowing through external pad to VSS if the input is pushed to VSS. When ENINB=1 (input disabled), DINxB = 1. The programmer must enable inputs by setting bit ENIN of P7 at least 5us before reading the input port P3 (see section “I/O ports”). The debouncing of inputs must be done by software.

Parameter

Symbol

Test Conditions

Min Typ Max Units

Pull-up current

Ipu1 Input to Vss

40 70

100 uA Low level threshold

Vthinl

30 %Vdd

High level threshold

Vthinh

70 %Vdd

Hysteresis

Vhystin

5 %Vdd

Multipurpose inputs:

Inp uts 3 and 6 ca n be used al so as pul l-dow n output s: the pul l down tr ansis tors ar e turn ed on by sett ing bit s PD3 and PD6 of P6 (see section ”I/O ports”). Inputs 1, 2 and 4 are used by the on-chip comparator (see section “comparator”) Input 5 can be tur n ed into sup ply for external cir cuitry by mask option OVEXT (see “Power s u p pl y ”).

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High voltage input

The MLX90719 has an eighth input that can be used either as a standard input (as described above) or as an hi

g

h volt age input to detect the mains via an external resistor. The high voltage mode is enabled if mask option OIN7 is set. Output DIN7B of this detector is hi

g

h when Vmains>Vthinh2 and low when Vmains<Vthinl2.

Note:

si

g

nal DIN7B is inverted whiti n the digital core.

Parameter

Symbol

Test Conditions

Min Typ Max Units

Pull-down current

Ipd2 12 uA

Low level threshold

Vthinl2

Rin = 1Mohm

6.9 V

High level threshold

Vthinh2

Rin = 1Mohm

12.3 V

External resistor

Rin

0.8 1 1.2 Mohm

Main oscillator

The MLX90719 contains a 4Mhz on-chip oscillator. In low power mode this oscillator is turned off.

Parameter

Symbol

Test Conditions

Min Typ Max Units

Master frequency of the

main oscillator (signal

CKM)

Fckm

Over full temp. and supply range

2.4 4.0 5.6 MHz

Low power crystal oscillator

In case of applications with battery and crystal (OXBAT = 1) the MLX90719 uses a low power crystal osci ll ato r as time reference for both normal and low power mode. This oscillator re

q

uires a standard 32kHz crystal connected between pin XTAL1 and pin XTAL2.

No external capacitor is re

q

uired for proper operation.

Parameter

Symbol

Test Conditions

Min Typ Max Units

Master frequency of the

crystal oscillator

Fckx Over full temp. and supply range

32768

Hz

Note:

This oscillator is disabled if OXBAT = 0.

VDD

INxB

ENINB

DINxB

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Low power RC oscillator

In case of applications without battery or crystal (OXBAT = 0) the MLX90719 uses an on-chip low power RC oscillator to count time during a few minutes after the mains has been disconnected (low power mode).

Parameter

Symbol

Test Conditions

Min Typ Max Units

Master frequency of the

low power RC oscillator

Fckl Over full temp. and supply range

1.0 2.5 5 kHz

Notes:

As the CPU must calibrate it in normal mode, the low power oscillator is running continuously. The low power RC oscillator is disabled if OXBAT = 1.

LCD outputs

The MLX90719 has 15 configurable LCD outputs able to drive either a backplane or a segment by mask option: OLCDx = 0 => segment OLCDx = 1 => backplane The LCD voltages are defined according to bits LCDx and CKLCD written in P3 and P4 (see section “I/O ports”). With Vcdl1 and Vlcd2 being respectively 1/3Vlcd and 2/3Vlcd, the MLX90719 is suitable for LCD having 1, 2, 3 or 4 backplanes.

Parameter

Symbol

Test Conditions

Min Typ Max Units

Output impedance

Rolcd

All cases

20

kohm

OLCDx

LCDx

CKLCD

OUT 0 0 0 Vlcd1

0 0 1

Vlcd2

0 1 0

Vlcd 0 1 1 Vss 1 0 0 Vlcd2

1 0 1

Vlcd1

1 1 0

Vss 1 1 1 Vlcd

Relay drivers

The MLX90719 includes 3 pull-down power outputs A, B, and C able to drive relays, triacs or LED’s. The gates of the drivers are controlled respectively by signals POUTA, POUTB and POUTC generated by the digital core (see section “PWM generator”). Each driver has its source and its drain connected to a pad (DRAINx and SOURCEx) except driver C of which the source is connected to the ground. This allows a series connection of the drivers. In such a configuration the current flowing through the relay is used to feed the LED’s.

Internal current generator

In a ppli cati ons b ased on th e foll owi ng sc hemati c, w here t he LE D(‘ s) may have t o be dr iven when the r elay is off, an internal current peak generator can be activated to supply the LED’s through pin SourceA. This function is enabled by bit INTCUR of P5 (see section “I/O ports”). When INTCUR is set the current generator is activated like a relay by signal PINT at frequenc y Fpwm and at 14.3% duty c ycle (see “PWM generator”).

Note:

If the application has no relay, this feature allows the MLX90719 to drive 2 LED’s without any external

resistors.

MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 9

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Parameter

Symbol

Test Conditions

Min Typ Max Units

Ron of driver A

RonA

Source A pushed to VSS

10 30 W Ron of driver B

RonB

Source B pushed to VSS

10 30 W Ron of driver C

RonC

10 30 W

Voltage on pin DrainA

Vda 85 V

Voltage on pin DrainB

Vdb 85 V

Voltage on pin DrainC

Vdc 85 V

Voltage on pin SourceA

Vsa 8 V

Voltage on pin SourceB

Vsb 4 V

Rising edge duration, all

drivers

Tr

Load = 5k from VDD4 = 70V

1 us

Falling edge duration, all

drivers

Tf

Load = 5k from VDD4 = 70V

1 us

VDD4

90719

DrainA

SourceA

DrainB

SourceB

DrainC

RELAY

LED1

LED2

8V

Current

gen.

PINT

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Buzzer driver

The MLX90719 includes a piezo buzzer driver. The push-pull output stage of this driver operates at 15V. An internal resistor between the output pin and the pus h-pul l stage protects the chip against reverse piezo effect.

Parameter

Symbol

Test Conditions

Min Typ Max Units

Output impedance

Rob

100 300 600 ohm Maximum output frequency

Fbuzm

8 kHz

Comparator

The MLX90719 includes a multi-purpose comparator. Setting bit ECOMP of P3 (see section “I/O ports”) enables this comparator. Inputs IN1B and IN2B become respectively the positive and negative inputs of the comparator and IN4B becomes its output via a tri-state buffer.

To reduce the number of external components in applications using the comparator, a resistive bridge and a feed back resistor (both internal) can be connected on the positive input of the comparator by mask option OCOMP.

Notes:

Some logic in the digital core ensures that ENIN12B and ENIN4B = 1 when ECOMP = 1. When ECOMP = 0 the comparator output is fixed to “1”.

A programmable prescaler has been implemented to allow frequency measurement at the output of the comparator (line IN4B). The status of bits CM0 and CM1 of P3 define the prescale ratio as described in table 15:

electrical c haracteristic s of the compa r ator .

Parameter

Symbol

Test Conditions

Min Typ Max Units

Common mode range

Vcm 20 80 %Vdd

Offset

Vcoff -30 30 mV

CM1 CM0 Divide ratio

0 0

Prescaler bypassed

0 1

/16 1 0 /32 1 1 /64

MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 11

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Tri state

COMP

R

OCOMP

ECOMP

A

SA

CKM*

CTST*

(* reserved for test)

R

VDD

IN1B

ENIN12B

VDD

IN2B

ENIN12B

VDD

IN4B

ENIN4B

DIN1B

DIN4B

DIN2B

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Digital fe at ur es

I/O ports

The MLX90719 has 9 port addresses. Read and write instructions to the same address do not access to the same port:

Note: * = reserved for test.

Out Description

Msb Lsb

P0 Timer compare low

TCP7 TCP6 TCP5 TCP4 TCP3 TCP2 TCP1 TCP0 P1 Timer compare high

TCP15

TCP14

TCP13

TCP12

TCP11

TCP10

TCP9 TCP8 P2 Timer ctrl, comparator

CM1 CM0 ECOMP

TRST COUNT

EN24H

MUX1

MUX0

P3

LCD port

LCD8 LCD9 LCD10

LCD11

LCD12

LCD13

LCD14

LCD15

P4

LCD port

CKLCDB

LCD1 LCD2 LCD3 LCD4 LCD5 LCD6 LCD7 P5 Power outputs

Not used

INTCUR

PC1 PC0 PB1 PB0 PA1 PA0 P6 PWM frequency adjust

PD6 PD3 DIV5 DIV4 DIV3 DIV2 DIV1 DIV0 P7 IT control, sleep, wdog

PWD RSTWD

FLAG ENIN RFHIT

ETIMI ECLKI

ESUPI

P8

Sound, test

CTST*

DTST*

MTST*

LTST*

SOUND3

SOUND2

SOUND1

SOUND0

in Description

Msb Lsb

P0 Timer low

T7 T6 T5 T4 T3 T2 T1 T0 P1

Timer high

T15 T14 T13 T12 T11 T10 T9 T8 P2 Timer msb, test

BATB*

X* X* X* X* X* X*

T16 P3 Chip inputs

IN7 IN6 IN5 IN4 IN3 IN2 IN1 IN0 P4 Not used

X P5

Not used

X

P6 Not used

X

P7 IT handler, flag

ZCD 0 FLAG 0 0 PTIMI PCLKI

PSUPI

P8 Not used

X

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Sleep manager and watch dog

At power-on-reset the MLX90719 is in low power mode (PWD = 1). When VDD3 reaches 65V

(

APORH = 1) PWD is reset and the main oscillator starts. To ensure a correct start of

the analo

g

blocks, the CPU is kept in reset status for 215 mai n clock p ulses (typically 8.2ms).

Once the microcontroller is workin

g

a watchdog circ uitry wil l generate a system r eset i f the user pr ogram fails to

reset the watchdo

g

counter. The watchdog delay is given by:

Twd = 57344 x 1/Fckm

(

= 14ms if Fckm = 4MHz)

The watchdo

g

counter is reset each time a 1 is written on bit RSTWD of P7.

To distin

g

uis h a wake-up after pow er-on reset and a wak e-up after low power mode, one can read the status of

bit FLAG

(

read/write bit in P7). This will be 0 after power on reset and 1 after low power mode if FLAG has been

set durin

g

normal mode.

The low power mode is set b

y

bit PWD of P7. Since the main oscillator stops as soon as PWD = 1, setting bit

PWD must be the last instruction of the suppl

y

interrupt subroutine (see interrupt controller).

Debouncing

A debounce circuit eliminates positive spikes on line APORH to avoid unexpected wake-up due to disturbances. The debounce time

(

tdaporh) depends on OXBAT.

If OXBAT = 1 it derives from the cr

y

stal oscillator frequency and:

7.8ms < tdaporh < 11.7ms If OXBAT = 0 it derives from the low power RC oscillator fre

q

uency and:

3.2ms < tdaporl < 24ms

Timer

The MLX90719 includes a 17-bit timer preceded by a 15-bi t pr esc a l er . T h e clo c k of th e ti mer can b e ta k en fr om four different sources defined b

y

the bits MUX0 and MUX1 of P2:

The batter

y

and crystal option (OXBAT) defines which clock is connected to the prescaler input:

If OXBAT =1: the cr

y

stal oscillator output (CKX) drives the prescaler input

If OXBAT = 0: the low power RC oscillator output

(

CKL) drives the prescaler input.

Control bits

(P2)

:

EN24H = 1 enables the 24h mode

(

see below). COUNT = 1 enables the counter TRST = 1 resets the counter and the prescaler.

Normal operation

In normal mode the timer is used as a free-runnin

g

counter on CK125K. It can be read at any time without stop.

An interrupt is

g

enerated when the value of th e timer reaches the value of t he timer compare w r itt en in P1-P0.

Low power mode if crystal oscillator (OXBAT = 1)

In this mode the clock of the timer must be connected to the /2

15

output of the prescaler (1Hz).

Settin

g

the 24h mode turns the timer into a modulo 86400 counter if a correct value has been written in P1-P0.

The timer bein

g

automatically reset when T16=1 and T[15:0] = TCP[15:0], this value must be 517Fh to give T

MUX1

MUX0

Timer clock source

Description

0 0

CK125K

Main clock divided by 32 (typically 125kHz)

0 1

D2P15

/215 prescale output

1 0

D2P9

/29 prescale output

1 1

D2P3

/23 prescale output

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[16:0] = 86399. At wake-up the value of the timer is the number of seconds passed since the beginning of sleep. An arbitrary time of 0.5s should be added to this number to compensate the error of 0/- 1s due to the timer resolution.

Low power mode without crystal oscillator (OXBAT = 0)

In this mode the timer clock must be connected to the /2

9

output of the prescaler (about 5Hz).

At wake up a calibration of the low power oscillator can be done by connecting the timer clock to the /2

3

output of the prescaler and counting during 250ms (given by 25 half period of the mains at 50Hz and 30 half period at 60Hz). Those prescale ratios allow a calibration of the low power oscillator with only one 16-bit division if its frequency is in the range of 1-5kHz and if the maximum time to count is 5min.

Interrupt controller

The MLX8 core accepts only one interrupt source. The MLX90719 has 3 interrupt sources: Suppl y Clock reference (crystal oscillator or zero crossing detector) Timer These three hardware parts will interrupt the MLX8 core to address 21h (interrupt address). In order to recognize the interrupting device, an interrupt handler is readable at port P7 (bits PSUPI, PCLKI and PTIMI). In case of interrupt: PSUPI is set if the voltage on VDD3 has decreased under 50V (APORL=0) PCLKI is set if a clock reference pulse has occurred. PTIMI is set if the timer has reached the timer compare value (16-bit word in P0-P1).

Option OXBAT defines which source generates the clock reference interrupt:

Main program

IT

Read P7

PSUPI=1

PCLKI=1

PTIMI=1

Interrupt subroutine

....

Clear IT: set & reset ECLKI

Interrupt subroutine

....

SLEEP

Interrupt subroutine

....

Clear IT: set & reset ETIMI

Refresh IT controller : set & reset RFHIT

Y

N

Y

N

Y

N

At address 21h :

interrupt processing

MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 15

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 15 Rev 1.0 30/Jul/00

If OXBAT = 1 the clock interrupts are generated at the rate of 128Hz (Crystal frequency divided by 256). If OXBAT = 0 the clock interrupts are

g

enera ted at t he r ate o f t wi ce t he m ains fr equency by the zer o c ro ssi ng

detector

(

combination o f s ignals ZOUT1 and ZOUT2) that is 100Hz or 120Hz.

The main purpose of the timer interrupt is to rate the multiplexin

g

of th e LCD but it can b e used to c ontro l a

triac. Each interrupt can be enabled/disabled and cleared b

y

setting or resetting ESUPI, ECLKI and ETIMI in P7.

As several interrupts ma

y

occur at the same time a fourth control bit RFHIT (of P7) has been implemented to

refresh the interrupt controller after each interrupt subroutine. The flow chart shows the interrupt process:

Debouncing

A debounce circuit eliminates ne

g

ative spikes on line APORL to avoid unexpected supply interrupts due to dis-

turbances. The debounce time

(

tdaporl) depends on OXBAT.

If OXBAT = 1 it derives from the cr

y

stal oscillator frequency and:

7.8ms < tdaporl < 11.7ms If OXBAT = 0 it derives from the low power RC oscillator fre

q

uency and:

3.2ms < tdaporl < 24ms Both outputs of the zero crossin

g

detector are combined in a debounce circuit that genera tes a per io dic signal

risin

g

at each zero crossing of the mains without delay. This signal (ZCD) is connected to the interrupt handler

(

if OXBAT = 0) at bit PCLKI. The debounce period is typically 2ms but can vary from 0.6ms to 6ms becau se is it

g

enerated from the lo w power RC osc illa tor.

Zero crossing signal on P7

The zer o c ro s si n

g

signal is readable at bit ZCD of P7. This feature may be used to detect zero crossing in crys-

tal-based applications.

PWM generator

The t h r ee r el ay drivers of the MLX90719 can be driven independently at 0%, 14.3%, 28.6% and 100% duty cycle

(

except driver A which can not be driven at 100% duty).

Bits PA0 to PC1 of P5 set the dut

y cy

cle of ea c h dr i ver (signal s PO U TA , PO UT B a n d PO U TC) and bit INTCUR

activates the current peak

g

enerator (signal PINT):

Note: * = 0% for driver A t30 is

g

iven by: tclki < t30 < 2tclki

where tclki is the dela

y

between two clock interrupts:

tclki = 10ms if zero crossin

g

detector is used and Fmains = 50Hz

tclki = 8.33ms if zero crossin

g

detector is used and Fmains = 60Hz

tclki = 7.81ms if cr

y

stal oscillator is used

In all cases: 7.81ms < t30 < 15ms The PWM fre

q

uency is programmable. It depends on the main oscillator frequency and on the 6-bit divide ratio

written in P6:

INTCUR

Px1 Px0 Duty cycle of

POUTx

Duty cycle of

PINT X 0 0 0 % X 0 1

14.3 %

X 1 0 100 % *

X 1 1 28.6 % for t30 then

14.3%

0 X X

0 % 1 X X

14.3%

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 16 Rev 1.0 30/Jul/00

Fpwm = Fckm /(7 x DIV[6:0]) (= 22kHz for Fckm = 4MHz and DIV[6:0] = 26) As Fckm can vary, the divide ratio must be calculated periodically by software to reference Fpwm to the crystal

frequency or to the mains frequency.

Sound g enerator

The MLX90719 includes a sound generator able to produce more than 8 tonalities. The output frequency Fbuz is defin ed by bit s SOUND3 to SOUND0 of P3: Fbuz = (7 x Fpwm) / (8 x S) (see table 21)

Mask options

The following table lists all options of the MLX90719 chip:

SOUND3

SOUND2

SOUND1

SOUND0

S

Fbuz if Fpwm = 22kHz

0 0 0 0 -

Off 0 0 0 1 2 (9.62kHz)

0 0 1 0 3

6.42kHz

0 0 1 1 4

4.81kHz

0 1 0 0 5

3.85kHz

0 1 0 1 6

3.21kHz

0 1 1 0 7

2.75kHz

0 1 1 1 8

2.41kHz

1 0 0 0 9

2.14kHz

1 0 0 1 10

1.93kHz

1 0 1 0 11

(1.75kHz)

1 0 1 1 12

(1.60kHz)

1 1 0 0 13

(1.48kHz)

1 1 0 1 14

(1.38kHz)

1 1 1 0 15

(1.28kHz)

1 1 1 1 16

(1.20kHz)

MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 17

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 17 Rev 1.0 30/Jul/00

Name

Value = 0

Value = 1

Bit* OXBAT

No battery, no crystal

Battery + crystal

0

OVLCD1

Vlcd = 3V

1

OVLCD2

Vlcd = 3.25V

2

OVLCD3

Vlcd = 3.5V

3

OVLCD4

Vlcd = 3.75V

4

OVLCD5

Vlcd = 4V

5

OVLCD6

Vlcd = 4.25V

6

OVLCD7

Vlcd = 4.5V

7

OVLCD8

Vlcd = 4.75V

8

OVLCD9

Vlcd = 5V

9

OVLCD10

Vlcd = 5.25V

10

OVLCD11

Vlcd = 5.5V

11

OVLCD12

Vlcd = 5.75V

12

OVLCD13

Vlcd = 6V

13

OVLCD14

Vlcd = 6.25V

14

OVEXT

No external 5V supply

External 5V supply on IN5B

15

OZCD

Low thresholds

High thresholds

16

OIN7 Low voltage

High voltage

17

OCOMP

Bridge + feedback disabled

Bridge + feedback enabled

18

OLCD1

LCD1 = segment

LCD1 = backplane

19

OLCD2

LCD2 = segment

LCD2 = backplane

20

OLCD3

LCD3 = segment

LCD3 = backplane

21

OLCD4

LCD4 = segment

LCD4 = backplane

22

OLCD5

LCD5 = segment

LCD5 = backplane

23

OLCD6

LCD6 = segment

LCD6 = backplane

24

OLCD7

LCD7 = segment

LCD7 = backplane

25

OLCD8

LCD8 = segment

LCD8 = backplane

26

OLCD9

LCD9 = segment

LCD9 = backplane

27

OLCD10

LCD10 = segment

LCD10 = backplane

28

OLCD11

LCD11 = segment

LCD11 = backplane

29

OLCD12

LCD12 = segment

LCD12 = backplane

30

OLCD13

LCD13 = segment

LCD13 = backplane

31

OLCD14

LCD14 = segment

LCD14 = backplane

32

OLCD15

LCD15 = segment

LCD15 = backplane

33

* Only applicable for the dev elopment v ersion of t he MLX90719

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 18 Rev 1.0 30/Jul/00

Name

Num. (CCW)

Description

Options

LCD15

18

LCD14

19

LCD13

20

LCD12

21

LCD11

22

LCD10

23

LCD9

24

LCD8

25

LCD7

26

LCD6

27

LCD5

28

LCD4

29

LCD3

30

LCD2

31

LCD1

32

XTAL1

33

XTAL2

34

BAT 35 Battery pin

IN0B 36 Input 0

IN1B 1 Input 1

Comparator “+”

IN2B 2 Input 2

Comparator “

-“

IN3B 3 Input 3

BUZ 4 Buzzer output

VSS 5 Vss

DRAINC

6

Drain of driver C

SOURCEB

7

Source of driver B

DRAINB

8

Drain of driver B

Pinout

Package type: SSOP36

MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 19

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 19 Rev 1.0 30/Jul/00

Name

Num. (CCW)

Description

Options

SOURCEA

9

Source of driver A

DRAINA

10

Drain of driver A

VDD4

11

Supply pin

IN4B 12 Input 4

Comparator output

IN5B 13 Input 5

Vext IN6B 14 Input 6

IN7B 15 Input 7 (with high voltage

capability)

ZCD 16 Main frequency detector i

n-

put

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 20 Rev 1.0 30/Jul/00

Development board

Melexis has available a development kit which contains a evaluation circuit board, a ROM emulator, interface cables, all necessary software and a sample of the MLX90917 (development version). The evaluation board is a standard version that can be customized to an extended range of applications. The standard version includes a buzzer, a LCD, a relay and some breadboard space to build up the customized application. (push buttons, high-power outputs, temperature measurement, …) The available software consists of assembler, linker, simulator and the interface software for the ROM emulator. By using this emulator the user is able to see and modify all int ernal registers an d the R AM contents. On a break event, th e user program is replaced by a shad ow mon i tor, which exchanges data with the host.

For s oftw are devel opm ent a speci al ver sion of the MLX9 0917 is a vail able. Th is ver sion di ffers from th e standard MLX90917 in two ways. It has a second ring of pads around the normal chip. In this way the chip can be used with ext ernal m emory, which makes it also possible to use t he RO M emulato r . With t he dev elopment version it is also possible to program the different ‘mask’ options. The state of the different options should be written by the programmer in specific ROM bytes. During the initialization phase of the chip, a dedicated part in the soft wa re r eads t hi s byt es an d writ es t he cont ent s in s pec ifi c mem ory el em ent s, d efi nin g in th is wa y the c hosen options.

More information about the development board and software can be found in the specific documentation describing the MLX90719 Development Kit.

MLX902xx Name of Sensor Rev Y.X 22/Aug/98 Page 21

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 21 Rev 1.0 30/Jul/00

Application Example

MLX90719

LCD 13 LCD 12 LCD 11 LCD 10

LCD 9 LCD 8 LCD 7 LCD 6 LCD 5 LCD 4 LCD 3 LCD 2 LCD 1

LCD

13

BUZ

DC SB DB SA DA

Rela

y

IN0B IN1B IN2B IN3B IN4B IN5B IN6B IN7B

XTAL1 XTAL2

Thermal Switch

BAT

VDD4

VSS

MAINS

SW1 SW2 SW3

SW4

SW5

SW6

Pot.

Rref

Cap

Decouplin

g

Cap

MLX9 0719

General purpos e timer

MLX90719 General purpose timer Page 22 Rev 1.0 30/Jul/00