9TCS1085BNLG Datasheet 9TCS1085BNLG, 9TCS1085BNLG8 | P28-P30

9TCS1085

MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR, & PWM FAN CONTROLLER FOR PORTABLE DEVICES

IDT®

MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR, & PWM FAN CONTROLLER FOR PORTABLE DEVICES 28

9TCS1085 REV 0.7 012012

(2) Critical Thermal Warning Temperature Hysteresis

(default 4°C)

Critical Thermal Warning Status

When a critical warning is activated, a status indicator bit is

also set. Register byte[14], bit[2] will be set when the critical

event happens.

Critical Thermal Warning THERM# Pin

The critical thermal warnings are sent to the THERM# pin

and requires a system register write to byte[15], bit[7] to

reset. This fault clear I2C write will also clear the

temperature threshold alerts

Active/Standby Mode

The thermal sensor has two modes in the temperature

conversion process:

(1) Active mode – In this mode the ADC will have a

selectable conversion rate for the temperature sensing.

(2) Standby mode – The system will command via I2C the

9TCS1085 to sample the temperature sensors. Once the

temperature reading from the ADC is updated, the

temperature sensor will be on stand-by awaiting the next

system request.

is in active or standby mode.

The conversion rate programmable register detail is as

follows:

* Valid when only one temperature sensor channel is used.

** Valid when the number of temperature sensor channel is

less than three.

The thermal sensor architecture has dynamic averaging to

smooth out the temperature conversion readings. To select

the number of temperature reading averages requires the

dynamic averaging function to be enabled, register byte[15],

bit[5]. The number of averages is then selected as follows:

Byte[12], Bit[4:0] Temperature

Bit[4] 16°C

Bit[3] 8°C

Bit[2] (default) 4°C

Bit[1] 2°C

Bit[0] 1°C

Byte[17], Bit[4:1] Conversion Rate

[0000] 16/sec *

[0001] 8/sec **

[0010] (default) 4/sec

[0011] 2/sec

[0100] 1/sec

[0101] 1/2 sec

[0110] 1/4 sec

[0111] 1/8 sec

[1000] 1/16 sec

[1001] 1/32 sec

[1010] 1/64 sec

Byte[6], Bit[1:0] Average the ADC Temperature

[00] 1

[01] 4

[10] 8

[11] 16

9TCS1085

MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR, & PWM FAN CONTROLLER FOR PORTABLE DEVICES

IDT®

MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR, & PWM FAN CONTROLLER FOR PORTABLE DEVICES 29

9TCS1085 REV 0.7 012012

Fan Controller

Fan Controller Description

The fan driver for the 9TCS1085 controls a 4-wire, 12V or

5V, multiple pole DC fan. The fan controller has three

modes of operation: (1) Direct drive, (2) Thermal trigger, and

(3) Dynamic PWM. All modes have register

programmability for the user to set the desired fan speed

and necessary parameters. The controller is also capable

of detecting stalled fans and upon detection will set the

appropriate alerts. The 9TCS1085 also has user

configuration registers to adjust both the ramp-rate and the

spin-up routine to accommodate different fan start up

requirements.

The fan controller uses the input from the external diode

connections. The 9TCS1085 fan controller can be set to run

a user specified fan speed. In this mode the tachometer

signal from the fan will be ignored. In thermal trigger mode,

the user specifies the temperature thresholds, the

temperature threshold hysteresis, and the corresponding

fan speed (fan tachometer target) for the different

temperature zones defined by the thresholds. The

controller will then run the fan at the specified fixed fan

speed settings depending on the temperature from the

sensors. In dynamic PWM mode, the fan controller will

adjust the PWM duty cycle to maintain the system defined

fan speed. In this mode, the system reads a temperature

sensor and the corresponding fan speed, tachometer

reading. The system will then determine and update the

9TCS1085 directly by writing the accessible registers byte

32 and byte 33. 9TCS1085 will then adjust the PWM to

achieve the desired system fan speed.

The PWM has ten bits of duty cycle resolution with a 25kHz

frequency. The PWM frequency is selectable between 22,

25, and 27kHz.

The 9TCS1085 includes hardware programmable

temperature limits and dedicated system shutdown output

for thermal protection.

Fan Controller System Diagram (Schematic

Example)

Fan Selection Detail

The 9TCS1085 fan controller will control 5V - 12V Brushless

DC fans. The fans need to be 4-wire fans and can have one

to four poles. The number of fan poles is specified in

Modes of Operation

The 9TCS1085 fan controller has three user selectable

methods to control the fan speed. The default fan speed

control mode is Thermal Trigger mode. The modes are

selected by writing the I2C register byte[24], bit[7:6] as

follows:

The PWM frequency can be set by writing register byte[24],

bit[5:4] as follows:

Byte[24], Bit[3:2] Fan Poles

[00] 1

[01] (default) 2

[10] 3

[11] 4

Fan Controller Modes Byte[24], Bit[7:6]

Direct Drive [00]

Thermal Trigger [01]

Dynamic PWM (default) [10]

PWM

Frequency

Duty Cycle

Resolution [# bits]

Byte[24],

Bit[5:4]

25kHz (default) 10 00

22kHz 11 01

27kHz 9 10

IDT

Mobile Access

9TCS1085

PWM

TACH

VCC

PWM

TACH

GND

5V/12V 4-wire FAN

5V/12V5V/12V

10K

3.3V/5V

10K

4.7K

9TCS1085

MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR, & PWM FAN CONTROLLER FOR PORTABLE DEVICES

IDT®

MOBILE ACCESS™—CLOCK SYNTHESIZER, TEMPERATURE SENSOR, & PWM FAN CONTROLLER FOR PORTABLE DEVICES 30

9TCS1085 REV 0.7 012012

Direct Drive Mode

In Direct Drive Mode, the fan speed is directly controlled by

setting a fixed PWM duty cycle. After a proper fan speed

spin-up, the tachometer signal will be ignored and the

9TCS1085 will output the fixed programmed PWM duty

cycle to the fan.

To operate in direct drive mode, Register byte[24], bit[7:6] =

[00].

The duty cycle is selectable through registers by writing

byte[26], bit[7:0] and byte[27], bit[7:5] as follows:

It is important to also set the required fan spin-up specifics

for proper use. The 9TCS1085 after completion of the fan

spin-up routine will then put out the correct programmed

PWM duty cycle.

Thermal Trigger Mode

In this mode the 9TCS1085 fan speed controller is

programmed to run at different fan speeds. The 9TCS1085

will monitor the fan tachometer and depending on the

temperature from a thermal sensor diode and the

pre-programmed temperature settings, the 9TCS1085 will

adjust the fan speed to the targeted tachometer settings.

thermal trigger mode.

Temperature Sensor

The temperature can be set to read from the external

thermal sensors; it is selected by byte33b[1:0]=00.

FAN_CH_SEL - byte[33], bit[1:0]

Tachometer Update

The tachometer reading can be updated at a rate of

700msec up to 100msecs. Tachometer Update Time,

byte[27], bit[4:2]

Byte[26], Bit[7:0] Logic "1", Selects Duty Cycle

Bit[7] 1

Bit[6] 1/2

Bit[5] 1/4

Bit[4] 1/8

Bit[3] 1/16

Bit[2] 1/32

Bit[1] 1/64

Bit[0] 1/128

Byte[27], Bit[7:5] Logic "1", Selects Duty Cycle

Bit[7] 1/256

Bit[6] 1/512

Bit[5] 1/1024

Byte[33], bit[1:0] Temperature Sensor

Enable/Disable

[00] 00=ON, 01~11=disable

Byte[27], bit[4:2] Tachometer Update Time

[000] 100 msec

[001] 200 msec

[010] 300 msec

[011] (default) 400 msec

[100] 500 msec

[101] 600 msec

[110] 700 msec

[111] 800 msec

P1-P3 P4-P6 P7-P9 P10-P12 P13-P15 P16-P18 P19-P21 P22-P24 P25-P27 P28-P30 P31-P33 P34-P36 P37-P38

9TCS1085BNLG

Mfr. #:

Buy 9TCS1085BNLG

Manufacturer:

IDT

Description:

Clock Synthesizer / Jitter Cleaner PLL THERMAL SENSOR AND FAN CONTROLLER

Lifecycle:

New from this manufacturer.

Delivery:

DHL FedEx Ups TNT EMS

Payment:

T/T Paypal Visa MoneyGram Western Union

9TCS1085BNLG

9TCS1085BNLG

Products related to this Datasheet