F75385M

F75385M ±1oC Accuracy Temperature Sensor IC Datasheet Release Date: July, 2006 Revision: V0.21P F75385 F75385 Datasheet Revision History Version 0.20P 0.21P Date March, 2006 July, 2006 Page 10 Original Release Version Revision History Modify VT1/VT2 High Limit and VT1 THERM Limit Default Value. Original (64h) New (55h) Please note that all data and specifications are subject to change without notice. All the trade marks of products and companies mentioned in this data sheet belong to their respective owners. LIFE SUPPORT APPLICATIONS These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Fintek for any damages resulting from such improper use or sales. F75385 -I- July, 2006 F75385 Table of Contents 1. 2. 3. 4. 5. 6. General Description................................................................................................................. 1 Features .................................................................................................................................. 1 Key Specifications ................................................................................................................... 2 Pin Configuration ..................................................................................................................... 2 Pin Descriptions ...................................................................................................................... 2 Functional Description ............................................................................................................. 3 6.1 General Description.......................................................................................................... 3 6.2 The warning message ...................................................................................................... 3 6.3 Access Interface............................................................................................................... 3 6.4 Temperature Monitoring ..................................................................................................... 4 6.5 Alert#................................................................................................................................ 5 6.5 THERM# ............................................................................................................................ 5 6.6 ADC Conversion Sequence ............................................................................................... 6 6.7 Thermal Mass and Self Heating......................................................................................... 6 6.8 ADC Noise Filtering ........................................................................................................... 6 6.9 PCB Layout Guide ............................................................................................................. 6 7. Registers Description .............................................................................................................. 8 7.1 Configuration Register  Index 03h(Read), 09h(Write)................................................... 8 7.2 Status Register  Index 02h .............................................................................................. 8 7.3 Conversion Rate Register  Index 04h(Read), 0Ah(Write)................................................ 8 7.4 One-Shot Register  Index 0Fh......................................................................................... 9 7.5 Alert Queue & Timeout Register  Index 22h .................................................................... 9 7.6 Status-with-ARA Control Register  Index 24h ............................................................... 9 7.7 Chip ID I Register  Index 5Ah........................................................................................ 10 7.8 Chip ID II Register  Index 5Bh....................................................................................... 10 7.9 Vendor ID I (Manufacturer ID) Register  Index 5Dh....................................................... 10 7.10 Vendor ID I (Manufacturer ID) Register  Index 5Eh ..................................................... 10 7.11 Vendor ID II (Manufacturer ID) Register  Index FEh .................................................... 10 7.12 Value RAM  Index 10h- 2Fh ........................................................................................ 10 8. Electrical characteristic.......................................................................................................... 12 8.1 Absolute Maximum Ratings .............................................................................................. 12 8.2 DC Characteristics ............................................................................................................ 12 8.3 AC Characteristics ............................................................................................................ 13 9. Ordering Information ............................................................................................................. 13 10. Package Dimensions (8 MSOP)............................................................................................ 14 F75385 -II- July, 2006 1. General Description The F75385 is a temperature sensor IC with alert signal which is specific designed for notebook, graphic cards etc. An 11-bit analog-to-digital converter (ADC) was built inside F75385. The F75385 can monitor two set of temperature which is very important for the system to work stably and properly. This chip provides 1 remote temperature sensor and 1 local temperature sensor. The remote temperature sensor can be performed by CPU thermal diode or transistor 2N3906. The users can set up the upper and lower limits (alarm thresholds) of all monitored parameters and this chip can also issue warning messages for system protection when there is something wrong with monitored items. Through the BIOS or application software, the users can read all the monitored parameters of system all the time. And a pop-up warning can be also activated when the monitored item was out of the proper/pre-setting range. The application software could be Fintek's application utility, or other management application software. The F75385 is in the package of 8-pin MSOP and powered by 3.3V. 2. Features Provide 1 on-chip local and 1 remote temperature sensing ±1 oC accuarcy on remote channel and ±3 oC accuarcy on local channel ±1 oC (+60 oC to +100 oC, remote) ±3 oC (+60 oC to +100 oC, local) ALERT# output for SMBus alert THERM# output for over temperature alert or for system shut down Programmable THERM# limits and THERM# hysteresis Programmable alert queue Programmable limited and setting points(alert threshold) for all monitored items 2 wire SMBus interface 3VCC operation and in 8-MSOP package The SMBus slave address: A6 F75385 1 A5 0 A4 0 A3 1 A2 1 A1 0 A0 0 --Patented: TW 235231-- -1- July 2006 V0.21P 3. Key Specifications Supply Voltage Supply Current Measured Range Remote Diode Temperature Accuracy Local Temperature Accuracy 3.0~3.6V 180 uA (typ) 0 ~ 145 oC ±1oC from +60oC to +100oC ±3oC from +60oC to +100oC 4. Pin Configuration VCC D+ DTHERM# 1 2 3 4 8 SCL SDA ALERT# GND F75382 F75385M 7 6 5 5. OD12 PWR INts AIN Pin Descriptions - Open-drain output pin with 12 mA sink capability - Power pin - TTL level input pin and schmitt trigger - Input pin(Analog) PIN NO 1 2 3 PIN NAME VCC D+ D- TYPE PWR 3VCC 3VCC 3VCC Power Pin DESCRIPTION PWR AIN AIN Positive connection to remote temperature sensor (ex: thermal diode anode) Negative connection to remote temperature sensor(ex: thermal diode cathode) 4 THERM# OD12 3VCC Active LOW output. This pin will be logic low when the temperature exceeds its limit. (Default 108 C enable) o 5 6 7 8 GND ALERT# SDA SCL PWR OD12 3VCC 3VCC 3VCC 3VCC Ground Active LOW output. Used as SMBus alert or Interrupt Serial bus data Serial bus clock INts/OD12 INt s -2- July 2006 V0.21P 6. Functional Description 6.1 General Description The F75385 is a simple temperature sensor with warning signal output. It includes a local and a remote temperature sensor. Both measured temperature are compared with its high, low and THERM limits which are stored in the registers. When one or more out-of-limit events occur, the flags in Status Register will be set and that may cause ALERT output to low. Also, measured temperature exceeding THERM limit may cause THERM output to low. 6.2 The warning message Pin4 and pin6 act as warning message when the temperature exceeds it threshold point. 6.3 Access Interface The F75385 can be connected to a compatible 2-wire serial system management bus as a slave device under the control of the master device, using two device terminals SCL and SDA. The F75385 supports SMBus protocol of, “Write Byte”, “Read Byte”, both with or without Packet Error checking(PEC) which is calculated using CRC-8. For detail information about PEC, please check SMBus 1.1 specification. F75385 supports 25ms timeout for no activity on the SMBus. This timeout function is programmed at 22h bit7 and default is disabled. F75385 also supports Alert Response Address (ARA) protocol. The operation of the protocol is described with details in the following sections. (a) SMBus write to internal address register followed by the data byte 0 SCL SDA Start By Master 7 8 0 7 8 1 0 0 1 1 0 0 R/W Ack by 382 D7 D6 D5 D4 D3 D2 D1 D0 Ack by 382 Frame 1 Serial Bus Address Byte 0 Frame 2 Internal Index Register Byte 7 SCL (Continued) SDA (Continued) D7 D6 D5 D4 D3 D2 D1 D0 8 Stop by Master Frame 3 Data Byte Figure 1. Serial Bus Write to Internal Address Register followed by the Data Byte -3- July 2006 V0.21P (b) Serial bus write to internal address register only 0 SCL SDA Start By Master 7 8 0 7 8 1 0 0 1 1 0 0 R/W Ack by 382 D7 D6 D5 D4 D3 D2 D1 D0 Ack by 382 Stop by Master Frame 1 Serial Bus Address Byte 0 Frame 2 Internal Index Register Byte Figure 2. Serial Bus Write to Internal Address Register Only (c) Serial bus read from a register with the internal address register prefer to desired location 0 SCL SDA Start By Master 7 8 0 7 8 1 0 0 1 1 0 0 R/W Ack by 382 D7 D6 D5 D4 D3 D2 D1 D0 Ack by Master Stop by Master Frame 1 Serial Bus Address Byte 0 Frame 2 Internal Index Register Byte Figure 3. Serial Bus Read from Internal Address Register (d) Alert Response Address 0 SCL SDA Start By Master 7 8 0 7 8 0 0 0 1 1 0 0 R/W Ack by 382 0 1 0 0 1 1 0 0 Ack by Master Stop by Master Frame 1 Alert Response Address 0 Frame 2 Device Address Figure 4. Alert Response Address 6.4 Temperature Monitoring The F75385 monitors a local and a remote temperature sensor. Both can be measured from 0°C to 145°C. The temperature format is as the following table: Temperature ( High Byte ) Digital Output Temperature ( Low Byte ) Digital Output 0°C 1°C 25°C 50°C 75°C 90°C 0000 0000 0000 0001 0001 1001 0011 0010 0100 1011 0101 1010 0°C 0.125°C 0.250°C 0.375°C 0.500°C 0.625°C 000 0 0000 001 0 0000 010 0 0000 011 0 0000 100 0 0000 101 0 0000 -4- July 2006 V0.21P 100°C 145°C 0110 0100 1001 0001 0.750°C 0.875°C 110 0 0000 111 0 0000 Remote-sensor transistor manufacturers Manufacturer Panasonic Philips Model Number 2SB0709 2N3906 PMBT3906 6.5 Alert# Five events can trigger ALERT# to low: (1). VT1(Local) temperature exceeds High Limit (2). VT1(Local) temperature goes below Low Limit (3). VT2(Remote) temperature exceeds High Limit (4). VT2(Remote) temperature goes below Low Limit (5). VT2(Remote) temperature is Open-circuit. These five events are wired-NOR together. This means that when one of out-of-limit event occurs, the ALERT# output goes low if the MASK control is disabled. ALERT# signal can be used as an IRQ-like interrupt or as an SMBALERT. When ALERT# acts as an IRQ-like interrupt, the ALERT# will be de-asserted until the following 2 conditions are matched: (1). The abnormal condition is gone (2). Reading the Status register to clear the status When ALERT# acts as a SMBALERT, the ALERT# will be de-asserted until the following 3 conditions are matched: (1). The abnormal condition is gone (2). Reading the Status register to clear the status (3). The ALERT# has been serviced by the SMBus master reading the device address. For more information about SMBALERT, please see SMBus 1.1 specification. 6.6 THERM# Either VT1(Local) or VT2(Remote) temperature exceeds the corresponding THERM limit, the THERM# output will assert low. The asserted output will be de-asserted until the temperature goes below (THERM Limit – Hysteresis). The hysteresis default value is 10°C and it can be programmed. Both VT1 and VT2 have their own THERM limits and -5- July 2006 V0.21P Hysteresis values. 6.7 ADC Conversion Sequence If a START command is written, both channels are converted and the results of both measurements are available after the end of conversion. A BUSY status bit in the status byte shows that the device is actually performing a new conversion; however, even if the ADC is busy, the results of the previous conversion are always available. 6.8 Thermal Mass and Self Heating Thermal mass effect can seriously degrade effective accuracy of the F75385. The thermal time constant of the SOP package is about 140 in still air. For the F75385 junction temperature to settle to within +1°C after a sudden +100°C change requires about five time constants or 12 minutes. The use of smaller packages for remote sensors such as SOT23, improves the situation. Take care to account for thermal gradients between the heat source and the sensor package do not interfere with measurement accuracy. Sel-heating does not significantly affect measurement accuracy. Remote sensor self-heating due to the diode current source is negligible. For the local diode, the worst case error occurs when auto-converting at the fastest rate and simultaneously sinking maximum current at the ALERT# output. For instance, at an 64Hz rate and ALERT# sink around 0.7mA when pull up resistor 4.7K ohm to 3.3VCC, the typical power dissipation is VCC x 220 uA plus 0.4V x 0.7mA. Package θJA is about 120 °C/W, so with VCC = 3.3V and no copper PC board heat-sinking, the resulting temperature rise is: dT = 1.01mW x 120 °C/W = 0.12 °C Even with these contrived circumstances, it is difficult to introduce significant self-heating errors. 6.9 ADC Noise Filtering The ADC is integrating type with inherently good noise rejection. Micro-power operation places constraints on high-frequency noise rejection; therefore, careful PCB board layout and suitable external filtering are required for high-accuracy remote measurement in electronically noisy environment. High frequency EMI is best filtered at D+ and D- with an external 2200pF capacitor. Too high capacitance may introduce errors due to the rise time of the switched current source. Nearly all noise sources tested cause the ADC measurement to be higher than the actual temperature, depending on the frequency and amplitude. 6.10 PCB Layout Guide PCB can be electrically noisy environments, and the F75385 is measuring very small voltage from the remote sensor, so care must be taken to minimize noise which is occurred at the sensor inputs. The following guideline should be taken to reduce the measurement error of the temperature sensors: -6- July 2006 V0.21P 1. Place the F75385 as close as practical to the remote sensing diode. In noisy environments, such as a computer main-board, the distance can be 4 to 8 inches. (typ). This length can be increased if the worst noise sources are avoided. Noise sources generally include clock generators, power control circuit, CRTs, memory buses and PCI/ISA bus etc. 2. Route the D+ and D- tracks close together, in parallel, with grounded guard tracks on each side. Provide a ground plane under the tracks if possible. Do not route D+ & D- lines next to the deflection coil of the CRT. And also don’t route the trace across fast digital signals which can easily induce bigger error. GND 10MILS DXP MINIMUM DXN 10MILS GND 10MILS 10MILS 3. Use wide tracks to minimize inductance and reduce noise pickup. 10 mil track minimum width and spacing is recommended. 4. Try to minimize the number of copper/solder joints, which can cause thermocouple effects. Where copper/solder joints are used, make sure that they are in both the D+ and D- path and at the same temperature. Thermocouple effects should not be a major problem as 1℃ corresponds to about 200µV. It means that a copper-solder thermocouple exhibits 3µV/℃, and takes about 200µV of the voltage error at D+ & D- to cause a 1℃ measurement error. Adding a few thermocouples causes a negligible error. 5. Place a 0.1µF bypass capacitor close to the VDD pin. In very noisy environments, place an external 2200pF input filter capacitors across D+, D- close to the F75385. 6. If the distance to the remote sensor is more than 8 inches, the use of twisted pair cable is recommended. It will work up to around 6 to 12 feet. 7. Because the measurement technique uses switched current sources, excessive cable and/or filter capacitance will affect the measurement accuracy. When using long cables, the filter capacitor may be reduced or removed. Cable resistance can also induce errors. 1 Ω series resistance introduces about 0.5℃ error. -7- July 2006 V0.21P 7. Registers Description 7.1 Configuration Register  Index 03h(Read), Power on default = 00h Bit Name Attribute 09h(Write) Description 7 6 5-0 ALERT_MASK RUN_STOP Reserved R/W R/W Set to 1, mask ALERT# signal output. Set to 0, monitor. Set to 1, stop to monitor(software power down). 7.2 Status Register  Index 02h Power on default = 00h Bit 7 6 Name ADC_BUSY VT1HIGH Attribute RO RO Set to 1, ADC is converting. Set to 1, VT1 temperature exceeds high limit. Set to 0, VT1 temperature does not exceed high limit. 5 VT1LOW RO Set to 1, VT1 temperature goes below low limit. Set to 0, VT1 temperature does not goes below low limit. 4 VT2HIGH RO Set to 1, VT2 temperature exceeds high limit. Set to 0, VT2 temperature does not exceed high limit. 3 VT2LOW RO Set to 1, VT2 temperature goes below low limit. Set to 0, VT2 temperature does not goes below low limit. 2 1 OPEN VT2THERM RO RO Set to 1, VT2 is open-circuit. Set to 1, VT2 temperature exceeds its THERM limit. Description 0 VT1THERM RO Set to 1, VT1 temperature exceeds its THERM limit. VT1(Local) ; VT2(Remote) 7.3 Conversion Rate Register  Index 04h(Read), 0Ah(Write) Power on default = 08h Bit Name Attribute Description 7-0 CONV_RATE R/W Set conversion times per second. Value Conversion/Sec Value Conversion/Sec -8- July 2006 V0.21P 00h 01h 02h 03h 04h 05h 0.0625 0.125 0.25 0.5 1 2 06h 07h 08h 09h 0Ah 0Bh ~ FFh 4 8 16 32 64 Reserved 7.4 One-Shot Register  Index 0Fh Power on default = xxh Bit Name Attribute Description 7-0 ONE-SHOT WO When F75385 is at standby mode, writing any value to this register will initiate a single conversion and comparison cycle. After the single cycle, F75385 will returns to standby mode. 7.5 Alert Queue & Timeout Register  Index 22h Power on default = 01h Bit Name Attribute Description 7 EN_I2CTMOUT R/W Set to 1, enable serial interface timeout function. (Timeout time = 25ms) Set to 0, disable. 6-4 3-1 Reserved ALERT_QUEUE R/W This number determines how many abnormal measurements must occur before ALERT signal is generated. 000 : Once 001 : Twice 011 : 3 times 111 : 4 times 0 Reserved RO Always read 1. 7.6 Status-with-ARA Control Register  Index 24h Power on default = 01h Bit Name Attribute Description 7-6 Reserved -9- July 2006 V0.21P 0 EN_ARA_STS R/W Set to 1, ALERT de-asserted condition is related with ARA. Set to 0, ALERT de-asserted condition is not related with ARA(Alert Response Address). 7.7 Chip ID I Register  Index 5Ah Power on default: 03h. 7.8 Chip ID II Register  Index 5Bh Power on default: 03h. 7.9 Vendor ID I (Manufacturer ID) Register  Index 5Dh Power on default: 19h. 7.10 Vendor ID I (Manufacturer ID) Register  Index 5Eh Power on default: 34h. 7.11 Vendor ID II (Manufacturer ID) Register  Index FEh Power on default: 23h. (programmable) 7.12 Value RAM  Index 10h- 2Fh VT1 : Local Temperature VT2 : Remote Temperature The value in quota is its power-on default value. Description Attribute Read Address (High Byte) Read Address (Low Byte) Write Address (High Byte) Write Address (Low Byte) VT1 reading VT2 reading VT1 High Limit VT1 Low Limit VT2 High Limit RO RO R/W R/W R/W 00h 01h 05h (55h) 06h (00h) 07h (55h) 1Ah 10h 1Bh (00h) 1Ch (00h) 13h (00h) 0Bh 0Ch 0Dh 1Bh 1Ch 13h -10- July 2006 V0.21P VT2 Low Limit VT1 THERM Limit VT1 THERM Hysteresis VT2 THERM Limit VT2 THERM Hysteresis R/W R/W R/W R/W R/W 08h (00h) 20h (55h) 21h (0Ah) 19h (6Ch) 23h (0Ah) 14h (00h) 0Eh 20h 21h 19h 23h 14h -11- July 2006 V0.21P 8. Electrical characteristic 8.1 Absolute Maximum Ratings PARAMETER RATING UNIT Power Supply Voltage Input Voltage Operating Temperature Storage Temperature -0.5 to 3.3 -0.5 to VDD+0.5 0 to +140 -55 to 150 V V °C °C Note: Exposure to conditions beyond those listed under Absolute Maximum Ratings may adversely affect the life and reliability of the device 8.2 DC Characteristics (TA = 0° C to 70° C, VDD = 3.3V ± 10%, VSS = 0V ) Parameter Conditions MIN TYP MAX ±1 ±3 ±1 ±3 o Unit o Temperature Error, Remote Diode 60 C < TD < 100 C, VCC = 3.0V to 3.6V 0 C