G751 Global Mixed-mode Technology Inc. Digital Temperature Sensor and Thermal Watchdog with Two-Wire Interface General Description Features The G751 is a temperature sensor, Delta-Sigma analog-to-digital converter, and digital over- temperature detector with SMBus interface. The host can query the G751 at any time to read temperature. The open-drain Over temperature Shutdown (O.S.) output becomes active when the temperature exceeds a programmable limit. This pin can operate in either “Comparator” or “Interrupt” mode. SMBus interface Programmable Trip Point (TOS) and Hysteresis (THYST) Separate open-drain output pin operates as interrupt or comparator at output Register readback capability Power up defaults permit stand-alone opera- tion as thermostat The host can program both the temperature alarm threshold (TOS) and the temperature at which the alarm condition goes away (THYST). In addition, the host can read back the contents of the G751’s TOS and THYST registers. The sensor powers up in Comparator mode with default thresholds of 50°C TOS 45°C THYST. for G751-1 and 80°C TOS , 75°C THYST for G751-2. Shutdown mode to minimize power consump- tion Up to 8 G751s can be connected to a single bus Key Specifications Supply Voltage Supply Current operating shutdown Temperature Accuracy -25°C to 100°C -55°C to 125°C 3.0V to 5.5V 280µA (typ) 1mA (max) 2µA(typ) Ordering Information PART ±2°C (max) ±3°C (max) TOS THYST Transport Media G751-1 50°C/45°C 2500 Units on Tape and Reel G751-2 80°C /75°C 2500 Units on Tape and Reel PACKAGE 8 SOP 8 SOP Applications System Thermal Management Personal Computers Office Electronics Electronic Test Equipment Typical Application Pin Configuration +VS 3V to 5.5V G751 7 SMBDATA SMBCLK 1 8 2 7 +Vs A0 Address(Set as desired) A0 A1 3 6 A1 GND 4 5 A2 8 6 5 A2 O.S. G751 1 SMBDATA Interface 2 SMBCLK 8Pin SOP Typical Bypass 0.1 µF (Unless mounted close to Processor) 4 3 To Processor O.S. Out Interrupt Line O.S. Set for active low for wire OR’d multiple interrupt line TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 1 G751 Global Mixed-mode Technology Inc. Absolute Maximum Ratings. Operating Ratings Supply Voltage………….…………………-0.3V to 6.5V Voltage at any Pin……………….…-0.3V to +Vs +0.3V Input Current at any Pin…………………………….5mA Package Input Current…………………………….20mA O.S. Output Sink Current………………………….10mA O.S. Output Voltage…………………….…………..6.5V Storage Temperature…………………-65°C to +150°C Soldering Information, Lead Temperature SOP Package Vapor Phase (60 seconds)……………………….215°C Infrared (15 seconds)……………………………..220°C ESD Susceptibility Human Body Model……………………………….2000V Machine Model……………………………………...200V Specified Temperature Range…………….TMIN to TMAX -55°C to +125°C Supply Voltage Range (+Vs)…………..+3.0V to +5.5V Temperature-to-Digital Converter Characteristics Unless otherwise noted, these specifications apply for +Vs=+3.3v Vdc. Boldface limits apply for TA=TJ=TMIN to TMAX; all other limits TA=TJ= +25°C, unless otherwise noted. PARAMETER Accuracy CONDITIONS TYPICAL TA=-25°C to +100°C TA=-55°C to +125°C Resolution Temperature Conversion Time Quiescent Current SMBus Inactive SMBus Active Shutdown Mode IOUT = 4.0mA O.S. Output Saturation Voltage O.S. Delay TOS Default Temperature G751-1/G751-2 THYST Default Temperature G751-1/G751-2 LIMITS ±2.0 ±3.0 9 100 0.25 1.0 1 0.8 1 6 50/80 45/75 UNITS °C (max) Bits Ms Ma mA (max) µA V (max) Conversions (min) Conversions (max) °C °C Block Diagram 8 +VS 3.0V - 5.5V Temperature 3 O.S. Threshold 9-Bit Delta-Sigma Analog-to-Digital Converter TOS Set Point Register Silicon Bandgap Temperature Sensor A0 A1 A2 7 6 5 Configuration Register Pointer Register Set Point Comparator Reset T HYST Set Point Register 1 Two-Wire Interface 2 SMBDATA SMBCLK 4 TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 2 G751 Global Mixed-mode Technology Inc. Logic Electrical Characteristics Digital DC Characteristics Unless otherwise noted, these specifications apply for +Vs=+3.3 Vdc. Boldface limits apply for TA=TJ=TMIN to TMAX; all other limits TA=TJ=+25°C, unless otherwise noted. SYMBOL PARAMETER CONDITIONS TYPICAL LIMITS UNITS Logical “1” Input Voltage × 0.7 +Vs× VIN (0) Logical “0” Input Voltage +Vs + 0.5 -0.3 × 0.3 +Vs× IIN (1) IIN (0) CIN IOH VOL tOF Logical “1”Intput Current Logical “0”Intput Current All Digital Inputs High Level Output Current Low Level Output Voltage Output Fall Time VIN (1) VIN=5V VIN=0V 0.005 -0.005 20 V (min) V (max) V (min) V (max) µA µA PF µA (max) V (max) ns (max) 1.0 -1.0 VOH=5V IOL=3ma CL=400pF,IO=3ma 100 0.4 250 SMBus Digital Switching Characteristics Unless otherwise noted, these specifications apply for +Vs = +3.3 Vdc and CL (load capacitance) on output lines = 80pF unless otherwise specified. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25°C, unless otherwise noted. The switching characteristics of the G751 fully meet or exceed the published specifications of the SMBus. The following parameters are the timing relationships between SMBCLK and SMBDATA signals related to the G751. They are not the SMBus specifications. SYMBOL PARAMETER CONDITIONS TYPICAL t1 t2 t3 t4 t5 SMBCLK (Clock) Period Data in Set-Up Time to SMBCLK High Data Out Stable after SMBCLK Low SMBDATA Low Set-Up Time to SMBCLK Low (Start Condition) SMBDATA High Hold Time after SMBCLK High (Stop Condition) LIMITS UNITS 2.5 100 0 100 100 µs (min) ns (min) ns (min) ns (min) ns (min) Pin Description PIN LABEL FUNCTION TYPICAL CONNECTION 1 SMBDATA SMBus Serial Bi-Directional Data Line 2 SMBCLK SMBus Clock Input 3 O.S. Overtemperature Shutdown Open Drain Output 4 GND Power Supply Ground 5,6,7 A0-A2 User-Set SMBus Address Inputs 8 +Vs Positive Supply Voltage Input From Controller From Controller Pull Up Resistor, Controller Interrupt Line Ground Ground (Low, “0”) or +Vs (High, “1”) DC Voltage from 3V to 5.5V t1 SMBCLK SMBDATA Data in t5 t4 t2 SMBDATA Data out t3 Logic Electrical Characteristics TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 3 G751 Global Mixed-mode Technology Inc. Output Code 0,1111,1010 +25°C +0.5°C 0,0011,0010 0,0000,0001 Temperature 0,0000,0000 0°C -55°C +125°C 1,1111,1111 1,1100,1110 -0.5°C -25°C 1,1001,0010 Temperature-to-Digital Transfer Function (Non-linear scale for clarity) Default Modes G751 always powers up in a known state. G751 power up default conditions are: 1. Comparator mode 2. TOS set to 50°C for G751-1, to 80°C for G751-2 3. THYST set to 45°C for G751-1, to 75°C for G751-2 4. O.S. active low 5. Pointer set to “00”; Temperature Register With these operating conditions G751 can act as a stand-alone thermostat with the above temperature settings. Connection to an SMBus is not required. Functional Description The G751 temperature sensor incorporates a band-gap type temperature sensor and 9-bit ADC (Delta-Sigma Analog- to-Digital Converter). The temperature data output of the G751 is available at all times via the SMBus. If a conversion is in progress, it will be stopped and restarted after the read. A digital comparator is also incorporated that compares a series of readings, the number of which is user-selectable, to user-programmable setpoint and hysteresis values. The comparator trips the O.S. output line, which is programmable for mode and polarity. SMBus Interface The G751 operates as a slave on the SMBus, so the SMBCLK line is an input (no clock is generated by the G751) and the SMBDATA line is a bi-directional serial data path. According to SMBus specifications, the G751 has a 7-bit slave address. The four most significant bits of the slave address are hard wired inside the G751 and are “1001”. The three least significant bits of the address are assigned to pins A2-A0, and are set by connecting these pins to ground for a low, (0); or to +Vs for a high, (1). O.S. Output, TOS and THYST Limits In Comparator mode the O.S. Output behaves like a thermostat. The output becomes active when temperature exceeds the TOS limit, and leaves the active state when the temperature drops below the THYST limit. In this mode the O.S. output can be used to turn a cooling fan on, initiate an emergency system shutdown, or reduce system clock speed. Shutdown mode does not reset O.S. state in a comparator mode. Therefore, the complete slave address is: In interrupt mode exceeding TOS also makes O.S. active but O.S. will remain active indefinitely until reset by reading any register via the SMBus interface. Once O.S. has been activated by crossing TOS, then reset, it can activated again only by Temperature going below THYST. Again, it will remain active indefinitely until being reset by a read. Placing the G751 in shutdown mode also resets the O.S. output. 1 MSB 0 0 1 A2 A1 A0 LSB TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 4 Global Mixed-mode Technology Inc. Shutdown Mode Shutdown mode is enabled by setting the shutdown bit in the Configuration register via the SMBus. Shutdown mode reduces power supply current to 1 µA typical. In interrupt mode O.S. is reset if previously set and is undefined in Compatator mode during shutdown. The SMBus interface remains active. Activity on the clock and data lines of the SMBus may slightly increase shutdown mode quiescent current. TOS, THYST, and Configuration registers can be read from and written to in shutdown mode. * Temperature response Shown for O.S. set for active low. O.S. (Interrupt Mode) O.S. (Comparator Mode) THYST TOS *read any register or placed in shut down Time * * Fault Queue A fault queue of up to 6 faults is provided to prevent false tripping of O.S. when the G751 is used in noisy environments. The number of faults set in the queue must occur consecutively to set the O.S. output. Comparator/Interrupt Mode As indicated in the O.S. Output Temperature Response Diagram, Figure 1, the events that trigger O.S. are identical for either Comparator or Interrupt mode. The most important difference is that in Interrupt mode the O.S. will remain set indefinitely once it has been set. To reset O.S. while in Interrupt mode, perform a read from any register in the G751. O.S. Output The O.S. output is an open-drain output and does not have an internal pull-up. A ”high” level will not be observed on this pin until pull-up current is provided from some external source, typically a pull-up resistor. Choice of resistor value depends on many system factors but, in general, the pull-up resistor should be as large as possible. This will minimize any errors due to internal heating of the G751. The maximum resistance of the pull up, based on G751 specification for High Level Output Current, to provide a 2V high level, is 30kΩ. Figure1 O.S. Output Temperature Response Diagram Temperature Data Format Temperature data can be read from the Temperature, TOS Set Point, and THYST Set Point registers; and written to the TOS Set Point, and THYST Set Point registers. Temperature data is represented by a 9-bit, two’s complement word with an LSB (Least Significant Bit) equal to 0.5°C: TEMPERATURE +125°C +25°C +0.5°C 0°C -0.5°C -25°C -55°C G751 O.S. Polarity The O.S. output can be programmed via the configuration register to be either active low (default mode), or active high. In active low mode the O.S. output goes low when triggered exactly as shown on the O.S. Output Temperature Response Diagram, Figure 1. Active high simply inverts the polarity of the O.S. output. DIGITAL OUTPUT BINARY HEX 0 1111 1010 0FAh 0 0011 0010 032h 0 0000 0001 001h 0 0000 0000 000h 1 1111 1111 1FFh 1 1100 1110 1CEh 1 1001 0010 192h TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 5 G751 Global Mixed-mode Technology Inc. Internal Register Structure SMBDATA SMBCLK Interface Data Address Pointer Register (Selects register for communication Register Select Temperature (Read-only) Pointer = 00000000 Configuration (Read-write, sets operating Mode) Pointer = 00000001 TOS Set Point (Read-write) Pointer = 00000011 THYST Set Point (Read-write) Pointer = 00000010 The first data byte is the most significant byte with most signification bit first, permitting only as much data as necessary to be read to determine temperature condition. For instance, if the first four bits of the temperature data indicates an overtemperature condition, the host processor could immediately take action to remedy the excessive temperatures. At the end of a read, the G751 can accept either Acknowledge or No Acknowledge from the Master (No Acknowledge is typically used as a signal for the salve that the Master has read its last byte). There are four data registers in the G751, selected by the Pointer register. At power-up the Pointer is set to “00”; the location for the Temperature Register. The Pointer register latches whatever the last location it was set to. In Interrupt Mode, a read from the G751, or placing the device in shutdown mode, resets the O.S. output. All registers are read and write, except the Temperature register which is read only. A write to the G751 will always include the address byte and the Pointer byte. A write to the Configuration register requires one data byte, and the TOS and THYST registers require two data bytes. An inadvertent 8-bit read from a 16-bit register, with the D7 bit low, can cause the G751 to stop in a state where the SDA line is held low as shown in Figure 2. This can prevent any further bus communication until at least 9 additional clock cycles have occurred. Alternatively, the master can issue clock cycles until SDA goes high, at which time issuing a “Stop” condition will reset the G751. Reading the G751 can take place either of two ways: If the location latched in the Pointer is correct (most of the time it is expected that the Pointer will point to Temperature register because it will be the data most frequently read from the G751), then the read can simply consist of an address byte, followed by retrieving the corresponding number of data bytes. If the Pointer needs to be set, than an address byte, pointer byte, repeat start, and another address byte will accomplish a read. SMBCLK SMBDATA A2 Start by Master A1 A0 D15 R/W Bit D14 D13 D12 D11 D10 Ack by G751 Address Byte Most Significant Data Byter D9 D7 D8 D6 D5 D4 D3 D2 D0 Ack Stop by Cond Master by Master Ack by Master Intended Stop by Master but G751 locks SMBDATA low D1 Master detects the error of its ways Figure 2. Inadvertent 8-Bit Read from 16-Bit Register where D7 is Zero TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 6 G751 Global Mixed-mode Technology Inc. Pointer Register (Selects which registers will be read from or written to): P7 P6 P5 P4 P3 P2 0 0 0 0 0 0 P1 P0 Register Select P0-P1 :Register Select: P1 P0 0 0 1 1 0 1 0 1 REGISTER Temperature (Read only) (Power-up default) Configuration (Read/Write) THYST (Read/Write) TOS (Read/Write) P2-P7 :Must be kept zero. Temperature Register (Read Only): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 MSB Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 LSB X X X X X X X D0-D6 :Undefined D7-D15 :Temperature Data. One LSB = 0.5°C. Two’s complement format. Configuration Register (Read/Write): D7 D6 D5 0 0 0 D4 D3 Fault Queue D2 D1 D0 O.S. Polarity Cmp/Int Shutdown Power up default is with all bits “0” (zero). D0 :Shutdown : When set to 1 the G751 goes to low power shutdown mode. D1 :Comparator / Interrupt mode : 0 is Comparator mode, 1 is Interrupt mode. D2 :O.S. Polarity : 0 is active low, 1 is active high. O.S. is an open-drain output under all conditions. D3-D4 :Fault Queue : Number of faults necessary to detect before setting O.S. output to avoid false tripping due to noise : D4 D3 0 0 1 1 0 1 0 1 NUMBER OF FAULTS 1 (Power-up default) 2 4 6 D5-D7 :These bits are used for production testing and must be kept zero for normal operation. THYST and TOS Register (Read/Write): D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 MSB Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 LSB X X X X X X X D0-D6 :Undefined D7-D15 :THYST Or TOS Trip Temperature Data. Power up default is TOS = 50°C /80°C for G751-1/G751-2, THYST = 45°C /75°C for G751-1/G751-2. TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 7 G751 Global Mixed-mode Technology Inc. SMBus Timing Diagrams 1 1 9 1 0 0 1 A2 A1 A0 D7 R/W Start by Master 9 D6 D5 D4 D3 D2 D1 0 A2 1 A1 A0 Start by Master 0 0 0 0 D1 0 1 9 1 A1 A2 A0 D7 R/W 9 D6 D5 D4 D3 D2 D1 1 9 0 0 1 A2 A1 A0 D4 D3 D2 D1 D0 Stop Cond by Master 9 D6 D5 D4 D2 D3 Ack by G751 Address Byte D5 Least Significant Data Byte 1 D7 R/W D6 No Ack by Master Most Significant Data Byte 1 9 Ack by Master Address Byte Start by Master 1 D7 D0 Ack by G751 Repeat Start by Master Stop Cond by Master Pointer Byte 1 0 D0 Ack by G751 Address Byte 0 D1 D0 Ack by G751 1 D2 9 0 R/W D3 Least Significant Data Byte 1 9 D4 No Ack by Master Most Significant Data Byte 1 D5 D6 Ack by Master Address Byte 0 9 D7 D0 Ack by G751 1 1 D1 D0 Ack by G751 Pointer Byte Stop Cond by Master TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 8 Start by Master Start by Master Start by Master 1 1 Ver: 2.2 Nov 07 2001 9 1 1 1 1 0 0 0 0 0 A1 0 A2 A1 A0 A2 A1 Address Byte 1 Address Byte 1 Address Byte 1 A2 A0 A0 Ack by G751 0 1 0 0 0 0 Pointer Byte 0 D1 D0 Ack Repeat by Start Master by Master 9 1 1 0 0 A2 A1 Address Byte 1 A0 R/W Ack by G751 9 D7 D6 D5 D4 R/W R/W Ack by G751 9 Ack by G751 9 0 1 0 1 0 0 0 0 0 0 D1 D0 Ack by Master 0 1 0 0 0 Pointer Byte 0 D1 Ack by Master D7 1 D6 D3 D2 D4 D3 D2 D1 D0 D1 Configuration Byte D4 Most Significant Data Byte D5 0 (c) TOS and THYST Write D0 9 (b) Configuration Register Write Pointer Byte 0 9 9 D6 Stop Cond by Master 1 D7 Ack by G751 Ack by G751 D0 9 D4 D3 D1 D3 D2 Data Byte D2 D1 D0 D0 9 Ack by G751 No Ack Stop Cond by Master by Master 9 Least Significant Data Byte D5 (a) Typical Pointer Set followed by Immediate Read from Configuration Register R/W 9 Stop Cond by Master Global Mixed-mode Technology Inc. G751 Timing Diagrams (Continued) TEL: 886-3-5788833 http://www.gmt.com.tw G751 Global Mixed-mode Technology Inc. Package Information C E H L D θ 7° (4X) A2 A A1 y e B Note: 1. Package body sizes exclude mold flash and gate burrs 2. Dimension L is measured in gage plane 3. Tolerance 0.10mm unless otherwise specified 4. Controlling dimension is millimeter converted inch dimensions are not necessarily exact. SYMBOL A A1 A2 B C D E e H L y θ MIN. DIMENSION IN MM NOM. MAX. MIN. 1.35 0.10 ----0.33 0.19 4.80 3.80 ----5.80 0.40 ----0º 1.60 ----1.45 ----------------1.27 ----------------- 1.75 0.25 ----0.51 0.25 5.00 4.00 ----6.20 1.27 0.10 8º 0.053 0.004 ----0.013 0.007 0.189 0.150 ----0.228 0.016 ----0º DIMENSION IN INCH NOM. 0.063 ----0.057 ----------------0.050 ----------------- MAX. 0.069 0.010 ----0.020 0.010 0.197 0.157 ----0.244 0.050 0.004 8º Taping Specification Feed Direction Typical SOP Package Orientation TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 2.2 Nov 07 2001 10