Datasheet MCP9902, MCP9903, MCP9904 (Microchip) - 9

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MCP9902/3/4 4.0 FUNCTIONAL DESCRIPTION 4.2 Conversion Rates
Thermal management is performed in cooperation The MCP9902/3/4 may be configured for different con- with a host device. This consists of the host reading version rates based on the system requirements. The the temperature data of both the external and internal default conversion rate is 4 conversions per second. temperature diodes of the MCP9902/3/4 and using Other available conversion rates are shown in Table 4-1. that data to control the speed of one or more fans.
TABLE 4-1: CONVERSION RATE
The MCP9902/3/4 has two levels of monitoring. The first provides a maskable ALERT signal to the host
CONV<3:0> Conversions/
when the measured temperatures exceed user pro-
Second HEX 3 2 1 0
grammable limits. This allows the MCP9902/3/4 to be used as an independent thermal watchdog to warn the 0h 0 0 0 0 1/16 host of temperature hot spots without direct control by 1h 0 0 0 1 1/8 the host. The second level of monitoring provides a 2h 0 0 1 0 1/4 non-maskable interrupt on the THERM output if the measured temperatures meet or exceed a second pro- 3h 0 0 1 1 1/2 grammable limit. 4h 0 1 0 0 1 Figure 4-1 shows a system level block diagram of the 5h 0 1 0 1 2 MCP9902/3/4. 6h 0 1 1 0 4 (default) 7h 0 1 1 1 8 VDD = 3.3V 8h 1 0 0 0 16
CPU/GPU
DP1 3.3V – 5V V 9h DD 1 0 0 1 32 Thermal Host DN1 Junction Ah 1 0 1 0 64 SMCLK Bh - Fh All others 1
MCP990X
SMDATA SMBus Interface ALERT
4.3 Dynamic Averaging MCP9903/4
only DP2/ Optional DN3 Dynamic averaging allows the MCP9902/3/4 to Anti-parallel THERM/ADDR Power measure the external diode channel for an extended diode DN2/ Control DP3 time based on the selected conversion rate. This GND functionality can be disabled for increased power savings at the lower conversion rates (see Register 5-6). When dynamic averaging is enabled,
FIGURE 4-1:
MCP9902/3/4 System the device will automatically adjust the sampling and Diagram. measurement time for the external diode channels. This allows the device to average 2x or 16x longer
4.1 Power States
than the normal 11 bit operation (nominally 21 ms per channel) while still maintaining the selected The MCP9902/3/4 has two modes of operation: conversion rate. The benefits of dynamic averaging • Active (Run) - In this mode of operation, the ADC are improved noise rejection due to the longer is converting on all temperature channels at the integration time as wel as less random variation of the programmed conversion rate. The temperature temperature measurement. data is updated at the end of every conversion When enabled, the dynamic averaging applies when a and the limits are checked. In Active mode, writing one-shot command is issued. The device wil perform to the one-shot register will do nothing. the desired averaging during the one-shot operation • Standby (Stop) - In this mode of operation, the according to the selected conversion rate. majority of circuitry is powered down to reduce When enabled, the dynamic averaging will affect the supply current. The temperature data is not typical supply current based on the chosen conversion updated and the limits are not checked. In this rate as shown in the power supply characteristics in mode of operation, the SMBus is fully active and
Table 1.2 "DC Characteristics"
. the part will return requested data. Writing to the one-shot register will enable the device to update all temperature channels. Once all the channels are updated, the device will return to the Standby mode.  2015-2016 Microchip Technology Inc. DS20005382C-page 9 Document Outline Multi-Channel Low-Temperature Remote Diode Sensor Features Typical Applications Description Package Types MCP9902/3/4 Functional Block Diagram 1.0 Electrical Characteristics 1.1 Electrical Specifications Absolute Maximum Ratings 1.2 DC Characteristics 1.3 Thermal Specifications FIGURE 1-1: POR and POR Rearm With Slow Rising VDD. 1.4 SMBUS Module Specifications FIGURE 1-2: SMBus Timing Diagram. 2.0 Typical Operating Curves FIGURE 2-1: Supply Current vs. Conversion Rate (TA = +25°C, VDD = 3.3V). FIGURE 2-2: IDD vs. Temperature. FIGURE 2-3: Temperature Error vs. Filter Capacitor (VDD = 3.3V, TA = TD = +25°C, 2N3904). FIGURE 2-4: Temperature Error vs. Ambient Temperature (VDD = 3.3V, TD = +25°C, 16 Units, 2N3904). FIGURE 2-5: Temperature Error vs. Remote Temperature. (VDD = 3.3V, TD = +25°C, 16 Units, 2N3904). FIGURE 2-6: Temperature Error vs. Series Resistance (TA = +25°C, VDD = 3.3V). 3.0 Pin Descriptions TABLE 3-1: Pin Function Table 3.1 Power Supply (VDD) 3.2 Diode 1 Pair (DN1/DP1) 3.3 Diode 2 Pair (DN2/DP2) 3.4 Anti-Parallel Diode Pair (DN3/DP2 and DN2/DP3) (MCP9904 only) 3.5 THERM LIMIT ALERT (THERM/ADDR) 3.6 Ground (GND) 3.7 Maskable ALERT (ALERT/THERM2) 3.8 SMBus Data (SMDATA) 3.9 SMBus Clock (SMCLK) 3.10 Exposed Thermal Pad (EP) 4.0 Functional Description FIGURE 4-1: MCP9902/3/4 System Diagram. 4.1 Power States 4.2 Conversion Rates TABLE 4-1: Conversion Rate 4.3 Dynamic Averaging 4.4 THERM Output 4.5 THERM Pin Address Decoding TABLE 4-2: I2C/SMBus Address Decode 4.6 ALERT/THERM2 Output 4.7 Temperature Measurement 4.8 Beta Compensation 4.9 Resistance Error Correction (REC) 4.10 Programmable External Diode Ideality Factor TABLE 4-3: Ideality Factor Look-Up Table (Diode Model) TABLE 4-4: Substrate Diode Ideality Factor Look-Up Table (BJT Model) 4.11 Diode Faults 4.12 Consecutive Alerts TABLE 4-5: Consecutive Alert/ THERM Settings 4.13 Limit Register Interaction 4.14 Digital Filter TABLE 4-6: Filter Settings FIGURE 4-2: Temperature Filter Step Response. FIGURE 4-3: Temperature Filter Impulse Response. 4.15 Temperature Measurement Results and Data TABLE 4-7: Temperature Data Format 5.0 Communications Protocol 5.1 SMBus Control Bits 5.2 SMBus Timeout 5.3 SMBus and I2C Compatibility 5.4 SMBus Protocols TABLE 5-1: Protocol Format TABLE 5-2: Write Byte Protocol TABLE 5-3: Read Byte Protocol TABLE 5-4: Send Byte Protocol TABLE 5-5: Receive Byte Protocol 5.5 Alert Response Address TABLE 5-6: Alert Response Address Protocol 5.6 Register Description TABLE 5-7: Register Set in Hexadecimal Order (Continued) 5.7 Data Read Interlock Register 5-1: iNT TEMP HI BYTE: Internal Diode High Byte Temperature Data Register (ADDRESS 00h) Register 5-2: INT temp LO byte: Internal Diode LOW Byte Temperature Data Register (ADDRESS 29h) Register 5-3: EXT(n) TEMP hi byte: EXTERNAL Diode High Byte Temperature Data Register (Addresses 01h, 23h, 2Ah) Register 5-4: EXT(n) TEMP Lo Byte: EXTERNAL Diode LOW Byte Temperature Data Register (Addresses 10h, 24h, 2Bh) Register 5-5: Status: status register reporting state of internal and external diodes (ADDRESS 02h) Register 5-6: CONFIG: Configuration Register (Addresses 03h and 09h) Register 5-7: CONVERT: TEMPERATURE CONVERSION RATE REGISTER (ADDRESS 04h, 0AH) Register 5-8: int diode hi limit temp: INTERNAL DIODE HIGH LIMIT TEMPERATURE REGISTER (Addresses 05h and 0Bh) Register 5-9: int diode lo lim TEMP – INTERNAL DIODE LOW LIMIT TEMPERATURE REGISTER (addresses 06H AND 0CH) Register 5-10: EXT(n) hi lim temp HB – EXTERNAL DIODE N HIGH TEMPERATURE LIMIT, high byte REGISTER (addresses 07h and 0dh, 15h, 2Ch) Register 5-11: EXT(n) hi lim LB – EXTERNAL DIODE N HIGH LIMIT TEMPERATURE, low byte REGISTER (Addresses 13H, 17h, 2eh) Register 5-12: EXT(n) lo lim HB – EXTERNAL DIODE N low LIMIT, high byte TEMPERATURE REGISTER (addresses 08h and 0eh, 16h, 2Dh) Register 5-13: EXT(N) LO lim LB – EXTERNAL DIODE N LOW LIMIT, low byte TEMPERATURE REGISTER (Addresses 14H, 18h, 2fh) Register 5-14: scrtchpd(N): sCRATCHPAD REGISTER (addresses 11H AND 12H) Register 5-15: ONE SHOT – ONE-shot temperature conversion initiation REGISTER (address 0fh) Register 5-16: EXT(n) THrm lim – external diode (N) therm limit REGISTER (addresses 19h, 1Ah and 30h) Register 5-17: iNTD THrm lim – internal diode therm limit REGISTER (address 20h) Register 5-18: THRM HYS – therm limit hysteresis REGISTER (address 21h) Register 5-19: EXT FLT STS – external diode fault status REGISTER (address 1Bh) Register 5-20: DIODE FAULT MASK – diode fault mask REGISTER (address 1Fh) Register 5-21: CONSEC ALERT – Consecutive Alert Register (address 22h) Register 5-22: ext(N) beta cfg – beta compensation configuration Register (addresses 25h and 26h) Register 5-23: ext (n) IDEALITY FACTOR – External Diode N Ideality Factor Register (addresses 27h, 28h and 31h) Register 5-24: HI LIM STS – High Limit Status Register (address 35h) Register 5-25: LO LIM STS – Low Limit Status Register (address 36h) Register 5-26: THRM LIM STS – High Limit Status Register (address 37h) Register 5-27: FLTR SEL: Filter Selection Register (address 40h) Register 5-28: PROD_ID – Product ID Register (address FDh) Register 5-29: MCHP_ID – Manufacturer ID Register (address FEh) Register 5-30: REVISION – Revision Register (address FFh) 6.0 Packaging Information 6.1 Package Marking Information Appendix A: Revision History Revision C (July 2016) Revision B (March 2016) Revision A (December 2015) Product Identification System Trademarks Worldwide Sales and Service