ASC7521A ETC2 [List of Unclassifed Manufacturers], ASC7521A Datasheet
ASC7521A
Related parts for ASC7521A
ASC7521A Summary of contents
Page 1
... Product Description The aSC7521A is a high-precision CMOS temperature sensor and voltage monitor with Simple Serial Transport (SST) compatible serial digital interface, intended for use in PC hardware monitor applications. Communication of device capabilities readings takes place over the high-speed bi-directional SST interface. The SST temperature sensor provides a means for an analog signal to travel over a digital bus enabling remote temperature sensing in areas previously not monitored in the PC ...
Page 2
... Notes: 6. These specifications are guaranteed only for the test conditions listed. 7. Accuracy (expressed in °C) = Difference between the aSC7521A reported temperature and the device temperature. 8. The aSC7521A can be read at any time without interrupting the temperature conversion process. 9. Calibration of the remote diode sensor input is set to meet the accuracy limits with a CPU thermal diode that has a non-ideality factor of 1.009 with a series resistance of 4.52Ω ...
Page 3
... Input Digital Input / Output. SST Bi-directional Data Line. On-Chip Temperature ADC Remote Temperature Remote Diode Open / Short VSS Figure 1. Block Diagram - 3 - www.andigilog.com aSC7521A Description select device DD select device DD DIB Register Control and SST Interface ADD0 ADD1 SST October 2006 - 70A05011 ...
Page 4
... Andigilog, Inc. 2006 Device Power-on Timing Following a power-on reset, such as a system transitioning from S3-S5 to S0, the aSC7521A will be able to participate in the address and message timing negotiation and respond to required SST bus commands such as respond to a GetDIB() command within 10ms of the device’s V The aSC7521A has an internal power on reset and will be fully functional within 50ms of power on ...
Page 5
... The aSC7521A will write one of the values from the table below to appropriate memory locations for GetIntTemp() and/or GetExtTemp(). The aSC7521A uses the OEM defined values of 0x8102 (open) and 0x8103 (short) rather than the generic errors defined for codes 0x8000 to 0x8003 ...
Page 6
... Write Data Length: 0x01 Read Data Length: 0x08/0x10 Command Code: 0xF7 Note: Un-shaded table entries are created by the host. Shaded entries are the response bytes from the aSC7521A to the host. Host Sending 8 8 Target Address Write Length 0x48 ...
Page 7
... Returns a 4-byte block of data containing both the Internal and External temperatures in the following order Internal then External temperatures. © Andigilog, Inc. 2006 8 8 ResetDevice Read Length Command 0x00 0xF6 8 8 ResetDevice Read Length Command 0x00 0xF6 8 8 Read Length Command 0x02 0x00 8 8 MSB FCS 0x0F 0x2D - 7 - www.andigilog.com aSC7521A 8 FCS 0x8C October 2006 - 70A05011 ...
Page 8
... Command Code: 0x00 Optional SST Device Commands The optional SST commands Alert(), Suspend() are not supported in the aSC7521A. Vendor Specific Extensions The vendor specific command codes are in the range from 0xE0 and 0xE7. Reading and writing to specific internal registers is provided for custom tuning of sensor response characteristics. ...
Page 9
... An Abort FCS will be formed by creating a 1’s complement of the the good FCS get temperature command and the read length is not equal then te aSC7521A will send an Abort FCS and wait for a stop on the SST bus. See the Command Summary section for the expected Write and Read lengths of the legal commands. ...
Page 10
... The Device Identifier Block describes the identity and functions of a client device on the SST bus. Sixteen bytes are allocated for this function as shown in Figure 13. Device Identifier Block is returned by the aSC7521A with a GetDIB() command. The aSC7521A returned values are shown with the description of each field below. ...
Page 11
... This field provides a mechanism for a device to pass higher-layer SST device-specific information. Value = 0x00 © Andigilog, Inc. 2006 Minor Revision 0000 (default) 0000 Figure 15. Version / Revision Field Stored Value (LS,MS) 0x2175 Meaning Table 4. Device Interface Field - 11 - www.andigilog.com aSC7521A LSB for V1.0 Pre-production for V1.0 Production October 2006 - 70A05011 ...
Page 12
... SST Client Device Address is set according to the connection of pins ADD0 and ADD1. Float is defined as an unconnected pin. ADD0 ADD1 Ground Ground Float Ground V Ground DD Ground Float Float Float V Float DD Ground V DD Float © Andigilog, Inc. 2006 Address 0x48 0x49 0x4A 0x4B 0x4C 0x4D 0x4E 0x4F 0x50 - 12 - www.andigilog.com aSC7521A October 2006 - 70A05011 ...
Page 13
... Applications Information Remote Diodes The aSC7521A is designed to work with a variety of remote sensors in the form of a diode-connected transistor or the substrate thermal diode of a CPU or graphics controller. Actual diodes are not suited for these measurements. There is some variation in the performance of these diodes, described in terms of its departure from the ideal diode equation ...
Page 14
... Thermal Considerations The temperature of the aSC7521A will be close to that of the PC board on which it is mounted. Conduction through the leads is the primary path for heat flow. The reported local - 14 - www.andigilog.com aSC7521A Board Interconnect Place a 0.1µF bypass capacitor to digital ground as close as possible to the power pin of the aSC7521A ...
Page 15
... PC board. A TO-92 packaged transistor is recommended. The power consumption of the aSC7521A is relatively low and should have little self-heating effect on the local sensor reading. At the highest measurement rate the dissipation is less than 2mW, resulting in only a few tenths of a degree rise. © ...
Page 16
... A 0.94mm (max) A 0.05mm (min) 0.15mm (max www.andigilog.com aSC7521A Detail B α 0° (min) 6° (max) 0.40mm (min) 0.70mm (max) 0.95mm BSC Detail B 2.85mm (min) 3.05mm (max) 2.90mm (min) 3.10mm (max) 4 ...
Page 17
... Notes: Andigilog, Inc. 8380 S. Kyrene Rd., Suite 101 Tempe, Arizona 85284 Tel: (480) 940-6200 Fax: (480) 940-4255 © Andigilog, Inc. 2006 - 17 - www.andigilog.com aSC7521A October 2006 - 70A05011 ...
Page 18
... A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system affect its safety or effectiveness. Andigilog, Inc. 8380 S. Kyrene Rd., Suite 101 Tempe, Arizona 85284 Tel: (480) 940-6200 Fax: (480) 940-4255 © Andigilog, Inc. 2006 - 18 - www.andigilog.com aSC7521A October 2006 - 70A05011 ...