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ADM1021AARQZ-R Datasheet(PDF) 9 Page - ON Semiconductor |
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ADM1021AARQZ-R Datasheet(HTML) 9 Page - ON Semiconductor |
9 / 15 page ![]() ADM1021A http://onsemi.com 9 corresponding low temperature limit, then one or more of these flags are set. Bit 2 is a flag that is set if the remote temperature sensor is open−circuit. These five flags are NOR’d together so that if any of them are high, the ALERT interrupt latch is set and the ALERT output goes low. Reading the status register clears the five flag bits, provided the error conditions that caused the flags to be set have gone away. While a limit comparator is tripped due to a value register containing an out−of−limit measurement, or the sensor is open−circuit, the corresponding flag bit cannot be reset. A flag bit can only be reset if the corresponding value register contains an in−limit measurement, or the sensor is good. Table 2. Status Register Bit Assignments Bit Name Function 7 BUSY 1 when ADC converting 6 LHIGH* 1 when local high temp limit tripped 5 LLOW* 1 when local low temp limit tripped 4 RHIGH* 1 when remote high temp limit tripped 3 RLOW* 1 when remote low temp limit tripped 2 OPEN* 1 when remote sensor open−circuit 1 to 0 Reserved *These flags stay high until the status register is read or they are reset by POR. Table 3. List of ADM1021A Registers Read Address (Hex) Write Address (Hex) Name Power−On Default Not applicable Not applicable Address pointer Undefined 00 Not applicable Local temperature value 1000 0000 (0x80) (−128 °C) 01 Not applicable Remote temperature value 1000 0000 (0x80) (−128 °C) 02 Not applicable Status Undefined 03 09 Configuration 0000 0000 (0x00) 04 0A Conversion rate 0000 0010 (0x02) 05 0B Local temperature high limit 0111 1111 (0x7F) (+127 °C) 06 0C Local temperature low limit 1100 1001 (0xC9) (−55 °C) 07 0D Remote temperature high limit 0111 1111 (0x7F) (+127 °C) 08 0E Remote temperature low limit 1100 1001 (0xC9) (−55 °C) Not applicable 0F (Note 1) One−shot 10 Not applicable Reserved Reserved for future versions 11 11 Remote temperature offset 0000 0000 (0 °C) 12 12 Reserved Reserved for future versions 13 13 Reserved Reserved for future versions 14 14 Reserved Reserved for future versions 15 16 Reserved Reserved for future versions 17 18 Reserved Reserved for future versions 19 Not applicable Reserved Reserved for future versions 20 21 Reserved Reserved for future versions FE Not applicable Manufacturer device ID 0100 0001 (0x41) FF Not applicable Die revision code 0011 xxxx (0x3x) 1. Writing to Address 0F causes the ADM1021A to perform a single measurement. It is not a data register and data written to it is irrelevant. The ALERT interrupt latch is not reset by reading the status register, but is reset when the ALERT output is serviced by the master reading the device address, provided the error condition has gone away and the status register flag bits have been reset. Configuration Register Two bits of the configuration register are used. If Bit 6 is 0, which is the power−on default, the device is in operating mode with the ADC converting. If Bit 6 is set to 1, the device is in standby mode and the ADC does not convert. Standby mode can also be selected by taking the STBY pin low. In standby mode, the values stored in the remote and local temperature registers remain at the values they were when the part was placed in standby. Bit 7 of the configuration register is used to mask the ALERT output. If Bit 7 is 0, which is the power−on default, the ALERT output is enabled. If Bit 7 is set to 1, the ALERT output is disabled. |
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