COP8AME9_14 Datasheet, PDF (68/102 Pages) Texas Instruments – COP8AME9 8-Bit CMOS Flash Microcontroller with 8k Memory, Dual Op Amps, Virtual EEPROM, Temperature Sensor, 10-Bit A/D and Brownout Reset

COP8AME9, COP8ANE9
SNOS930F – MARCH 2001 – REVISED MARCH 2013
www.ti.com
where T is the temperature in °C.
The user can achieve greater temperature sensor accuracy by performing a two temperature calibration to
compensate for device-to-device variations in slope and base value for V_OUT.
OPERATION
The Temperature Sensor is used in conjunction with the on-chip Programmable Gain Amplifier and A/D converter
to read the Temperature Sensor output voltage. The Programmable Gain Amplifier must be used and the gain
can be set at either 1 or 2, depending on the operating voltage of the device. To use a gain of 2, V_CC should be
greater than 4.5V. The output voltage given in the above equation is for a gain of 1. The Temperature Sensor is
connected to channel 7 on the A/D Converter multiplexor. See the A/D Converter section for more details on
using the ENAD and ADGAIN registers.
The Temperature Sensor is enabled by setting the ENTS bits in the ADGAIN register to a 1. The circuit will draw
power when it's enabled. When disabled, the current drawn is extremely low. When using the HALT mode of the
device, the Temperature Sensor will draw current unless it is disabled by software. Therefore, for minimal current
in HALT mode, the Temperature Sensor should be disabled prior to entering HALT. A Reset will disable the
Temperature Sensor.
Procedure for Reading the Temperature Sensor Voltage
The following steps should be followed for measuring the temperature sensor voltage:
1. Enable the Temperature Sensor by setting the ENTS bit in the ADGAIN register to 1. The Programmable
Gain Amplifier gain should also be selected to be either 1 or 2.
2. Wait 350 µs for the temperature sensor to stabilize. This is only required after ENTS bit is changed from 0 to
1.
3. Load the ENAD register with the channel number for the temperature sensor, and the desired prescale value.
The ADMOD, MUX, and ADBSY bits should be 0.
4. Wait for the Programmable Gain Amplifier to stabilize with the voltage for the newly selected channel.
5. Set the ADBSY bit in the ENAD register. The other bits in the ENAD register should be the same as in step
3.
6. Wait for the ADBSY bit to go to 0 and then read the output of the A/D Converter result registers, ADRSTH
and ADRSTL.
7. Subsequent readings of the temperature sensor can be done by repeating steps 5 and 6, as long as the
channel number in ENAD has not changed from that of the temperature sensor. If the channel number has
been changed to measure other channels, in between two successive temperature sensor readings, then
steps 1–6 should be followed.
Stand-Alone Amplifier
A stand-alone Amplifier, AMP1, is provided on Port B. It supports rail-to-rail inputs and outputs, and operates
over the entire V_CC and temperature range. This amplifier is in addition to the programmable gain amplifier in the
A/D Converter. It is an alternate function on Port B.
It is enabled/disabled by the ENAMP1 bit in the ADGAIN register described in the A/D Converter section. The
normal port B3–B5 pins should be configured in their high Z state when using AMP1. It is disabled after Reset.
The circuit will only draw current when it's enabled. When disabled, the current drawn is extremely low.
When using the HALT mode of the device, AMP1 will draw current unless it is disabled by software. Therefore,
for minimal current in HALT mode, AMP1 should be disabled prior to entering HALT.
The electrical parameters of AMP1 are shown in the Electrical Characteristics section.
BLOCK DIAGRAM
Figure 32. Amplifier1 Block Diagram
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