MAXQ7665BATM+ Maxim Integrated Products, MAXQ7665BATM+ Datasheet - Page 20

• Manufacturer Part Number: MAXQ7665BATM+
• Description: IC MCU-BASED DAS 16BIT 48-TQFN
• Manufacturer: Maxim Integrated Products
• Series: MAXQ™r

Specifications of MAXQ7665BATM+

• Core Processor: RISC
• Core Size: 16-Bit
• Speed: 8MHz
• Connectivity: CAN, LIN, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 8
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Ram Size: 256 x 16
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.25 V
• Data Converters: A/D 8x12b, D/A 1x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 48-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

16-Bit RISC Microcontroller-Based
Smart Data-Acquisition Systems
The MAXQ7665A–MAXQ7665D ADC uses a fully differ-
ential SAR conversion technique and an on-chip T/H
block to convert temperature and voltage signals into a
12-bit digital result. Differential configurations are sup-
ported using an analog input channel MUX that sup-
ports eight differential channels.
The differential analog inputs are selected from the fol-
lowing pairs: AIN0/AIN1, AIN2/AIN3, AIN4/AIN5,
AIN6/AIN7, AIN8/AIN9, AIN10/AIN11, AIN12/AIN13,
and AIN14/AIN15.
Remote temperature-sensor configuration in differential
mode uses analog input channel pairs AIN2/AIN3 and
AIN0/AIN1. In single-ended remote temperature-sensor
configuration, only channels AIN2 and AIN0 are used.
Internal temperature-sensor configuration measures
local die temperature and does not use any analog
input channel.
There are four ways to control the ADC conversion timing:
1) Software register bit control
2) Continuous conversion
3) Internal timers (T0, T1, or T2)
4) External input through pin ADCCNV
Refer to the MAXQ7665/MAXQ7666 User’s Guide for
more detailed information on the ADC and MUX.
The MAXQ7665A–MAXQ7665D contain a 12-bit voltage-
output DAC with its own output buffer. The data path to
the DAC is double buffered and the output register can
be updated using the DACLOAD digital input. Refer to
the MAXQ7665/MAXQ7666 User’s Guide for detailed
programming information. The DAC also supports a
square-wave-output toggle mode with precise ampli-
tude control for applications that require pulse-ampli-
tude modulation (PAM) and/or pulse-width modulation
(PWM) signals. See Figure 2 for a simplified block dia-
gram of the DAC.
20
12-Bit Digital-to-Analog Converter (DAC)
_______________________________________________________________________________________
The DAC output buffer is in a voltage follower configu-
ration (gain of 1V/V from REFDAC). The buffer can be
disabled when not in use. When the buffer is disabled,
the output is connected internally to AGND through a
100kΩ resistor. The reference input REFDAC accepts
an input voltage of less than or equal to AV
maximum output swing of 0V to AV
The µC measures temperature by using the on-chip
ADC and a ROM-based tempConv subroutine. Use the
tempConv subroutine to initiate a measurement (refer to
the MAXQ7665/MAXQ7666 User’s Guide for detailed
information). The device supports conversions of two
external and one on-chip (internal) temperature sen-
sors. The external temperature sensor is typically a
diode-connected small-signal transistor, connected
between two analog inputs (differential) or one analog
input and AGND (single-ended). Figures 3 and 4 illus-
trate these two configurations.
Figure 2. Simplified DAC Diagram
P0.5/DACLOAD
DAC INPUT
REGISTER
DAC LOAD
CONTROL
DAC OUTPUT
REGISTER
MAXQ7665A–MAXQ7665D
Temperature Sensor
REFDAC
12-BIT DAC
DACE
DD
.
R
R
DD
DACOUT
for a