maxq7667 Maxim Integrated Products, Inc., maxq7667 Datasheet - Page 13

• Manufacturer Part Number: maxq7667
• Description: 16-bit, Risc, Microcontroller-based, Ultrasonic Distance-measuring System
• Manufacturer: Maxim Integrated Products, Inc.

28, 31, 33
27, 32
PIN
21
22
23
24
25
26
29
30
34
35
36
37
38
49
40
41
45
46
47
48
P1.0/TDO
P1.1/TMS
REG2P5
REG3P3
P1.2/TDI
ECHON
ECHOP
REFBG
GATE5
BURST
NAME
AGND
AVDD
XOUT
AIN0
AIN1
AIN2
AIN3
AIN4
N.C.
FILT
REF
______________________________________________________________________________________
Ultrasonic Distance-Measuring System
Crystal Oscillator Output. Connect an external crystal or resonator between XIN and XOUT. Leave
XOUT unconnected when driving XIN with a 2.5V level clock or when an external clock source is
not used.
+2.5V Voltage Regulator Output
+3.3V Voltage Regulator Output
+5V DVDDIO Voltage Regulator Control Output. GATE5 controls an external npn or nMOS
transistor that passes power to DVDDIO.
Reset Input/Output.
circuitry pulls
enabled and the watchdog timeout period expires. Force
PLL VCO Control Input. Connect external filter components on FILT for the internal PLL circuit. See
the Typical Application Circuit/Functional Diagram.
Analog Supply Voltage. Connect all AVDD inputs directly to a +3.3V source or to REG3P3 for self-
powered operation. Bypass each AVDD to AGND with a 0.1µF capacitor as close as possible to
the device.
Analog Ground. Connect all AGND nodes together. Connect to DGND at a single point.
Negative Echo Input. AC-couple ECHON to an ultrasonic transducer.
Positive Echo Input. AC-couple ECHOP to an ultrasonic transducer.
ADC Reference Input/Reference Buffer Output. When using the internal reference, the buffered
bandgap reference voltage (V
external reference, apply an external voltage source ranging between 1V and V
Disable the reference buffer when applying an external reference at REF. Bypass REF to AGND
with a 0.47µF capacitor.
+2.5V Reference Output/Reference Buffer Input. Bypass to AGND with a 0.47µF capacitor.
SAR ADC Input 0. AIN0 pairs with AIN1 in differential mode.
SAR ADC Input 1. AIN1 pairs with AIN0 in differential mode.
SAR ADC Input 2. AIN2 pairs with AIN3 in differential mode.
SAR ADC Input 3. AIN3 pairs with AIN2 in differential mode.
SAR ADC Input 4
No Connection. Internally connected. Leave unconnected.
Burst Output. Burst is the ultrasonic transducer excitation pulse output. BURST remains in three-
state mode on power-up.
Port 1 Data 0/JTAG Output. P1.0 is a general-purpose digital I/O. TDO is the JTAG serial data
output. Refer to the MAXQ7667 User’s Guide Sections 5 and 11.
Port 1 Data 1/JTAG Test Mode-Select Input. P1.1 is a general-purpose digital I/O. TMS is the JTAG
mode-select input. Refer to the MAXQ7667 User’s Guide Sections 5 and 11.
Port 1 Data 2/JTAG Input. P1.2 is a general-purpose digital I/O. TDI is the JTAG serial data input.
Refer to the MAXQ7667 User’s Guide Sections 5 and 11.
16-Bit, RISC, Microcontroller-Based,
low when V
is open drain with an internal pullup resistor to DVDDIO. Internal
REF
DVDDIO
) is provided for both SAR and sigma-delta ADCs. When using an
falls below its brownout reset value or watchdog reset is
FUNCTION
Pin Description (continued)
low externally for manual reset.
AVDD
at REF.
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