Datasheet

MAXQ7667
16-Bit, RISC, Microcontroller-Based,
Ultrasonic Distance-Measuring System
8 _______________________________________________________________________________________
Note 1: Noise measured at bandpass filter output with ECHO+ and ECHO- shorted divided by the gain with f
BPF
= 50kHz.
Note 2: Gain adjust resolution typically ranges between 6.25% and 12.5%.
Note 3: LIN 2.0 specifies a maximim data rate of 20kbps. Higher data rates could be possible with compatible devices and suitable
line conditions.
ELECTRICAL CHARACTERISTICS (continued)
(V
DVDDIO
= +5V, V
AVDD
= +3.3V; V
DVDD
= +2.5V, system clock (f
SYSCLK
) = 16MHz, burst frequency (f
BURST
) = bandpass frequency
(f
BPF
) = 50kHz, C
REFBG
= C
REF
= 1µF in parallel with 0.01µF, f
ADCCLK
= 2MHz (SAR data rate = 125ksps), T
A
= T
MIN
to T
MAX
, unless
otherwise specified. Typical values are at T
A
= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SPI INTERFACE TIMING (Figures 11 and 12)
SPI Master Operating
Frequency
1/t
MCK
0.5 x f
SYSCLK
8 MHz
SPI Slave Operating
Frequency
1/t
SCK
0.25 x f
SYSCLK
4 MHz
SCLK Output Pulse-Width
High/Low
t
MCH
,
t
MCL
t
MCK
/2
- 25
ns
MOSI Output Hold Time
After SCLK Sample Edge
t
MOH
t
MCK
/2
- 25
ns
MOSI Output Valid to Sample
Edge
t
MOV
t
MCK
/2
- 25
ns
MISO Input Valid to SCLK
Sample Edge
t
MIS
25 ns
MISO Input Hold Time After
SCLK Sample Edge
t
MIH
0ns
SCLK Inactive to MOSI
Inactive
t
MLH
0ns
SCLK Input Pulse-Width
High/Low
t
SCH
,
t
SCL
t
SCK
/2 ns
SS Active to First Shift Edge t
SSE
4t
SYSCLK
ns
MOSI Input Setup Time to
SCLK Sample Edge
t
SIS
25 ns
MOSI Input Hold Time After
SCLK Sample Edge
t
SIH
25 ns
MISO Output Valid After
SCLK Shift Edge Transition
t
SOV
50 ns
SS Inactive Duration t
SSH
t
SYSCLK
+
25
ns
SCLK Inactive to SS Rising
Edge
t
SD
t
SYSCLK
+
25
ns
FLASH PROGRAMMING
Mass erase 200
Flash Erase Time
Page erase (512 bytes per page) 20
ms
Flash Programming Time 20µs per word 657 ms
Write/Erase Cycles 10,000 Cycles
Data Retention Average temperature = +85°C 15 Years