Datasheet

MAXQ7667
16-Bit, RISC, Microcontroller-Based,
Ultrasonic Distance-Measuring System
_______________________________________________________________________________________ 3
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
BANDPASS FILTER
Center Frequency f
BPF
25 100 kHz
Passband Width -3dB 0.14 x f
BPF
kHz
Minimum Stopband
Rejection
One decade away from center
frequency
-60 dB
Output Data Rate 10 x f
BPF
ksps
Output Data Resolution 16 Bits
LOWPAS S FILTER
Corner Frequency f
LPF
-3dB 0.1 x f
BPF
kHz
Rolloff 40 dB/Decade
Output Data Rate 5 x f
BPF
ksps
Output Data Resolution 16 Bits
SAR ADC
Measurement 12
Resolution
No missing codes 11
Bits
Integral Nonlinearity Tested at 125ksps ±1 ±2 LSB
Differential Nonlinearity Tested at 125ksps -2 +2 LSB
Offset Error ±1 ±3 mV
Offset-Error Drift ±5 µV/°C
Gain Error ±1 %
Gain-Error Temperature
Coefficient
±0.4 ppmFS/°C
Input-Referred Noise At ADC inputs 400 µV
RMS
Unipolar 0 V
REF
Differential Input Range
Bipolar -V
REF
/2 +V
REF
/2
V
Absolute Input Range 0 V
AVDD
V
Input Leakage Current ±0.1 µA
Conversion Time 13 ADCCLK cycles at 2MHz 6.5 µs
Input Capacitance 14 pF
Track-and-Hold Acquisition
Time
Three ADCCLK cycles at 2MHz 1.5 µs
Turn-On Time Eight ADCCLK cycles at 2MHz 4 µs
Conversion Clock
f
ADCCLK
0.5 4 MHz
Conversion Rate
f
ADCCLK
= 4MHz (not production
tested)
250 ksps