Cirrus Logic AN35 User Manual
An35, The cs5504 family characteristics
The CS5504/5/6/7/8/9 are a series of A/D
converters all derived from a high performance
∆Σ
architecture. The CS5504 family members
are based on a core architecture including both
an analog modulator and a digital filter, with
only subtle differences between the individual
products. The digital filter has been optimized
to attenuate ac line interference (50/60 Hz and
their harmonics) when the devices are operated
from a low-cost 32.768kHz crystal.
The use of a low-cost 32.768kHz clock provides
20 samples per second from the family. The
CS5505/6/7/8 can achieve up to 100
samples/second with a 163kHz system clock, while
the CS5504/9 can achieve up to 200
samples/second when operated from it’s maximum
input clock of 330 kHz. In achieving higher
conversion rates, the CS5504 requires slightly
higher operating currents than the CS5505/6/7/8.
The CS5509 achieves the same high conversion
rate as the CS5504 with lower power consumption,
but pays a slight penalty in linearity.
Table 1 summarizes the similarities and
differences of the CS5504 family.
The CS5504/9 come in smaller packages than
the CS5505/6/7/8, however, the CS5505/6/7/8
have more functionality and flexibility. The
CS5505/6/7/8 offer a sleep function, an on-chip
voltage reference, and multiple serial
communication modes.
Table 2 shows the CS5504 family’s wide array
of power supply options. Note: the CS5509 is
single supply, however, the VA+ supply for all
devices must always be the most positive
operating voltage under all operating conditions,
including start-up.
Application Note
The CS5504 Family Characteristics
Resolution
#Channels
Max.
Speed
3
Linearity
4
(Typical)
Sleep
Power
On-chip
VREF
Serial Port
Modes
5
Pin Count
CS5504
20-bits
2
1
200
0.0007%
No
4.4 mW
No
SEC
20
CS5505
16-bits
4
2
100
0.0015%
Yes
3 mW
Yes
SEC, SSC
24
CS5506
20-bits
4
2
100
0.0007%
Yes
3 mW
Yes
SEC, SSC
24
CS5507
16-bits
1
1
100
0.0015%
Yes
3 mW
Yes
SEC, SSC
20
CS5508
20-bits
1
1
100
0.0007%
Yes
3 mW
Yes
SEC, SSC
20
CS5509
16-bits
1
1
200
0.0015%
No
1.7 mW
No
SEC
16
Table 1. CS5504 Family Characteristics
Notes:
1. Fully-differential
2. Pseudo-differential
3. CS5509 is production tested at 330 kHz (200 samples/second)
All others are production tested at 32.768 kHz for the best 50/60 Hz rejection.
4. These linearity specifications are based on a 20Hz output rate using a 32.768kHz crystal.
5. SEC is synchronous external clocking of the data out while SSC is synchronous self-clocking.
VA+
VA-
VD+
CS5504/5/
6/7/8
+5 to +10V
0V
+5V
+5V
0 to -5V
+5V
+5V
0 to -5V
+3.3V
CS5509
+5V
-
+5V
+5V
-
+3.3V
Table 2. Power Supply Arrangements
JAN ’95
AN35REV2
1
Crystal Semiconductor Corporation
P.O. Box 17847, Austin, TX 78760
(512) 445-7222 FAX 445-7581
http://www.crystal.com
Copyright
Crystal Semiconductor Corporation 1996
(All Rights Reserved)
AN35