Cirrus Logic AN35 - Manual

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