CS5520-BSZ Cirrus Logic Inc, CS5520-BSZ Datasheet - Page 11

• Manufacturer Part Number: CS5520-BSZ
• Description: IC ADC 20BIT BRIDGE TRAS 24-SOIC
• Manufacturer: Cirrus Logic Inc

Specifications of CS5520-BSZ

• Number Of Bits: 20
• Sampling Rate (per Second): 60
• Data Interface: Serial
• Number Of Converters: 2
• Power Dissipation (max): 37.5mW
• Voltage Supply Source: Analog and Digital, Dual ±
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-SOIC (0.300", 7.50mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 598-1102-5

THEORY OF OPERATION
The front page of this data sheet illustrates the
block diagram of the CS5516 and CS5520 A/D
converter. The device includes an instrumenta-
tion amplifier with a fixed gain of 25. This
chopper-stabilized instrumentation amplifier is
followed by a programmable gain stage with
gain settings of 1, 2, 4, and 8. The sensitivity of
the input is a function of the programmable gain
setting and of the reference voltage connected
between the VREF+ and VREF- pins of the de-
vice. The full scale of the converter is VREF/( G
x 25) in unipolar, or VREF/(G x 25) in bipolar,
where VREF is the reference voltage between
the VREF+ and VREF- pins, G is the gain set-
ting of the programmable gain amplifier, and 25
is the gain of the instrumentation amplifier.
DS74F1
DS74F2
Unused logic inputs
must be connected
to DGND or VD+
Figure 2. System Connection Diagram: DC Excitation Mode (EXC bit = 0), F1 = F0 = 0.
Analog
Supply
Analog
Supply
+5V
-5V
-
1 F
+
0.1 F
0.1 F
1 F
1 F
10
2
1
9
6
7
5
8
MDRV-
MDRV+
VREF+
VREF-
AIN+
AIN-
AGND1
AGND2
After the programmable gain block, the output
of a 4-bit DAC is combined with the input sig-
nal. The DAC can be used to add or subtract
offset from the analog input signal. Offsets as
large as 200 % of full scale can be trimmed
from the input signal.
The CS5516 and CS5520 are optimized to per-
form ratiometric measurement of bridge-type
transducers. The devices support dc bridge exci-
tation or two modes of ac (switched dc) bridge
excitation. In the switched-dc modes of opera-
tion the converter fully demodulates both the
reference voltage and the analog input signal
from the bridge.
VA+
VA-
4
3
CS5516
CS5520
10
10
SMODE
VD+
VD-
DGND
DRDY
XOUT
SCLK
21
SOD
20
RST
XIN
SID
CS
1 F
23
22
16
18
17
24
15
13
14
19
0.1 F
CS5516, CS5520
0.1 F
Interface
Optional
Source
Control
Serial
Clock
Logic
Data
1 F
11
11