Cirrus Logic CS3302A User Manual
CS3302A
High-Z, Programmable Gain, Differential Amplifier
Features & Description
z Signal Bandwidth: DC to 2 kHz
z
Selectable Gain: x1, x2, x4, x8, x16, x32, x64
z
Differential Inputs, Differential Outputs
• Multiplexed inputs: INA, INB, 800Ω termination
• Rough / fine charge outputs for CS5371A / 72A / 73A
• Max signal amplitude: 5 V
• Ultra-low input bias: < 1 pA
z
Excellent Noise Performance
•1µV
• 8.5 nV/ √Hz
Low Total Harmonic Distortion
z
• -118 dB THD typical (0.000126%)
• -112 dB THD maximum (0.000251%)
Low Power Consumption
z
• Normal operation: 5 mA
• Power down: 10 µA
Dual Power Supply Configuration
z
• VA+ = +2.5 V; VA- = -2.5 V;VD = +3.3V
between 0.1 Hz and 10 Hz
p-p
from 200 Hz to 2 kHz
differential
pp
Description
The CS3302A is a high input-impedance, differential input, differential output amplifier with programmable
gain, optimized for amplifying signals from high-impedance sensors such as hydrophones. The gain settings
are binary weighted (x1, x2, x4, x8, x16, x32, x64) an d
are selected using simple pin settings. Two sets of external inputs, INA and INB, simplify system design as
inputs from a sensor and test DAC. An internal 80 0Ω
termination can also be selected for noise tests.
Amplifier input impedance is very high, requiring less
than 1 pA of input current. Nois e performance is very
good at 1 µ
density of 8.5 nV/ √Hz
width. Distortion performance is also extrem ely good,
typically -118 dB THD. Low input current, low noise, and
low total harmonic distortion make this amplifier ideal for
high-impedance differential sensors requiring maximum
dynamic range.
ORDERING INFORMATION
See page 15.
V
between 0.1 Hz and 10 Hz, and a noise
p-p
over the 200 Hz to 2 kHz band-
VA+
INA+
INB+
MUX0
MUX1
400 Ω 400 Ω
INAINB-
VA-
Preliminary Product Information
http://www.cirrus.com
GUARD
+
-
-
+
PWDN
This document contains information for a new product.
Cirrus Logic reserves the right to modify this product without notice.
Copyright © Cirrus Logic, Inc. 2007
(All Rights Reserved)
VD
OUTR+
OUTF+
GAIN0
GAIN1
GAIN2
OUTFOUTR-
GND
NOV '07
DS765PP1
CS3302A
TABLE OF CONTENTS
1. CHARACTERISTICS AND SPECIFICATIONS ....................................................................... 4
SPECIFIED OPERATING CONDITIONS ................................................................................ 4
ABSOLUTE MAXIMUM RATINGS .......................................................................................... 4
THERMAL CHARACTERISTICS ............................................................................................. 5
ANALOG CHARACTERISTICS ....................... ................................ ................................... ..... 5
DIGITAL CHARACTERISTICS ........................ ................................... ................................ ..... 8
POWER SUPPLY CHARACTERISTICS ................................................................................. 9
2. GENERAL DESCRIPTION..................................................................................................... 10
2.1. Analog Signals..............................................................................................................10
2.2.1.Analog Inputs....................................................................................................... 10
2.3.2.Analog Outputs .................................................................................................... 11
2.4.3.Differential Signals ............................................................................................... 11
2.5.4.Guard Output ....................................................................................................... 11
2.6. Digital Signals ............................................................................................................... 12
2.7.1.Gain Selection...................................................................................................... 12
2.8.2.Mux Selection....................................................................................................... 12
2.9.3.Power Down Selection......................................................................................... 12
2.10. Power Supplies.......................... ............................................. ... ... .... ............................12
2.11.1.Analog Power Supplies................................ ... ... .... ... ... ... ... .... ... ... ...................... 12
2.12.2.Digital Power Supplies . ... ... ... ... .... ... ... ... .... ... ............................................. ... ... ... 12
2.13. Connection Diagram ..................................................................................................... 13
3. PIN DESCRIPTION...................... .... ... ... ... ... .... ... ... ... .............................................. ............... 14
4. ORDERING INFORMATION .... ... .... ... ............................................. ...................................... 15
5. ENVIRONMENTAL, MANUFACTURING, & HANDLING INFORMATION ........................... 15
6. PACKAGE DIMENSIONS...................................................................................................... 16
DS765PP1
CS3302A
LIST OF FIGURES
Figure 1. CS3302A Noise Performance.......................................................................................... 5
Figure 2. Digital Input Rise and Fall Times .....................................................................................8
Figure 3. System Architecture....................................................................................................... 10
Figure 4. System Architecture....................................................................................................... 11
Figure 5. CS3302A Amplifier Connections.................................................................................... 13
Figure 6. CS3302A Pin Assignments............................................................................................ 14
LIST OF TABLES
Table 1. Digital Selection for Gain and Input Mux Control ........................... .... ... ... ... .... ... ... ... ... .... . 8
Table 2. Pin Descriptions ............................................................................................................. 14
2 DS765PP1
CS3302A
DS765PP1
REVISION HISTORY
Revision Date Changes
PP1 NOV 2007 Initial release.
CS3302A
Contacting Cirrus Logic Support
For all product questions and inquiries contact a Cirrus Logic Sales Representative.
To find one nearest you go to www.cirrus.com
IMPORTANT NOTI CE
"Preliminary" product information describes products that are in production, but for which full characterization data is not yet available.
Cirrus Logic, Inc. and its subsidiaries (“Cirrus”) believe that the information contained i n thi s doc umen t is ac cur at e an d r el i able. However, the information is subject
to change without not ice and is pr ovided “AS IS ” without warr anty of any k ind (expres s or implie d). Custo mers are advi sed to obtai n the late st versio n of releva nt
information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale
supplied at the time of order acknowledgment, including those pertaining to warranty, indemnification, and limitation of liability. No responsibility is assumed by Cirrus
for the use of this information, inclu ding use of th is inform ation as the b asis for ma nufactur e or sale of any item s, or for in fringement of patents or other rights of third
parties. This document is the property of Cir rus an d by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights,
copyrights, trademarks, trade secrets or other intellectual property rights. Cirrus owns the copyrights associated with the information contained herein and gives consent for copies to be made of t he information only for use within your organization with respect to Cirrus integrated circuits or other products of Cirrus. This consent
does not extend to other copying such as copying for gen eral distribution, advertising or promotional purp oses, or for creating any work for resale.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE N OT DESIGNED, AUTHO RIZED OR WARRANT ED FOR USE
IN AIRCRAFT SYSTEMS, MILITARY APP LICATI ONS, PRODUCTS SURGICALL Y IMPLANTED INTO THE B ODY, AUTOMOT IVE SAFET Y OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD
TO BE FULLY AT THE CUSTOMER'S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANT Y, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED
IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER'S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FULLY INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER
AGENTS FROM ANY AND ALL LIABILITY, INCLUDING ATTORNEY S' FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH
THESE USES.
Cirrus Logic, Cirrus, and the Cirrus Logic logo designs are trademarks of Cirrus Logic, Inc. All other brand and pr oduct nam es in this document may be trademarks
or service marks of their respective owners.
DS765PP1 3
CS3302A
DS765PP1
CS3302A
1. CHARACTERISTICS AND SPECIFICATIONS
• Min/Max characteristics and specifications are guaranteed over the Specified Operating Conditions.
• Typical performance characteristics and specifications are derived from measurements taken at nominal supply voltages and T
= 25°C.
A
• GND = 0 V, all voltages with respect to 0 V.
• Device connected as shown in Figure 5 on page 12 unless otherwise noted.
SPECIFIED OPERATING CONDITIONS
Parameter Symbol Min Nom Max Unit
Bipolar Power Supplies
Positive Analog +
Negative Analog (Note 1) +
Positive Digital (Note 2) +
Thermal
Ambient Operating Temperature Industrial (-IS, -ISZ) T
Notes: 1. VA- must be the most negative voltage to avoid potential SCR latch-up conditions.
2. VD must conform to Digital Supply Differential under Absolute Maximum Ratings.
2% VA+ 2.45 2.50 2.55 V
2% V A- -2.55 -2.50 -2.45 V
3% VD 3.20 3.30 3.40 V
A
-40 25 85 °C
ABSOLUTE MAXIMUM RATINGS
CS3302A
Parameter Symbol
DC Power Supplies Positive Analog
Negative Analog
Digital
Analog Supply Differential [(VA+) - (VA-)] VA
Digital Supply Differential [(VD) - (VA-)] VD
Input Current, Any Pin Except Supplies (Note 3)I
Input Current, Power Supplies (Note 3)I
Output Current (Note 3)I
Power Dissipation PD - 500 mW
Analog Input Voltages V
Digital Input Voltages V
Storage Temperature Range T
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
Notes: 3. Transient currents up to 100mA will not cause SCR latch-up.
VA+
VA-
VD
DIFF
DIFF
IN
PWR
OUT
INA
IND
STG
-0.3
-6.8
-0.3
-6.8V
-6.8V
-+10 mA
-+50 mA
-+25 mA
(VA-)-0.5 (VA+)+0.5 V
-0.5 (VD)+0.5 V
-65 150 ºC
6.8
0.3
6.8
UnitMin Max
V
V
V
4 DS765PP1
CS3302A
DS765PP1
CS3302A
THERMAL CHARACTERISTICS
CS3302A
Parameter Symbol
Storage Temperature Range T
STR
-65 - 150 ºC
UnitMin Typ Max
Allowable Junction Temperature - - 125 ºC
Junction to Ambient Thermal Impedance Θ
Ambient Operating Temperature T
JA
A
-
65
-40 - +85 ºC
-
ºC / W
ANALOG CHARACTERISTICS
CS3302A
Parameter Symbol
Noise Performance
Input Voltage Noise f
Input Voltage Noise Density f0 = 200 Hz to 2 kHz VN
Input Current Noise Density (Note 4)IN
= 0.1 Hz to 10 Hz VN
0
PP
D
D
Distortion Performance
Total Harmonic Distortion (Note 5) x1
x2
x4
THD
x8
x16
x32
x64
Linearity (Note 5) x1
x2
x4
LIN
x8
x16
x32
x64
-1 3µV
-8.5 12
-20 -
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-118
-119
-119
-119
-118
-115
-112
0.0001259
0.0001122
0.0001122
0.0001122
0.0001259
0.0001778
0.0002512
-112
-
-
-
-
-
-
0.0002512
-
-
-
-
-
-
UnitMin Typ Max
nV/ Hz
fA/ Hz
pp
dB
%
Notes: 4. Guaranteed by design and/or characterization.
5. Tested with a 31.25 Hz sine wave at -1 dB amplitude.
CS3302A In-Band Noise
20
15
10
5
0
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Noise Density (nV/rtHz)
Frequency (Hz)
300
250
200
150
100
50
0
0.1 1 10 100 1000 10000 100000 1E+06
Noise Density (nV/rtHz )
CS3302A Wide Band Noise
Frequency (Hz)
Figure 1. CS3302A Noise Performance
DS765PP1 5
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