CIRRUS LOGIC CS3001 Service Manual
CS3001
CS3002
Precision Low-voltage Amplifier; DC to 2 kHz
Features
Low Offset: 10 µV Max
Low Drift: 0.05 µV/°C Max
Low Noise
–6 nV/√Hz @ 0.5 Hz
– 0.1 to 10 Hz = 125 nVp-p
– 1/f corner @ 0.08 Hz
Open-loop Voltage Gain
– 300 dB Typical
– 200 dB Minimum
Rail-to-rail Output Swing
Slew Rate: 5 V/µs
Applications
Thermocouple/Thermopile Amplifiers
Load Cell and Bridge Transducer Amplifiers
Precision Instrumentation
Battery-powered Systems
Description
The CS3001 single amplifier and the CS3002 dual amplifier are designed for precision amplification of lowlevel signals and are ideally suited to applications that
require very high closed-loop gains. These amplifiers
achieve excellent offset stability, super-high open-loop
gain, and low noise over time and temperature. The devices also exhibit excellent CMRR and PSRR. The
common mode input range includes the negative supply
rail. The amplifiers operate with any total supply voltage
from 2.7 V to 6.7 V (±1.35 V to ±3.35 V).
Pin Configurations
PWDN
-In
+In
V-
CS3001
1
-
2
+
3
4
8-lead SOIC
8
7
6
5
NC
V+
Output
NC
Out A
-In A
+In A
CS3002
1
2
3
V-
4
8-lead SOIC
8
V+
A
+
-
7
Out B
B
6
+
-In B
-
5
+In B
Noise vs. Frequency (Measured)
100
10
nV/√Hz
1
0.001 0.01 0.1 1 10
Frequency (Hz)
http://www.cirrus.com
Dexter Research
Thermopile 1M
Copyright © Cirrus Logic, Inc. 2005
(All Rights Reserved)
CS3001
R2
64.9k
R1
100
Thermopile Amplifier with a Gain of 650 V/V
0.015
C1
µF
AUG ‘05
DS490F4
TABLE OF CONTENTS
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1. CHARACTERISTICS AND SPECIFICATIONS ............................................................3
1.1 Electrical Characteristics ......................................................................................3
1.2 Absolute Maximum Ratings ................ ...................... ....................... ..................... 4
2. PERFORMANCE PLOTS .............................................................................................4
3. CS3001/CS3002 OVERVIEW .......................................................................................7
3.1 Open Loop Gain and Phase Response ................. ... .... ... ... ... ... .... ... ... ... .... ... ... ... ..7
3.2 Open Loop Gain and Stability Compensation .......... .... ... ... ... ... .... ... ... ... .... ... ... ... ..8
3.3 Powerdown (PDWN) ... ... .... ... ... ... .................................................... ... ... .............10
3.4 Applications ..................................................... ... ... ... ..........................................10
4. PACKAGE DRAWING ...............................................................................................13
5. ORDERING INFORMATION ......................................................................................14
LIST OF FIGURES
Figure 1. Noise vs Frequency (Measured) .........................................................................4
Figure 2. 0.01 Hz to 10 Hz Noise .......................................................................................4
Figure 3. Noise vs Frequency ............................. ... ... .... ... ... ... .... ... ... ... ... .... ... ... ..................4
Figure 4. Offset Voltage Stability (DC to 3.2 Hz) ...............................................................4
Figure 5. Open Loop Gain and Phase vs Frequency .........................................................5
Figure 6. Open Loop Gain and Phase vs Frequency (Expanded) .....................................5
Figure 7. Input Bias Current vs Supply Voltage (CS3002) .................................................6
Figure 8. Input Bias Current vs Common Mode Voltage ...................................................6
Figure 9. CS3001/CS3002 Open Loop Gain and Phase Response ....................... ... ... ... ..7
Figure 10. Non-Inverting Gain Configuration .....................................................................8
Figure 11. Non-Inverting Gain Configuration with Compensation .............. ... ... ..................9
Figure 12. Loop Gain Plot: Unity Gain and with Pole-Zero Compensation ......... .............10
Figure 13. Thermopile Amplifier with a Gain of 650 V/V ..................................................11
Figure 14. Load Cell Bridge Amplifier and A/D Converter ...............................................12
CS3001
CS3002
Contacting Cirrus Logic Support
For all product questions and inquiries contact a Cirrus Logic Sales Representative.
To find the one nearest to you go to www.cirrus.com
IMPORTANT NOTICE
Cirrus Logic, Inc. and i ts subsidiaries (“Cirrus”) believe that the information contained in this document is accurate and reliable. However, the information is subject t
change without notice and is provided “AS IS” without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant info
mation to verify, before placing orders, that inform ation being relied on is current and complete. All pr oducts are sold subject to the term s and conditions of sale supplie
at the time of order acknowl edgment, i ncludin g those per taining to warra nty, in demnifica tion, an d limitat ion of l iabili ty. No r esponsibility is assumed by Cirrus for th
use of this information, including use of this information as the basis for manufacture or sale of any items, or for infring ement of patents or other rights of third partie
This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights, copyright
trademarks, trade secrets or other intellectual property rights. Cirrus owns the copyrights associated with the information contained herein and gives consent for copie
to be made of the information on l y for use wi t h i n you r or g aniz a ti on wit h r esp ect to Cirr u s integrated circuits or other pr oduc t s of Cirrus. This consent does not exten
to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale.
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPE
TY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE I
AIRCRAFT SYSTEMS, MILITARY APPLICATIONS, PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICE
LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO B
FULLY AT THE CUSTOMER'S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIE
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH
MANNER. IF THE CUSTOMER OR CUSTOMER'S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTO
ER AGREES, BY SUCH USE, TO FULLY INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER AGENTS FROM AN
AND ALL LIABILITY, INCLUDING ATTORNEYS' 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 product names in this document may be trademar ks
service marks of their respective owners.
2 DS490F4
1. CHARACTERISTICS AND SPECIFICATIONS
CS3001
CS3002
ELECTRICAL CHARACTERISTICS
V+ = +5 V, V- = 0V, VCM = 2.5 V
(Note 1)
CS3001/CS3002
Parameter
UnitMin Typ Max
Input Offset Voltage (Note 2) • --±10 µV
Average Input Offset Drift (Note 2) • - ±0.01 ±0.05 µV/ºC
Long Term Input Offset Voltage Stability (Note 3)
Input Bias Current T
Input Offset Current T
Input Noise Voltage DensityR
= 100 Ω, f0 = 1 Hz
S
R
= 100 Ω, f0 = 1 kHz
S
Input Noise Voltage 0.1 to 10 Hz - 125 nV
Input Noise Current Densityf0 = 1 Hz - 100
Input Noise Current 0.1 to 10 Hz - 1.9 pA
= 25º C
A
= 25º C
A
-
•
-
-
•
-
-
-
±100
-
±200
-
6
6
-
±1000
-
±2000
pA
pA
pA
pA
nV/ Hz
nV/ Hz
p-p
fA/ Hz
p-p
Input Common Mode Voltage Range • -0.1 - (V+)-1.25 V
Common Mode Rejection Ratio (dc) (Note 4) • 115 120 - dB
Power Supply Rejection Ratio • 120 136 - dB
Large Signal Voltage Gain R
Output Voltage Swing R
R
Slew Rate R
= 2 kΩ to V+/2 (Note 5) • 200 300 - dB
L
= 2 kΩ to V+/2
L
= 100 kΩ to V+/2
L
= 2 k, 100 pF 5 - V/µs
L
• +4.7 +4.99
-V
V
Overload Recovery Time - 100 - µs
Supply Current CS3001
CS3002
PWDN
PWDN
Threshold (Note 6)
active (CS3001 Only) (Note 6)
•
•
•
-
-
2.1
3.6
2.8
4.8
15
mA
mA
µA
• (V+) -1.0 - - V
Start-up Time (Note 7) • -912 ms
Notes: 1. Symbol “•” denotes specification applies over -40 to +85
° C.
2. This parameter is guaranteed by design and laboratory characterization. Thermocouple effects prohibit
accurate measurement of these parameters in automatic test systems.
3. 1000-hour life test data @ 125 °C indicates randomly distributed variation approximately equal to
measurement repeatability of 1 µV.
4. Measured within the specified common mode range limits.
5. Guaranteed within the output limits of (V+ -0.3 V) to (V- +0.3 V). Tested with proprietary production test
method.
6. PWDN
current consumption when PWDN
input has an internal pullup resistor to V+ of approximately 800 kΩ and is the major source of
is active low.
7. The device has a controlled start-up behavior due to its complex open loop gain characteristics. Startup time applies when supply voltage is applied or when PDWN
is released.
DS490F4 3
CS3001
0
0
5
0
0
5
0
0
0
CS3002
ABSOLUTE MAXIMUM RATINGS
Parameter Min Typ Max Unit
Supply Voltage [(V+) - (V-)] 6.8 V
Input Voltage V- -0.3 V+ +0.3 V
Storage Temperature Range -65 +150 ºC
2. PERFORMANCE PLOTS
Noise vs. Frequency (Measured)
100
10
nV/√Hz
1
0.001 0.01 0.1 1 10
Frequency (Hz)
Figure 1. Noise vs Frequency (Measured)
0
1
34 5
2
TIM E ( Se c)
6
78
9
10
1000
100
10
1
10 100 1K 10K 100K 1M 10M
Frequency ( Hz)
Figure 3. Noise vs Frequency
100
75
50
25
0
nV
-25
-50
-75
-100
Time (1 Hour)
= 13 nVσ
Figure 2. 0.01 Hz to 10 Hz Noise
Figure 4. Offset Voltage Stability (DC to 3.2 Hz)
4 DS490F4
Performance Plots (Cont.)
M
500
400
300
200
100
0
Gain (dB)
-100
-200
Phase (Degrees)
-300
-400
-500
GAIN
PHASE
1
1 10 100 1000 10000 100000 10000001E+07
10 100 1 K
Frequency (Hz)
Fre quency (Hz)
Figure 5. Open-loop Gain and Phase vs Frequency
10 K
100 K
1 M 10 M
CS3001
CS3002
100
80
60
40
Gain (dB)
20
0
-45
-90
-135
-180
-225
-270
Phase (Degrees)
-315
-360
10K
100K
1M
10
Figure 6. Open-loop Gain and Phase vs Frequency (Expanded)
DS490F4 5
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