Cirrus CS3302 High z programmable gain differential amplifier Datasheet

CS3302
High-Z Programmable Gain Differential Amplifier
Features
Description
Signal bandwidth: DC to 2 kHz
Selectable gain: x1, x2, x4, x8, x16, x32, x64
Differential inputs, differential outputs
•
•
•
•
Multiplexed inputs: INA, INB, 800Ω termination
Rough / fine charge outputs for CS5371/72
Max signal amplitude: 5 Vp-p differential
Ultra-low input bias: < 1 pA
Excellent noise performance
The CS3302 is a high input impedance differential in, differential out 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) and 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 800Ω termination can also be selected for noise tests.
• Normal / LPWR / PWDN: 5 mA, 3.3 mA, 10 µA
Amplifier input impedance is very high, requiring less
than 1 pA of input current. Noise performance is very
good at 1 µVp-p between 0.1 Hz and 10 Hz, and a noise
density of 8.5 nV/ √Hz over the 200 Hz to 2 kHz bandwidth. Distortion performance is also extremely 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.
Single or dual power supply configurations
ORDERING INFORMATION
• 1 µVp-p between 0.1 Hz and 10 Hz
• 8.5 nV/ √Hz from 200 Hz to 2 kHz
Low total harmonic distortion
• -118 dB THD typical (0.000126%)
• -112 dB THD maximum (0.000251%)
Low power consumption
• VA+ = +5 V; VA- = 0 V; VD = +3.3 V to +5 V CS3302-IS
• VA+ = +2.5 V;VA- = -2.5 V;VD = +3.3 V
VA+
INA+
INB+
GUARD
-40ºC to +85ºC
VD
750 Ω
500
+
OUTR+
OUTF+
400 Ω
750 Ω
500
GAIN0
GAIN1
GAIN2
400 Ω
MUX0
MUX1
500
750 Ω
-
INAINB-
750 Ω
500
+
VA-
Preliminary Product Information
Cirrus Logic, Inc.
www.cirrus.com
24-pin SSOP
LPWR
PWDN
OUTFOUTR-
DGND
This document contains information for a new product.
Cirrus Logic reserves the right to modify this product without notice.
Copyright  Cirrus Logic, Inc. 2003
(All Rights Reserved)
JUN ‘03
DS596PP2
1
CS3302
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..................................................................................................... 10
2.4.3.Differential Signals ............................................................................................... 11
2.5.4.Guard Output........................................................................................................ 11
2.6. Digital Signals................................................................................................................ 11
2.7.1.Gain Selection ...................................................................................................... 11
2.8.2.Mux Selection ....................................................................................................... 11
2.9.3.Low Power Selection ............................................................................................ 11
2.10.4.Power Down Selection ....................................................................................... 11
2.11. Power Supplies ............................................................................................................. 11
2.12.1.Analog Power Supplies ...................................................................................... 11
2.13.2.Digital Power Supplies ....................................................................................... 12
2.14. Connection Diagram...................................................................................................... 13
3. PIN DESCRIPTION ................................................................................................................ 14
4. PACKAGE DIMENSIONS ...................................................................................................... 15
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 NOTICE
“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 in this document is accurate and reliable. However, the information is subject to 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 information to verify, before
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or service marks of their respective owners.
2
CS3302
LIST OF FIGURES
Figure 1. CS3302 Noise Performance ............................................................................................ 5
Figure 2. Digital Input Rise and Fall Times ..................................................................................... 8
Figure 3. System Architecture....................................................................................................... 10
Figure 4. CS3302 Amplifier Connections ...................................................................................... 13
Figure 5. CS3302 Pin Assignments .............................................................................................. 14
LIST OF TABLES
Table 1. Digital Selection for Gain and Input Mux Control ............................................................. 8
Table 2. Pin Descriptions ............................................................................................................. 14
3
CS3302
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 TA = 25°C.
•
DGND = 0 V, all voltages with respect to 0 V.
SPECIFIED OPERATING CONDITIONS
Parameter
Symbol
Min
Nom
Max
Unit
VA+
4.75
5.0
5.25
V
Unipolar Power Supplies
Positive Analog
Negative Analog
(Note 1)
VA-
-0.25
0
0.25
V
Positive Digital
(Note 2)
VD
3.135
3.3
5.25
V
VA+
2.375
2.5
2.625
V
Bipolar Power Supplies
Positive Analog
Negative Analog
(Note 1)
VA-
-2.625
-2.5
-2.375
V
Positive Digital
(Note 2)
VD
3.135
3.3
3.465
V
Industrial (-IS)
TA
-40
-
85
°C
Thermal
Ambient Operating Temperature
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.
ABSOLUTE MAXIMUM RATINGS
CS3302
Parameter
DC Power Supplies
Positive Analog
Negative Analog
Digital
Symbol
Min
Max
Unit
VA+
VAVD
-0.3
-6.8
-0.3
6.8
0.3
6.8
V
V
V
Analog Supply Differential
[(VA+) - (VA-)]
VADIFF
-
6.8
V
Digital Supply Differential
[(VD) - (VA-)]
VDDIFF
-
6.8
V
Input Current, Any Pin Except Supplies
(Note 3)
IIN
-
+10
mA
Input Current, Power Supplies
(Note 3)
IIN
-
+50
mA
Output Current
(Note 3)
IOUT
-
+25
mA
Power Dissipation
PDN
-
500
mW
Analog Input Voltages
VINA
(VA-)-0.3
(VA+)+0.3
V
Digital Input Voltages
VIND
-0.3
(VD)+0.3
V
TA
-40
85
ºC
TSTG
-65
150
ºC
Ambient Operating Temperature (Power Applied)
Storage Temperature Range
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.
4
CS3302
THERMAL CHARACTERISTICS
CS3302
Parameter
Symbol
Allowable Junction Temperature
Min
Typ
Max
Unit
-
-
135
ºC
65
-
ºC / W
-
+85
ºC
Junction to Ambient Thermal Impedance
ΘJA
-
Ambient Operating Temperature (Power Applied)
TA
-40
ANALOG CHARACTERISTICS
CS3302
Parameter
Symbol
Min
Typ
Max
Unit
Noise Performance, Normal Power
Input Voltage Noise
f0 = 0.1 Hz to 10 Hz
VN PP
-
1
1.5
µVp-p
Input Voltage Noise Density
f0 = 200 Hz to 2 kHz
VND
-
8.5
12
nV/ Hz
Input Current Noise Density
(Note 4)
IND
-
1
-
fA/ Hz
Noise Performance, Low Power (LPWR=1)
Input Voltage Noise
f0 = 0.1 Hz to 10 Hz
VN PP
-
1
1.5
µVp-p
Input Voltage Noise Density
f0 = 200 Hz to 2 kHz
VND
-
10
15
nV/ Hz
Input Current Noise Density
(Note 4)
IND
-
1
-
fA/ Hz
Total Harmonic Distortion
(Note 5, 6)
THD
-
-118
-112
dB
Linearity
(Note 5, 6)
LIN
-
0.000126
0.000251
%
Distortion Performance, Normal Power
Distortion Performance, Low Power (LPWR=1)
Total Harmonic Distortion
(Note 5, 6)
THD
-
-118
-110
dB
Linearity
(Note 5, 6)
LIN
-
0.000126
0.000316
%
Notes: 4. Guaranteed by design and/or characterization.
5. Tested with a full scale input signal of 31.25 Hz.
6. Noise in the harmonic bins dominates THD and linearity measurements for x16, x32, and x64 gains.
CS3302 In-Band Noise
CS3302 Wide Band Noise
300
Noise Density (nV/rtHz)
Noise Density (nV/rtHz)
20
15
10
5
250
200
150
100
50
0
0
0
200 400
600
800 1000 1200 1400 1600 1800 2000
0.1
1
10
100
1000
10000 100000 1E+06
Frequency (Hz)
Frequency (Hz)
Figure 1. CS3302 Noise Performance
5
CS3302
ANALOG CHARACTERISTICS (CONT.)
CS3302
Parameter
Symbol
Min
Typ
Max
Gain, Differential
GAINDM
x1
-
x64
Gain, Common Mode
GAINCM
-
x1
-
GAABS
-
+1
+2
Unit
Gain
%
Gain Accuracy, Absolute
(Note 7, 9)
Gain Accuracy, Relative
(Note 8, 9)
GAREL
-
+0.4
+0.8
%
(Note 4)
GAIN TC
-
5
-
ppm / ºC
OFST
-
+250
+750
µV
Gain Drift
Offset
Offset Voltage, Input Referred
(Note 9, 10)
Offset After Calibration, Absolute
(Note 11) OFSTCAL
-
+1
-
µV
Offset Calibration Range
(Note 12) OFSTRNG
(Note 4) OFSTTC
-
100
-
% F.S.
-
1
-
µV / ºC
Offset Voltage Drift
Notes: 7. Absolute gain accuracy tests the matching of x1 gain across multiple CS3302 devices.
8. Relative gain accuracy tests the tracking of x2 - x64 gain relative to x1 gain on a single CS3302 device.
9. Specification is for the parameter over the specified temperature range and is for the CS3302 device
only. It does not include the effects of external components.
10. Offset voltage is tested with the amplifier inputs connected to the internal 800Ω termination.
11. The absolute offset after calibration specification applies to the effective offset voltage of the CS3302
output when used with the CS5371/72 modulator and CS5376A digital filter, and is measured from the
digitally calibrated output codes of the CS5376A.
12. The CS3302 offset calibration is performed digitally with the CS5371/72 modulator and CS5376A digital
filter and includes the full scale signal range. Calibration offsets of greater than + 5% of full scale will
begin to subtract from system dynamic range.
6
CS3302
ANALOG CHARACTERISTIC (Cont.)
CS3302
Parameter
Symbol
Min
Typ
Max
Unit
BW
DC
VIN
(VA-)+0.7
(VA-)+0.7
-
2000
Hz
-
(VA+)-1.25
(VA+)-1.75
V
VINFS
-
-
5
2.5
1.25
625
312.5
156.25
78.125
Vp-p
Vp-p
Vp-p
mVp-p
mVp-p
mVp-p
mVp-p
Input Impedance, Differential
ZINDIFF
-
1, 20
-
TΩ, pF
Input Impedance, Common Mode
ZINCM
-
0.5, 40
-
TΩ, pF
Analog Input Characteristics
Input Signal Frequencies
Input Voltage Range (Signal + Vcm)
(Note 13)
Full Scale Input, Differential
x1
x2 - x64
x1
x2
x4
x8
x16
x32
x64
IIN
-
1
40
pA
XT
-
-130
-
dB
CDMR
90
100
-
dB
VOUT
(VA-)+0.5
-
(VA+)-0.5
V
VOUTFS
-
-
5
Vp-p
ZOUT
-
750
-
Ω
IOUT
-
-
3.33
mA
CL
-
-
100
nF
Guard Output Voltage
VGUARD
-
Vcm
-
V
Guard Output Impedance
ZGOUT
-
500
-
Ω
Guard Output Current
IG OUT
-
40
-
µA
CGL
-
-
100
pF
Input Bias Current
Crosstalk, Multiplexed Inputs
(Note 4)
Common Mode to Differential Mode Rejection (Note 14)
Analog Output Characteristics
Output Voltage Range (Signal + Vcm)
Full Scale Output, Differential
Output Impedance
Output Current
Load Capacitance
(Note 15)
Guard Output Characteristics
Guard Load Capacitance
Notes: 13. No signal sources operating from external supplies should be applied to pins of the device prior to its
own supplies being established. Connecting any terminal to voltages greater than VA+ or less than VAmay cause destructive latch-up.
14. Common-to-differential mode rejection tested with a 50 Hz, 500 mVp-p common mode sine wave
applied to the analog inputs.
15. Output impedance is primarily determined by the integrated anti-alias resistors. Value is approximate
and can vary +/- 30% depending on process parameters.
7
CS3302
DIGITAL CHARACTERISTICS
CS3302
Parameter
Symbol
Min
Typ
Max
Unit
Digital Characteristics
High Level Input Drive Voltage
(Note 16)
VIH
0.6*VD
-
VD
V
Low Level Input Drive Voltage
(Note 16)
VIL
0.0
-
0.8
V
IIN
-
+1
+10
µA
Input Leakage Current
CIN
-
9
-
pF
Rise Times
tRISE
-
-
100
ns
Fall Times
tFALL
-
-
100
ns
Digital Input Capacitance
Notes: 16. Device is intended to be driven with CMOS logic levels.
t risein
t fallin
(0.8*VD)
(0.2*VD)
Figure 2. Digital Input Rise and Fall
Input Selection
MUX1
MUX0
Gain Selection
GAIN2
GAIN1
GAIN0
800 Ω termination
0
0
x1
0
0
0
INA only
1
0
x2
0
0
1
INB only
0
1
x4
0
1
0
INA + INB
1
1
x8
0
1
1
x16
1
0
0
x32
1
0
1
x64
1
1
0
Reserved
1
1
1
Table 1. Digital Selection for Gain and Input Mux Control
8
CS3302
POWER SUPPLY CHARACTERISTICS
CS3302
Parameter
Symbol
Min
Typ
Max
Unit
Power Supply Current, Normal Mode
Analog Power Supply Current
(Note 17)
IA
-
5.0
5.75
mA
Digital Power Supply Current
(Note 17)
ID
-
0.1
0.2
mA
Power Supply Current, Low Power Mode
Analog Power Supply Current, LPWR = 1
(Note 17)
IA
-
3.4
4.0
mA
Digital Power Supply Current, LPWR = 1
(Note 17)
ID
-
0.1
0.2
mA
Analog Power Supply Current, PWDN = 1
(Note 17)
IA
-
9
11
µA
Digital Power Supply Current, PWDN = 1
(Note 17)
ID
-
2
8
µA
(Note 18)
PSRR
95
120
-
dB
Power Supply Current, Power Down Mode
Power Supply Rejection
Power Supply Rejection Ratio
Notes: 17. All outputs unloaded. Analog inputs connected to the internal 800 Ω termination. Digital inputs forced to
VD or DGND respectively.
18. Power supply rejection tested with a 50 Hz, 400 mVp-p sine wave applied separately to each supply.
9
CS3302
2.
GENERAL DESCRIPTION
The CS3302 is a high impedance low-noise CMOS
differential input, differential output amplifier for
precision analog signals between DC and 2 kHz. It
has multiplexed inputs, rough/fine charge outputs,
and programmable gains of x1, x2, x4, x8, x16,
x32, and x64.
The amplifier’s performance makes it ideal for
low-frequency, high dynamic range applications
requiring low distortion and minimal power consumption. It’s optimized for use in acquisition systems designed around the CS5371/72 single/dual
∆Σ modulators and the CS5376A quad digital filter. Figure 3 shows the system level architecture
of a 4-channel acquisition system using four
CS3302, two CS5372, and one CS5376A.
Differential
Sensor
2.1
Analog Signals
2.1.1
Analog Inputs
The amplifier analog inputs are designed for high
impedance differential sensors. Input multiplexing
simplifies system connections by providing separate inputs for a sensor and test DAC (INA, INB) as
well as an internal termination for noise tests. The
MUX0, MUX1 digital pins determine which multiplexed input is connected to the amplifier.
2.1.2
Analog Outputs
The amplifier analog outputs are separated into
rough charge / fine charge signals to easily connect
to the CS5371/72 inputs. Each output also includes
a series resistor, requiring only two differential capacitors to create the CS5371/72 input anti-alias
filter.
CS3302
M
U
X
CS5371/72
AMP
CS89712
∆Σ
Modulator
Differential
Sensor
EP7312
CS3302
M
U
X
AMP
CS5376
CS5376A
µController
or
Configuration
EEPROM
Digital Filter
Differential
Sensor
CS3302
M
U
X
CS8900A
CS5371/72
AMP
System
Telemetry
∆Σ
Modulator
Differential
Sensor
CS3302
M
U
X
AMP
Test
DAC
Figure 3. System Architecture
10
CS4373
CS3302
2.1.3
Differential Signals
Analog signals into and out of the CS3302 are differential, consisting of two halves with equal but
opposite magnitude varying about a common mode
voltage.
A full scale 5 Vpp differential signal centered on a
2.5 V common mode can have:
SIG+ = 2.5 V + 1.25 V = 3.75 V
SIG- = 2.5 V - 1.25 V = 1.25 V
SIG+ is +2.5 V relative to SIGFor the reverse case:
SIG+ = 2.5 V - 1.25 V = 1.25 V
SIG- = 2.5 V + 1.25 V = 3.75 V
SIG+ is -2.5 V relative to SIGThe total swing for SIG+ relative to SIG- is
(+2.5 V) - (-2.5 V) = 5 Vpp. A similar calculation
can be done for SIG- relative to SIG+. Note that a
5 Vpp differential signal centered on a 2.5 V common mode voltage never exceeds 3.75 V and never
drops below 1.25 V on either half of the signal.
2.1.4
Guard Output
The GUARD pin outputs the common mode voltage of the currently selected analog signal input. It
can be used to drive the cable shield between a high
impedance sensor and the amplifier inputs. Driving
the cable shield with the analog signal common
mode voltage minimizes leakage and improves signal integrity from high impedance sensors.
The GUARD output is defined as the midpoint
voltage between the + and - halves of the currently
selected differential input signal, and will vary as
the signal common mode varies. The GUARD output will not drive a significant load, it only provides
a shielding voltage.
2.2
2.2.1
Digital Signals
Gain Selection
The CS3302 supports gain ranges of x1, x2, x4, x8,
x16, x32, and x64. They are selected using the
GAIN0, GAIN1, and GAIN2 pins as shown in
Table 1 on page 8.
2.2.2
Mux Selection
The analog inputs to the amplifier are multiplexed,
with external signals applied to the INA+, INA- or
INB+, INB- pins. An internal termination is also
available for noise tests. Input mux selection is
made using the MUX0 and MUX1 pins as shown in
Table 1 on page 8.
Although a mux selection is provided to enable the
INA and INB switches simultaneously, significant
current should not be driven through them in this
mode. The CS3302 mux switches will maintain
good linearity only with minimal signal current.
2.2.3
Low Power Selection
For applications where power is critical, a lowpower mode can be selected. This mode reduces
amplifier power consumption at the expense of
slightly degraded performance. Low power mode
is selected using the LPWR pin, which is active
high.
2.2.4
Power Down Selection
A power-down mode is available to shut down the
amplifier when not in use. When enabled, all internal circuitry is disabled, the analog inputs and outputs go high-impedance, and the device enters a
micro-power state. Power down mode is selected
using the PWDN pin, which is active high.
2.3
2.3.1
Power Supplies
Analog Power Supplies
The analog power pins of the CS3302 are to be supplied with a total of 5 V between VA+ and VA-.
This voltage can be from a unipolar +5 V / 0 V supply or a bipolar +2.5 V / -2.5 V supply. When using
a unipolar supply, analog signal common mode
should be biased to 2.5 V, and when using bipolar
supplies it should be biased to 0 V. The analog
power supplies are recommended to be bypassed to
system ground using 0.1 µF X7R type capacitors.
11
CS3302
The VA- supply is connected to the CMOS substrate and as such must remain the most negative
applied voltage to prevent potential latch-up conditions. Care should be taken to ensure analog input
voltages do not drop more than -0.3 V below the
VA- supply. Care should also be taken to establish
the VA- supply before analog signals are applied to
the device. It is recommended to clamp the VAsupply to system ground using a reverse biased
Schottky diode to prevent possible latch-up condi-
12
tions related to mismatched supply rail initialization.
2.3.2
Digital Power Supplies
The digital power supply across the VD and DGND
pins is flexible and can be set to interface with
3.3 V or 5 V logic. The digital power supply should
be bypassed to system ground using a 0.01 µF X7R
type capacitor.
CS3302
2.4
Connection Diagram
Figure 4 shows a connection diagram for the
CS3302 amplifier when used with the CS5372 dual
∆Σ modulator and CS5376A digital filter. The diagram shows differential sensors, a test DAC, and
analog outputs with anti-alias capacitors; power
supply connections including recommended bypassing; and digital control connections back to the
CS5376A GPIO pins.
G PIO (x3)
G PIO (x2)
G PIO
G PIO
3
2
GA IN
MUX
PWDN
To CS 5376 A
D ig ital C on tro l
LPW R
VA +
VD
VA +
VA +
VD
0 .1 µF
0 .0 1µF
VD
0 .1 µF
C S3302
D ifferential
Am p lifier
0.0 1 µF
VA -
VA +
VA -
0 .1 µF
IN A +
VD
D GN D
IN A -
GU AR D
IN B -
IN B + O UT R -
OU TF -
OU T F+
O UT R+
M DA TA 1
M FL A G1
PW DN 1
INR +
INF +
0.0 2 µF
C0 G
0 .0 2µF
C 0G
INF INR -
D ifferential
Senso r
M C LK
M SYN C
V RE F+
CS4373
Test
DAC
2.5 V
R eference
C S5372
∆Σ M o du lator
V RE F-
D ifferential
Senso r
LP W R
OF ST
INR INF 0.0 2 µF
C0 G
0 .0 2µF
C 0G
INF +
INR +
IN A +
IN A -
G U AR D
IN B -
IN B + O UT R -
OU TF -
OU T F+
O UT R+
VA +
VD
V A+
VD
VA -
0 .1 µF
C S3302
D ifferential
Am p lifier
0.0 1 µF
VA V A0 .1 µF
M DA TA 2
M FL A G2
PW DN 2
0.1µF
D GN D
G A IN
M UX
PW D N
2
3
D GN D
V A-
LP W R
G PIO
G PIO
G PIO (x2)
G PIO (x3)
To CS 5376 A
D ig ital C on tro l
Figure 4. CS3302 Amplifier Connections
13
CS3302
3.
PIN DESCRIPTION
Positive Analog Power Supply
VA+
1
24
MUX0
Input Mux Select
Negative Analog Rough Output
OUTR-
2
23
MUX1
Input Mux Select
Negative Analog Fine Output
OUTF-
3
22
GAIN0
Gain Range Select
Negative Analog Power Supply
VA-
4
21
GAIN1
Gain Range Select
Non-Inverting Input A
INA+
5
20
GAIN2
Gain Range Select
Inverting Input A
INA-
6
19
PWDN
Power Down Mode Enable
Inverting Input B
INB-
7
18
LPWR
Low Power Mode Enable
Non-Inverting Input B
INB+
8
17
TEST1
Test Mode Select
Test Mode Output
TESTOUT
9
16
VD
Positive Digital Power Supply
Positive Analog Fine Output
OUTF+
10
15
DGND
Digital Ground
Positive Analog Rough Output
OUTR+
11
14
TEST2
Test Mode Select
Test Mode Select
TEST0
12
13
GUARD
Guard Voltage Output
Figure 5. CS3302 Pin Assignments
Pin Name
Pin #
I/O
1
I
Positive analog supply voltage.
VA-
4
I
Negative analog supply voltage.
VD
16
I
Positive digital supply voltage.
DGND
15
I
Digital ground.
INA+, INA-
5, 6
I
Channel A differential analog inputs. Selected via MUX pins.
INB+, INB-
8, 7
I
Channel B differential analog inputs. Selected via MUX pins.
13
O
Guard voltage output.
OUTR+, OUTR-
11, 2
O
Rough charge differential analog outputs.
OUTF+, OUTF-
10, 3
O
Fine charge differential analog outputs.
GAIN0, GAIN1,
GAIN2
22, 21,
20
I
Gain range select. See Gain Selection table in Digital Characteristics section.
LPWR
18
I
Low power mode enable. Active high.
PWDN
19
I
Power down mode enable. Active high.
24, 23
I
Analog input select. See Input Selection table in Digital Characteristics section.
VA+
GUARD
MUX0, MUX1
TEST0
TEST1, TEST2
TESTOUT
Pin Description
12
I
17, 14
I
Test mode select, factory use only. Connect to VA- during normal operation.
Test mode select, factory use only. Connect to DGND during normal operation.
9
O
Test mode output, factory use only. Connect to VA- during normal operation.
Table 2. Pin Descriptions
14
CS3302
4.
PACKAGE DIMENSIONS
24 PIN SSOP PACKAGE DRAWING
N
D
E11
A2
E
A1
b2
e
A
L
SIDE VIEW
END VIEW
SEATING
PLANE
1 2 3
TOP VIEW
INCHES
DIM
MIN
MAX
MILLIMETERS
MIN
MAX
A
A1
A2
b
D
E
E1
e
L
-0.002
0.064
0.009
0.311
0.291
0.197
0.024
0.025
0°
0.084
0.010
0.074
0.015
0.335
0.323
0.220
0.027
0.040
8°
-0.05
1.62
0.22
7.90
7.40
5.00
0.61
0.63
0°
∝
2.13
0.25
1.88
0.38
8.50
8.20
5.60
0.69
1.03
8°
NOTE
2,3
1
1
Notes: 1. “D” and “E1” are reference datums and do not included mold flash or protrusions, but do include mold
mismatch and are measured at the parting line, mold flash or protrusions shall not exceed 0.20 mm per
side.
2. Dimension “b” does not include dambar protrusion/intrusion. Allowable dambar protrusion shall be
0.13 mm total in excess of “b” dimension at maximum material condition. Dambar intrusion shall not
reduce dimension “b” by more than 0.07 mm at least material condition.
3. These dimensions apply to the flat section of the lead between 0.10 and 0.25 mm from lead tips.
15
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