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CS3301A

Low-noise, Programmable Gain, Differential Amplifier

Features & Desription

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 outputs for CS5371A / 72A / 73A

• Max signal amplitude: 5 V

differential

• Low input bias: 1 nA typical

Outstanding Noise Performance

• 8.5 from 0.1 Hz to 2 kHz

•0.180µV

p-p

between 0.1 Hz and 10 Hz

Low Total Harmonic Distortion

• -121 dB THD typical (0.0000891%)

• -112 dB THD maximum (0.0002512%)

Low Power Consumption

• Normal operation: 5.5 mA typical

• Power down: 10 µA typical

Small 24-pin SSOP Package

z Bipolar Power Supply Configuration

• VA+ = +2.5 V; VA- = -2.5 V; VD = +3.3 V

Description

The CS3301A is a low-noise differential input, dif-

ferential output amplifier with programmable gain,

optimized for amplifying signals from low-imped-

ance sensors such as geophones. The gain

settings are binary weighted (x1, x2, x4, x8, x16,

x32, x64) and are selected using simple pin set-

tings. Two sets of external inputs, INA and INB,

simplify system design as inputs from a sensor and

test DAC. An internal 800 Ω termination can also be

selected for noise tests.

Amplifier noise performance is outstanding with a

noise density of 8.5 over the 0.1 Hz to

2 kHz bandwidth. Distortion performance is also ex-

tremely good, typically -121 dB THD at x1 gain. Flat

noise down to 0.1 Hz and low total harmonic distor-

tion make this amplifier ideal for low-frequency,

low-amplitude, differential signals requiring maxi-

mum dynamic range.

ORDERING INFORMATION

See page 15.

nV/ Hz

INA+

INB+

MUX0

MUX1

INB-

INA-

VA+

VA-

GND

CLK

OUTR+

OUTF+

GAIN0

GAIN1

GAIN2

OUTF-

OUTR-

PWDN

400 Ω 400 Ω

MAR ‘07

DS757F1

Summary of content (16 pages)

PAGE 1
CS3301A Low-noise, Programmable Gain, Differential Amplifier Features & Desription Description z Signal Bandwidth: DC to 2 kHz z Selectable Gain: x1, x2, x4, x8, x16, x32, x64 The CS3301A is a low-noise differential input, differential output amplifier with programmable gain, optimized for amplifying signals from low-impedance sensors such as geophones. The gain settings are binary weighted (x1, x2, x4, x8, x16, x32, x64) and are selected using simple pin settings.
PAGE 2
CS3301A TABLE OF CONTENTS 1. CHARACTERISTICS AND SPECIFICATIONS .............................................................................. 3 SPECIFIED OPERATING CONDITIONS ....................................................................................... 3 ABSOLUTE MAXIMUM RATINGS ................................................................................................. 3 TEMPERATURE CONDITIONS ..................................................................................................
PAGE 3
CS3301A 1. CHARACTERISTICS AND SPECIFICATIONS • Min / Max characteristics and specifications are guaranteed over the Specified Operating Conditions. • Typical performance characteristics and specifications are measured at nominal supply voltages and TA = 25°C. • GND = 0 V. Single-ended voltages with respect to GND, differential voltages with respect to opposite half. • Device is connected as shown in Figure 5 on page 12 unless otherwise noted.
PAGE 4
CS3301A ANALOG CHARACTERISTICS CS3301A Parameter Symbol Min Typ Max Unit Noise Performance Input Voltage Noise f0 = 0.1 Hz to 10 Hz VNPP - 0.18 0.40 µVp-p Input Voltage Noise Density f0 = 0.1 Hz to 2 kHz VND - 8.5 12.0 nV/ Hz Input Current Noise Density (Note 4) IND - 100 - fA/ Hz THD - -121 -120 -120 -120 -120 -119 -116 -112 - dB LIN - 0.0000891 0.0001000 0.0001000 0.0001000 0.0001000 0.0001122 0.0001585 0.
PAGE 5
CS3301A ANALOG CHARACTERISTICS (CONT.) CS3301A Parameter Symbol Min Typ Max GAIN x1 - x64 Unit Gain Gain, Differential Gain, Common Mode (Note 6) GAINCM - x1 - Gain Accuracy, Absolute (Note 7) GAINABS - ±1 ±2 2x -0.4 -0.2 0 4x - -0.2 - - -0.2 - - -0.2 - 32x - -0.3 - 64x - -0.
PAGE 6
CS3301A ANALOG CHARACTERISTICS (CONT.) CS3301A Parameter Symbol Min Typ Max Unit BW DC - 2000 Hz VIN (VA-)+0.7 (VA-)+0.7 - (VA+)-1.25 (VA+)-1.75 V VINFS - - 5 2.5 1.25 625 312.5 156.25 78.
PAGE 7
CS3301A DIGITAL CHARACTERISTICS CS3301A Parameter Symbol Min Typ Max Unit Digital Characteristics High Level Input Drive Voltage (Note 15) VIH 0.6*VD - VD V Low Level Input Drive Voltage (Note 15) VIL 0.0 - 0.8 V Input Leakage Current IIN - ±1 ±10 µA Digital Input Capacitance CIN - 9 - pF Rise Times, Digital Inputs Except CLK tRISE - - 100 ns Fall Times, Digital Inputs Except CLK tFALL - - 100 ns fCLK 2.0 2.048 2.
PAGE 8
CS3301A POWER SUPPLY CHARACTERISTICS CS3301A Parameter Symbol Min Typ Max Unit Power Supply Current, Normal Analog Power Supply Current (Note 17) IA - 5.5 6.8 mA Digital Power Supply Current (Note 17) ID - 0.2 0.25 mA Power Supply Current, Power Down (PWDN=1) Analog Power Supply Current (Note 17) IA - 8 12 µA Digital Power Supply Current (Note 17) ID - 2 8 µA PSRR 100 120 - dB Power Supply Rejection Power Supply Rejection Ratio (Note 4, 18) Notes: 17.
PAGE 9
CS3301A 2. GENERAL DESCRIPTION The CS3301A is a low-noise chopper-stabilized CMOS differential input, differential output amplifier for precision analog signals between DC and 2 kHz. It has multiplexed inputs, rough / fine 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.
PAGE 10
CS3301A CS5373A Differential Sensor CS3301A CS3302A M U X AMP CS5378 ∆Σ Modulator µController or Configuration EEPROM Digital Filter System Telemetry Test DAC Figure 4. Single-Channel System Architecture 2.1.3 Differential Signals Analog signals into and out of the CS3301A 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 -0.15 V common mode can have: SIG+ = -0.15 V + 1.25 V = 1.
PAGE 11
CS3301A made using the MUX0 and MUX1 pins as shown in Table 1 on page 7. Although a mux selection is provided to enable the INA and INB switches simultaneously, signal current should not be driven through them in this mode. The CS3301A mux switches will maintain good linearity only with minimal signal currents. 2.2.4 Power Down Selection A power-down mode is available to shut down the amplifier when not in use.
PAGE 12
CS3301A 2.4 Connection Diagram Figure 5 on page 12 shows a connection diagram for the CS3301A amplifier when used with the CS5372A dual ∆Σ modulator, the CS4373A Test DAC, and the CS5376A digital filter. The diagram shows differential sensors and test DAC inputs, and analog outputs with anti-alias RC components; power supply connections including recommended bypassing; and digital control connections back to the CS5376A GPIO pins.
PAGE 13
CS3301A 3.
PAGE 14
CS3301A 4. PACKAGE DIMENSIONS 24 PIN SSOP PACKAGE DRAWING N D E11 A2 E b2 e SIDE VIEW A A1 L END VIEW SEATING PLANE 1 2 3 TOP VIEW INCHES DIM A A1 A2 b D E E1 e L ∝ MIN -0.002 0.064 0.009 0.311 0.291 0.197 0.024 0.025 0° MAX 0.084 0.010 0.074 0.015 0.335 0.323 0.220 0.027 0.040 8° MILLIMETERS MIN MAX -2.13 0.05 0.25 1.62 1.88 0.22 0.38 7.90 8.50 7.40 8.20 5.00 5.60 0.61 0.69 0.63 1.03 0° 8° NOTE 2,3 1 1 Notes: 1.
PAGE 15
CS3301A 5. ORDERING INFORMATION Model CS3301A-IS CS3301A-ISZ (lead free) 6. Temperature Package -40 to +85 °C 24-pin SSOP ENVIRONMENTAL, MANUFACTURING, & HANDLING INFORMATION Model Number Peak Reflow Temp MSL Rating* Max Floor Life CS3301A-IS 240 °C 2 365 Days CS3301A-ISZ (lead free) 260 °C 3 7 Days * MSL (Moisture Sensitivity Level) as specified by IPC/JEDEC J-STD-020.
PAGE 16
CS3301A 7. REVISION HISTORY Revision Date PP1 FEB 2007 Preliminary release. Changes F1 MAR 2007 Updated to final for QPL (Quality Process Level). 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 Cirrus Logic, Inc. and its subsidiaries ("Cirrus") believe that the information contained in this document is accurate and reliable.